ANRO

Find winning stocks in any market cycle. Join 7 million investors using Simply Wall St's investing ideas for FREE. Alto Neuroscience (ANRO) is back in focus after reporting second quarter 2026 results. The company reported a net loss of US$27.64 million and a basic loss per share from continuing operations of US$0.65. See our latest analysis for Alto Neuroscience. Alto Neuroscience’s latest quarterly loss lands against a backdrop of rapid share price gains, with a 90 day share price return of 47.43% and a year to date share price return of 93.73%, suggesting strong recent momentum. The 1 year total shareholder return is very large, reflecting how investors have reacted to news around the expanded ALTO-207 program, fresh funding and recent analyst commentary on the stock’s risk and growth profile. If Alto Neuroscience’s surge has caught your attention, it could be a good moment to see what else is moving in healthcare AI and related themes through 42 healthcare AI stocks After a move this sharp in Alto Neuroscience, the upside case around ALTO-207 and fresh funding now sits against a much richer share price. Does the current valuation still leave enough potential reward for the clinical and dilution risks? The recent rally in Alto Neuroscience now sits on top of a relatively full valuation on book value, with the stock trading at a P/B ratio of 5.8x against both peers and the broader US pharmaceuticals industry. The price to book ratio compares the company’s share price to its net assets on the balance sheet. For a clinical stage biopharmaceutical stock like Alto Neuroscience, this often reflects how much investors are willing to pay above the current asset base for the potential of its pipeline and future cash flows, even though the company is currently unprofitable and makes less than $1m in revenue. Right now Alto Neuroscience’s 5.8x P/B is described as expensive compared with the US pharmaceuticals industry average of 2.5x and a peer group average of 4x. That is a clear premium and suggests the market is attaching a higher value to the company’s portfolio of ALTO programs and its recent share price momentum than to the sector on average. See what the numbers say about this price — find out in our valuation breakdown. Result: Price to book ratio of 5.8x (OVERVALUED) However, Alto Neuroscience’s story could shift quickly if key ALTO trials disappoint or if ongoing losses and future funding needs dilute existing shareholders. Find out about the key risks to this Alto Neuroscience narrative. With Alto Neuroscience attracting strong attention, it helps to stress test the story against the underlying risks and data. Take a closer look at the 3 important warning signs If Alto Neuroscience has sharpened your interest in healthcare and growth stories, do not stop here. Use this moment to widen your watchlist with focused stock ideas. Spot potential value opportunities early and compare Alto Neuroscience with companies featured in the 52 high quality undervalued stocks. Strengthen your focus on capital preservation by checking companies screened through the 80 resilient stocks with low risk scores. Hunt for less crowded opportunities by scanning the screener containing 20 high quality undiscovered gems before others catch on. This article by Simply Wall St is general in nature. We provide commentary based on historical data and analyst forecasts only using an unbiased methodology and our articles are not intended to be financial advice. It does not constitute a recommendation to buy or sell any stock, and does not take account of your objectives, or your financial situation. We aim to bring you long-term focused analysis driven by fundamental data. Note that our analysis may not factor in the latest price-sensitive company announcements or qualitative material. Simply Wall St has no position in any stocks mentioned. Companies discussed in this article include ANRO. Have feedback on this article? Concerned about the content? Get in touch with us directly. Alternatively, email [email protected]

– ALTO-207 development expanded: an additional Phase 3 trial evaluating ALTO-207 as monotherapy in treatment-resistant depression (TRD) is now planned, alongside the ongoing potentially registrational Phase 2b trial; topline Phase 2b data on track for 2H 2027 – – Independent investigator-led study results published in Nature Medicine reinforce the dopaminergic mechanism underlying ALTO-207, demonstrating significant effects on anhedonia (Hedges' g=0.62, p=0.006) – – Approximately $100 million financing completed in July 2026; pro forma cash of approximately $338 million expected to fund planned operations through 2030 – MOUNTAIN VIEW, Calif., August 12, 2026--(BUSINESS WIRE)--Alto Neuroscience, Inc. ("Alto") (NYSE: ANRO), a clinical-stage biopharmaceutical company focused on the development of novel precision medicines for neuropsychiatric disorders, today reported financial results for the quarter ended June 30, 2026, and highlighted recent progress across its pipeline of clinical-stage product candidates. "The second quarter further strengthened the case for ALTO-207 and our conviction in the opportunity ahead of it," said Amit Etkin, M.D., Ph.D., founder and chief executive officer of Alto Neuroscience. "The Nature Medicine publication of PRIME-PRAXOL provides another independent, peer-reviewed dataset showing that dopaminergic treatment produces large effects in depression, and, just as importantly, a reminder of the tolerability challenge that ALTO-207 is designed to address. With enrollment in our potentially registrational Phase 2b trial tracking as planned and pro forma cash of approximately $338 million, we are now positioned to pursue ALTO-207 in both the adjunctive and monotherapy settings, broadening the potential label and the commercial opportunity, with expected runway through 2030." Second Quarter and Recent Pipeline Highlights ALTO-207: Independent Nature Medicine publication reinforces mechanism; monotherapy Phase 3 trial added to development plan ALTO-207 is a fixed-dose combination of pramipexole, a dopamine D3-preferring D3/D2 agonist with demonstrated antidepressant effect across multiple independent trials, and ondansetron, a selective 5-HT3 receptor antagonist. The fixed-dose combination is designed to enable rapid titration to higher pramipexole doses by mitigating the dose-limiting nausea and vomiting associated with pramipexole. This combination approach — and its use to enable higher pramipexole dosing in the treatment of depression — is the subject of Alto's issued method-of-treatment patent estate described below. ALTO-207 is being developed to address the significant unmet medical need in TRD, which is estimated to affect approximately 7 million adults in the United States. In June 2026, results from PRIME-PRAXOL — an independent, randomized, double-blind, placebo-controlled trial conducted by investigators at Lund University, Sweden — were published in Nature Medicine. Adults with major depressive disorder (MDD), dysthymia, or bipolar depression and clinically significant anhedonia received flexible-dose pramipexole or placebo added to ongoing treatment for nine weeks, followed by a six-month open-label extension. These findings are consistent with the broader body of evidence supporting ALTO-207, including the PAX-D study conducted by the University of Oxford and published in The Lancet Psychiatry (Cohen's d=0.87 versus placebo at 12 weeks in TRD) and a meta-analysis of pramipexole in depression (Hedges' g=0.64, p<0.001). The broad development program for ALTO-207, collectively the PACE program (Pramipexole-ondansetron Assessment of Clinical Efficacy in depression), remains on track across three large, well-controlled clinical trials; Alto's patent estate covering ALTO-207 includes multiple method-of-treatment patents protecting the use of ondansetron to mitigate pramipexole-related side effects to enable higher pramipexole dosing in the treatment of depression. Together with the Company's broader estate of issued and pending patents, Alto expects patent coverage of ALTO-207 through at least the mid-2040s. ALTO-300 and ALTO-100: Phase 2b trials on track Enrollment remains ongoing in the Phase 2b trials of ALTO-300 in MDD and ALTO-100 in bipolar depression (BPD), conducted under the enhanced eligibility review and patient data quality procedures the Company implemented earlier this year, which continue to perform as intended. Topline data remain expected in 1H 2027 for the ALTO-300 Phase 2b MDD trial and mid-2027 for the ALTO-100 Phase 2b BPD trial. Corporate Highlights In July 2026, Alto completed an underwritten registered direct offering of 3,776,436 shares of common stock at $26.48 per share, for gross proceeds of approximately $100.0 million and net proceeds of approximately $94.6 million. The Company intends to use the proceeds, together with existing cash, to accelerate and expand the clinical development of ALTO-207, including the additional planned Phase 3 monotherapy trial in TRD, and for general working capital purposes. In June 2026, Alto was added to the Russell 2000® Index and the broad-market Russell 3000® Index, effective June 29, 2026, as part of the 2026 Russell US Indexes reconstitution. In May 2026, Alto appointed Andrew Miller, Ph.D., founder of Karuna Therapeutics, to its Board of Directors. During his tenure, Dr. Miller was CEO, COO, and led research and development at Karuna through its acquisition by Bristol Myers Squibb, and brings extensive neuropsychiatric drug development and company-building experience to Alto. Expected Upcoming Milestones Early 2027 — ALTO-207 PACE-2 (Phase 3 adjunctive TRD) trial initiation 1H 2027 — ALTO-300 Phase 2b MDD trial topline data Mid-2027 — ALTO-100 Phase 2b BPD trial topline data 2H 2027 — ALTO-207 PACE-1 (Phase 2b adjunctive TRD) trial topline data 2H 2027 — ALTO-207 PACE-3 (Phase 3 monotherapy TRD) trial initiation Second Quarter 2026 Financial Highlights Cash Position: As of June 30, 2026, the Company had cash, cash equivalents, and restricted cash of approximately $244.2 million, compared to approximately $177.0 million as of December 31, 2025. Giving effect to the net proceeds of the July 2026 offering, the Company's pro forma cash position following the offering was approximately $338 million. R&D Expenses: Research and development expenses for the quarter ended June 30, 2026, were $22.1 million, as compared to $13.1 million for the same period in 2025. G&A Expenses: General and administrative expenses for the quarter ended June 30, 2026, were $7.0 million, as compared to $5.6 million for the same period in 2025. Net Loss: The Company incurred a net loss of $27.6 million for the quarter ended June 30, 2026, as compared to a net loss of $17.7 million for the same period in 2025. About Alto Neuroscience Alto Neuroscience is a clinical-stage biopharmaceutical company with a mission to redefine psychiatry by leveraging neurobiology to develop personalized and highly effective treatment options. Alto’s Precision Psychiatry Platform™ measures brain biomarkers by analyzing EEG activity, neurocognitive assessments, wearable data, and other factors to better identify which patients are more likely to respond to Alto product candidates. Alto’s clinical-stage pipeline includes novel drug candidates in treatment-resistant depression, major depressive disorder, bipolar depression, schizophrenia, and other mental health conditions. For more information, visit www.altoneuroscience.com or follow Alto on X. Forward-Looking Statements This press release may contain forward-looking statements made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. These statements may be identified by words such as "aims," "anticipates," "believes," "could," "estimates," "expects," "forecasts," "goal," "intends," "look forward," "may," "on track," "plans," "possible," "potential," "seeks," "will" and variations of these words or similar expressions that are intended to identify forward-looking statements, although not all forward-looking statements contain these words. Forward-looking statements in this press release include, but are not limited to, statements regarding Alto’s expectations with regard to the potential benefits, activity, effectiveness and safety of its product candidates and Precision Psychiatry Platform ("Platform"); statements regarding patient compliance and the effectiveness of Alto’s clinical trial execution measures, including its eligibility review and patient and data quality procedures, and the impact of those measures on patient and data quality and the timing of trial readouts; statements regarding Alto’s expectations for the design, timing, and results of its Phase 2b and planned Phase 3 trials of ALTO-207; Alto’s expectations with regard to the design and results of its research and development programs and clinical trials, including the timing of enrollment and the timing and availability of data from such trials; Alto’s clinical and regulatory development plans for its product candidates, including the timing or likelihood of regulatory filings and approvals for its product candidates and regulatory alignment; Alto’s business strategy, financial position, including anticipated cash runway, and the sufficiency of its financial resources to fund its operations through expected milestones; and other statements that are not historical fact. Actual results or events could differ materially from the plans, intentions and expectations disclosed in these forward-looking statements as a result of various factors, including: uncertainties inherent in the initiation, progress and completion of clinical trials and clinical development of Alto’s product candidates; the risk that Alto may not realize the intended benefits of its Platform or its eligibility review and patient and data quality procedures; availability and timing of results from clinical trials; whether initial or interim results from a clinical trial will be predictive of the final results of the trial or the results of future trials; the risk that clinical trials may have unsatisfactory outcomes; the risk that Alto’s projections regarding its financial position and expected cash runway are inaccurate or that its conduct of its business requires more cash than anticipated; and other important factors, any of which could cause Alto’s actual results to differ from those contained in the forward-looking statements, which are described in greater detail in Alto’s Annual Report on Form 10-K for the fiscal year ended December 31, 2025 and other filings Alto may make with the SEC. Any forward-looking statements contained in this press release speak only as of the date hereof, and Alto expressly disclaims any obligation to update any forward-looking statements contained herein, whether because of any new information, future events, changed circumstances or otherwise, except as required by law. Availability of Information on Alto's Website Alto routinely uses its investor relations website to post presentations to investors and other important information, including information that may be material. Accordingly, Alto encourages investors and others interested in Alto to review the information it makes public on its investor relations website. View source version on businesswire.com: https://www.businesswire.com/news/home/20260812450316/en/ Contacts Investor & Media Contact: Nick [email protected] [email protected]

– Phase 2b clinical trial of ALTO-207 in treatment-resistant depression (TRD) initiated – – New ALTO-101 analyses support significant effects on EEG markers of general cognition as well as a test of attention – – Closed $120 million PIPE in March 2026; cash balance of approximately $264 million expected to fund planned operations through 2029, including a potential NDA submission for ALTO-207 – MOUNTAIN VIEW, Calif., May 13, 2026--(BUSINESS WIRE)--Alto Neuroscience, Inc. ("Alto") (NYSE: ANRO), a clinical-stage biopharmaceutical company focused on the development of novel precision medicines for neuropsychiatric disorders, today reported financial results for the quarter ended March 31, 2026, and highlighted recent progress across its pipeline of clinical-stage product candidates. "2026 is off to a strong start across our pipeline, highlighted by the initiation of the Phase 2b trial of ALTO-207 in TRD," said Amit Etkin, M.D., Ph.D., founder and chief executive officer of Alto Neuroscience. "ALTO-207 is supported by one of the largest independently validated efficacy signals reported in TRD, and we believe the potentially registrational Phase 2b trial is designed to build on those results, and we are ahead of schedule on site initiations and patient recruitment. With $264 million on the balance sheet, Alto is well capitalized — with runway expected to extend through 2029 and, importantly, through a planned Phase 3 trial and potential NDA submission for ALTO-207." Pipeline Highlights ALTO-207: Phase 2b trial in TRD initiated; potentially pivotal trial designed to replicate PAX-D antidepressant effects ALTO-207 is a fixed-dose combination of pramipexole, a dopamine D3-preferring D3/D2 agonist with demonstrated antidepressant effect, and ondansetron, a selective 5-HT3 receptor antagonist. The fixed-dose combination is designed to enable rapid titration to higher pramipexole doses by mitigating the dose-limiting nausea and vomiting historically associated with pramipexole. ALTO-207 is being developed to address the significant unmet medical need in TRD, which is estimated to affect up to 7 million adults in the United States. The core mechanism of ALTO-207 is supported by the PAX-D study, conducted by the University of Oxford and published in The Lancet Psychiatry, which demonstrated a Cohen’s d = 0.87 effect size for pramipexole versus placebo at 12 weeks — an effect more than two times larger than that observed for currently approved TRD therapies. A meta-analysis of pramipexole in depression has also reported a Hedges’ g = 0.64 (p < 0.001). In April 2026, Alto initiated a randomized, double-blind, placebo-controlled Phase 2b trial of ALTO-207 as an adjunctive treatment in approximately 178 adults with TRD who have experienced between two and five prior treatment failures and continue to have moderate-to-severe depression symptoms. The trial design and patient eligibility criteria build on the PAX-D study while employing MADRS as the primary endpoint, an approach aligned with FDA standards in depression and intended to support a streamlined registrational pathway. In January 2026, the U.S. Patent and Trademark Office issued U.S. Patent No. 12,521,374, a method-of-treatment patent specifically protecting the use of ondansetron to mitigate pramipexole-related side effects to enable higher pramipexole dosing for the treatment of depression. Together with Alto’s broader estate of issued and pending patents, the Company expects patent coverage of ALTO-207 through at least the mid-2040s. Alto remains on track to initiate a Phase 3 trial in TRD by early 2027, following alignment with the FDA on the planned trial design. ALTO-101: New analyses support biomarker hypothesis In April 2026, Alto reported topline results from the Phase 2 proof-of-concept (POC) trial of ALTO-101, a brain-penetrant PDE4 inhibitor evaluated as a transdermal formulation in cognitive impairment associated with schizophrenia (CIAS). The pre-specified primary analysis focused on electroencephalography (EEG) markers associated most strongly with CIAS. The trial did not achieve statistical significance on its primary CIAS EEG outcome, theta-band inter-trial coherence (or theta-ITC), though directional improvement was observed in this measure. Subsequent analyses focused on general EEG cognitive biomarkers, as well as exploratory analyses of cognitive test performance, yielding findings that suggest potential clinical effect of ALTO-101 in other cognitive disorders. In the overall study population (n = 83), ALTO-101 produced a Cohen’s d = 0.34 on theta-ITC versus placebo (p = 0.052). In a prespecified analysis of a more cognitively impaired subgroup (n = 59), ALTO-101 demonstrated a nominally significant effect on theta-ITC versus placebo (Cohen’s d = 0.44, p = 0.03). Alto views this signal as supportive of the relevance of theta-ITC as an objective EEG biomarker in CIAS and consistent with prior replicated analyses of large schizophrenia datasets. Further analyses identified large and statistically significant effects of ALTO-101 in the overall study population on multiple EEG markers relevant broadly to cognition. This included an increase in the individual alpha peak frequency (d=0.59, p=0.001), a robust and highly heritable index of an individual’s neurophysiological efficiency that tracks a range of cognitive functions. Analyses also revealed a shift to greater cortical excitability, as evidenced by an increase in high frequency power (beta: d=0.70, p<0.001; gamma: d=0.61, p=0.001) and decrease in low frequency power (theta: d=0.50, p=0.007). This resulted in a decrease in the theta/beta ratio (d=0.57, p=0.003), an FDA-cleared measure of attentional deficit/hyperactivity disorder that is likewise relevant to cognitive deficits in neurodegenerative disorders such as Parkinson’s and Alzheimer’s. Significant improvement was also observed with ALTO-101 in sustained attention, as measured by the Continuous Performance Task (d=0.41, p=0.02). No significant effects were observed in processing speed or memory. Alto has developed a modified-release, once-daily, well-tolerated oral formulation of ALTO-101 and the Company plans to explore partnering opportunities for this formulation. Enhanced eligibility review and patient quality measures implemented in ongoing Phase 2b trials for ALTO-300 and ALTO-100 Following the Company’s full analysis of its previously completed ALTO-100 MDD Phase 2b trial, Alto instituted an enhanced sponsor eligibility review process, site-level risk scoring, and certain new patient and data quality requirements into the ongoing Phase 2b trials for ALTO-300 in MDD and ALTO-100 in bipolar depression (BPD). The ongoing blinded data review supports the importance of these new enhanced procedures on the overall data quality in these trials. The Company believes the eligibility review process has resulted in a reduced risk of enrolling professional patients, a common risk across the field, with patients better reflecting the true treatment-seeking clinical population in the respective indications. Key metrics supporting the effectiveness of these efforts are as follows: In periodic batch testing of pharmacokinetic (PK) levels, 97% of samples demonstrated expected drug concentration levels. 100% of patients in the ALTO-300 MDD trial have demonstrated ongoing compliance with their underlying antidepressant as evaluated through urinalysis during trial conduct (the short half-life of ALTO-300 makes it undetectable in blood the day after dosing). 11% and 13% of patients have been screened out of the ALTO-100 and ALTO-300 trials, respectively, through Alto's sponsor eligibility review process – these represent patients who may have otherwise been included in the trial. Due to this new process, and the Company’s continued emphasis on patient quality, the topline data readouts are now expected in 1H 2027 for the ALTO-300 trial and mid-2027 for the ALTO-100 trial. These timing changes do not impact Alto’s overall cash runway guidance, and the Company still expects its existing cash to support planned operations through 2029. The company has incorporated these enrollment learnings into the ALTO-207 Phase 2b trial guidance and therefore does not expect these timing changes to impact the ALTO-207 Phase 2b readout timing, which is guided to 2H 2027. Corporate Updates In March 2026, the Company closed a private placement financing ("PIPE") for gross proceeds of approximately $120 million led by Commodore Capital. In the PIPE, Alto sold an aggregate of 2,900,000 shares of its common stock at a price of $20 per share and, in lieu of common stock for certain investors, pre-funded warrants to purchase up to an aggregate of 3,100,000 shares of common stock at a purchase price of $19.9999 per pre-funded warrant. Together with existing cash, the proceeds from the PIPE are expected to support the development of ALTO-207 through a planned Phase 3 trial and to a potential NDA submission. Expected Upcoming Milestones Early 2027 — ALTO-207 Phase 3 TRD trial initiation 1H 2027 — ALTO-300 Phase 2b MDD trial topline data Mid 2027 — ALTO-100 Phase 2b BPD trial topline data 2H 2027 — ALTO-207 Phase 2b TRD trial topline data First Quarter 2026 Financial Highlights Cash Position: As of March 31, 2026, the Company had cash, cash equivalents, and restricted cash of approximately $264.2 million, compared to approximately $177.0 million as of December 31, 2025. The increase reflects net proceeds of approximately $115 million from the March 2026 PIPE, partially offset by cash used in operations during the quarter. The Company expects its cash balance to support planned operations — including the execution of the ALTO-207 Phase 2b trial, the planned ALTO-207 Phase 3 trial, and the ALTO-300 and ALTO-100 Phase 2b readouts — through 2029, including a potential NDA submission for ALTO-207. R&D Expenses: Research and development expenses for the quarter ended March 31, 2026, were $20.3 million, as compared to $10.0 million for the same period in 2025. G&A Expenses: General and administrative expenses for the quarter ended March 31, 2026, were $6.8 million, as compared to $5.7 million for the same period in 2025. Net Loss: The Company incurred a net loss of $26.2 million for the quarter ended March 31, 2026, as compared to a net loss of $15.2 million for the same period in 2025. About Alto Neuroscience Alto Neuroscience is a clinical-stage biopharmaceutical company with a mission to redefine psychiatry by leveraging neurobiology to develop personalized and highly effective treatment options. Alto’s Precision Psychiatry Platform™ measures brain biomarkers by analyzing EEG activity, neurocognitive assessments, wearable data, and other factors to better identify which patients are more likely to respond to Alto product candidates. Alto’s clinical-stage pipeline includes novel drug candidates in treatment-resistant depression, major depressive disorder, bipolar depression, schizophrenia, and other mental health conditions. For more information, visit www.altoneuroscience.com or follow Alto on X. Forward-Looking Statements This press release may contain forward-looking statements made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. These statements may be identified by words such as "aims," "anticipates," "believes," "could," "estimates," "expects," "forecasts," "goal," "intends," "look forward," "may," "on track," "plans," "possible," "potential," "seeks," "will" and variations of these words or similar expressions that are intended to identify forward-looking statements, although not all forward-looking statements contain these words. Forward-looking statements in this press release include, but are not limited to, statements regarding Alto’s expectations with regard to the potential benefits, activity, effectiveness and safety of its product candidates and Precision Psychiatry Platform ("Platform"); statements regarding patient compliance and the effectiveness of Alto’s clinical trial execution measures, including its eligibility review and patient and data quality measures, and the impact of those measures on patient and data quality and the timing of trial readouts; statements regarding Alto’s expectations for the design, timing, and results of its Phase 2b and planned Phase 3 trials of ALTO-207; Alto’s expectations with regard to the design and results of its research and development programs and clinical trials, including the timing of enrollment and the timing and availability of data from such trials; Alto’s clinical and regulatory development plans for its product candidates, including the timing or likelihood of regulatory filings and approvals for its product candidates; Alto’s business strategy, financial position, including anticipated cash runway, and the sufficiency of its financial resources to fund its operations through expected milestones; and other statements that are not historical fact. Actual results or events could differ materially from the plans, intentions and expectations disclosed in these forward-looking statements as a result of various factors, including: uncertainties inherent in the initiation, progress and completion of clinical trials and clinical development of Alto’s product candidates; the risk that Alto may not realize the intended benefits of its Platform or its eligibility review and patient and data quality measures; availability and timing of results from clinical trials; whether initial or interim results from a clinical trial will be predictive of the final results of the trial or the results of future trials; the risk that clinical trials may have unsatisfactory outcomes; the risk that Alto’s projections regarding its financial position and expected cash runway are inaccurate or that its conduct of its business requires more cash than anticipated; and other important factors, any of which could cause Alto’s actual results to differ from those contained in the forward-looking statements, which are described in greater detail in Alto’s Annual Report on Form 10-K for the fiscal year ended December 31, 2025 and other filings Alto may make with the SEC. Any forward-looking statements contained in this press release speak only as of the date hereof, and Alto expressly disclaims any obligation to update any forward-looking statements contained herein, whether because of any new information, future events, changed circumstances or otherwise, except as required by law. Availability of Information on Alto’s Website Alto routinely uses its investor relations website to post presentations to investors and other important information, including information that may be material. Accordingly, Alto encourages investors and others interested in Alto to review the information it makes public on its investor relations website. View source version on businesswire.com: https://www.businesswire.com/news/home/20260513295402/en/ Contacts Investor & Media Contact: Nick Smith [email protected] [email protected]

– Acquisition of ALTO-207 targets Treatment-Resistant Depression (TRD) with a clinically-validated mechanism; Phase 2b trial on track to be initiated in the first half of 2026 – – External PAX-D study published in The Lancet Psychiatry demonstrated a 0.87 effect size for the core mechanism of ALTO-207; this effect represents a significantly larger effect size than current standard-of-care treatments – – ALTO-101 granted FDA Fast Track Designation for CIAS; Topline Phase 2 Proof-of Concept data expected around the end of 1Q 2026 – – Year-end cash balance of $177 million expected to fund planned operations into 2028, covering four key data readouts across Alto’s precision psychiatry pipeline – MOUNTAIN VIEW, Calif., March 16, 2026--(BUSINESS WIRE)--Alto Neuroscience, Inc. ("Alto") (NYSE: ANRO), a clinical-stage biopharmaceutical company focused on the development of novel precision medicines for neuropsychiatric disorders, today reported financial results for the full year ended December 31, 2025, and highlighted recent progress across its pipeline of clinical-stage product candidates. "Alto enters 2026 with a very strong clinical and financial foundation," said Amit Etkin, M.D., Ph.D., founder and chief executive officer of Alto Neuroscience. "The acquisition of ALTO-207 is a potential game-changer for the millions of patients who fail to respond to current depression therapies. We believe the Lancet-published PAX-D study provides robust, independent validation of our approach, and we are moving ALTO-207 into a potentially pivotal Phase 2b trial with high conviction. Our $177 million cash balance puts us in an excellent position to reach the finish line on four major data readouts, providing shareholders with multiple value-inflection points over the next 2 years." Recent Business Highlights Acquisition and Accelerated Development of ALTO-207 for TRD: In June 2025, Alto acquired ALTO-207, a fixed-dose combination of pramipexole (a dopamine D3/D2 agonist) and ondansetron (an antiemetic 5-HT3 receptor antagonist). ALTO-207 is designed to overcome historic tolerability barriers associated with dopamine agonists, potentially unlocking a rapid and robust antidepressant effect for patients in need. Following a successful FDA meeting and a $50 million private placement financing (PIPE) in October 2025, Alto has accelerated the program's development. The Company expects to initiate a potentially pivotal Phase 2b trial in the first half of 2026 and a Phase 3 trial by early 2027. In January 2026, the Company announced the issuance of a new method-of-treatment patent for ALTO-207, which together with its broader estate of issued and pending patents, Alto expects to have patent coverage of ALTO-207 through at least the mid 2040’s. The planned Phase 2b trial of ALTO-207 will be a randomized, double-blind, placebo-controlled study evaluating ALTO-207 as an adjunctive treatment in approximately 178 adults with treatment-resistant depression (TRD). Eligible patients will have experienced two to five prior treatment failures and have a MADRS score ≥25, and will remain on their baseline antidepressant medication. Participants will be randomized 1:1 to receive ALTO-207 or placebo during an eight-week double-blind treatment period, which includes dose titration to a target total daily dose of 3.2mg pramipexole/15mg ondansetron. The study will be conducted at clinical sites in the U.S. and U.K. The primary endpoint is change from baseline in MADRS. The Company expects to report topline data from the trial in the second half of 2027. PAX-D Study Validates Pramipexole in TRD: The strategic acquisition of ALTO-207 was guided by the independent PAX-D study, the results of which were published in The Lancet Psychiatry in June 2025. The study demonstrated that pramipexole augmentation drove a large, statistically significant reduction in depressive symptoms (Cohen’s d=0.87) relative to placebo at 12 weeks in patients with TRD. This represents an effect size more than two times larger than what has historically been demonstrated with standard-of-care treatments in depression or TRD. However, the study also highlighted a high rate of adverse effects (nausea) that hinder pramipexole's standard clinical adoption—a barrier ALTO-207 is explicitly designed to overcome. Alto recently conducted a meta-analysis across randomized studies of pramipexole for depression. The analysis highlights the large effect size observed on depression symptoms with pramipexole and a clear dose-response relationship. The analysis, including all pramipexole doses studied in randomized depression trials, resulted in a meta-analytic Hedges’ g effect size of 0.64 (p<0.001 [95% CI 0.41 - 0.86]) across all doses studied. The meta-analysis also revealed a significant dose-response relationship (p=0.027), showing that higher doses of pramipexole result in larger effects on depression symptoms. See here for an interactive meta-analysis of pramipexole in depression. ALTO-101 in Cognitive Impairment Associated with Schizophrenia (CIAS): In October 2025, the FDA granted Fast Track Designation to ALTO-101. In February 2026, Alto announced the completion of enrollment in the ongoing Phase 2 proof-of-concept (POC) trial. The Company expects to report topline data from the trial around the end of the first quarter of 2026. The primary endpoint in the study is theta-band inter-trial coherence (ITC), an EEG measure strongly correlated with cognitive performance, measured during an auditory oddball paradigm. Additional EEG endpoints include resting-state theta power, mismatch negativity, and auditory steady-state response. Cognitive performance will be assessed using select domains of the MATRICS Consensus Cognitive Battery (MCCB) and a computerized measure of processing speed. A recent blinded pharmacokinetic, or PK, analysis from the first cohort of patients showed 100% of samples evaluated qualified as PK positive. ALTO-300 and ALTO-100 Ongoing Phase 2b Trials: Enrollment continues in the Phase 2b trial of ALTO-300 in Major Depressive Disorder (MDD), with topline data expected in mid-2026. The Phase 2b trial of ALTO-100 in Bipolar Depression (BPD) is also ongoing, with topline data anticipated in the second half of 2026. Upcoming Milestones Near-Term Expected Milestones Approximately end of 1Q 2026 – ALTO-101 POC CIAS trial topline data 1H 2026 – ALTO-207 Phase 2b TRD trial initiation Mid-2026 – ALTO-300 Phase 2b MDD trial topline data 2H 2026 – ALTO-100 Phase 2b BPD trial topline data Early 2027 – ALTO-207 Phase 3 TRD trial initiation Full Year 2025 Financial Highlights Cash Position: As of December 31, 2025, the Company had cash, cash equivalents, and restricted cash of approximately $177 million, compared to approximately $169 million in cash, cash equivalents, and restricted cash as of December 31, 2024. The Company expects its cash balance to support planned operations into 2028. R&D Expenses: Research and development expenses for the full year ended December 31, 2025 were $45.6 million, as compared to $47.0 million for the same period in 2024. The decrease was primarily attributable to the completion of our Phase 2b clinical study for ALTO-100 in 2024 and the completion of our proof-of-concept study for ALTO-203, partially offset by increases related to the costs of our ongoing trials of ALTO-101 and ALTO-100. G&A Expenses: General and administrative expenses for the full year ended December 31, 2025 were $20.7 million, as compared to $21.6 million for the same period in 2024. Net Loss: The Company incurred a net loss of $63.2 million for the full year ended December 31, 2025, as compared to $61.4 million for the year ended December 31, 2024. About Alto Neuroscience Alto Neuroscience is a clinical-stage biopharmaceutical company with a mission to redefine psychiatry by leveraging neurobiology to develop personalized and highly effective treatment options. Alto’s Precision Psychiatry Platform™ measures brain biomarkers by analyzing EEG activity, neurocognitive assessments, wearable data, and other factors to better identify which patients are more likely to respond to Alto product candidates. Alto’s clinical-stage pipeline includes novel drug candidates in bipolar depression, major depressive disorder, treatment resistant depression, schizophrenia, and other mental health conditions. For more information, visit www.altoneuroscience.com or follow Alto on X. Forward-Looking Statements This press release may contain forward-looking statements made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. These statements may be identified by words such as "aims," "anticipates," "believes," "could," "estimates," "expects," "forecasts," "goal," "intends," "look forward," "may," "plans," "possible," "potential," "seeks," "will" and variations of these words or similar expressions that are intended to identify forward-looking statements, although not all forward-looking statements contain these words. Forward-looking statements in this press release include, but are not limited to, statements regarding Alto’s expectations with regard to the potential benefits, activity, effectiveness and safety of its product candidates and Precision Psychiatry Platform ("Platform"); statements regarding patient compliance and the effectiveness of Alto’s clinical trial execution measures; Alto’s expectations with regard to the design and results of its research and development programs and clinical trials, including the timing of enrollment and the timing and availability of data from such trials; Alto’s clinical and regulatory development plans for its product candidates, including the timing or likelihood of regulatory filings and approvals for its product candidates; Alto’s business strategy, financial position, including anticipated cash runway, and the sufficiency of its financial resources to fund its operations through expected milestones; and other statements that are not historical fact. Actual results or events could differ materially from the plans, intentions and expectations disclosed in these forward-looking statements as a result of various factors, including: uncertainties inherent in the initiation, progress and completion of clinical trials and clinical development of Alto’s product candidates; the risk that Alto may not realize the intended benefits of its Platform; availability and timing of results from clinical trials; whether initial or interim results from a clinical trial will be predictive of the final results of the trial or the results of future trials; the risk that clinical trials may have unsatisfactory outcomes; the risk that Alto’s projections regarding its financial position and expected cash runway are inaccurate or that its conduct of its business requires more cash than anticipated; and other important factors, any of which could cause Alto’s actual results to differ from those contained in the forward-looking statements, which are described in greater detail in Alto's Annual Report on Form 10-K for the fiscal year ended December 31, 2024 and Alto’s Quarterly Report on Form 10-Q for the fiscal quarter ended September 30, 2025 filed with the Securities and Exchange Commission ("SEC") as well as in other filings Alto may make with the SEC in the future. Any forward-looking statements contained in this press release speak only as of the date hereof, and Alto expressly disclaims any obligation to update any forward-looking statements contained herein, whether because of any new information, future events, changed circumstances or otherwise, except as required by law. Availability of Information on Alto’s Website Alto routinely uses its investor relations website to post presentations to investors and other important information, including information that may be material. Accordingly, Alto encourages investors and others interested in Alto to review the information it makes public on its investor relations website. View source version on businesswire.com: https://www.businesswire.com/news/home/20260316041876/en/ Contacts Investor & Media Contact: Nick Smith [email protected] [email protected]

– Successful outcome from FDA meeting on ALTO-207 in treatment-resistant depression; on track to initiate Phase 2b trial in the first half of 2026 and Phase 3 trial by early 2027 – – Positive blinded pharmacokinetic (PK) analyses from ALTO-100 and ALTO-101 trials support clinical execution – – Topline data for Phase 2 trials of ALTO-101 in CIAS expected 1Q 2026 and ALTO-300 in MDD expected mid-2026 – – Closed $50 million PIPE; strong cash position of $184.2 million as of October 31 expected to fund planned operations into 2028, and through 4 upcoming clinical study readouts – MOUNTAIN VIEW, Calif., November 12, 2025--(BUSINESS WIRE)--Alto Neuroscience, Inc. ("Alto") (NYSE: ANRO) a clinical-stage biopharmaceutical company focused on the development of novel precision medicines for neuropsychiatric disorders, today reported financial results for the quarter ended September 30, 2025, and highlighted recent progress across its pipeline of clinical-stage product candidates. "These past months marked a period of significant strategic execution and validation for Alto. The successful outcome of our FDA meeting for ALTO-207 and the subsequent $50 million financing allow us to rapidly accelerate this promising program for patients with treatment-resistant depression," said Amit Etkin, M.D., Ph.D., founder and chief executive officer of Alto Neuroscience. "With cash supporting operations into 2028, we are in an excellent position to deliver on multiple anticipated upcoming data readouts, including for ALTO-101, ALTO-300, ALTO-100, and ALTO-207, as we advance our mission of developing personalized, more effective medicines for patients." Pipeline Highlights ALTO-207: Accelerating development following successful FDA meeting, on track to initiate a Phase 2b trial in the first half of 2026 and a Phase 3 trial by early 2027. ALTO-207 is a fixed-dose combination of pramipexole, a dopamine D3-preferring D3/D2 agonist, approved for the treatment of Parkinson’s disease with demonstrated antidepressant effect, and ondansetron, an antiemetic, selective 5-HT3 receptor antagonist. As a fixed-dose combination, ALTO-207 is designed to enable rapid titration and higher dosing by mitigating the dose-limiting adverse events typically experienced with pramipexole. ALTO-207 is being developed to address the significant unmet need for patients with TRD. In October 2025, the Company announced a successful outcome from an FDA meeting regarding the development of ALTO-207. Based on the feedback received, Alto is accelerating the development of ALTO-207 and expects to initiate a Phase 3 trial in patients with TRD by early 2027, following alignment with the FDA on the planned study design. Following the acquisition of ALTO-207 in May 2025, Alto has made substantial progress towards the initiation of the planned Phase 2b, potentially pivotal trial, which the Company is on track to initiate in the first half of 2026. ALTO-101: Enrollment is ongoing in Phase 2 proof-of-concept (POC) CIAS trial; topline data expected in the first quarter of 2026. ALTO-101, a brain-penetrant PDE4 inhibitor designed as a novel transdermal formulation, is being developed for the treatment of cognitive impairment in schizophrenia (CIAS). The novel formulation is designed to retain the desired brain effects shown with the oral formulation while avoiding the tolerability challenges and adverse effects known to be associated with PDE4 inhibitors. Enrollment remains ongoing in the Phase 2 POC trial in CIAS, with topline data expected in the first quarter of 2026. The Phase 2 POC trial consists of a dose-escalating treatment with ALTO-101 and is designed to enroll approximately 70 adult participants with schizophrenia between the ages of 21 and 55. The primary outcome in the study is the effect of ALTO-101 on theta band activity, the EEG measure shown to be most clearly associated with CIAS in replicated analyses of large schizophrenia datasets. Objective cognitive performance is also being evaluated. In October 2025, the Company announced that ALTO-101 was granted Fast Track Designation by the FDA for the treatment of CIAS. The Company believes this designation reflects the significant unmet need in CIAS, and the potential of ALTO-101 to be an important new treatment for this patient population. In October 2025, the Company announced the positive outcome of a blinded PK analysis from the first cohort evaluated in the ongoing Phase 2 study to evaluate the enhanced execution efforts implemented by the Company. 100% of the samples evaluated for ALTO-101 qualified as PK positive. In September 2025, the Company announced the prospective replication and validation of theta-band inter-trial coherence, or theta ITC, as the most robust objective EEG marker to distinguish patients with schizophrenia from healthy individuals. In the analysis, there was also a statistically significant correlation observed between theta ITC and cognitive performance. The results from this analysis further support the utilization of theta ITC as the primary outcome in the ongoing Phase 2 POC trial of ALTO-101. Alto believes that a positive result on theta ITC would strongly support the advancement of ALTO-101 into large, late-stage trials to evaluate the efficacy of ALTO-101 on cognitive measures. ALTO-300: Enrollment ongoing in Phase 2b adjunctive major depressive disorder (MDD) trial; data expected in mid-2026. ALTO-300, also known as agomelatine, is an oral, small molecule designed to act as a melatonin agonist and 5-HT2C antagonist, and is being developed at 25mg as an adjunctive treatment in the United States for patients with MDD, characterized by an EEG biomarker. Agomelatine is an approved antidepressant medication in Europe and Australia, at both 25mg and 50mg, but has not been approved in the United States. In comparison to the 50mg dose of agomelatine, the 25mg dose has been shown to have equivalent antidepressant efficacy and has not been associated with reversible, low liver enzyme elevations observed with the 50mg dose. Topline data from the double-blind, placebo-controlled, randomized Phase 2b trial is expected in mid-2026. The Company expects to enroll approximately 200 biomarker positive patients for the final analysis sample. ALTO-100: Enrollment ongoing in Phase 2b bipolar depression trial; data expected in the second half of 2026. ALTO-100, a first-in-class, oral small molecule believed to work through enhancing neuroplasticity, is in development for the treatment of bipolar depression (BPD) in patients characterized by a cognitive biomarker. Enrollment in the randomized, double-blind, placebo-controlled Phase 2b trial remains ongoing with topline data expected in the second half of 2026. The Company expects to enroll approximately 200 patients with BPD. Patients will be evaluated over a six-week treatment period and the primary endpoint is the change from baseline on the Montgomery Åsberg Depression Rating Scale (MADRS) in the patient population characterized by a cognitive biomarker. In October 2025, the Company announced the positive outcome of a blinded PK analysis from the first cohort evaluated in the ongoing Phase 2b study to assess the enhanced execution efforts implemented by the Company. Of the samples evaluated for ALTO-100 in the blinded PK analysis, 96% qualified as PK positive. Corporate Updates In October 2025, the Company announced a $50 million private placement financing (PIPE) to support the accelerated development of ALTO-207 following the successful FDA meeting. The financing was led by Perceptive Advisors, with participation from other biotech dedicated investors. Upcoming Milestones and Events Near-Term Expected Milestones 1Q 2026 — ALTO-101 Phase 2 POC CIAS trial topline data Mid-2026 — ALTO-300 Phase 2b MDD trial topline data 1H 2026 — ALTO-207 Phase 2b TRD trial initiation 2H 2026 — ALTO-100 Phase 2b BPD trial topline data Upcoming Conferences The Company is expected to present at the following upcoming conferences: Stifel 2025 Healthcare Conference: November 11-13, 2025 Jefferies London Healthcare Conference: November 17-20, 2025 Third Quarter 2025 Financial Highlights Cash Position: As of September 30, 2025, the Company had cash, cash equivalents, and restricted cash of approximately $138.3 million, compared to approximately $168.7 million in cash, cash equivalents, and restricted cash as of December 31, 2024. Inclusive of net proceeds of $49.9 million from the PIPE, the Company had a cash balance of approximately $184.2 million as of October 31, 2025. The Company expects its cash balance, inclusive of the proceeds from the PIPE, to support planned operations, which now includes expanded execution on ALTO-207, into 2028. R&D Expenses: Research and development expenses for the quarter ended September 30, 2025 were $10.5 million, as compared to $13.1 million for the same period in 2024. G&A Expenses: General and administrative expenses for the quarter ended September 30, 2025 were $4.4 million, as compared to $5.8 million for the same period in 2024. Net Loss: The Company incurred a net loss of $14.2 million for the quarter ended September 30, 2025, as compared to $16.8 million for the same period in 2024. About Alto Neuroscience Alto Neuroscience is a clinical-stage biopharmaceutical company with a mission to redefine psychiatry by leveraging neurobiology to develop personalized and highly effective treatment options. Alto’s Precision Psychiatry Platform™ measures brain biomarkers by analyzing EEG activity, neurocognitive assessments, wearable data, and other factors to better identify which patients are more likely to respond to Alto product candidates. Alto’s clinical-stage pipeline includes novel drug candidates in bipolar depression, major depressive disorder, treatment resistant depression, and schizophrenia, and other mental health conditions. For more information, visit www.altoneuroscience.com or follow Alto on X. Forward-Looking Statements This press release may contain forward-looking statements made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. These statements may be identified by words such as "aims," "anticipates," "believes," "could," "estimates," "expects," "forecasts," "goal," "intends," "look forward," "may," "plans," "possible," "potential," "seeks," "will" and variations of these words or similar expressions that are intended to identify forward-looking statements, although not all forward-looking statements contain these words. Forward-looking statements in this press release include, but are not limited to, statements regarding Alto’s expectations with regard to the potential benefits, activity, effectiveness and safety of its product candidates and Precision Psychiatry Platform ("Platform"); statements regarding patient compliance and the effectiveness of Alto’s clinical trial execution measures; Alto’s expectations with regard to the design and results of its research and development programs and clinical trials, including the timing of enrollment and the timing and availability of data from such trials; Alto’s clinical and regulatory development plans for its product candidates, including the timing or likelihood of regulatory filings and approvals for its product candidates; Alto’s business strategy, financial position, including anticipated cash runway, and the sufficiency of its financial resources to fund its operations through expected milestones; and other statements that are not historical fact. Actual results or events could differ materially from the plans, intentions and expectations disclosed in these forward-looking statements as a result of various factors, including: uncertainties inherent in the initiation, progress and completion of clinical trials and clinical development of Alto’s product candidates; the risk that Alto may not realize the intended benefits of its Platform; availability and timing of results from clinical trials; whether initial or interim results from a clinical trial will be predictive of the final results of the trial or the results of future trials; the risk that clinical trials may have unsatisfactory outcomes; the risk that Alto’s projections regarding its financial position and expected cash runway are inaccurate or that its conduct of its business requires more cash than anticipated; and other important factors, any of which could cause Alto’s actual results to differ from those contained in the forward-looking statements, which are described in greater detail in Alto's Annual Report on Form 10-K for the fiscal year ended December 31, 2024 and Alto’s Quarterly Report on Form 10-Q for the fiscal quarter ended June 30, 2025 filed with the Securities and Exchange Commission ("SEC") as well as in other filings Alto may make with the SEC in the future. Any forward-looking statements contained in this press release speak only as of the date hereof, and Alto expressly disclaims any obligation to update any forward-looking statements contained herein, whether because of any new information, future events, changed circumstances or otherwise, except as required by law. Availability of Information on Alto’s Website Alto routinely uses its investor relations website to post presentations to investors and other important information, including information that may be material. Accordingly, Alto encourages investors and others interested in Alto to review the information it makes public on its investor relations website. View source version on businesswire.com: https://www.businesswire.com/news/home/20251112497891/en/ Contacts Investor & Media Contact: Nick Smith [email protected] [email protected]

The third-quarter 2025 reporting cycle of the Medical sector is currently approaching its end. The sector primarily comprises pharma/biotech and medical device companies. Many pharma giants, like Amgen, Novo Nordisk and Pfizer, reported earnings last week. While results for Amgen and Pfizer were strong on both earnings and sales, both companies also raised their EPS outlook for 2025. However, things did not look good for Novo Nordisk, which reported weaker-than-expected Q3 results. The Danish drugmaker also slashed its guidance outlook for the full year due to the slower growth of its GLP-1 portfolio amid increased availability of compounded alternatives and intensifying competition from arch-rival Eli Lilly. The Earnings Trends report indicates that as of Nov. 5, nearly 82% of the companies in the Medical sector — representing 92% of the sector’s market capitalization — reported quarterly earnings. While about 92% of participants beat on earnings, around 84% outperformed revenues. Earnings rose over 4% year over year, while revenues increased nearly 11%. Overall, third-quarter earnings and sales are expected to rise 3.0% and 10.5%, respectively, from the year-ago quarter’s reported figures. While most companies in the sector have reported earnings, there are some companies which are yet to report. Out of them, we have highlighted four biotech companies — Alto Neuroscience ANRO, Autolus Therapeutics AUTL, Ascendis Pharma ASND and Immuneering IMRX — that seem poised to deliver a beat in their upcoming quarterly results. Earnings ESP is our proprietary methodology for determining the stocks with the best chance to deliver an earnings surprise. It shows the percentage difference between the Most Accurate Estimate and the Zacks Consensus Estimate. According to the Zacks model, the combination of a positive Earnings ESP and a Zacks Rank #1 (Strong Buy), 2 (Buy) or 3 (Hold) increases the odds of an earnings beat. The selection can be made with the help of the Zacks Stock Screener. Our research shows that the chance of an earnings surprise for stocks with this combination is as high as 70%. You can uncover the best stocks to buy or sell before they’re reported with our Earnings ESP Filter. Alto is a clinical-stage biotech focused on developing a broad range of novel pipeline therapies targeting neuroscience indications like bipolar depression, major depressive disorder and schizophrenia. The company has an Earnings ESP of +16.41% and a Zacks Rank #2 at present. You can see the complete list of today’s Zacks #1 Rank stocks here. The Zacks Consensus Estimate for the third quarter is pegged at a loss of 66 cents per share. ANRO beat on earnings in three of the trailing four quarters and missed the mark once, delivering an average surprise of 4.36%. Alto Neuroscience, Inc. price-eps-surprise | Alto Neuroscience, Inc. Quote A commercial-stage company, Autolus is primarily focused on developing, manufacturing and marketing next-generation T cell therapies targeting cancer and autoimmune diseases. The company has an Earnings ESP of +22.30% and a Zacks Rank #2 at present. The Zacks Consensus Estimate for third-quarter bottom line is pegged at a loss of 23 cents per share. AUTL beat on earnings in two of the trailing four quarters and missed the mark on the other two occasions, delivering an average surprise of 6.55%. The company is scheduled to release results on Nov. 12, before the opening bell. Autolus Therapeutics PLC Sponsored ADR price-eps-surprise | Autolus Therapeutics PLC Sponsored ADR Quote The company is a commercial-stage biotech focused on developing and marketing therapies targeting growth disorders and rare endocrine diseases. Ascendis has an Earnings ESP of +34.28% and a Zacks Rank #3 at present. The Zacks Consensus Estimate for third-quarter bottom line is pegged at a loss of 41 cents per share. ASND beat on earnings in two of the trailing four quarters and missed the mark on the other two occasions, delivering an average surprise of 11.15%. It is scheduled to report earnings on Nov. 12, after the market closes. Ascendis Pharma A/S price-eps-surprise | Ascendis Pharma A/S Quote The company is a clinical-stage biotech focused on developing its lead pipeline candidate targeting tumors harboring the RAS mutation. It has an Earnings ESP of +21.62% and a Zacks Rank #3 at present. The Zacks Consensus Estimate for third-quarter earnings is pegged at a loss of 37 cents per share. IMRX beat on earnings in one of the trailing four quarters, met the mark once, but missed the mark on the other two occasions. It delivered a negative average surprise of 7.82%. The company is scheduled to report earnings on Nov. 12, after the market closes. Immuneering Corporation price-eps-surprise | Immuneering Corporation Quote Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report Ascendis Pharma A/S (ASND) : Free Stock Analysis Report Autolus Therapeutics PLC Sponsored ADR (AUTL) : Free Stock Analysis Report Immuneering Corporation (IMRX) : Free Stock Analysis Report Alto Neuroscience, Inc. (ANRO) : Free Stock Analysis Report This article originally published on Zacks Investment Research (zacks.com). Zacks Investment Research

– Acquisition of potentially best-in-class dopamine agonist combination product candidates, including ALTO-207, expands precision psychiatry pipeline; guided by compelling PAX-D study results published in The Lancet Psychiatry – – ALTO-207 adds expected late-stage readout in treatment resistant depression within current cash runway; planned Phase 2b trial, designed to be a potentially pivotal study expected to initiate by mid-2026 – – Topline data expected from Phase 2 proof-of-concept (POC) trial of ALTO-101 in schizophrenia in the second half of 2025; Phase 2b topline data readouts include ALTO-300 in MDD expected mid-2026 followed by ALTO-100 in bipolar depression expected in the second half of 2026 – – Identified a patient selection biomarker and reported positive pharmacodynamic results from the Phase 2 POC trial of ALTO-203, a non-stimulant product candidate demonstrating pro-cognitive and wake-promoting effects – – Strong cash position of approximately $148.1 million expected to fund planned operations into 2028, and through four upcoming clinical study readouts – MOUNTAIN VIEW, Calif., August 13, 2025--(BUSINESS WIRE)--Alto Neuroscience, Inc. ("Alto") (NYSE: ANRO) a clinical-stage biopharmaceutical company focused on the development of novel precision medicines for neuropsychiatric disorders, today reported financial results for the quarter ended June 30, 2025, and highlighted recent progress across its pipeline of clinical-stage product candidates. "We have had an exciting past few months marked by a promising addition to our pipeline with ALTO-207 and encouraging clinical data that provide further validation of our biomarker-driven approach to drug development," said Amit Etkin, M.D., Ph.D., Founder and CEO of Alto Neuroscience. "The robust clinical effects of pramipexole observed in the PAX-D study give us strong conviction in the therapeutic potential of ALTO-207 to become a meaningful option for patients with treatment resistant depression (TRD), and we look forward to initiating a potentially pivotal Phase 2b trial by mid-2026. We continued our diligent execution across our pipeline to enroll high-quality subjects and are looking forward to the upcoming clinical study readouts." Dr. Etkin continued, "The recent data from our exploratory study of ALTO-203 highlights our ability to better guide indication selection and trial design through our use of biomarkers, which we believe will drive better patient outcomes. Recent clinical readouts in cognitive impairment in schizophrenia (CIAS) further our view that this is an area of incredible unmet need. To our knowledge, ALTO-101, which previously demonstrated pro-cognitive effects, now represents the most advanced therapeutic candidate in a space with no currently approved treatments. We look forward to completing the ongoing study this year to further guide its development." Pipeline Highlights ALTO-207: Acquired novel combination product with robust clinical validation; Phase 2b trial, designed to be a potentially pivotal study, in patients with treatment resistant depression expected to initiate by mid-2026. ALTO-207 is a fixed-dose combination of pramipexole, a dopamine D3-preferring D3/D2 agonist, approved for the treatment of Parkinson’s disease with demonstrated antidepressant effect, and ondansetron, an antiemetic, selective 5-HT3 receptor antagonist. As a fixed-dose combination, ALTO-207 is designed to enable rapid titration and higher dosing by mitigating the dose-limiting adverse events typically experienced with pramipexole. ALTO-207 is being developed to address the significant unmet need for patients with TRD. The planned Phase 2b trial of ALTO-207, designed to be a potentially pivotal study, is expected to initiate by mid-2026. In May 2025, the Company acquired from Chase Therapeutics Corporation (Chase) a portfolio of potentially best-in-class dopamine agonist combination product candidates, including ALTO-207, formerly known as CTC-501. The link to the conference call replay is accessible on the Company’s website and here. Prior to the acquisition by Alto, Chase completed a randomized, placebo-controlled Phase 2a clinical trial evaluating CTC-501 in 32 patients with depression. The primary endpoint was achieved in the study. Patients randomized to receive CTC-501 reached a mean dose of 4.1mg per day, with 67% of patients achieving the highest allowable dose of 5mg/day. CTC-501 was generally well tolerated in the maintenance period of the study. The clinical efficacy measures were evaluated as secondary endpoints and across measures CTC-501 demonstrated large, clinically meaningful effects. CTC-501 demonstrated statistically significant and clinically meaningful improvements from baseline compared to placebo on depression symptoms as measured by the Montgomery Åsberg Depression Rating Scale, or MADRS (LSM Δ vs. placebo at Week 8 = -8.2, p=0.025, Cohen’s d=1.1). CTC-501 also demonstrated a significantly greater improvement compared to placebo on the Clinician Global Impression Scale of Severity, or CGI-S (LSM Δ vs. placebo at Week 8 = -0.76, p=0.04, Cohen’s d=1.0). The acquisition of ALTO-207 was prompted by Alto’s novel insights on dopamine biomarkers in TRD patients and the robust antidepressant effects of pramipexole exhibited in the PAX-D study conducted by the University of Oxford. Results, which were recently published in The Lancet Psychiatry, showed pramipexole augmentation of antidepressant treatment, at a target dose of 2.5mg, demonstrated a large (Cohen’s d=0.87) reduction in symptoms relative to placebo at 12 weeks, but was associated with a high rate of adverse effects. The link to the online publication can be found here. The Company plans to collaborate with the National Health Service network, including PAX-D clinical sites for the planned Phase 2b trial of ALTO-207. ALTO-101: Enrollment is ongoing in Phase 2 POC CIAS trial; topline data expected in the second half of 2025. ALTO-101, a brain-penetrant PDE4 inhibitor designed as a novel transdermal formulation, is being developed for the treatment of CIAS. The novel formulation is designed to retain the desired brain effects shown with the oral formulation while avoiding the tolerability challenges and adverse effects known to be associated with PDE4 inhibitors. Enrollment remains ongoing in the Phase 2 POC trial in CIAS, with topline data expected in the second half of 2025. The Phase 2 POC trial consists of a dose-escalating treatment with ALTO-101 and is designed to enroll approximately 70 adult participants with schizophrenia between the ages of 21 and 55. The primary outcome in the study is the effect of ALTO-101 on theta band activity, the EEG measure shown to be most clearly associated with CIAS in replicated analyses of large schizophrenia datasets. Objective cognitive performance is also being evaluated. ALTO-300: Enrollment ongoing in Phase 2b adjunctive major depressive disorder trial; data expected in mid-2026. ALTO-300, also known as agomelatine, is an oral, small molecule designed to act as a melatonin agonist and 5-HT2C antagonist, and is being developed at 25mg as an adjunctive treatment in the United States for patients with major depressive disorder (MDD), characterized by an EEG biomarker. Agomelatine is an approved antidepressant medication in Europe and Australia, at both 25mg and 50mg, but has not been approved in the United States. In comparison to the 50mg dose of agomelatine, the 25mg dose has been shown to have equivalent antidepressant efficacy and has not been associated with reversible, low liver enzyme elevations observed with the 50mg dose. Topline data from the double-blind, placebo-controlled, randomized Phase 2b trial is expected in mid-2026. The Company expects to enroll approximately 200 biomarker positive patients for the final analysis sample. In the ongoing Phase 2b trial, patients who have had an inadequate response to their current antidepressant are randomized to receive either 25mg of ALTO-300 or placebo over a six-week treatment period. The study medication is being taken in addition to a patient’s background antidepressant. The primary outcome is the change from baseline in MADRS score in patients with the EEG biomarker. In May 2025, the Company presented additional analyses at the American Society of Clinical Psychopharmacology Annual Meeting (ASCP) Annual Meeting supporting the unique biomarker opportunity for patient stratification and reinforcing the well-established safety and tolerability profile for ALTO-300 in MDD. The most common adverse event observed in the completed Phase 2a trial of ALTO-300 was headache. Additionally, the Phase 2a and Phase 2b trials have involved monitoring for elevated liver enzymes (≥ 3 times the upper limit of normal), with the Phase 2b trial including a stopping rule for elevated liver enzymes. No liver function test (LFT) elevations ≥ 3 times the upper limit of normal were observed in the Company’s 239-patient completed Phase 2a trial, and no patients have been stopped in the ongoing Phase 2b trial due to liver enzyme elevation, which remains blinded. The ALTO-300 biomarker signal likely reflects increased neural noise due to elevated 5-HT2C tone and reduced dopaminergic activity. Increasing 5-HT2C activity in a preclinical rodent model or directly depleting dopamine in a healthy human volunteer study—both the opposite mechanistic effect of ALTO-300—resulted in greater EEG irregularity, consistent with a biomarker positive profile. These data reinforce the direct link between ALTO-300 and the EEG biomarker used to identify MDD patients who are more likely to be responders to treatment. ALTO-100: Enrollment ongoing in Phase 2b bipolar depression trial; data expected in the second half of 2026. ALTO-100, a first-in-class, oral small molecule believed to work through enhancing neuroplasticity, is in development for the treatment of bipolar depression (BPD) in patients characterized by a cognitive biomarker. Enrollment in the randomized, double-blind, placebo-controlled Phase 2b trial remains ongoing with topline data expected in the second half of 2026. The Company expects to enroll approximately 200 patients with BPD. Patients will be evaluated over a six-week treatment period and the primary endpoint is the change from baseline on the MADRS in the patient population characterized by a cognitive biomarker. The completed Phase 2b trial evaluating ALTO-100 as a treatment for MDD demonstrated a clinically meaningful signal in the adjunctive subgroup and evidence of biomarker enrichment in the compliant subset of patients. These data support the ongoing Phase 2b trial of ALTO-100 as an adjunctive treatment in BPD. ALTO-203: Reported topline results from Phase 2 POC MDD trial. ALTO-203 is a novel, oral small molecule designed to uniquely act as a histamine H3 inverse agonist, designed to modulate circuits underlying cognition, wakefulness, and alertness. In June 2025, the Company announced the identification of a patient selection biomarker and positive pharmacodynamic results from its exploratory Phase 2 POC trial of ALTO-203 in MDD patients with elevated levels of anhedonia. The findings in the study replicated results from the Phase 1 study in healthy volunteers, where ALTO-203 treatment led to improvements in sustained attention and reductions in the EEG theta/beta ratio. Baseline EEG theta/beta ratio predicted attentional benefits of ALTO-203 in both the Phase 1 study and Phase 2 POC trial. Alto plans to report additional results from this exploratory study at a future medical meeting and expects to determine the next development steps for ALTO-203 following the complete analysis of the data set. Corporate Updates In August 2025, the Company appointed to its Board of Directors, Raymond Sanchez, M.D., a highly accomplished executive with a strong background in medicine and over 20 years of strategic experience in the life sciences industries. With the addition of Ray, Alto’s Board has increased to six members. Upcoming Milestones and Events Near-Term Expected Milestones 2H 2025 — ALTO-101 Phase 2 POC CIAS trial topline data Mid-2026 — ALTO-300 Phase 2b MDD trial topline data Mid-2026 — ALTO-207 Phase 2b TRD trial initiation 2H 2026 — ALTO-100 Phase 2b BPD trial topline data Upcoming Conferences The Company is expected to present at the following upcoming conferences: H.C. Wainwright 27th Annual Global Investment Conference: September 8-10, 2025 Baird 2025 Global Healthcare Conference: September 10, 2025 TD Cowen's 5th Annual Novel Mechanisms in Neuropsychiatry & Epilepsy Summit: September 17-18, 2025 Second Quarter 2025 Financial Highlights Cash Position: As of June 30, 2025 the Company had cash, cash equivalents, and restricted cash of approximately $148.1 million, compared to approximately $168.7 million in cash, cash equivalents, and restricted cash as of December 31, 2024. The Company expects its cash balance to support planned operations into 2028. R&D Expenses: Research and development expenses for the quarter ended June 30, 2025 were $13.1 million, as compared to $13.2 million for the same period in 2024. G&A Expenses: General and administrative expenses for the quarter ended June 30, 2025 were $5.6 million, as compared to $5.2 million for the same period in 2024. Net Loss: The Company incurred a net loss of $17.7 million for the quarter ended June 30, 2025, as compared to $16.0 million for the quarter ended June 30, 2024. About Alto Neuroscience Alto Neuroscience is a clinical-stage biopharmaceutical company with a mission to redefine psychiatry by leveraging neurobiology to develop personalized and highly effective treatment options. Alto’s Precision Psychiatry Platform™ measures brain biomarkers by analyzing EEG activity, neurocognitive assessments, wearable data, and other factors to better identify which patients are more likely to respond to Alto product candidates. Alto’s clinical-stage pipeline includes novel drug candidates in bipolar depression, major depressive disorder, treatment resistant depression, and schizophrenia, and other mental health conditions. For more information, visit www.altoneuroscience.com or follow Alto on X. Forward-Looking Statements This press release may contain forward-looking statements made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. These statements may be identified by words such as "aims," "anticipates," "believes," "could," "estimates," "expects," "forecasts," "goal," "intends," "look forward," "may," "plans," "possible," "potential," "seeks," "will" and variations of these words or similar expressions that are intended to identify forward-looking statements, although not all forward-looking statements contain these words. Forward-looking statements in this press release include, but are not limited to, statements regarding Alto’s expectations with regard to the potential benefits, activity, effectiveness and safety of its product candidates and Precision Psychiatry Platform ("Platform"); Alto’s expectations with regard to the design and results of its research and development programs and clinical trials, including the timing of enrollment and the timing and availability of data from such trials; Alto’s clinical and regulatory development plans for its product candidates, including the timing or likelihood of regulatory filings and approvals for its product candidates; Alto’s business strategy, financial position, including anticipated cash runway, and the sufficiency of its financial resources to fund its operations through expected milestones; and other statements that are not historical fact. Actual results or events could differ materially from the plans, intentions and expectations disclosed in these forward-looking statements as a result of various factors, including: uncertainties inherent in the initiation, progress and completion of clinical trials and clinical development of Alto’s product candidates; the risk that Alto may not realize the intended benefits of its Platform; availability and timing of results from clinical trials; whether initial or interim results from a clinical trial will be predictive of the final results of the trial or the results of future trials; the risk that clinical trials may have unsatisfactory outcomes; the risk that Alto’s projections regarding its financial position and expected cash runway are inaccurate or that its conduct of its business requires more cash than anticipated; and other important factors, any of which could cause Alto’s actual results to differ from those contained in the forward-looking statements, which are described in greater detail in Alto's Annual Report on Form 10-K for the fiscal year ended December 31, 2024 filed with the Securities and Exchange Commission ("SEC") as well as in other filings Alto may make with the SEC in the future. Any forward-looking statements contained in this press release speak only as of the date hereof, and Alto expressly disclaims any obligation to update any forward-looking statements contained herein, whether because of any new information, future events, changed circumstances or otherwise, except as required by law. Availability of Information on Alto’s Website Alto routinely uses its investor relations website to post presentations to investors and other important information, including information that may be material. Accordingly, Alto encourages investors and others interested in Alto to review the information it makes public on its investor relations website. View source version on businesswire.com: https://www.businesswire.com/news/home/20250813841679/en/ Contacts Investor Contact: Nick Smith [email protected] Media Contact: Mari Purpura [email protected]

– Demonstrated target engagement and response prediction for ALTO-203 by theta/beta ratio, a commonly used EEG index of cortical arousal and attentional control – – ALTO-203, a non-stimulant compound which demonstrated pro-cognitive and wake-promoting effects, has the potential to address sustained attention abnormalities in EEG biomarker characterized patients – – Pharmacodynamic activity is aligned with the proposed mechanism of ALTO-203; improvements in attention and corresponding reductions in EEG theta/beta ratio, as well as response prediction biomarker replicate Phase 1 study findings – MOUNTAIN VIEW, Calif., June 26, 2025--(BUSINESS WIRE)--Alto Neuroscience, Inc. ("Alto") (NYSE: ANRO) a clinical-stage biopharmaceutical company focused on the development of novel precision medicines for neuropsychiatric disorders, today announced the identification of a patient selection biomarker and positive pharmacodynamic results from its exploratory Phase 2 proof-of-concept (POC) trial of ALTO-203 in major depressive disorder (MDD) patients with elevated levels of anhedonia. ALTO-203 is a novel, oral, histamine H3 inverse agonist, designed to modulate circuits underlying cognition, wakefulness, and alertness. The profile exhibited by ALTO-203 in the exploratory POC trial demonstrated clear effects on objective measures of attention and wakefulness, with observed improvements linked to changes in the EEG theta/beta ratio—a biomarker indexing cortical arousal and attentional control. These findings replicate results from the Phase 1 study in healthy volunteers, where ALTO-203 treatment led to improvements in sustained attention and reductions in the EEG theta/beta ratio. Baseline EEG theta/beta ratio predicted attentional benefits of ALTO-203 in both the Phase 1 study and Phase 2 POC trial. "We aim to leverage objective biomarkers to enable targeted neuropsychiatric drug development so that patients can get better, faster," said Amit Etkin, M.D., Ph.D., founder and CEO of Alto Neuroscience. "In this exploratory trial, we identified a robust biomarker for ALTO-203, EEG high-theta/beta ratio, which is a well-validated measure of abnormal cortical arousal and poor attentional control. Notably, this biomarker is FDA-cleared for use alongside clinical evaluation in the diagnosis of ADHD, reinforcing its clinical relevance. These positive results replicate findings from an ALTO-203 Phase 1 study and enhance our understanding of the patient subtypes most likely to benefit from the drug, further strengthening the foundation of our precision psychiatry approach. We believe our platform has the potential to enable data-driven indication selection and trial design early in development—accelerating the path to more effective, personalized treatment." The exploratory Phase 2 POC trial, which enrolled 69 patients, was conducted in two sequential, double-blind, placebo-controlled periods. The trial was designed to characterize the pharmacodynamic, pharmacokinetic, safety, and tolerability profile of ALTO-203 across two dose levels compared to placebo in a crossover design and was not powered to detect statistical significance on traditional depression outcome scales (e.g., MADRS). Adam Savitz, M.D., Ph.D., Chief Medical Officer of Alto Neuroscience, commented, "We are encouraged by the positive pharmacodynamic activity observed in the study, which aligns with the proposed mechanism of ALTO-203. The wake-promoting and pro-cognitive effects demonstrated, suggest clear potential for ALTO-203 to be a meaningful treatment across various neuropsychiatric conditions in which sleep and attention are significantly impaired." Topline, prespecified results from the exploratory Phase 2 POC trial of ALTO-203 include: Subjective Effects on Bond & Lader Visual Analog Scale (BL-VAS): Patients reported significant improvements from baseline on BL-VAS for alertness & mood at the 5-hour timepoint post dosing with ALTO-203. A higher-than-expected placebo response was observed on the Bond & Lader measurements – no significant separation between ALTO-203 and placebo was observed. EEG Biomarker of Drug Effect Identified: The theta/beta ratio, a neurophysiological marker linked to attentional control, was confirmed as a key pharmacodynamic readout. The effects of ALTO-203 on reducing theta/beta ratio were significant compared to placebo (25µg: p<0.05). This marker was previously shown to be significantly reduced by ALTO-203 in the completed Phase 1 study in healthy subjects, as well as in preclinical studies. Cognitive Enhancement Observed: ALTO-203 treatment led to significant improvements in sustained attention (25µg: p<0.05; 75µg: p=0.06 vs. placebo), aligning with reductions in the EEG theta/beta ratio. Improvement in attention was greatest in patients with high baseline theta/beta ratios (i.e., more abnormal) (25µg: p<0.01; 75µg: p<0.05 vs. placebo). The observed improvements in attention and corresponding changes in EEG theta/beta ratio replicated significant findings from the Phase 1 study. Wearable Device Confirmation: Objective sleep measures from wearable devices supported the wake-promoting effects of ALTO-203, and the increased wakefulness exhibited by ALTO-203 was significant for both doses (25µg: p<0.05; 75µg: p<0.001 vs. placebo). Pharmacokinetics and Safety: ALTO-203 displayed predictable accumulation over multiple doses with no adverse pharmacokinetic signals. ALTO-203 was well tolerated, with insomnia as the most frequent adverse event, consistent with its wake-promoting profile. MADRS Improvements: Patients taking 25µg of ALTO-203 exhibited a mean improvement of 2 points at week 3 and 0.9 points at week 4 compared to placebo. The differences were not observed in the 75µg dose group. MADRS improvements were evaluated during the 28-day multi-dose period, which was not powered to detect significance. Alto plans to report additional results from this exploratory study at a future medical meeting and expects to determine the next development steps for ALTO-203 following the complete analysis of the data set. About the Phase 2 POC Trial of ALTO-203 The Phase 2 POC trial enrolled 69 MDD patients with higher levels of anhedonia consisted of two dosing periods (63 completed the primary single-dose period): Single-dose period: Patients received two single-doses of ALTO-203 (25µg and 75µg), and placebo in a randomized, three-way crossover design. The powered primary outcome was an acute change in positive emotion assessed by the alertness and mood components of the Bond-Lader Visual Analog Scale (BL-VAS), an established scale of subjective feelings. Key pre-specified exploratory outcomes included measures of cognition, EEG changes, and effects on sleep. Multi-dose period: Patients were randomized to receive daily administration of ALTO-203 (25µg or 75µg QD) or placebo over 28 days. This period was designed to evaluate extended safety, tolerability, and pharmacokinetics, as well as exploratory biomarkers across EEG, cognitive testing, and wearable device data. About Alto Neuroscience Alto Neuroscience is a clinical-stage biopharmaceutical company with a mission to redefine psychiatry by leveraging neurobiology to develop personalized and highly effective treatment options. Alto’s Precision Psychiatry Platform™ measures brain biomarkers by analyzing EEG activity, neurocognitive assessments, wearable data, and other factors to better identify which patients are more likely to respond to Alto product candidates. Alto’s clinical-stage pipeline includes novel drug candidates in bipolar depression, major depressive disorder, treatment resistant depression (TRD), and schizophrenia, and other mental health conditions. For more information, visit www.altoneuroscience.com or follow Alto on X. Forward-Looking Statements This press release may contain forward-looking statements made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. These statements may be identified by words such as "expects," "plans," "will" and variations of these words or similar expressions that are intended to identify forward-looking statements, although not all forward-looking statements contain these words. Forward-looking statements in this press release include, but are not limited to, statements regarding Alto’s expectations about the potential benefits, activity, effectiveness and safety of its product candidates and Precision Psychiatry Platform ("Platform"); the reproducibility of any favorable results seen in the exploratory Phase 2 POC trial of ALTO-203 in major depressive disorder; and Alto’s expectations with regard to the design and results of its clinical trials. Actual results or events could differ materially from the plans, intentions and expectations disclosed in these forward-looking statements as a result of various factors, including uncertainties inherent in the initiation, progress and completion of clinical trials and other important factors, any of which could cause Alto’s actual results to differ from those contained in the forward-looking statements, which are described in greater detail in the section titled "Risk Factors" in Alto’s Annual Report on Form 10-K for the fiscal year ended December 31, 2024 filed with the Securities and Exchange Commission ("SEC") as well as in other filings Alto may make with the SEC in the future. Any forward-looking statements contained in this press release speak only as of the date hereof, and Alto expressly disclaims any obligation to update any forward-looking statements contained herein, whether because of any new information, future events, changed circumstances or otherwise, except as required by law. Availability of Information on Alto’s Website Alto routinely uses its investor relations website to post presentations to investors and other important information, including information that may be material. Accordingly, Alto encourages investors and others interested in Alto to review the information it makes public on its investor relations website. View source version on businesswire.com: https://www.businesswire.com/news/home/20250626096968/en/ Contacts Investor and Media Contact: Mari Purpura [email protected] [email protected]

– Phase 2 proof-of-concept trials remain on track: Topline data expected from ALTO-203 in MDD in the second quarter of 2025 followed by ALTO-101 in schizophrenia in the second half of 2025 – – Late-stage programs advancing: Topline data expected from the Phase 2b trial of ALTO-300 in MDD in mid-2026 followed by the Phase 2b trial of ALTO-100 in bipolar depression in the second half of 2026 – – New data presented at recent scientific conferences support Alto’s biomarker-driven pipeline and patient stratification approach – – Strong cash position of approximately $161.3 million expected to fund planned operations into 2028, and through at least four upcoming clinical study readouts – MOUNTAIN VIEW, Calif., May 14, 2025--(BUSINESS WIRE)--Alto Neuroscience, Inc. ("Alto") (NYSE: ANRO) a clinical-stage biopharmaceutical company focused on the development of novel precision medicines for neuropsychiatric disorders, today reported financial results for the first quarter ended March 31, 2025, and highlighted recent progress across its pipeline of clinical-stage product candidates. "In the first quarter of 2025 we took important steps to deliver on our clinical and corporate objectives," said Amit Etkin, M.D., Ph.D., founder and chief executive officer of Alto Neuroscience. "We have continued to execute across each of our four ongoing clinical trials, and in addition we have advanced our biomarker platform to further support our precision psychiatry approach. We believe the recent presentation of our EEG-based placebo response biomarker and dopamine-related biomarkers highlight our leadership position in targeted neuropsychiatric drug development. We look forward to exploring opportunities to maximize the therapeutic impact of our platform to address the high unmet needs of patients. With a strong balance sheet expected to support several key clinical milestones in the coming years, we believe we are well positioned to redefine how neuropsychiatric conditions are treated." Pipeline Highlights ALTO-100: Enrollment ongoing in Phase 2b bipolar depression trial; data expected in the second half of 2026. ALTO-100, a first-in-class, oral small molecule believed to work through enhancing neuroplasticity, is in development for the treatment of bipolar depression (BPD) in patients characterized by a cognitive biomarker. Enrollment in the randomized, double-blind, placebo-controlled Phase 2b trial remains ongoing with topline data expected in the second half of 2026. The Company expects to enroll approximately 200 patients with BPD. Patients will be evaluated over a six-week treatment period and the primary endpoint is the change from baseline on the Montgomery-Åsberg Depression Rating Scale (MADRS) in the patient population characterized by a cognitive biomarker. In the fourth quarter of 2024, the Company completed the Phase 2b trial evaluating ALTO-100 as a treatment for major depressive disorder (MDD). The clinically meaningful signal in the adjunctive subgroup and evidence of biomarker enrichment in the compliant subset of patients supports the ongoing Phase 2b trial of ALTO-100 as an adjunctive treatment in BPD. The Company presented additional analyses of the ALTO-100 MDD Phase 2b trial at the Society of Biological Psychiatry (SOBP) Annual Meeting highlighting the utilization of an EEG-based biomarker to account for potential placebo responders. As presented, these results build on the Company’s successful identification and prospective replication of an EEG-based biomarker for placebo response in MDD. The analysis prospectively demonstrated that weighting patient outcomes based on an EEG marker for placebo response resulted in a larger treatment response. These data demonstrate the applications of this biomarker to potentially enable more precise identification of high placebo responders and improve detection of treatment response in a clinical trial. The Company expects to employ this biomarker in the ongoing ALTO-100 BPD trial. ALTO-300: Enrollment ongoing in Phase 2b adjunctive major depressive disorder trial; data expected in mid-2026. ALTO-300, also known as agomelatine, is an oral, small molecule designed to act as a melatonin agonist and 5-HT2C antagonist, and is being developed at 25mg as an adjunctive treatment in the United States for patients with MDD, characterized by an EEG biomarker. Agomelatine is an approved antidepressant medication in Europe and Australia, at both 25mg and 50mg, but has not been approved in the United States. In comparison to the 50mg dose of agomelatine, the 25mg dose has been shown to have equivalent antidepressant efficacy and has not been associated with reversible, low liver enzyme elevations observed with the 50mg dose. Topline data from the double-blind, placebo-controlled, randomized Phase 2b trial is expected in mid-2026. The Company expects to enroll approximately 200 biomarker positive patients for the final analysis sample. The final analysis sample is based on the favorable outcome from the interim analysis announced in February 2025, which resulted in a recommendation to continue the study and increase the biomarker positive sample by approximately 50 subjects. While the trial includes both biomarker positive and biomarker negative patients, the primary analysis will be conducted in the biomarker positive subgroup. In the ongoing Phase 2b trial, patients who have had an inadequate response to their current antidepressant are randomized to receive either 25mg of ALTO-300 or placebo over a six-week treatment period. The study medication is being taken in addition to a patient’s background antidepressant. The primary outcome is the change from baseline in MADRS score in patients with the EEG biomarker. Across the Company’s clinical trials, and in clinical practice, agomelatine has demonstrated a favorable safety and tolerability profile. The most common adverse event observed in the Phase 2a trial of ALTO-300 was headache. Additionally, the Phase 2a and Phase 2b trials have involved monitoring for elevated liver enzymes (≥ 3 times the upper limit of normal), with the Phase 2b trial including a stopping rule for elevated liver enzymes, as measured by liver function tests (LFT). No LFT elevations ≥ 3 times the upper limit of normal were observed in the Company’s 239-patient completed Phase 2a trial, and no patients have been stopped in the ongoing Phase 2b trial due to liver enzyme elevation. Across three large, United States-based clinical trials in MDD, the 25mg dose of agomelatine (being developed by the Company as ALTO-300) has not led to liver enzyme elevation, exhibiting rates similar to placebo. Evidence from meta-analyses and real-world clinical care reinforces the consistent safety of the 25mg dose and suggests that higher doses of agomelatine do not result in greater efficacy. The Company believes these data support development of the 25mg dose to optimize clinical efficacy while balancing safety and tolerability. The Company presented new data at SOBP highlighting the mechanistic link between ALTO-300 and the machine learning-derived, EEG biomarker, used to identify patients who are more likely to respond to treatment. Increasing 5-HT2C activity or directly depleting dopamine—both the opposite mechanistic effect of ALTO-300—resulted in greater EEG irregularity, consistent with a biomarker positive profile. ALTO-203: Enrollment completed in Phase 2 proof-of-concept MDD trial; data expected in the second quarter of 2025. ALTO-203, a novel, oral small molecule designed to uniquely act as a histamine H3 inverse agonist, is being developed for the treatment of MDD associated with increased levels of anhedonia. In February, the Company completed enrollment in the 69-patient Phase 2 proof-of-concept (POC) trial in MDD patients with higher levels of anhedonia and expects to report topline data in the second quarter of 2025. The trial is the first evaluation of ALTO-203 in a patient population and consists of two sequential, double-blind, placebo-controlled treatment periods to evaluate two different dose levels of ALTO-203 as a monotherapy. In the first period, patients receive two single-doses of ALTO-203 (high-dose and low-dose), and placebo in a randomized, three-way crossover design, and the outcome measures are designed to evaluate pharmacodynamic effects. An acute change in positive emotion is assessed by the alertness and mood components of the Bond-Lader Visual Analog Scale (BL-VAS), an established scale of subjective emotion. The trial is designed to broadly explore the effects of ALTO-203 and is not powered to detect statistical significance on clinical depression outcome scales (e.g., MADRS). In the second period, patients receive high-or low-dose ALTO-203 or placebo once-daily over a 28-day treatment period to further explore the safety and pharmacokinetics of ALTO-203. Pharmacodynamic effects on cognition, EEG, and wearable measures will be evaluated to characterize the profile of ALTO-203 and guide next steps in development. The Company presented new preclinical data at SOBP demonstrating the distinct behavioral effects of ALTO-203, which may be driven by enhanced function and control of dopamine in the reward system. ALTO-203 effectively reversed anhedonia-like behavior induced by dopamine depletion and demonstrated a significantly higher sucrose preference. Pitolisant, the only FDA approved H3R inverse agonist, showed no significant effect at any dose. ALTO-101: Enrollment is ongoing in Phase 2 proof-of-concept CIAS trial; data expected in the second half of 2025. ALTO-101, a brain-penetrant PDE4 inhibitor designed as a novel transdermal formulation, is being developed for the treatment of Cognitive Impairment Associated with Schizophrenia (CIAS). The novel formulation is designed to retain the desired brain effects shown with the oral formulation while avoiding the tolerability challenges and adverse effects known to be associated with PDE4 inhibitors. Enrollment remains ongoing in the Phase 2 POC trial in CIAS, with topline data expected in the second half of 2025. The Phase 2 POC trial consists of a dose-escalating treatment with ALTO-101 and is designed to enroll approximately 70 adult participants with schizophrenia between the ages of 21 and 55. The primary outcome in the study is the effect of ALTO-101 on theta band activity, the EEG measure shown to be most clearly associated with CIAS in replicated analyses of large schizophrenia datasets. Objective cognitive performance is also evaluated. A poster was presented at the Annual Congress of the Schizophrenia International Research Society (SIRS), demonstrating ALTO-101 significantly enhanced theta responses in humans. Additionally, the Company presented new preclinical data at SOBP, exhibiting increased theta response in a preclinical rescue study with ALTO-101. The Company believes these data underscore the robustness of theta response as a translational biomarker for CIAS and the potential pro-cognitive drug effect. Upcoming Milestones and Events Near-Term Expected Milestones 2Q 2025 — ALTO-203 Phase 2 POC MDD trial topline data 2H 2025 — ALTO-101 Phase 2 POC CIAS trial topline data Mid-2026 — ALTO-300 Phase 2b MDD trial topline data 2H 2026 — ALTO-100 Phase 2b BPD trial topline data Upcoming Conferences The Company is expected to present at the following upcoming conferences: American Society of Clinical Psychopharmacology (ASCP) Annual Meeting: May 27-30, 2025 Jefferies Healthcare Conference: June 3-5, 2025 H.C. Wainwright 6th Annual Neuro Perspectives Hybrid Conference: June 16-17, 2025 Biotechnology Innovation Organization (BIO) International Convention: June 16-19, 2025 First Quarter 2025 Financial Highlights Cash Position: As of March 31, 2025 the Company had cash, cash equivalents, and restricted cash of approximately $161.3 million, compared to approximately $168.7 million in cash, cash equivalents, and restricted cash as of December 31, 2024. The Company expects its cash balance to support planned operations into 2028. R&D Expenses: Research and development expenses for the quarter ended March 31, 2025 were $10.0 million, as compared to $10.0 million for the same period in 2024. G&A Expenses: General and administrative expenses for the quarter ended March 31, 2025 were $5.7 million, as compared to $4.4 million for the same period in 2024. The increase was primarily attributable to costs associated with higher headcount to support expanded clinical development efforts, growing operational requirements, and costs associated with operating as a public company. $0.3 million of the increase is related to non-cash, stock-based compensation. Net Loss: The Company incurred a net loss of $15.2 million for the quarter ended March 31, 2025, as compared to $13.4 million for the quarter ended March 31, 2024. About Alto Neuroscience Alto Neuroscience is a clinical-stage biopharmaceutical company with a mission to redefine psychiatry by leveraging neurobiology to develop personalized and highly effective treatment options. Alto’s Precision Psychiatry Platform™ measures brain biomarkers by analyzing EEG activity, neurocognitive assessments, wearable data, and other factors to better identify which patients are more likely to respond to Alto product candidates. Alto’s clinical-stage pipeline includes novel drug candidates in bipolar depression, major depressive disorder, schizophrenia, and other mental health conditions. For more information, visit www.altoneuroscience.com or follow Alto on X. Forward-Looking Statements This press release may contain forward-looking statements made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. These statements may be identified by words such as "aims," "anticipates," "believes," "could," "estimates," "expects," "forecasts," "goal," "intends," "look forward," "may," "plans," "possible," "potential," "seeks," "will" and variations of these words or similar expressions that are intended to identify forward-looking statements, although not all forward-looking statements contain these words. Forward-looking statements in this press release include, but are not limited to, statements regarding Alto’s expectations with regard to the potential benefits, activity, effectiveness and safety of its product candidates and Precision Psychiatry Platform ("Platform"); Alto’s expectations with regard to the design and results of its research and development programs and clinical trials, including the timing of enrollment and the timing and availability of data from such trials; Alto’s clinical and regulatory development plans for its product candidates, including the timing or likelihood of regulatory filings and approvals for its product candidates; Alto’s business strategy, financial position and the sufficiency of its financial resources to fund its operations through expected milestones; and other statements that are not historical fact. Actual results or events could differ materially from the plans, intentions and expectations disclosed in these forward-looking statements as a result of various factors, including: uncertainties inherent in the initiation, progress and completion of clinical trials and clinical development of Alto’s product candidates; the risk that Alto may not realize the intended benefits of its Platform; availability and timing of results from clinical trials; whether initial or interim results from a clinical trial will be predictive of the final results of the trial or the results of future trials; the risk that clinical trials may have unsatisfactory outcomes; the risk that Alto’s projections regarding its financial position and expected cash runway are inaccurate or that its conduct of its business requires more cash than anticipated; and other important factors, any of which could cause Alto’s actual results to differ from those contained in the forward-looking statements, which are described in greater detail in Alto's Annual Report on Form 10-K for the fiscal year ended December 31, 2024 filed with the Securities and Exchange Commission ("SEC") as well as in other filings Alto may make with the SEC in the future. Any forward-looking statements contained in this press release speak only as of the date hereof, and Alto expressly disclaims any obligation to update any forward-looking statements contained herein, whether because of any new information, future events, changed circumstances or otherwise, except as required by law. Availability of Information on Alto’s Website Alto routinely uses its investor relations website to post presentations to investors and other important information, including information that may be material. Accordingly, Alto encourages investors and others interested in Alto to review the information it makes public on its investor relations website.   View source version on businesswire.com: https://www.businesswire.com/news/home/20250514582274/en/ Contacts Investor Contact: Nick [email protected] Media Contact: Mari [email protected]

– Favorable outcome from interim analysis of ongoing ALTO-300 Phase 2b MDD trial; topline results expected in mid-2026 – – Completed enrollment in ALTO-203 Phase 2 proof-of-concept MDD trial; on track to report topline data in the second quarter of 2025 – – Novel transdermal formulation of ALTO-101 demonstrated greater drug exposure and improved tolerability profile; topline data from Phase 2 trial of ALTO-101 in schizophrenia expected in the second half of 2025 – – Company’s precision psychiatry approach underpins recently granted patents covering the use of ALTO-100 and ALTO-300 in biomarker defined populations – – Strong cash position of approximately $169 million expected to fund planned operations into 2028, and through at least four upcoming clinical study readouts – MOUNTAIN VIEW, Calif., March 20, 2025--(BUSINESS WIRE)--Alto Neuroscience, Inc. ("Alto") (NYSE: ANRO) a clinical-stage biopharmaceutical company focused on the development of novel precision medicines for neuropsychiatric disorders, today reported financial results for the full-year ended December 31, 2024, and highlighted recent progress across its pipeline of clinical-stage product candidates. "In 2024 we continued to advance our mission to change the way medicines are developed for neuropsychiatric conditions," said Amit Etkin, M.D., Ph.D., founder and chief executive officer of Alto Neuroscience. "Using our proprietary platform we have evaluated brain-based biomarkers in over 2,000 participants and have completed six clinical studies across our pipeline programs since our founding. Further, we believe the outcome of the recent interim analysis of the ongoing ALTO-300 trial is suggestive of antidepressant activity, and we believe the sample re-estimation improves the overall probability of success in that trial." Dr. Etkin continued, "Successfully completing our IPO in 2024 has provided us with a strong balance sheet to support several key clinical milestones in the coming years. As a scientific founder with a sincere passion to move the field forward, I am very proud of all our team has accomplished and I look forward to building on this momentum." Pipeline Highlights ALTO-100: Enrollment ongoing in Phase 2b in Bipolar Depression; Phase 2b in MDD complete. ALTO-100, a first-in-class, oral small molecule believed to work through enhancing neuroplasticity, is in development for the treatment of bipolar depression (BPD) in patients characterized by a cognitive biomarker. Enrollment in the randomized, double-blind, placebo-controlled Phase 2b trial remains ongoing with topline data expected in the second half of 2026. The Company expects to enroll approximately 200 patients with BPD. Patients will be evaluated over a six-week treatment period and the primary endpoint is the change from baseline on the Montgomery-Åsberg Depression Rating Scale (MADRS) in the patient population characterized by a cognitive biomarker. In October 2024, the Company reported topline results from the Phase 2b trial evaluating ALTO-100 as a treatment for major depressive disorder (MDD). The cognitive biomarker-defined MDD (biomarker positive) patient group treated with ALTO-100 (n=196) did not demonstrate a statistically significant improvement in depressive symptoms compared to placebo in the modified intention to treat (mITT) population. ALTO-100 continued to demonstrate a favorable safety and tolerability profile, with no new safety signals observed in this study. In a pre-specified analysis of biomarker positive patients taking ALTO-100 or placebo adjunctively to a stable background antidepressant (n=61), ALTO-100 demonstrated a clinically meaningful effect compared to placebo at week 6 (Cohen’s d=0.47, p=0.09). The pre-specified analysis of this population was not powered to achieve statistical significance. Detailed analysis of the study results revealed a significantly lower rate of study medication compliance within the monotherapy group compared to the adjunctive group (56% in monotherapy vs. 100% in adjunctive) It was observed that in a subset of patients that had evidence of taking ALTO-100 through blood sample analysis, the patients with the ALTO-100 cognitive biomarker demonstrated a greater improvement compared to placebo and demonstrated a greater improvement than those without the biomarker. Based on the clinically meaningful signal in the adjunctive subgroup and the evidence of biomarker enrichment in the compliant subset of patients, the Company made the decision to continue the Phase 2b trial of ALTO-100 as an adjunctive treatment in BPD. ALTO-300: Completed interim analysis, resulting in a recommendation to continue the Phase 2b adjunctive MDD trial. ALTO-300, also known as agomelatine, is an oral, small molecule designed to act as a melatonin agonist and 5-HT2C antagonist, is being developed as an adjunctive treatment in the United States for patients with MDD, characterized by an EEG biomarker. Agomelatine is an approved antidepressant medication in Europe and Australia, but has not been approved in the United States. Topline data from the double-blind, placebo-controlled, randomized Phase 2b trial is expected in mid-2026. In the study, patients who have had an inadequate response to their current antidepressant are randomized to receive ALTO-300 or placebo over a six-week treatment period. The study medication is being taken in addition to a patient’s background antidepressant. The primary outcome is the change from baseline in MADRS score in patients with the EEG biomarker. In February 2025, the Company reported a favorable outcome from the planned interim analysis for the Phase 2b trial of ALTO-300 as an adjunctive treatment for patients with MDD. Based on the results of the interim analysis, the Phase 2b trial is continuing with a target enrollment of approximately 200 biomarker positive patients for the final analysis sample. Prior to the interim analysis, a blinded committee conducted an in-depth site and patient eligibility review that resulted in the prospective exclusion of sites and patients from the analysis population. Following the eligibility review, the biomarker positive population in the interim analysis consisted of 87 patients. The Company presented clinical advancements at multiple scientific conferences that provide further insight into the patient phenotype being studied in the Phase 2b trial. Approximately 50% of patients with MDD are estimated to be positive for the ALTO-300 EEG biomarker. In February 2025, a poster was presented at the International Society for CNS Clinical Trials and Methodology (ISCTM) 21st Annual Scientific Meeting, demonstrating the successful standardization of EEG enrichment marker acquisition through a platform that facilitates the identification of patients more likely to respond to ALTO-300. In December 2024, a poster was presented at the 63rd Annual Meeting of the American College of Neuropsychopharmacology (ACNP) from a reverse-translation preclinical study demonstrating that the ALTO-300 biomarker is a measure of reduced neural signal stability and can be generated by activating the 5-HT2C receptor. These findings mechanistically tie the EEG biomarker to ALTO-300’s mechanism of action as a 5-HT2C antagonist. ALTO-203: Enrollment completed in Phase 2 proof-of-concept MDD trial; data expected in the second quarter of 2025. ALTO-203, a novel, oral small molecule designed to uniquely act as a histamine H3 inverse agonist, is being developed for the treatment of MDD associated with increased levels of anhedonia. In February, the Company completed enrollment in the Phase 2 proof-of-concept (POC) trial in MDD patients with higher levels of anhedonia. The trial enrolled 69 patients and consists of two sequential double-blind, placebo-controlled treatment periods with two dose levels of ALTO-203 as a monotherapy. The proof-of-concept trial is designed to evaluate the subjective and objective effects of ALTO-203 in patients with MDD. The Company expects to report topline data in the second quarter of 2025. ALTO-101: Enrollment ongoing in Phase 2 proof-of-concept CIAS trial. ALTO-101, a brain-penetrant PDE4 inhibitor designed as a novel transdermal formulation, is being developed for the treatment of Cognitive Impairment Associated with Schizophrenia (CIAS). Through this unique formulation, ALTO-101 is designed to retain the desired brain effects shown with the oral formulation and avoid tolerability challenges and adverse effects known to be associated with PDE4 inhibitors. Enrollment remains ongoing in the Phase 2 POC trial in CIAS, with topline data expected in the second half of 2025. The Phase 2 POC trial consists of a dose-escalating treatment with ALTO-101 and is designed to enroll approximately 70 adult participants with schizophrenia between the ages of 21 and 55. The primary outcome in the study is the effect of ALTO-101 on theta band activity, the EEG measure shown to be best related to CIAS in replicated analyses of large schizophrenia datasets. Objective cognitive performance will also be evaluated. In April 2024, the Company reported positive Phase 1 results for ALTO-101 in healthy subjects. The Company’s proprietary transdermal formulation of ALTO-101 exhibited greater systemic drug exposure than orally administered ALTO-101 while also demonstrating a significant reduction in typical class-related adverse events. All adverse events reported in the study were mild in severity, and there were no reported serious adverse events. The transdermal formulation demonstrated favorable adhesion properties and there were no application site reactions that led to removal or intolerance. Business Highlights In the first quarter of 2025, the Company strengthened its patent estate: Development of ALTO-300 in the U.S. is protected by granted patents covering the use of ALTO-300 as an adjunctive therapy and patient selection characterized by an EEG biomarker. As granted, not accounting for any potential patent term extensions, the patent is expected to cover the use of ALTO-300 in the EEG-defined patient population until 2044. Development of ALTO-100 in the U.S. is protected by granted patents covering methods of treating BPD and MDD in patients with objectively determined impaired learning and/or memory with a specific dose range of ALTO-100. As granted, not accounting for any potential patent term extensions, the patents are expected to cover the use of ALTO-100 in the specified patient populations until 2043. In July 2024, the Company received an $11.7 million funding award from the Wellcome Trust to advance the clinical development of ALTO-100 through a Phase 2b study in patients with BPD. In February 2024, the Company successfully completed its upsized initial public offering resulting in net proceeds of approximately $133 million. Upcoming Milestones and Events Near-Term Expected Milestones 2Q 2025 — ALTO-203 Phase 2 POC MDD trial topline data 2H 2025 — ALTO-101 Phase 2 POC CIAS trial topline data Mid 2026 — ALTO-300 Phase 2b MDD trial topline data 2H 2026 — ALTO-100 Phase 2b bipolar depression trial topline data Upcoming Conferences Members of the Company’s management team are expected to present at the following upcoming conferences: Annual Congress of the Schizophrenia International Research Society (SIRS): March 29-April 2, 2025 Society of Biological Psychiatry (SOBP) Annual Meeting: April 24-26, 2025 American Society of Clinical Psychopharmacology (ASCP) Annual Meeting: May 27-30, 2025 Full-Year 2024 Financial Highlights Cash Position: As of December 31, 2024 the Company had cash, cash equivalents, and restricted cash of approximately $169 million, compared to approximately $83 million in cash, cash equivalents, and restricted cash as of December 31, 2023. The Company expects its cash balance to support planned operations into 2028. R&D Expenses: Research and development expenses for the full year ended December 31, 2024 were $47.0 million, as compared to $30.3 million for the same period in 2023. The increase was primarily attributable to increased personnel costs; including $1.5 million of non-cash, stock-based compensation; as well as costs associated with the Phase 2b clinical study for ALTO-300, and the Phase 2 POC studies for ALTO-203 and ALTO-101. G&A Expenses: General and administrative expenses for the full year ended December 31, 2024 were $21.6 million, as compared to $7.5 million for the same period in 2023. The increase was primarily attributable to costs associated with higher headcount to support expanded clinical development efforts, growing operational requirements, and costs associated with operating as a public company. $3.3 million of the increase is reflective of non-cash, stock-based compensation. Net Loss: The Company incurred a net loss of $61.4 million for the full year ended December 31, 2024, as compared to $36.3 million for the year ended December 31, 2023. About Alto Neuroscience Alto Neuroscience is a clinical-stage biopharmaceutical company with a mission to redefine psychiatry by leveraging neurobiology to develop personalized and highly effective treatment options. Alto’s Precision Psychiatry Platform™ measures brain biomarkers by analyzing EEG activity, neurocognitive assessments, wearable data, and other factors to better identify which patients are more likely to respond to Alto product candidates. Alto’s clinical-stage pipeline includes novel drug candidates in bipolar depression, major depressive disorder, schizophrenia, and other mental health conditions. For more information, visit www.altoneuroscience.com or follow Alto on X. Forward-Looking Statements This press release may contain forward-looking statements made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. These statements may be identified by words such as "aims," "anticipates," "believes," "could," "estimates," "expects," "forecasts," "goal," "intends," "look forward," "may," "plans," "possible," "potential," "seeks," "will" and variations of these words or similar expressions that are intended to identify forward-looking statements, although not all forward-looking statements contain these words. Forward-looking statements in this press release include, but are not limited to, statements regarding Alto’s expectations with regard to the potential benefits, activity, effectiveness and safety of its product candidates and Precision Psychiatry Platform ("Platform"); Alto’s expectations with regard to the design and results of its research and development programs and clinical trials, including the timing of enrollment and the timing and availability of data from such trials; Alto’s clinical and regulatory development plans for its product candidates, including the timing or likelihood of regulatory filings and approvals for its product candidates; Alto’s business strategy, financial position and the sufficiency of its financial resources to fund its operations through expected milestones; and other statements that are not historical fact. Actual results or events could differ materially from the plans, intentions and expectations disclosed in these forward-looking statements as a result of various factors, including: uncertainties inherent in the initiation, progress and completion of clinical trials and clinical development of Alto’s product candidates; the risk that Alto may not realize the intended benefits of its Platform; availability and timing of results from clinical trials; whether initial or interim results from a clinical trial will be predictive of the final results of the trial or the results of future trials; the risk that clinical trials may have unsatisfactory outcomes; the risk that Alto’s projections regarding its financial position and expected cash runway are inaccurate or that its conduct of its business requires more cash than anticipated; and other important factors, any of which could cause Alto’s actual results to differ from those contained in the forward-looking statements, which are described in greater detail in Alto's Quarterly Report on Form 10-Q for the quarter ended September 30, 2024 filed with the Securities and Exchange Commission ("SEC") as well as in other filings Alto may make with the SEC in the future. Any forward-looking statements contained in this press release speak only as of the date hereof, and Alto expressly disclaims any obligation to update any forward-looking statements contained herein, whether because of any new information, future events, changed circumstances or otherwise, except as required by law. Availability of Information on Alto’s Website Alto routinely uses its investor relations website to post presentations to investors and other important information, including information that may be material. Accordingly, Alto encourages investors and others interested in Alto to review the information it makes public on its investor relations website.   View source version on businesswire.com: https://www.businesswire.com/news/home/20250320870964/en/ Contacts Investor Contact: Nick [email protected] Media Contact: Mari [email protected]