PMN

This article first appeared on GuruFocus. Release Date: August 13, 2026 For the complete transcript of the earnings call, please refer to the full earnings call transcript. Reported zero cases of ARIA-E across all genotypes, including high-risk APOE4 carriers, in the Phase 1b PRECISE-AD trial. Blinded interim biomarker data showed directionally consistent declines in plasma p-tau217 and CSF MTBR tau243, suggesting target engagement. Strong cash position of $53.4 million, sufficient to fund operations through 2027, covering the anticipated 12-month top-line readout. Pipeline advancement with PMN267 (ALS) and PMN442 (synucleinopathies) progressing toward IND-enabling studies. Positive KOL and investor reception to interim data, with plans for a potential single registration study and subcutaneous formulation development. Interim data are blinded and exploratory, not a determination of clinical efficacy. Biomarker results are pooled across drug and placebo groups, limiting interpretation of a definitive drug effect. No unblinded efficacy data on cognitive outcomes until the 12-month readout in Q1 2027. Increased net cash used in operating activities ($22.8 million for six months) reflects higher clinical spending, with net loss widening. Subcutaneous formulation development is early-stage, with no clarity on how it will integrate into the registration study. Warning! GuruFocus has detected 2 Warning Signs with PMN. Is PMN fairly valued? Test your thesis with our free DCF calculator. Q: What was the KOL and investor reaction to the blinded six-month interim data from the PRECISE-AD trial, and what are the next steps for PMN310?A: Neil Warma, President and CEO, stated that the reaction from KOLs, investors, and shareholders was very positive and exceeded internal expectations. The safety profile and target engagement signals were particularly encouraging. Looking ahead, the company is actively planning the next clinical trial, anticipating a single registration study if the top-line data is positive. They are also preparing for an FDA meeting (given Fast Track designation), developing a subcutaneous formulation, and exploring expansion into the asymptomatic preclinical AD population. Additionally, they are in discussions with strategic partners regarding future collaboration or funding options. Q: Can you elaborate on the biomarker results and the safety profile, specifically regarding ARIA-E and whether the zero-case result holds beyond the six-month mark?A: Dr. Larry Altstiel, Chief Medical Officer, explained that the decline in plasma p-tau217 (approximately 15%) and CSF MTBR tau243 (approximately 13.3%) in the blinded pooled analysis is consistent with target engagement, as these markers typically rise in untreated patients. He noted that the safety data reflects the total dataset up to the July 22nd cutoff, with a substantial number of patients having crossed the six-month threshold and nearly half completing the full 12 months. The absence of ARIA-E is attributed to PMN310's design, which avoids binding to amyloid plaque in the brain and vasculature. The low ARIA-H rate (4.4%, all mild and asymptomatic) is considered consistent with baseline rates seen in Alzheimer's patients due to cerebral amyloid angiopathy. Q: Regarding the novel assay for detecting A-beta oligomers presented at AAIC, can you discuss its outcomes and when we might see a similar analysis for the Phase 1b trial?A: Dr. Altstiel confirmed that the assay, developed with German colleagues, successfully measured A-beta oligomer concentrations in cerebrospinal fluid for the first time, demonstrating a dose response after a single dose of PMN310 in the Phase 1a study. Neil Warma added that this assay is crucial for validating the mechanism of actionbinding and removing toxic oligomers. The assay is being refined and will be implemented in the Phase 1b study to compare pre- and post-treatment levels. A more fulsome presentation of all biomarkers and clinical outcomes will be provided when the data is unblinded after the study concludes, with no interim unblinded data releases planned. Q: How are you thinking about the potential subcutaneous (sub-Q) formulation for PMN310, and how might it be incorporated into the development plan?A: Neil Warma stated that a sub-Q formulation is a high priority to improve patient compliance and market competitiveness. Formulation development has already begun, including hiring a lead for the effort. While it is considered feasible, key parameters like viscosity, volume, and PK/PD need to be determined. The company has not yet decided whether the sub-Q formulation will be a separate arm of the registration study or require a bridging study, as this depends on FDA feedback and the final clinical trial design. They aim to provide more clarity as the program progresses. Q: What is the company's strategy for advancing its early-stage pipeline candidates, PMN267 (TDP-43 for ALS) and PMN442 (alpha-synuclein for synucleinopathies)?A: Neil Warma explained that while the primary focus remains on executing the PRECISE-AD trial, the company is advancing both candidates toward IND-enabling studies. The goal is to generate preclinical proof-of-concept data for these assets, potentially aligning with the Alzheimer's clinical readout, to demonstrate the robustness of the EpiSelect discovery platform. Both candidates are expected to be ready for IND-enabling studies within the next six to nine months and could enter the clinic within the next year, with resource allocation carefully managed to prioritize the lead Alzheimer's program. Q: What will the company present at the upcoming CTAD meeting?A: Neil Warma noted that the company has submitted abstracts to the CTAD conference (Clinical Trials on Alzheimer's Disease) in November. While acceptance is pending, they plan to attend in force to engage with KOLs and pharma companies. If given the platform, they would ideally present the same interim analysis data shared a few weeks prior, with no plans to present additional new data at this time. Q: Assuming a positive Phase 1b readout, how are you thinking about the design of the registrational study, and what can be learned from the lecanemab and donanemab Phase III trials?A: Dr. Altstiel indicated that the primary endpoint will likely be the CDR Sum of Boxes, as recommended by the FDA, with secondary endpoints including ADAS-Cog and composite scores like iADRS. The trial will need to be large enough and long enough to show a credible effect on disease progression. Neil Warma added that the company expects a differentiated safety profile, potentially requiring a smaller safety database than competitors. They plan to run a global study and will provide more clarity after interacting with the FDA, leveraging their Fast Track designation. Q: At the top-line readout, what magnitude of change in p-tau217 or MTBR tau243 would be considered meaningful, and how will placebo separation and dose-response factor into interpretation?A: Neil Warma declined to provide specific numeric expectations, emphasizing the importance of looking at the biomarkers holistically. Dr. Altstiel added that the biomarkers were chosen to reflect the biology affected by A-beta oligomers and are expected to move at different times and magnitudes. Success will not be tied to a specific percentage change in a single biomarker, but rather the totality of the data, which will guide subsequent studies. Q: Have you run controls to rule out PMN310 interference with the assay capture or detection, ensuring a lower signal reflects a true reduction?A: Dr. Altstiel confirmed that yes, such controls have been run for the new assay, which is currently being optimized, and the company is confident in the assay's accuracy. Q: What is the company's financial position and cash runway?A: Neil Warma reported that the company ended Q2 2026 with approximately $53.4 million in cash and short-term investments, up from $6.1 million at the end of 2025, primarily due to $70.1 million in net proceeds from a January For the complete transcript of the earnings call, please refer to the full earnings call transcript.

Interested in Promis Neurosciences? Here are five stocks we like better. PMN310’s Phase 1b interim results showed a favorable safety profile: No ARIA-E cases, no treatment-related serious adverse events or drug-related discontinuations were reported; total ARIA was 4.4%, with all cases mild and asymptomatic. Blinded biomarker data showed declines in plasma p-tau217 and CSF MTBR-tau243, though the company emphasized these are exploratory and not efficacy results. All PRECISE-AD participants are expected to complete 12 months of dosing in the fourth quarter of 2026, with unblinded top-line data planned for the first quarter of 2027. Promis is preparing potential registration plans and evaluating a more convenient subcutaneous formulation of PMN310. Promis ended the quarter with approximately C$53.4 million in cash and short-term investments, expected to fund operations through 2027, including the PMN310 readout. The company is also advancing PMN267 for ALS and PMN442 for synucleinopathies toward IND-enabling studies over the next six to nine months. Promis Neurosciences (NASDAQ:PMN) reported second-quarter 2026 results and highlighted blinded six-month interim data from its Phase 1b PRECISE-AD study of PMN310, an investigational antibody for early Alzheimer’s disease. President and Chief Executive Officer Neil Warma said the company is using its EpiSelect platform to develop antibody therapies and therapeutic vaccines targeting misfolded proteins implicated in neurodegenerative diseases. Its lead program, PMN310, is designed to selectively target toxic amyloid-beta oligomers while avoiding amyloid plaque. The company also has preclinical programs targeting misfolded TDP-43 in amyotrophic lateral sclerosis and pathogenic alpha-synuclein in dementia with Lewy bodies and Parkinson’s disease. → AST SpaceMobile Earnings Just Reminded Investors How Risky Space Can Be Chief Medical Officer Dr. Larry Altstiel said PRECISE-AD is a randomized, double-blind, placebo-controlled, multiple-ascending-dose study in patients with mild cognitive impairment due to early Alzheimer’s disease. The trial enrolled 144 subjects at 21 U.S. sites and randomized them in a three-to-one ratio to PMN310 or placebo across monthly intravenous dose cohorts of 5, 10 and 20 milligrams per kilogram for 12 months. The interim safety analysis included 136 patients as of a July 22 data cutoff. Their average age was 73.3 years, 58% were female and 61% carried at least one ApoE4 allele, including 11% who were ApoE4 homozygotes. ApoE4 carriers are associated with a higher risk of amyloid-related imaging abnormalities, or ARIA, with plaque-binding anti-amyloid treatments. → Nebius’ Q2 Beat Shows the AI Bottleneck Is Capacity, Not Demand Altstiel said the company observed no cases of ARIA-E, a form of ARIA involving brain swelling, across all genotypes in the analysis. Total ARIA was 4.4%, including milder ARIA-H microhemorrhage findings, and all reported cases were mild and asymptomatic. The company also reported no treatment-related serious adverse events, no drug-related discontinuations and one non-serious infusion reaction. “These are descriptive comparisons against published data and not head-to-head studies,” Altstiel said when discussing the safety profile relative to approved anti-amyloid therapies. → On Holding's Price Stumble May Be an Opening for a Company Built to Run The blinded, pooled biomarker analysis included patients receiving both PMN310 and placebo. Plasma p-tau217 declined about 15% from baseline, while cerebrospinal fluid MTBR-tau243 declined about 13.3%, with approximately 62.5% of patients showing a decline in the latter biomarker. Altstiel characterized the findings as early exploratory signals rather than efficacy data, noting that the study remains blinded. Management said all patients are expected to complete 12 months of dosing during the fourth quarter of 2026. Following database lock and statistical analysis, Promis expects to report unblinded top-line data in the first quarter of 2027. That update is expected to include safety data, additional biomarker results and clinical cognitive outcome measures. Warma said the company is preparing for the potential next stage of PMN310 development rather than waiting for the top-line readout. If the data are positive, Promis anticipates pursuing a single registration study and expects to meet with the FDA after the final data set is available. PMN310 has received Fast Track designation, according to the company. Dr. Altstiel said the FDA recommends the Clinical Dementia Rating-Sum of Boxes, or CDR-SB, as a primary clinical outcome measure for Alzheimer’s trials because it evaluates both cognitive and functional measures. He said additional measures could include ADAS-Cog and composite scores such as the Integrated Alzheimer’s Disease Rating Scale. The company is also developing a subcutaneous formulation of PMN310. Warma said the current study uses monthly intravenous dosing, but Promis views a subcutaneous option as important for patient convenience and compliance. He said the company is evaluating formulation considerations, dosing, pharmacokinetics, delivery devices and how a subcutaneous version could be incorporated into future development plans. During the call, management also discussed an assay designed to measure amyloid-beta oligomers in cerebrospinal fluid. Altstiel said the company presented Phase 1a data at the Alzheimer’s Association International Conference showing that the assay detected a dose response following a single dose of PMN310. Promis plans to use the refined assay in the Phase 1b study and expects to present related data after the study is completed. Beyond PMN310, Warma said PMN267, an antibody candidate targeting misfolded TDP-43 for ALS, and PMN442, targeting pathogenic alpha-synuclein for synucleinopathies, have been humanized in an IgG1 framework and are advancing toward investigational new drug-enabling studies. The company aims to advance the candidates over the next six to nine months, subject to data and available resources. Cash and short-term investments totaled approximately C$53.4 million at June 30, compared with C$6.1 million at Dec. 31, 2025. The increase reflected approximately C$70.1 million in net proceeds from a January 2026 private placement. Second-quarter net loss was approximately C$11.7 million, or C$1.28 per share, compared with a loss of C$10.1 million, or C$7.26 per share, a year earlier. Research and development expense rose to approximately C$9.5 million from C$8.7 million in the prior-year quarter. General and administrative expense increased to C$2.7 million from C$1.4 million, which the company attributed to higher professional fees and headcount. For the first half of 2026, Promis reported a net loss of approximately C$20 million, compared with C$17.5 million in the prior-year period. Net cash used in operating activities was approximately C$22.8 million, compared with C$8.8 million a year earlier, reflecting increased clinical activity. The company said its current cash and investments are expected to fund operations through 2027, including the anticipated first-quarter 2027 PMN310 top-line readout. Promis Neurosciences, Inc is a clinical‐stage biopharmaceutical company focused on the discovery and development of novel therapeutics for central nervous system disorders. The company's research programs target cognitive impairment and other neurological symptoms associated with diseases such as Alzheimer's disease and multiple sclerosis. Leveraging a proprietary small‐molecule discovery platform, Promis Neurosciences advances both preclinical and early clinical candidates designed to modulate neural pathways involved in memory, learning and neuroinflammation. This instant news alert was generated by narrative science technology and financial data from MarketBeat in order to provide readers with the fastest reporting and unbiased coverage. Please send any questions or comments about this story to [email protected]. The article "Promis Neurosciences Q2 Earnings Call Highlights" was originally published by MarketBeat. View MarketBeat's top stocks for August 2026.

Announced positive blinded six-month interim safety and biomarker results from PRECISE-AD, the Company's Phase 1b trial of PMN310 in patients with early Alzheimer's disease (AD), including zero cases of amyloid-related imaging abnormalities-edema (ARIA-E) across all participants and genotypes, including APOE4 homozygotes. Observed early, directionally consistent declines in two complementary biomarkers, plasma pTau217 and CSF MTBR-tau243, in a blinded analysis pooling both active- and placebo-treated patients under the trial’s ongoing 3-to-1 randomization. The second quarter ended with $53.4 million in cash and short-term investments, which is expected to fund operations through 2027, beyond the Company’s anticipated 12-month topline PRECISE-AD readout expected in the first quarter of 2027. Cambridge, Massachusetts, Aug. 13, 2026 (GLOBE NEWSWIRE) -- ProMIS Neurosciences Inc. (Nasdaq: PMN), a clinical-stage biotechnology company focused on the generation and development of antibody therapeutics targeting toxic misfolded proteins in neurodegenerative diseases, today announced its financial results for the quarter ended June 30, 2026, and provided a corporate update. “The second quarter of 2026 was a pivotal period for ProMIS, as we continued to advance PRECISE-AD while maintaining a strong financial position,” said Neil Warma, President and Chief Executive Officer of ProMIS Neurosciences. “We ended the quarter with $53.4 million in cash and short-term investments, providing runway through 2027, beyond our next major anticipated catalyst.” “Subsequent to quarter end, on July 28th, we announced positive blinded six-month interim safety and biomarker results from PRECISE-AD, our Phase 1b trial of PMN310 in patients with early AD. Across all 136 safety-evaluable participants and APOE genotypes, we observed no cases of ARIA-E. We also observed an early and directionally consistent movement in plasma pTau217 and CSF MTBR-tau243 in the blinded analysis, which pooled active and placebo-treated patients.” “We believe these data reinforce the thesis behind PMN310: that selectively targeting toxic amyloid-beta oligomers and avoiding plaque may offer a path to amyloid-directed therapy with a significantly improved safety profile, including a substantially reduced ARIA burden, and a potential for improved efficacy. We look forward to the 12-month unblinded topline results from PRECISE-AD, expected in the first quarter of 2027, which will include cognitive outcomes, and we believe will represent an important next step in evaluating PMN310’s potential for patients with early AD.” Corporate Highlights Alzheimer’s Disease (AD) Program (PMN310) — PRECISE-AD Interim Data PRECISE-AD is a randomized, double-blind, placebo-controlled Phase 1b trial evaluating PMN310 in patients with mild cognitive impairment due to early AD. The trial completed enrollment in December 2025 with 144 subjects across 22 U.S. sites, randomized 3-to-1 to active drug versus placebo across three different dose cohorts (5, 10, and 20 mg/kg), dosed monthly by intravenous infusion over 12 months. The evaluable number of patients in the interim analysis was 136 of the 144 enrolled. The population was genetically and demographically representative: mean age of 73.3 years, 58% female, and 61% carrying at least one APOE4 allele, including 11% APOE4 homozygotes, the population at highest risk of ARIA with plaque-binding antibodies. As of the July 22, 2026 data cutoff date, all 136 safety-evaluable patients had been dosed for at least six months, 78% for at least nine months, and 49% had completed the full 12 months of dosing. Safety: The interim data demonstrated a favorable safety profile across all genotypes, including APOE4 homozygotes. There were no cases of ARIA-E and a 4.4% incidence of total ARIA (all mild and asymptomatic, consisting of only amyloid-related imaging abnormalities -microhemorrhages (ARIA-H)), with no treatment-related serious adverse events and no drug-related discontinuations at the interim. Biomarkers: In the blinded, pooled analysis, plasma pTau217 declined approximately 15% from baseline through Day 169, with roughly 68.5% of patients showing a decline, and CSF MTBR-tau243 declined approximately 13.3%, with approximately 62.5% of patients showing a decline. Both the direction and proportion of patients showing a favorable response are broadly consistent with the trial’s 75% active-drug allocation. The trial remains blinded and ongoing. The Company expects all patients to complete 12-month dosing by the fourth quarter of 2026 and, following database lock and statistical analysis, to report unblinded 12-month topline data, including the full safety dataset, an expanded biomarker panel, and clinical cognitive outcome measures, in the first quarter of 2027. Pipeline Progress and Scientific Presentations PMN267 (ALS/FTD): The Company’s program targeting misfolded TDP-43 has been humanized in a human IgG1 framework and is progressing through investigational new drug (IND)-enabling studies. PMN442 (Parkinson’s Disease, Dementia with Lewy Bodies, Multiple System Atrophy): The Company’s lead candidate targeting pathogenic alpha-synuclein has been humanized and is advancing toward IND-enabling studies based on its selective binding activity. The Company presented a poster at the 2026 Alzheimer’s Association International Conference (AAIC) highlighting the first human evidence of amyloid-beta oligomer target engagement and removal by PMN310. Corporate and Investor Activities Mr. Warma presented at multiple investor conferences during the quarter, including the Jefferies Global Healthcare Conference, the Wolfe Research R&D Day focused on Alzheimer’s disease, and the H.C. Wainwright Neuro Perspectives Expert Summit. An additional four research firms initiated coverage of ProMIS during the quarter: Cantor Fitzgerald, Roth Capital, Brookline Capital Markets, and Chardan Capital Markets. ProMIS hosted a live webinar to share the interim blinded data results with two independent key opinion leaders, Dr. Will Mantyh of the University of Minnesota and Dr. Michael Weiner of University of California San Francisco, who offered their perspective on the data and its clinical relevance. Future Activities and Upcoming Milestones Participation and presentations at multiple investor and medical conferences, including Clinical Trials on AD (CTAD) Presentation of unblinded 12-month topline data from PRECISE-AD, anticipated in the first quarter of 2027. Second Quarter 2026 Financial Highlights Cash Position: As of June 30, 2026, the Company’s cash and short-term investments were $53.4 million, compared to $6.1 million as of December 31, 2025. The increase primarily reflects $70.1 million in net proceeds received in January 2026 from a private placement financing in which certain of the Company’s own directors and management participated alongside external investors. Cash Runway: Based on the current operating plan, existing cash resources are expected to fund planned operations through 2027, beyond the anticipated 12-month topline readout from PRECISE-AD expected in Q1 2027. Net Loss: For the quarter ended June 30, 2026, the Company reported a net loss of $11.7 million, or $1.28 per share, compared to a net loss of $10.1 million, or $7.26 per share, for the same period in 2025. The improvement in loss per share reflects the increase in weighted-average shares outstanding following the January 2026 financing. About ProMIS Neurosciences Inc. ProMIS Neurosciences is a clinical-stage biotechnology company committed to the discovery and development of therapeutic antibodies and vaccines selective for toxic oligomers associated with the development and progression of neurodegenerative and other misfolded protein diseases. The Company’s proprietary target discovery engine, EpiSelect™, has been shown to predict novel targets known as Disease Specific Epitopes (DSEs) on the molecular surface of misfolded proteins that cause neurodegenerative and other misfolded protein diseases, including Alzheimer’s disease (AD), amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), multiple system atrophy (MSA), and Parkinson’s Disease (PD). ProMIS has offices in Cambridge, Massachusetts (USA) and Toronto, Ontario (CAN). About PMN310 and the PRECISE-AD Trial for Alzheimer’s Disease (AD) PMN310, the Company’s lead product candidate for the treatment of AD, is a humanized IgG1 monoclonal antibody designed to selectively target toxic oligomers while avoiding plaque, thereby potentially reducing or eliminating amyloid-related imaging abnormalities (ARIA) liability. Because PMN310 may not be limited by off-target binding or side effects, it could potentially offer an improved efficacy profile over other amyloid-directed antibody therapeutics. PMN310 was granted Fast Track designation by the U.S. Food and Drug Administration in July 2025. PRECISE-AD (NCT06750432) is a randomized, double-blind, placebo-controlled Phase 1b study evaluating the safety, tolerability, and pharmacokinetics of multiple ascending doses (5, 10, 20 mg/kg) of intravenous PMN310 in patients with Mild Cognitive Impairment due to AD or mild AD (Stage 3 and Stage 4 AD). PRECISE-AD is the first study to examine the effects of a monoclonal antibody directed solely against Aβ oligomers on biomarkers associated with AD pathology and clinical outcomes. Safety is a primary outcome of the study, with particular emphasis on assessing whether, as a non-plaque binder, PMN310 may have a reduced risk of ARIA. The study is powered to provide 95% confidence for detection of ARIA and is designed to provide meaningful insight into the effects of PMN310 on biomarkers and clinical outcomes. EpiSelect™ Drug Discovery Engine Toxic misfolded proteins underlie the pathogenesis of neurodegenerative diseases such as Alzheimer’s disease, Parkinson’s disease (PD), amyotrophic lateral sclerosis (ALS), and frontotemporal dementia (FTD). Generation of therapeutic antibodies selectively targeting only disease-misfolded protein isoforms, while sparing normal or irrelevant isoforms of the same protein, has not yet been successfully achieved by conventional immunization strategies. ProMIS Neurosciences has developed a computational platform (EpiSelect™) to identify conformational epitopes that are uniquely exposed on toxic misfolded proteins, which can then be used to generate misfolding-specific antibodies or vaccine formulations. Forward-Looking Statements This press release contains forward-looking statements that are made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. Certain information in this news release constitutes forward-looking statements and forward-looking information (collectively, “forward-looking information”) within the meaning of applicable securities laws. Statements that refer to expectations, projections or other characterizations of future events or circumstances contain forward-looking information. Specifically, this news release contains forward-looking information relating to the Company’s PRECISE-AD Phase 1b clinical trial, the interpretation and clinical significance of the blinded six-month interim safety and biomarker data (including ARIA, Ptau217, and MTBR-tau243 findings) described in this release, the expected timing and  nature of topline clinical data of PMN310, its mechanism of action and potential benefits, the potential for PMN310 to offer a differentiated efficacy and safety profile relative to plaque-directed antibodies; the Company’s belief that toxic soluble amyloid-beta oligomers are a primary driver of cognitive decline in AD; statements related to the Company’s preclinical programs; and the Company’s expectation that existing cash resources will fund planned operations through 2027. Statements containing forward-looking information are not historical facts but instead represent management’s current expectations, estimates, and projections regarding the future of the business, future plans, strategies, projections, anticipated events and trends, the economy and other future conditions. Forward-looking information is necessarily based on a number of opinions, assumptions, and estimates that, while considered reasonable by the Company as of the date of this news release, are subject to known and unknown risks, uncertainties and assumptions, and other factors that may cause actual results, level of activity, performance or achievement to differ materially from those expressed or implied, including, but not limited to, the risk that early or interim results may not be indicative of final or top-line results, the Company’s accumulated deficit, and the expectation for continued losses. Important factors that could cause actual results to differ materially are discussed in the “Risk Factors” section of the Company’s most recently filed Annual Report on Form 10-K and in its subsequent filings with the U.S. Securities and Exchange Commission, including its Quarterly Report on Form 10-Q for the quarter ended June 30, 2026. Except as required by applicable securities laws, the Company undertakes no obligation to publicly update any forward-looking information, whether written or oral, that may be made from time to time, whether as a result of new information, future developments or otherwise. Condensed Consolidated Balance Sheets (Unaudited) Condensed Consolidated Statements of Operations (Unaudited) For Investor Relations, please contact: Carie Pierce VP, Investor Relations & External Affairs [email protected]

Company closed PIPE financing with gross proceeds of up to $175 million, including the possible exercise of warrants, from long-term global investors. Proceeds are expected to fund the Company through 2027, including completion of the ongoing Phase 1b clinical trial in Alzheimer's disease (AD). PRECISE-AD Phase 1b trial is fully enrolled and progressing on schedule, with the blinded 6-month interim analysis anticipated in early Q3 2026 and 12-month top-line data anticipated in early 2027. The planned interim analysis is expected to include a qualitative assessment of aggregated safety data, including amyloid-related imaging abnormalities (ARIA) incidence, as well as key biomarker trends across all study participants at the 6-month timepoint. Cambridge, Massachusetts, May 12, 2026 (GLOBE NEWSWIRE) -- ProMIS Neurosciences Inc. (Nasdaq: PMN), a clinical-stage biotechnology company focused on the generation and development of antibody therapeutics targeting toxic misfolded proteins in neurodegenerative diseases, today announced its financial results for the quarter ended March 31, 2026, and provided a corporate update. "2026 has the potential to be a significant year for patients with Alzheimer's disease and their caregivers,” said Neil Warma, Chief Executive Officer of ProMIS Neurosciences. “We believe ProMIS is well-positioned with PMN310 as a potentially differentiated treatment for patients with early AD. We are coming off a productive quarter, having closed a transformational financing of up to $175 million, including potential proceeds from warrant exercises, and have executed well on our Phase 1b clinical trial. Near-term data catalysts, including the blinded 6-month interim analysis, are anticipated in early Q3 2026, and could provide important insight into the potential of our lead drug candidate, PMN310. With currently marketed AD therapies, safety remains a central concern. Both approved plaque-directed antibodies carry black box warnings for a serious side effect known as ARIA, which encompasses cerebral edema (ARIA-E) and microhemorrhages (ARIA-H) in the brain. ARIA is believed to be associated with therapies that bind amyloid plaque. Given the modest clinical benefit observed with these therapies, ARIA-related risk has been a meaningful consideration in real-world treatment decisions for many patients and physicians. A growing body of evidence supports the view that toxic soluble amyloid-beta oligomers, small soluble species that form upstream of plaque, are a primary driver of cognitive decline in AD. PMN310 has been designed to selectively target these toxic oligomers while sparing plaque, a mechanism we believe may enable improved efficacy and a differentiated safety profile relative to plaque-directed antibodies. ProMIS’s Phase 1b trial, PRECISE-AD, was fully enrolled in December 2025, exceeding the company’s target, and we are now approaching the 6-month timepoint of the trial. The upcoming blinded interim data analysis anticipated in early Q3 2026 will summarize aggregate safety data and overall trends in key biomarkers across all study participants, without revealing treatment assignments. Because the analysis pools active and placebo groups under the blind, even modest directional changes could provide early indications of target engagement while preserving the integrity of the trial. ProMIS expects to complete 12-month dosing for all patients by year-end and to report unblinded top-line results in early 2027, providing a comprehensive view of PMN310's safety, biomarker, and clinical outcomes by treatment group, and an important clinical test of PMN310’s selective targeting approach." Corporate Highlights Alzheimer’s Disease (AD) Program (PMN310) The Company is conducting the PRECISE‑AD Phase 1b clinical trial, which is fully enrolled with 144 participants across three dosing cohorts receiving treatment over a 12‑month period. A blinded interim analysis is anticipated in early third quarter 2026, providing a mid‑study review of aggregated safety data and overall biomarker trends across all participants. As this analysis remains blinded, individual treatment assignments will not be disclosed, and results will represent combined data from both active and placebo groups. While this interim analysis is not designed to assess clinical efficacy, this early look may reveal directional biomarker trends that offer early insight into target engagement. Full patient dosing is expected to be completed by year‑end 2026, with unblinded top‑line results anticipated in early 2027. At that time, the Company expects to evaluate biomarker outcomes and clinical measures by treatment group, providing a comprehensive understanding of PMN310’s potential in Alzheimer’s disease. Pipeline Progress and Scientific Presentations AD/PD™ 2026 Presentations: ProMIS featured two key presentations at the Alzheimer’s Disease/Parkinson’s Disease International Conference highlighting the versatility of its discovery platform: Dr. Neil Cashman, CSO, presented on the rational design of a vaccine against TDP-43 proteinopathies using a pathogenic epitope of misfolded TDP-43. Dr. Johanne Kaplan, CDO, presented data on how vaccination with conformational epitopes derived from computational modeling elicits an active antibody response selective for toxic alpha-synuclein species. Subcutaneous Formulation: The Company has accelerated the development of a subcutaneous formulation for PMN310 to enhance patient convenience and further strengthen the asset’s competitive profile. Recent and Future Activities and Upcoming Milestones Closed Private Placement: Completed a private placement in February 2026 for gross up-front proceeds of $75.5 million, with the potential to secure an additional $100 million upon exercise of warrants. Bloom Burton & Co. Healthcare Investor Conference: Neil Warma, CEO, participated and presented a corporate overview. View here: PMN Corporate Overview Fierce Biotech Week: Neil Warma, CEO, will participate in a panel discussion titled “Combination, Prevention, and New Biology in Neurodegenerative Drug Development”. Alzheimer’s Association International Conference (AAIC): Poster presentation titled “Activity and clinical progress of PMN310 designed to selectively target toxic Aß oligomers for greater potency in Alzheimer’s disease” will be presented by Johanne Kaplan, Chief Development Officer. Interim Data Readout: Blinded interim analysis of PRECISE-AD safety and biomarker data anticipated early Q3 2026. Top-line Results: Presentation of 12-month unblinded top-line data anticipated in early 2027. Key Pipeline Programs Development of subcutaneous formulation for PMN310 We have accelerated the development of a subcutaneous formulation of PMN310 and established a dedicated development plan, reflecting our conviction in the potential of this approach to improve patient experience and strengthen the asset's competitive profile. Amyotrophic Lateral Sclerosis Disease Program (PMN267) PMN267 is the lead preclinical candidate antibody directed against toxic misfolded TDP-43 as a potential therapeutic target for ALS and other TDP-43 proteinopathies (e.g. frontotemporal dementia). It has demonstrated strict selectivity for pathogenic TDP-43 and protective activity in antibody and intrabody formats. PMN267 has been humanized in a human IgG1 framework for IND-enabling studies. Parkinson’s Disease (PD), Dementia with Lewy Bodies and Multiple System Atrophy (MSA) Disease Program (PMN442) ProMIS selected PMN442 as the lead candidate antibody for PD and other synucleinopathies based on its selective binding and protective activity against pathogenic forms of alpha-synuclein. It has been humanized in a human IgG1 framework for IND-enabling studies. First Quarter 2026 Financial Highlights Cash Position: As of March 31, 2026, the Company’s cash and cash equivalents were $63.8 million, reflecting the $75.5 million in gross up-front proceeds from the February financing. Cash Runway: Based on the current operating plan, existing cash resources are expected to fund planned operations through 2027, including the completion of the PRECISE-AD trial. Net Loss: For the quarter ended March 31, 2026, the Company reported a net loss of $8.2 million, compared to a net loss of $7.3 million for the same period in 2025. About ProMIS Neurosciences Inc. ProMIS Neurosciences is a clinical-stage biotechnology company committed to the discovery and development of therapeutic antibodies and vaccines selective for toxic oligomers associated with the development and progression of neurodegenerative and other misfolded protein diseases. The Company’s proprietary target discovery engine, EpiSelect™, has been shown to predict novel targets known as Disease Specific Epitopes (DSEs) on the molecular surface of misfolded proteins that cause neurodegenerative and other misfolded protein diseases, including Alzheimer’s disease (AD), amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), multiple system atrophy (MSA), and Parkinson’s Disease (PD). ProMIS has offices in Cambridge, Massachusetts (USA) and Toronto, Ontario (CAN). About PMN310 and the PRECISE-AD Trial for Alzheimer’s Disease (AD) PMN310, the Company’s lead product candidate for the treatment of AD, is a humanized IgG1 monoclonal antibody that has been designed to selectively target only the toxic oligomers, avoiding plaque, thereby potentially reducing, or eliminating amyloid-related imaging abnormalities (ARIA) liability. In addition, because PMN310 may not be limited by off-target binding or side effects, PMN310 could potentially offer an improved efficacy profile over other amyloid-directed antibody therapeutics. PMN310 was granted Fast Track designation by the U.S. Food and Drug Administration in July 2025. Based on the encouraging results from the Phase 1a trial (NCT06105528) of PMN310 in healthy volunteers, ProMIS initiated PRECISE-AD, a Phase 1b clinical trial in AD patients. PRECISE-AD (NCT06750432) is a randomized, double-blind, placebo-controlled study to evaluate the safety, tolerability and pharmacokinetics (PK) of multiple ascending doses (5, 10, 20 mg/kg) of intravenous PMN310 in patients with Mild Cognitive Impairment due to AD or mild AD (Stage 3 and Stage 4 AD). PRECISE-AD will be the first study to examine the effects of a monoclonal antibody directed solely against Aβ oligomers on biomarkers associated with AD pathology and clinical outcomes. Safety will be a primary outcome of the study with particular emphasis on assessing whether, as a non-plaque binder, PMN310 may have a reduced risk of ARIA. The study is powered to provide 95% confidence for detection of ARIA and is designed to provide meaningful insight into the effects of PMN310 on biomarkers and clinical outcomes. EpiSelectTM Drug Discovery Engine Toxic misfolded proteins underlie the pathogenesis of neurodegenerative diseases such as Alzheimer’s disease, Parkinson’s disease (PD), amyotrophic lateral sclerosis (ALS), and frontotemporal dementia (FTD). Generation of therapeutic antibodies selectively targeting only disease-misfolded protein isoforms, while sparing normal or irrelevant isoforms of the same protein, has not yet been successfully achieved by conventional immunization strategies. ProMIS Neurosciences has developed a computational platform (EpiSelect™) to identify conformational epitopes that are uniquely exposed on toxic misfolded proteins, which can then be used to generate misfolding-specific antibodies or vaccine formulations. Application of the ProMIS platform produced PMN310, a clinical stage, humanized monoclonal antibody candidate that has been shown to be highly selective for toxic amyloid-beta oligomers (AβO) without significant reactivity with amyloid-beta monomers or fibrils, thereby avoiding target distraction by these more abundant species, and potentially reducing the risk of brain edema and microhemorrhages associated with the targeting of vascular/parenchymal amyloid. Similarly, specific epitopes for alpha-synuclein toxic oligomers/soluble fibrils that drive synucleinopathies, and for pathogenic TDP-43 in ALS and FTD have been identified and lead candidate antibodies generated. The precise conformation of these epitopes has been translated into vaccines inducing an antibody response selective for pathogenic molecular species in preclinical mouse vaccination studies. Forward-looking Statements This press release contains forward-looking statements that are made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. Certain information in this news release constitutes forward-looking statements and forward-looking information (collectively, “forward-looking information”) within the meaning of applicable securities laws. In some cases, but not necessarily in all cases, forward-looking information can be identified by the ‎use of forward-looking terminology such as “plans”, “pleased to”, “look forward to”, “potential to”, “targets”, “expects” or “does not expect”, “is expected”, “excited about”, “an opportunity exists”, “is positioned”, “estimates”, “intends”, “assumes”, “expects”, “anticipates” or “does not anticipate” or “believes”, or variations of such words and ‎phrases or state that certain actions, events or results “may”, “could”, “would”, “might”, “will” or “will be taken”, “occur” or “be achieved”. In addition, any statements that refer to expectations, projections or other characterizations of future events or circumstances contain forward-looking information. Specifically, this news release contains forward-looking information relating to the Company’s Phase 1b study in AD patients, including planned timing for completion and anticipated data read out of interim results in the third quarter of 2026 and topline results by early 2027, statements relating to the Company's progress, including enrollment and dosing for its Phase 1b clinical trial, the potential for PMN310 to positively benefit patients with AD, the targeting of toxic misfolded proteins in neurodegenerative diseases that the Company believes may directly address fundamental AD pathology (including the belief and understanding that toxic oligomers of Aß are a major driver of AD) and have greater therapeutic potential due to reduction of off-target activity, and the ability of the Company’s cash runway to fund operations through 2027. Statements containing forward-looking information are not historical facts but instead represent management’s current expectations, estimates and projections regarding the future of our business, future plans, strategies, projections, anticipated events and trends, the economy and other future conditions. Forward-looking information is necessarily based on a number of opinions, assumptions and estimates that, while considered reasonable by the Company as of the date of this news release, are subject to ‎known and unknown risks, uncertainties and assumptions and other factors that may cause the actual results, level of activity, performance or achievements to be materially different from those expressed or implied by such forward-looking information, including, but not limited to, including, but not limited to, the risk that preclinical results or early results may not be indicative of future results, its accumulated deficit and the expectation for continued losses and future financial results. Important factors that could cause actual results to differ materially from those indicated in the forward-looking information include, among others, the factors discussed throughout the “Risk Factors” section of the Copany’s most recently filed Annual Report on form-10-K for the year ended December 31, 2025 and in its subsequent filings filed with the United States Securities and Exchange Commission. Except as required by applicable securities laws, the Company undertakes no obligation to publicly update any forward-looking information, whether written or oral, that may be made from time to time, whether as a result of new information, future developments or otherwise. Condensed Consolidated Balance Sheets (Unaudited) Condensed Consolidated Statement of Operations (Unaudited) For Investor Relations, please contact: Carie Pierce VP, Investor Relations & External Affairs [email protected]

Phoenix Mecano AG's (VTX:PMN) stock was strong despite it releasing a soft earnings report last week. Our analysis suggests that investors may have noticed some promising signs beyond the statutory profit figures. We've found 21 US stocks that are forecast to pay a dividend yield of over 6% next year. See the full list for free. Importantly, our data indicates that Phoenix Mecano's profit was reduced by €9.6m, due to unusual items, over the last year. It's never great to see unusual items costing the company profits, but on the upside, things might improve sooner rather than later. We looked at thousands of listed companies and found that unusual items are very often one-off in nature. And that's hardly a surprise given these line items are considered unusual. If Phoenix Mecano doesn't see those unusual expenses repeat, then all else being equal we'd expect its profit to increase over the coming year. That might leave you wondering what analysts are forecasting in terms of future profitability. Luckily, you can click here to see an interactive graph depicting future profitability, based on their estimates. Because unusual items detracted from Phoenix Mecano's earnings over the last year, you could argue that we can expect an improved result in the current quarter. Because of this, we think Phoenix Mecano's earnings potential is at least as good as it seems, and maybe even better! On the other hand, its EPS actually shrunk in the last twelve months. The goal of this article has been to assess how well we can rely on the statutory earnings to reflect the company's potential, but there is plenty more to consider. If you'd like to know more about Phoenix Mecano as a business, it's important to be aware of any risks it's facing. For example, we've discovered 1 warning sign that you should run your eye over to get a better picture of Phoenix Mecano. Today we've zoomed in on a single data point to better understand the nature of Phoenix Mecano's profit. But there is always more to discover if you are capable of focussing your mind on minutiae. For example, many people consider a high return on equity as an indication of favorable business economics, while others like to 'follow the money' and search out stocks that insiders are buying. So you may wish to see this free collection of companies boasting high return on equity, or this list of stocks with high insider ownership. Have feedback on this article? Concerned about the content? Get in touch with us directly. Alternatively, email editorial-team (at) simplywallst.com. 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.

PRECISE-AD Phase 1b trial fully enrolled. Completion of six-month assessments expected in Q2 2026 with blinded interim analysis anticipated early Q3 2026; twelve-month top-line data anticipated in early 2027 PMN310 continues to demonstrate a favorable safety profile, with no treatment-related serious adverse events reported to date Cambridge, Massachusetts,, March 25, 2026 (GLOBE NEWSWIRE) -- ProMIS Neurosciences Inc. (Nasdaq: PMN), a clinical-stage biotechnology company focused on the generation and development of antibody therapeutics targeting toxic misfolded proteins in neurodegenerative diseases, such as Alzheimer’s disease (AD), amyotrophic lateral sclerosis (ALS) and Parkinson’s disease (PD), today announced its financial results for the year ended December 31, 2025, and provided a corporate update. "We are extremely pleased with the significant progress our team achieved in 2025 and the strong momentum we have carried into 2026," said Neil Warma, Chief Executive Officer of ProMIS Neurosciences. "We believe 2026 has the potential to be a watershed year for patients living with Alzheimer's disease. In 2025, our primary focus was the enrollment and treatment of patients in PRECISE-AD, our Phase 1b clinical trial in Alzheimer's disease. We are proud to report that enrollment was completed on time in December 2025 and was oversubscribed with a total of 144 patients; an outcome we believe reflects meaningful interest in PMN310's therapeutic potential. A key differentiating feature of PMN310, in our view, is its potential to meaningfully reduce treatment-related side effects, including the incidence of Amyloid-Related Imaging Abnormalities (ARIA). PMN310 has been purposefully designed to avoid binding to amyloid plaque, a mechanism we believe to be a primary driver of ARIA. After more than 12 months of dosing, PMN310 has continued to demonstrate a favorable safety profile. To date, there have been no Serious Adverse Events (SAEs) associated with study treatment, and overall patient retention and reported safety data are meeting or exceeding our expectations. We are on track to complete a six-month interim analysis of blinded safety and biomarker data in mid-2026. Full patient dosing is expected to be completed by year-end 2026, with presentation of unblinded top-line data anticipated in early 2027. In early 2026, the Company closed a transformational financing of up to $175 million in proceeds, including $75 million up front and $100 million tied to future potential exercise of warrants, providing a cash runway through 2027. This financing was supported by a distinguished syndicate of new and existing institutional investors. With this financing, we have accelerated the development of a subcutaneous formulation of PMN310 and the design of our next clinical study. Subject to the results of the PRECISE-AD Phase 1b trial and feedback from the United States Food and Drug Administration (FDA), our current strategic goal is to advance directly into a single registrational study. PMN310 was granted Fast Track Designation by the FDA in July 2025, which we believe may facilitate our development efforts by providing opportunity for engagement with the FDA. We are also closely monitoring the evolution of preclinical and asymptomatic Alzheimer's disease trials. Should PMN310 continue to demonstrate a differentiated safety profile, we believe this earlier patient population may represent a longer-term area of scientific interest, though any expansion into this space would be subject to clinical data, regulatory guidance, and further study design.” Corporate Highlights Alzheimer’s Disease (AD) Program (PMN310) ProMIS’ lead candidate, PMN310, is a humanized IgG1 antibody directed toward toxic amyloid-beta oligomers (AβO) that are believed to be a major driver of AD. This selectivity may reduce or eliminate amyloid-related imaging abnormalities (ARIA) commonly associated with plaque-binding antibodies. PMN310 was granted Fast Track Designation by the U.S. Food and Drug Administration. The Company completed enrollment of the Phase 1b trial in December 2025 with 144 participants enrolled (vs a target of 128) across 3 dosing cohorts. PMN310 continues to demonstrate a generally favorable safety profile. Based on current clinical trial patient visit schedules, the Company expects to complete the six-month assessments in the second quarter of 2026. The blinded interim analysis is anticipated in early third quarter 2026. Completion of all patient visits is expected in the fourth quarter of 2026, with top-line data anticipated in early 2027 following database lock and statistical analysis. Recent and Upcoming Milestones Closed a private placement led by distinguished biotechnology investors in February 2026 for gross up-front proceeds of $75.5 million. The Data and Safety Monitoring Board recommended advancement to cohort 3, the study’s highest planned dose level, with no safety concerns identified. Completed enrollment of 144 participants in PRECISE-AD Phase 1b trial. Six-month blinded interim data expected early third quarter 2026. Top‑line results anticipated in early 2027, subject to completion of the final patient visit and database lock. Key Pipeline Programs Development of subcutaneous formulation for PMN310 We have accelerated the development of a subcutaneous formulation of PMN310 and established a dedicated development plan, reflecting our conviction in the potential of this approach to improve patient experience and strengthen the asset's competitive profile. Amyotrophic Lateral Sclerosis Disease Program (PMN267) PMN267 is the lead preclinical candidate antibody directed against toxic misfolded TDP-43 as a potential therapeutic target for ALS and other TDP-43 proteinopathies (e.g. frontotemporal dementia). It has demonstrated strict selectivity for pathogenic TDP-43 and protective activity in antibody and intrabody formats. PMN267 has been humanized in a human IgG1 framework for IND-enabling studies. Parkinson’s Disease (PD), Dementia with Lewy Bodies and Multiple System Atrophy (MSA) Disease Program (PMN442) ProMIS selected PMN442 as the lead candidate antibody for PD and other synucleinopathies based on its selective binding and protective activity against pathogenic forms of alpha-synuclein. It has been humanized in a human IgG1 framework for IND-enabling studies. 2025 Financial Highlights For the year ended December 31, 2025, the Company reported a net loss of $39.7 million and cash of $6.1 million, consistent with its planned investment in advancing the PRECISE-AD Phase 1b trial and supporting its broader pipeline. Following the Company’s February 2026 private placement for gross proceeds of $75.5 million, and based on the Company’s current operating plan, existing cash resources are expected to fund planned operations through 2027, including completion of the PRECISE-AD Phase 1b trial. Research and development expenses for the year ended December 31, 2025 were $33.4 million compared to $10.6 million during the year ended December 31, 2024, primarily reflecting costs incurred to run the PRECISE-AD trial. General and administrative expenses for the year ended December 31, 2025 were $6.8 million compared to $6.2 million during the year ended December 31, 2024, primarily driven by a moderate increase in employee headcount. About ProMIS Neurosciences Inc. ProMIS Neurosciences is a clinical-stage biotechnology company committed to the discovery and development of therapeutic antibodies and vaccines selective for toxic oligomers associated with the development and progression of neurodegenerative and other misfolded protein diseases. The Company’s proprietary target discovery engine, EpiSelect™, has been shown to predict novel targets known as Disease Specific Epitopes (DSEs) on the molecular surface of misfolded proteins that cause neurodegenerative and other misfolded protein diseases, including Alzheimer’s disease (AD), amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), multiple system atrophy (MSA), and Parkinson’s Disease (PD). ProMIS has offices in Cambridge, Massachusetts (USA) and Toronto, Ontario (CAN). About PMN310 and the PRECISE-AD Trial for Alzheimer’s Disease (AD) PMN310, the Company’s lead product candidate for the treatment of AD, is a humanized IgG1 monoclonal antibody that has been designed to selectively target only the toxic oligomers, avoiding plaque, thereby potentially reducing, or eliminating amyloid-related imaging abnormalities (ARIA) liability. In addition, because PMN310 may not be limited by off-target binding or side effects, PMN310 could potentially offer an improved efficacy profile over other amyloid-directed antibody therapeutics. PMN310 was granted Fast Track designation by the U.S. Food and Drug Administration in July 2025. Based on the encouraging results from the Phase 1a trial (NCT06105528) of PMN310 in healthy volunteers, ProMIS initiated PRECISE-AD, a Phase 1b clinical trial in AD patients. PRECISE-AD (NCT06750432) is a randomized, double-blind, placebo-controlled study to evaluate the safety, tolerability and pharmacokinetics (PK) of multiple ascending doses (5, 10, 20 mg/kg) of intravenous PMN310 in patients with Mild Cognitive Impairment due to AD or mild AD (Stage 3 and Stage 4 AD). PRECISE-AD will be the first study to examine the effects of a monoclonal antibody directed solely against Aβ oligomers on biomarkers associated with AD pathology and clinical outcomes. Safety will be a primary outcome of the study with particular emphasis on assessing whether, as a non-plaque binder, PMN310 may have a reduced risk of ARIA. The study is powered to provide 95% confidence for detection of ARIA and is designed to provide meaningful insight into the effects of PMN310 on biomarkers and clinical outcomes. EpiSelectTM Drug Discovery Engine Toxic misfolded proteins underlie the pathogenesis of neurodegenerative diseases such as Alzheimer’s disease, Parkinson’s disease (PD), amyotrophic lateral sclerosis (ALS), and frontotemporal dementia (FTD). Generation of therapeutic antibodies selectively targeting only disease-misfolded protein isoforms, while sparing normal or irrelevant isoforms of the same protein, has not yet been successfully achieved by conventional immunization strategies. ProMIS Neurosciences has developed a computational platform (EpiSelect™) to identify conformational epitopes that are uniquely exposed on toxic misfolded proteins, which can then be used to generate misfolding-specific antibodies or vaccine formulations. Application of the ProMIS platform produced PMN310, a clinical stage, humanized monoclonal antibody candidate that has been shown to be highly selective for toxic amyloid-beta oligomers (AβO) without significant reactivity with amyloid-beta monomers or fibrils, thereby avoiding target distraction by these more abundant species, and potentially reducing the risk of brain edema and microhemorrhages associated with the targeting of vascular/parenchymal amyloid. Similarly, specific epitopes for alpha-synuclein toxic oligomers/soluble fibrils that drive synucleinopathies, and for pathogenic TDP-43 in ALS and FTD have been identified and lead candidate antibodies generated. The precise conformation of these epitopes has been translated into vaccines inducing an antibody response selective for pathogenic molecular species in preclinical mouse vaccination studies. Forward-looking Statements This press release contains forward-looking statements that are made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. Certain information in this news release constitutes forward-looking statements and forward-looking information (collectively, ‎‎“forward-looking information”) within the meaning of applicable securities laws. In some cases, but not necessarily in all cases, forward-looking information can be identified by the ‎use of forward-looking terminology such as “plans”, “pleased to”, “look forward to”, “potential to”, “targets”, “expects” or “does not expect”, “is expected”, “excited about”, “an opportunity exists”, ‎‎“is positioned”, “estimates”, “intends”, “assumes”, “anticipates” or “does not anticipate” or “believes”, or variations of such words and ‎phrases or state that certain actions, events or results “may”, “could”, “would”, “might”, “will” or “will be taken”, “occur” or “be ‎achieved”. In addition, any statements that refer to expectations, projections or other characterizations of future events or ‎circumstances contain forward-looking information. Specifically, this news release contains forward-looking information relating to the Company’s Phase 1b study in AD patients, including planned timing for completion and anticipated data read out of interim results in the second half of 2026, interim analysis in the third quarter of 2026 and topline results by the early 2027, statements relating to the Company's progress, including enrollment and dosing for its Phase 1b clinical trial, the potential for such studies to provide the first proof-of-concept data for PMN310, the potential that PMN310 has the potential to positively benefit patients with AD, the targeting of toxic misfolded proteins in neurodegenerative diseases that the Company believes may directly address fundamental AD pathology (including the belief and understanding that toxic oligomers of Aβ are a major driver of AD) and have greater therapeutic potential due to reduction of off-target activity, management’s belief that its patented platform technology has created an antibody candidate specific to toxic misfolded oligomers known to be present in AD, therapeutic activity and preferential targeting of toxic soluble aggregates by Aß-directed antibodies and the potential implications thereof, the Company’s pipeline, including its platform, including the capabilities thereof and the application of its platform to other diseases, statements regarding trial design and approach to develop a subcutaneous formulation for potential future self-administration with an auto-injector, statements regarding discovery candidates, timing of IND-enabling studies, preclinical data, use of capital expenses, future accumulated deficit and other financial results in the future, statements relating to use of proceeds from financing and cash runway through 2027, and ability to fund operations and the ability to maintain enough liquidity to execute its business plan. Statements containing forward-looking information are not historical facts but instead represent management's current ‎expectations, estimates and projections regarding the future of our business, future plans, strategies, projections, anticipated events ‎and trends, the economy and other future conditions. Forward-looking information is necessarily based on a number of opinions, assumptions and estimates that, while considered reasonable by the Company as of the date of this news release, are subject to ‎known and unknown risks, uncertainties and assumptions and other factors that may cause the actual results, level of activity, ‎performance or achievements to be materially different from those expressed or implied by such forward-looking information, including, but not limited to, the risk that preclinical results or early results may not be indicative of future results, its accumulated deficit and the expectation for continued losses and future financial results. Important factors that could cause actual results to differ materially from those indicated in the forward-looking information include, among others, the factors discussed throughout the “Risk Factors” section of the Company's most recently filed Annual Report on Form 10-K for the year ended December 31, 2025 and in its subsequent filings filed with the United States Securities and Exchange Commission. Except as required by applicable securities laws, the Company undertakes no obligation to publicly update any forward-looking information, whether written or oral, that may be made from time to time, whether as a result of new information, future developments or otherwise. For further information: Visit us at www.promisneurosciences.com Please submit media inquiries to [email protected] For Investor Relations, please contact: Carie Pierce [email protected] PROMIS NEUROSCIENCES INC. Consolidated Balance Sheets (expressed in U.S. dollars, except share amounts) (unaudited) Consolidated Statements of Operations (expressed in U.S. dollars, except share amounts) (unaudited)

Phase 1b trial in Alzheimer’s disease is over 85% enrolled: Cohorts 1 and 2 are fully enrolled PMN310 continues to demonstrate a favorable safety profile On track to report 6-month interim data in Q2 2026 and final 12-month top-line results in Q4 2026 Cambridge, Massachusetts, Nov. 12, 2025 (GLOBE NEWSWIRE) -- ProMIS Neurosciences Inc. (Nasdaq: PMN), a clinical-stage biotechnology company focused on the generation and development of antibody therapeutics targeting toxic misfolded proteins in neurodegenerative diseases, such as Alzheimer’s disease (AD), amyotrophic lateral sclerosis (ALS) and Parkinson’s disease (PD), today announced financial results for the third quarter ended September 30, 2025. “2025 has been a year of intense focus and successful execution for the team at ProMIS,” said Neil Warma, Chief Executive Officer of ProMIS Neurosciences. “We have reinforced the Company’s strong foundation both strategically and clinically by bringing in additional capital to support our stated goals and adding Slanix Paul Alex, Pharm.D., President and Portfolio Manager for Ally Bridge Group’s Public Equity strategy to our Board. Collectively, this amplifies awareness amongst the investment community as we approach the nearing completed enrollment of our PRECISE-AD trial evaluating our first clinical candidate, PMN310, which was designed using our proprietary EpiSelectTM computational drug discovery engine. All of this is ultimately preparing the Company for its multiple key anticipated inflection points in 2026 and endeavoring to deliver on its promise of developing next-generation therapies for AD and for other neurogenerative disorders.” Corporate Highlights Alzheimer’s Disease Program (PMN310) ProMIS’ lead candidate, PMN310, is a humanized IgG1 antibody directed toward toxic AβO that are believed to be a major driver of AD. PMN310 was granted Fast Track Designation by the U.S. Food and Drug Administration. As of November 12, 2025, ProMIS has fully enrolled Cohorts 1 and 2 and is well into Cohort 3, with complete enrollment expected before the end of the year. PMN310 continues to demonstrate a favorable safety profile, with respect to incidence of amyloid-related imaging abnormalities (ARIA) and serious adverse events (SAEs). On September 3, 2025, ProMIS announced that the independent Data and Safety Monitoring Board (DSMB) for its ongoing PRECISE-AD Phase 1b clinical trial unanimously recommended that the Company proceed to the third and final dose escalation cohort evaluating PMN310 for the treatment of AD. Key Pipeline Programs Amyotrophic Lateral Sclerosis Disease Program (PMN267) PMN267 is a humanized IgG1 antibody directed against toxic misfolded TDP-43 as a potential therapeutic target for ALS and is ready to progress to IND-enabling studies. Parkinson’s Disease (PD) and Multiple System Atrophy (MSA) Disease Program (PMN442) PMN442 is a humanized IgG1 antibody and is ProMIS’s lead candidate for PD, MSA and other synucleinopathies based on its selective binding and protective activity against pathogenic forms of alpha-synuclein and is ready to progress to IND-enabling studies. Third Quarter 2025 Financial Highlights Cash and cash equivalents were $15.4 million as of September 30, 2025, compared to $13.3 million as of December 31, 2024. The increase in cash was attributable to multiple transactions in July 2025, including a registered direct offering, private placements and discounted warrant exercises, where we received aggregate gross proceeds of approximately $21.6 million. Research and development expenses were $9.8 million for the third quarter ended September 30, 2025, compared to $2.6 million for the same period in 2024. The increase was primarily attributable to expenditures on the PRECISE-AD Phase 1b clinical trial for PMN310. General and administrative expenses were $2.0 million for the third quarter ended September 30, 2025, compared to $1.9 million for the same period in 2024. Loss from operations was $11.8 million for the third quarter ended September 30, 2025, compared to an operating loss of $4.4 million for the same period in 2024. The increased operating loss was primarily attributable to expenditures on the PRECISE-AD Phase 1b clinical trial for PMN310. About ProMIS Neurosciences Inc. ProMIS Neurosciences is a clinical-stage biotechnology company committed to the discovery and development of therapeutic antibodies and vaccines selective for toxic oligomers associated with the development and progression of neurodegenerative and other misfolded protein diseases. The Company’s proprietary target discovery engine, EpiSelect™, has been shown to predict novel targets known as Disease Specific Epitopes (DSEs) on the molecular surface of misfolded proteins that cause neurodegenerative and other misfolded protein diseases, including Alzheimer’s disease (AD), amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), multiple system atrophy (MSA), and Parkinson’s Disease (PD). ProMIS has offices in Cambridge, Massachusetts (USA) and Toronto, Ontario (CAN). About PMN310 and the PRECISE-AD Trial for Alzheimer’s Disease (AD) PMN310, the Company’s lead product candidate for the treatment of AD, is a humanized monoclonal antibody that has been designed to selectively target only the toxic oligomers, avoiding plaque, thereby potentially reducing or eliminating amyloid-related imaging abnormalities (ARIA) liability. In addition, because PMN310 may not be limited by off-target binding or side effects, PMN310 could potentially offer an improved efficacy profile over other amyloid-directed antibody therapeutics. PMN310 was granted Fast Track designation by the U.S. Food and Drug Administration in July 2025. Based on the encouraging results from the Phase 1a trial (NCT06105528) of PMN310, ProMIS initiated PRECISE-AD, a Phase 1b clinical trial in AD patients. PRECISE-AD (NCT06750432) is a randomized, double-blind, placebo-controlled study to evaluate the safety, tolerability and pharmacokinetics (PK) of multiple ascending doses (5, 10, 20 mg/kg) of intravenous PMN310 in patients with Mild Cognitive Impairment due to AD and mild AD (Stage 3 and Stage 4 AD). PRECISE-AD will be the first study to examine the effects of a monoclonal antibody directed solely against AβO on biomarkers associated with AD pathology and clinical outcomes. Safety will be a primary outcome of the study with particular emphasis on assessing whether, as a non-plaque binder, PMN310 may have a reduced risk of ARIA. The study is powered to provide 95% confidence for detection of ARIA. The study has been designed with a sample size intended to provide sufficient power to provide meaningful insight into effects of PMN310 on biomarkers and clinical outcomes. EpiSelectTM Drug Discovery Engine Toxic misfolded proteins underlie the pathogenesis of neurodegenerative diseases such as Alzheimer’s disease (AD), Parkinson’s disease (PD), amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Generation of therapeutic antibodies selectively targeting only disease-misfolded protein isoforms, while sparing normal or irrelevant isoforms of the same protein, has not yet been successfully achieved by conventional immunization strategies. ProMIS Neurosciences has developed a computational platform (EpiSelectTM) to identify conformational epitopes that are uniquely exposed on toxic misfolded proteins, which can then be used to generate misfolding-specific antibodies or vaccine formulations. Application of the ProMIS platform produced PMN310, a clinical stage, humanized monoclonal antibody candidate that has been shown to be highly selective for toxic amyloid-beta oligomers (AβO) without significant reactivity with amyloid-beta monomers or fibrils, thereby avoiding target distraction by these more abundant species, and potentially reducing the risk of brain edema and microhemorrhages associated with the targeting of vascular/parenchymal amyloid. Similarly, specific epitopes for alpha-synuclein toxic oligomers/soluble fibrils that drive synucleinopathies, and for pathogenic TDP-43 in ALS and FTD have been identified and lead candidate antibodies generated. The precise conformation of these epitopes has been translated into vaccines inducing an antibody response selective for pathogenic molecular species in preclinical mouse vaccination studies. Forward-looking Statements Nasdaq has not reviewed and does not accept responsibility for the adequacy or accuracy of this release. Certain information in this news release constitutes forward-looking statements and forward-looking information (collectively, ‎‎“forward-looking information”) within the meaning of applicable securities laws. In some cases, but not necessarily in all cases, forward-looking information can be identified by the ‎use of forward-looking terminology such as “plans”, “targets”, “expects” or “does not expect”, “is expected”, “excited about”, “an opportunity exists”, ‎‎“is positioned”, “estimates”, “intends”, “assumes”, “anticipates” or “does not anticipate” or “believes”, or variations of such words and ‎phrases or state that certain actions, events or results “may”, “could”, “would”, “might”, “will” or “will be taken”, “occur” or “be ‎achieved”. In addition, any statements that refer to expectations, projections or other characterizations of future events or ‎circumstances contain forward-looking information. Specifically, this news release contains forward-looking information relating to the Company’s Phase 1b study in AD patients, including DSMB approval to advance to third and final dose escalation cohort and planned timing for completion and anticipated data read out of interim results in the second half of 2026 and topline results by the end of 2026, statements relating to the Company's progress, including enrollment and dosing for its Phase 1b clinical trial, the potential for such studies to provide the first proof-of-concept data for PMN310, the potential that PMN310 has the potential to positively benefit patients with AD, the targeting of toxic misfolded proteins in neurodegenerative diseases that the Company believes may directly address fundamental AD pathology (including the belief and understanding that toxic oligomers of Aβ are a major driver of AD) and have greater therapeutic potential due to reduction of off-target activity, a computationally-derived Aβ vaccine for AD and the Company’s PMN310 antibody and vaccine candidate, management’s belief that its patented platform technology has created an antibody candidate specific to toxic misfolded oligomers known to be present in AD, therapeutic activity and preferential targeting of toxic soluble aggregates by Aß-directed antibodies and the potential implications thereof, the Company’s pipeline, including its platform, including the capabilities thereof and the application of its platform to other diseases, statements regarding discovery candidates, timing of IND-enabling studies, preclinical data, the ability to continue its growth and realize the anticipated contribution of the members of its board of directors and executives to its operation and progress, use of capital expenses, future accumulated deficit and other financial results in the future, ability to fund operations, the ability to maintain enough liquidity to execute its business plan and its ability to continue as a going concern. Statements containing forward-looking information are not historical facts but instead represent management's current ‎expectations, estimates and projections regarding the future of our business, future plans, strategies, projections, anticipated events ‎and trends, the economy and other future conditions. Forward-looking information is necessarily based on a number of opinions, assumptions and estimates that, while considered reasonable by the Company as of the date of this news release, are subject to ‎known and unknown risks, uncertainties and assumptions and other factors that may cause the actual results, level of activity, ‎performance or achievements to be materially different from those expressed or implied by such forward-looking information, including, but not limited to, the risk that preclinical results or early clinical results may not be indicative of future results, the Company’s ability to fund its operations and continue as a going concern, its accumulated deficit and the expectation for continued losses and future financial results. Important factors that could cause actual results to differ materially from those indicated in the forward-looking information include, among others, the factors discussed throughout the “Risk Factors” section of the Company's most recently filed Annual Report on Form 10-K for the year ended December 31, 2024 and in its subsequent filings filed with the United States Securities and Exchange Commission. Except as required by applicable securities laws, the Company undertakes no obligation to publicly update any forward-looking information, whether written or oral, that may be made from time to time, whether as a result of new information, future developments or otherwise. For further information: Visit us at www.promisneurosciences.com Please submit media inquiries to [email protected] For Investor Relations, please contact: Kaytee Bock Zafereo [email protected] PROMIS NEUROSCIENCES INC. Consolidated Balance Sheets (expressed in U.S. dollars, except share amounts) (unaudited) PROMIS NEUROSCIENCES INC. Consolidated Statements of Operations (expressed in U.S. dollars, except share amounts) (unaudited)

U.S. FDA Grants Fast Track Designation for PMN310 in Alzheimer’s Disease, enhancing program’s potential for priority review PRECISE-AD Phase 1b Trial in Alzheimer’s Disease Progressing on Schedule: Over 50% enrolled, no cases of ARIA and no patient dropouts to date Strengthened Financial Position with $21.6 Million in Gross Proceeds Raised in July 2025 Cambridge, Massachusetts, Aug. 13, 2025 (GLOBE NEWSWIRE) -- ProMIS Neurosciences Inc. (Nasdaq: PMN), a clinical-stage biotechnology company focused on the generation and development of antibody therapeutics targeting toxic misfolded proteins in neurodegenerative diseases, such as Alzheimer’s disease (AD), amyotrophic lateral sclerosis (ALS) and Parkinson’s disease (PD), today announced financial results for the second quarter ended June 30, 2025. “The team’s exceptional focus and execution in the first half of 2025 culminated in what has been an extraordinary past month for ProMIS and its key stakeholders,” said Neil Warma, Chief Executive Officer of ProMIS Neurosciences. “As of August 12, enrollment in the PRECISE-AD Phase 1b Alzheimer’s disease trial has surpassed 50% of the planned 128 patients, marking strong recruitment progress. Importantly, no cases of amyloid-related imaging abnormalities (ARIA), including brain swelling or microhemorrhage, have been observed to date, and no patient dropouts have been reported, reinforcing PMN310’s potential favorable safety profile. At this stage, we remain on track to deliver 6-month blinded interim results in 2Q 2026 and final topline results in 4Q 2026." “In addition, our recent FDA Fast Track designation for PMN310 underscores the urgent need for safer, more effective Alzheimer’s treatments. Building on this regulatory milestone and the positive clinical progress of PRECISE-AD, we secured approximately $21.6 million in gross proceeds to accelerate PMN310’s advancement toward its next phase of development,” added Mr. Warma. Corporate Highlights EpiSelectTM Drug Discovery Engine In July 2025, ProMIS presented on its proprietary protein-misfolding platform, EpiSelectTM at AAIC 2025 in a presentation titled Protein misfolding-specific epitope identification for passive and active immunotherapy of neurodegenerative diseases (Abstract Number: 98670) The presentation highlighted the following: Toxic misfolded proteins underlie the pathogenesis of neurodegenerative diseases such as Alzheimer’s disease, Parkinson’s disease (PD), amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Generation of therapeutic antibodies selectively targeting only disease-misfolded protein isoforms, while sparing normal or irrelevant isoforms of the same protein, has not yet been successfully achieved by conventional immunization strategies ProMIS Neurosciences has developed a computational platform (EpiSelectTM) to identify conformational epitopes that are uniquely exposed on toxic misfolded proteins, which can then be used to generate misfolding-specific antibodies or vaccine formulations Application of the ProMIS platform produced PMN310, a clinical stage, humanized monoclonal antibody candidate that has been shown to be highly selective for toxic amyloid-beta oligomers (AβO) without significant reactivity with amyloid-beta monomers or fibrils, thereby avoiding target distraction by these more abundant species, and reducing the risk of brain edema and microhemorrhages associated with the targeting of vascular/ parenchymal amyloid. Similarly, specific epitopes for alpha-synuclein toxic oligomers/soluble fibrils that drive synucleinopathies, and for pathogenic TDP-43 in ALS/FTD have been identified and lead candidate antibodies generated The precise conformation of these epitopes has been translated into vaccines inducing an antibody response selective for pathogenic molecular species in preclinical mouse vaccination studies Alzheimer’s Disease Program (PMN310) ProMIS’ lead candidate, PMN310, is a humanized IgG1 antibody directed toward toxic AβO that are believed to be a major driver of AD. As of August 12, 2025, ProMIS has enrolled over 50% of the planned 128 patients in the PRECISE-AD Phase 1b Alzheimer’s disease trial. No cases of ARIA, including brain swelling or microhemorrhage, have been observed to date and no patient dropouts have been reported. In May 2025, the DSMB recommended continuation of the trial as planned without any modification and clearance to proceed to the next dosing level, from the 5mg/kg dose of PMN310 in the first cohort to the 10mg/kg dose for the second cohort In July 2025, the Company announced PMN310 was granted Fast Track Designation by the FDA In July 2025 at AAIC, the Company showcased the following posters: Title: PRECISE-AD, A Phase 1b, Double-Blind, Placebo-Controlled, Multiple Ascending Dose Study of the Safety, Tolerability, Pharmacokinetics, Pharmacodynamics, and Preliminary Efficacy of PMN310 in Patients with Early Alzheimer's Disease (Poster Number: 103159). Based on the encouraging results from the Phase 1a trial (NCT06105528) of PMN310, ProMIS initiated PRECISE-AD, a Phase 1b clinical trial in AD patients. PRECISE-AD (NCT06750432) is a randomized, double-blind, placebo-controlled study to evaluate the safety, tolerability and pharmacokinetics (PK) of multiple ascending doses of PMN310 in patients with AD. PRECISE-AD will be the first study to examine the effects of a monoclonal antibody directed solely against AβO on biomarkers associated with AD pathology and clinical outcomes. Safety will be a primary outcome of the study with particular emphasis on assessing the expectation that, as a non-plaque binder, PMN310 will have a reduced risk of ARIA. In addition, the study has been designed with a sample size intended to provide sufficient power to provide meaningful insight into effects of PMN310 on biomarkers and clinical outcomes. Title: Leveraging recent advances in biomarkers to optimize early phase drug development in Alzheimer’s Disease (Poster Number: 103841). Biomarkers are now used in both AD diagnosis and prediction of disease progression. Several clinical trials have utilized biomarker outcomes (amyloid-PET scans and cerebrospinal fluid (CSF) measures of Aβ and tau). Blood-based biomarkers offer advantages of lower costs and easier sample collection. Given their potential to predict both disease trajectory and clinical benefit, we investigated the relationship between biomarkers and clinical outcomes in recent trials of anti-amyloid antibodies for AD. Compared to amyloid-PET, downstream biomarkers like plasma pTau have the potential to provide a more broadly applicable read-out for treatment efficacy, especially for treatments whose mechanism of action is not directly aimed at plaque removal. ProMIS expects to report blinded six-month interim results from PRECISE-AD in 2Q 2026, with topline results anticipated in 4Q 2026. The six-month interim analysis will include biomarker and safety data (including incidence of ARIA), with final analysis to include clinical outcome measures ProMIS continues to advance its PMN311 Aβ vaccine program in AD based on its oligomer target epitope. Key Pipeline Programs Amyotrophic Lateral Sclerosis Disease Program (PMN267) PMN267 is a humanized IgG1 antibody directed against toxic misfolded TDP-43 as a potential therapeutic target for ALS and is ready to progress to IND-enabling studies Parkinson’s Disease (PD) and Multiple System Atrophy (MSA) Disease Program (PMN442) PMN442 is a humanized IgG1 antibody and is ProMIS’s lead candidate for PD, MSA and other synucleinopathies based on its selective binding and protective activity against pathogenic forms of alpha-synuclein and is ready to progress to IND-enabling studies Second Quarter 2025 Financial Highlights Cash and cash equivalents were $4.5 million as of June 30, 2025, compared to $1.0 million as of June 30, 2024. Subsequently, in July 2025, ProMIS received aggregate gross proceeds of $21.6 million across multiple transactions, including a Registered Direct Offering, Private Placements and Warrant Exercises. Research and development expenses were $8.7 million for the second quarter ended June 30, 2025, compared to $1.6 million for the same period in 2024. The increase was primarily attributable to expenditures on the PRECISE-AD Phase 1b trial for PMN310. General and administrative expenses were $1.4 million for the second quarter ended June 30, 2025, compared to $1.1 million for the same period in 2024. Net loss was $10.1 million for the second quarter ended June 30, 2025, compared to a net loss of $2.6 million for the same period in 2024. The net loss was primarily attributable to the increase in clinical trial expenditures. About ProMIS Neurosciences Inc. ProMIS Neurosciences is a clinical-stage biotechnology company committed to the discovery and development of therapeutic antibodies and vaccines selective for toxic oligomers associated with the development and progression of neurodegenerative and other misfolded protein diseases. The Company’s proprietary target discovery engine, EpiSelect™, has been shown to predict novel targets known as Disease Specific Epitopes (DSEs) on the molecular surface of misfolded proteins that cause neurodegenerative and other misfolded protein diseases, including Alzheimer’s disease (AD), amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), multiple system atrophy (MSA), and Parkinson’s Disease (PD). ProMIS has offices in Cambridge, Massachusetts (USA) and Toronto, Ontario (CAN). About PMN310 and the PRECISE-AD Trial for Alzheimer’s Disease (AD) PMN310, the Company’s lead product candidate for the treatment of AD, is a humanized monoclonal antibody that has been designed to selectively target only the toxic oligomers, avoiding plaque, thereby potentially reducing or eliminating ARIA liability. In addition, because PMN310 may not be limited by off-target binding or side effects, PMN310 could potentially offer an improved efficacy profile over other amyloid-directed antibody therapeutics. PMN310 was granted Fast Track designation by the U.S. Food and Drug Administration in July 2025. Based on the encouraging results from the Phase 1a trial (NCT06105528) of PMN310, ProMIS initiated PRECISE-AD, a Phase 1b clinical trial in AD patients. PRECISE-AD (NCT06750432) is a randomized, double-blind, placebo-controlled study to evaluate the safety, tolerability and pharmacokinetics (PK) of multiple ascending doses (5, 10, 20 mg/kg) of intravenous PMN310 in patients with Mild Cognitive Impairment due to AD and mild AD (Stage 3 and Stage 4 AD). PRECISE-AD will be the first study to examine the effects of a monoclonal antibody directed solely against AβO on biomarkers associated with AD pathology and clinical outcomes. Safety will be a primary outcome of the study with particular emphasis on assessing whether, as a non-plaque binder, PMN310 may have a reduced risk of ARIA. The study is powered to provide 95% confidence for detection of ARIA. The study has been designed with a sample size intended to provide sufficient power to provide meaningful insight into effects of PMN310 on biomarkers and clinical outcomes. Forward-looking Statements Nasdaq has not reviewed and does not accept responsibility for the adequacy or accuracy of this release. Certain information in this news release constitutes forward-looking statements and forward-looking information (collectively, ‎‎“forward-looking information”) within the meaning of applicable securities laws. In some cases, but not necessarily in all cases, forward-looking information can be identified by the ‎use of forward-looking terminology such as “plans”, “targets”, “expects” or “does not expect”, “is expected”, “excited about”, “an opportunity exists”, ‎‎“is positioned”, “estimates”, “intends”, “assumes”, “anticipates” or “does not anticipate” or “believes”, or variations of such words and ‎phrases or state that certain actions, events or results “may”, “could”, “would”, “might”, “will” or “will be taken”, “occur” or “be ‎achieved”. In addition, any statements that refer to expectations, projections or other characterizations of future events or ‎circumstances contain forward-looking information. Specifically, this news release contains forward-looking information relating to the Company’s Phase 1b study in AD patients and expectations of such study results, including interim results in the first half of 2026 and topline results by the end of 2026, statements relating to the Company's progress, including enrollment and dosing for its Phase 1b clinical trial, the potential for such studies to provide the first proof-of-concept data for PMN310, the potential that PMN310 has the potential to positively benefit patients with AD, the targeting of toxic misfolded proteins in neurodegenerative diseases that the Company believes may directly address fundamental AD pathology (including the belief and understanding that toxic oligomers of Aβ are a major driver of AD) and have greater therapeutic potential due to reduction of off-target activity, a computationally-derived Aβ vaccine for AD and the Company’s PMN310 antibody and vaccine candidate, management’s belief that its patented platform technology has created an antibody candidate specific to toxic misfolded oligomers known to be present in AD, therapeutic activity and preferential targeting of toxic soluble aggregates by Aß-directed antibodies and the potential implications thereof, the Company’s pipeline, including its platform, including the capabilities thereof and the application of its platform to other diseases, statements regarding discovery candidates, timing of IND-enabling studies, preclinical data, recent presentations of such preclinical data and the takeaways therefrom, the ability to continue its growth and realize the anticipated contribution of the members of its board of directors and executives to its operation and progress, use of capital expenses, future accumulated deficit and other financial results in the future, ability to fund operations, the ability to maintain enough liquidity to execute its business plan and its ability to continue as a going concern. Statements containing forward-looking information are not historical facts but instead represent management's current ‎expectations, estimates and projections regarding the future of our business, future plans, strategies, projections, anticipated events ‎and trends, the economy and other future conditions. Forward-looking information is necessarily based on a number of opinions, assumptions and estimates that, while considered reasonable by the Company as of the date of this news release, are subject to ‎known and unknown risks, uncertainties and assumptions and other factors that may cause the actual results, level of activity, ‎performance or achievements to be materially different from those expressed or implied by such forward-looking information, including, but not limited to, the risk that preclinical results or early clinical results may not be indicative of future results, the Company’s ability to fund its operations and continue as a going concern, its accumulated deficit and the expectation for continued losses and future financial results. Important factors that could cause actual results to differ materially from those indicated in the forward-looking information include, among others, the factors discussed throughout the “Risk Factors” section of the Company's most recently filed Annual Report on Form 10-K for the year ended December 31, 2024 and in its subsequent filings filed with the United States Securities and Exchange Commission. Except as required by applicable securities laws, the Company undertakes no obligation to publicly update any forward-looking information, whether written or oral, that may be made from time to time, whether as a result of new information, future developments or otherwise. For further information: Visit us at www.promisneurosciences.com Please submit media inquiries to [email protected] For Investor Relations, please contact: Kaytee Bock Zafereo [email protected] PROMIS NEUROSCIENCES INC. Consolidated Balance Sheets (expressed in U.S. dollars, except share amounts) (unaudited) PROMIS NEUROSCIENCES INC. Consolidated Statements of Operations (expressed in U.S. dollars, except share amounts) (unaudited)

First Cohort Completed in PRECISE-AD Trial Evaluating PMN310 in Alzheimer’s Disease Six Month Interim Results Expected in 1H 2026 Topline Results Anticipated by end of 2026 CAMBRIDGE, Massachusetts, May 12, 2025 (GLOBE NEWSWIRE) -- ProMIS Neurosciences Inc. (Nasdaq: PMN), a clinical-stage biotechnology company focused on the generation and development of antibody therapeutics targeting toxic misfolded proteins in neurodegenerative diseases, such as Alzheimer’s disease (AD), amyotrophic lateral sclerosis (ALS), Parkinson’s disease (PD) and multiple system atrophy (MSA), today announced financial results for the first quarter ended March 31, 2025. “We made significant progress in the first quarter of 2025, advancing our lead clinical program in Alzheimer’s disease with rapid enrollment of the first cohort in the PRECISE-AD trial,” said Neil Warma, Chief Executive Officer of ProMIS Neurosciences. “The pace of enrollment exceeded our expectations, reflecting the growing enthusiasm from investigators for PMN310’s differentiated profile. Based on its selective targeting of toxic Aβ oligomers and the potential to avoid ARIA—a serious safety concern seen with existing therapies—we believe PMN310 could set a new standard as a best-in-class treatment for Alzheimer’s treatment. Delivering a therapy that combines strong efficacy with a substantially improved safety profile would be a transformative milestone for patients and caregivers.” “While PRECISE-AD is designed as a 12-month, double-blind study, it is powered to detect biomarker changes as early as six months,” Mr. Warma continued. “We view the planned interim analysis in the first half of 2026 as an important opportunity to generate early insights into PMN310’s potential to drive both clinical benefit and improved tolerability, particularly with respect to reducing or avoiding ARIA, a key differentiator in this space. Coupled with our directed targeting of toxic oligomers, we believe the benefit:risk profile will surpass current marketed therapies” Recent Highlights Alzheimer’s Disease Program (PMN310) ProMIS’ lead candidate, PMN310, is a humanized IgG1 antibody directed toward toxic amyloid-beta oligomers (AβO) that are believed to be a major driver of AD. Announced in early January 2025, ProMIS initiated PRECISE-AD based on the encouraging results from the Phase 1a trial of PMN310 and has since completed enrollment of the first cohort of patients and successfully dosed multiple patients with PMN310 in the Phase 1b trial. PRECISE-AD (NCT06750432) is a randomized, double-blind, placebo-controlled study to evaluate the safety, tolerability and pharmacokinetics (PK) of multiple ascending doses (5, 10, 20 mg/kg) of intravenous PMN310 in patients with Mild Cognitive Impairment due to Alzheimer’s disease and mild Alzheimer’s disease (Stage 3 and Stage 4 AD). The study plans to enroll approximately 128 patients across 22 active sites in the United States. Eligible patients will be dosed monthly at one of the three dose levels or placebo over 12 months with assessment of safety, tolerability, PK, and pharmacodynamic blood-based markers of treatment effect at baseline and every three months and cerebrospinal fluid biomarkers at baseline and every 6 months. Frequent MRI scans, especially early in treatment, and throughout the study will be conducted to monitor for any emergence of ARIA. Cognitive clinical outcomes will also be assessed at baseline, 6 months and 12 months. Safety will be a primary outcome of the study with particular emphasis on assessing the expectation that, as a non-plaque binder, PMN310 will have a reduced risk of ARIA. The study is powered to provide 95% confidence for detection of ARIA. The study has been designed with a sample size intended to provide sufficient power to provide meaningful insight into effects of PMN310 on biomarkers and clinical outcomes. PRECISE-AD will be the first study to examine the effects of a monoclonal antibody directed solely against AβO on biomarkers associated with AD pathology and clinical outcomes. ProMIS expects to report six-month interim results from PRECISE-AD in the first half of 2026, with topline results anticipated by the end of 2026. We anticipate the six-month interim analysis will include impact of biomarkers and safety (including incidence of ARIA), with final analysis to include clinical outcome measures. ProMIS continues to advance its Aβ vaccine program in AD based on its oligomer target epitope(s) – PMN311. In April 2025, ProMIS presented preclinical data at the American Alzheimer’s and Parkinson’s Disease International Conference (AD/PD Conference) and the Academy of Neurology Annual Meeting (AAN Annual Meeting). Key highlights from the presentation titled, “Novel approach to optimization of Alzheimer’s vaccine configuration for maximal targeting of toxic amyloid-beta oligomers” include: A large body of evidence indicates that soluble toxic AβO are a primary driver of AD. Through computational modeling, four different conformational B cell epitopes of AβOs were identified. A novel approach was utilized to select an optimal vaccine composition amongst 15 possible combinations of one to four epitopes to provide maximal binding to a toxic oligomer-enriched low molecular weight fraction of soluble AD brain extract. Results from the preclinical study showed that immunization with a single conformational epitope, peptide 301, the target of PMN310 antibody, was sufficient to produce maximal reactivity against AD brain oligomers. Amyotrophic Lateral Sclerosis Disease Program (PMN267) PMN267 is a humanized IgG1 antibody directed against toxic misfolded TDP-43 as a potential therapeutic target for ALS. ProMIS presented a virtual oral presentation of preclinical data at the AD/PD Conference. Key highlights from the presentation titled, “Selective targeting of pathogenic TDP-43 with misfolding-specific monoclonal antibodies and intrabodies against a pathogenic loss-of-structure epitope in the N-terminal domain” include: Proof-of-concept evidence that supports selective targeting of misfolded toxic aggregates of TDP-43 by monoclonal antibodies (mAbs) such as PMN267 as a potentially safe and effective avenue to treat ALS and other TDP-43 proteinopathies. TDP-43 mAbs Display high affinity against the misfolded TDP-43 epitope Selectively react with pathological TDP-43 and not normal TDP-43 Inhibit cell-to-cell transmission of misfolded TDP-43 TDP-43 mAbs and corresponding intrabodies specifically react with cytoplasmic aggregates of misfolded TDP-43 Intrabodies accelerate the degradation of misfolded TDP-43 Intrabody reduces TDP-43 aggregates in iPSC-derived ALS motor neurons under chronic stress conditions Multiple Synucleinopathies Disease Vaccine Program (PMN440) In April 2025, ProMIS presented preclinical data at the AD/PD Conference and at the AAN Annual Meeting. Key highlights from the presentation titled, “Novel approach to optimization of alpha-synuclein vaccine composition for maximal targeting of toxic alpha-synuclein species” and “Rational design of a vaccine for synucleinopathies using computationally-derived conformational B cell epitopes to selectively target pathogenic alpha-synuclein species” include: Vaccination against pathogenic species of alpha-synuclein (ASyn); (toxic oligomers, small soluble seeding fibrils), has the potential to protect against synucleinopathies, which include PD, dementia with Lewy bodies and MSA. Vaccine constructs containing computationally-derived conformational B cell epitopes of misfolded pathogenic ASyn were tested in mice. The potential advantage of this approach, as opposed to inducing pan-ASyn reactivity, lies in preserving normal ASyn function and minimizing the diversion of active antibody by the more abundant non-toxic forms of the protein in the blood and central nervous system. Results from the preclinical study showed that vaccination with conformational B cell epitopes produced high affinity antibodies with the desired selectivity for pathogenic ASyn and identified optimal vaccine configurations for further development. These data sets showcase the potential of vaccinations with conformational B cell epitopes to produce high affinity antibodies with the desired selectivity for pathogenic Asyn and supports the development of PMN440 vaccine as a treatment for synucleinopathies, such as PD, dementia with Lewy bodies and MSA. First Quarter 2025 Financial Highlights Cash and cash equivalents were $8.4 million as of March 31, 2025, compared to $13.3 million as of December 31, 2024. Research and development expenses were $5.5 million for the first quarter ended March 31, 2025, compared to $2.1 million for the same period in 2024. The increase was primarily attributable to costs related to the execution of the PMN310 Phase 1b clinical trial. General and administrative expenses increased to $2.0 million for the first quarter ended March 31, 2025, compared to $1.6 million for the same period in 2024. Net loss was $7.3 million for the first quarter ended March 31, 2025, compared to a net loss of $3.6 million for the same period in 2024. The net loss was primarily attributable to the increase in clinical trial expenses. About ProMIS Neurosciences Inc. ProMIS Neurosciences Inc. is a clinical stage biotechnology company focused on generating and developing antibody therapeutics selectively targeting toxic misfolded proteins in neurodegenerative diseases such as Alzheimer’s disease (AD), amyotrophic lateral sclerosis (ALS) and multiple system atrophy (MSA). The Company’s proprietary target discovery engine applies a thermodynamic, computational discovery platform to predict novel targets known as Disease Specific Epitopes on the molecular surface of misfolded proteins. PMN310, the Company’s lead product candidate for the treatment of AD, is a differentiated, humanized monoclonal antibody that has been designed to specifically bind toxic Aβ oligomers and to not bind plaque or monomers. Oligomers are known to drive disease progression in AD and PMN310 appears to selectively bind oligomers. PMN310 has successfully completed a Phase 1a clinical study and is dosing AD patients in its Phase 1b clinical trial. ProMIS has offices in Cambridge, Massachusetts and Toronto, Ontario. Forward-looking Statements Nasdaq has not reviewed and does not accept responsibility for the adequacy or accuracy of this release. Certain information in this news release constitutes forward-looking statements and forward-looking information (collectively, ‎‎“forward-looking information”) within the meaning of applicable securities laws. In some cases, but not necessarily in all cases, forward-looking information can be identified by the ‎use of forward-looking terminology such as “plans”, “targets”, “expects” or “does not expect”, “is expected”, “excited about”, “an opportunity exists”, ‎‎“is positioned”, “estimates”, “intends”, “assumes”, “anticipates” or “does not anticipate” or “believes”, or variations of such words and ‎phrases or state that certain actions, events or results “may”, “could”, “would”, “might”, “will” or “will be taken”, “occur” or “be ‎achieved”. In addition, any statements that refer to expectations, projections or other characterizations of future events or ‎circumstances contain forward-looking information. Specifically, this news release contains forward-looking information relating to the Company’s Phase 1b study in AD patients and expectations of such study results, including first cohort completion in the second quarter of 2025,interim results in the first half of 2026 and topline results by the end of 2026, statements relating to the Company's progress, including enrollment and dosing for its Phase 1b clinical trial, the potential for such studies to provide the first proof-of-concept data for PMN310, the potential that PMN310 has the potential to positively benefit patients with AD, the targeting of toxic misfolded proteins in neurodegenerative diseases that the Company believes may directly address fundamental AD pathology (including the belief and understanding that toxic oligomers of Aβ are a major driver of AD) and have greater therapeutic potential due to reduction of off-target activity, a computationally-derived Aβ vaccine for AD and the Company’s PMN310 antibody and vaccine candidate, management’s belief that its patented platform technology has created an antibody candidate specific to toxic misfolded oligomers known to be present in AD, therapeutic activity and preferential targeting of toxic soluble aggregates by Aß-directed antibodies and the potential implications thereof, the Company’s pipeline, including application of its platform to other diseases, statements regarding preclinical data, recent presentations of such preclinical data and the takeaways therefrom, the ability to continue its growth and realize the anticipated contribution of the members of its board of directors and executives to its operation and progress, use of capital expenses, future accumulated deficit and other financial results in the future, ability to fund operations, the ability to maintain enough liquidity to execute its business plan and its ability to continue as a going concern. Statements containing forward-looking information are not historical facts but instead represent management's current ‎expectations, estimates and projections regarding the future of our business, future plans, strategies, projections, anticipated events ‎and trends, the economy and other future conditions. Forward-looking information is necessarily based on a number of opinions, assumptions and estimates that, while considered reasonable by the Company as of the date of this news release, are subject to ‎known and unknown risks, uncertainties and assumptions and other factors that may cause the actual results, level of activity, ‎performance or achievements to be materially different from those expressed or implied by such forward-looking information, including, but not limited to, the risk that preclinical results or early clinical results may not be indicative of future results, the Company’s ability to fund its operations and continue as a going concern, its accumulated deficit and the expectation for continued losses and future financial results. Important factors that could cause actual results to differ materially from those indicated in the forward-looking information include, among others, the factors discussed throughout the “Risk Factors” section of the Company's most recently filed Annual Report on Form 10-K for the year ended December 31, 2024 and in its subsequent filings filed with the United States Securities and Exchange Commission. Except as required by applicable securities laws, the Company undertakes no obligation to publicly update any forward-looking information, whether written or oral, that may be made from time to time, whether as a result of new information, future developments or otherwise. For further information: Visit us at www.promisneurosciences.com Please submit media inquiries to [email protected] For Investor Relations, please contact: Kaytee Bock Zafereo [email protected] PROMIS NEUROSCIENCES INC. Consolidated Balance Sheets (expressed in U.S. dollars, except share amounts) (unaudited) PROMIS NEUROSCIENCES INC. Consolidated Statements of Operations (expressed in U.S. dollars, except share amounts) (unaudited)