ALEC

Advancing the Alector Brain Carrier (ABC) blood-brain barrier platform across antibodies, enzymes, and siRNA, with AL137 advancing as Alector’s lead ABC-enabled anti-amyloid beta (Aβ) antibody program for Alzheimer’s disease (AD). Continued progress across AL064/AL164 (ABC-enabled Tau siRNA for AD and other tauopathies) and AL050 (ABC-enabled GCase Enzyme Replacement Therapy for Parkinson’s disease (PD)). $172.8 million in cash, cash equivalents and investments provide runway at least through 2027 SOUTH SAN FRANCISCO, Calif., Aug. 06, 2026 (GLOBE NEWSWIRE) -- Alector, Inc. (Nasdaq: ALEC), a biotechnology company focused on developing therapies to counteract the devastating progression of neurodegeneration, today reported second quarter 2026 financial results and recent portfolio and business updates. As of June 30, 2026, Alector’s cash, cash equivalents, and investments totaled $172.8 million. "We continue to make steady progress across our ABC-enabled preclinical and research pipeline,” said Arnon Rosenthal, Ph.D., Chief Executive Officer of Alector. “Our work across antibodies, enzymes, and siRNA reflects the versatility of the ABC platform and our strategy to apply it to programs where enhanced brain delivery may address important limitations in the treatment of neurodegenerative diseases. We remain focused on disciplined execution as we advance our portfolio toward clinical development, with the goal of addressing important unmet needs for patients living with neurodegenerative diseases.” Recent Program Updates Alector Brain Carrier (ABC): Preclinical and Research Pipeline Alector’s proprietary Alector Brain Carrier (ABC) blood-brain barrier platform is central to the company’s strategy to enhance therapeutic delivery to the brain. ABC is designed to achieve efficient, enhanced brain delivery through differentiated binding to a distinct region of the transferrin receptor (TfR) and to enable peripheral dosing, while preserving a favorable safety profile. It is adaptable across multiple drug modalities, including antibodies, enzymes, and siRNA. Core to the platform's design are the principles of versatility, translatability, and differentiated binding. Preclinical studies across multiple ABC-enabled programs have shown robust brain penetration, supporting the advancement of a broad pipeline directed at the underlying drivers of neurodegenerative diseases. AL137 Following successful completion of IND-enabling studies evaluating both subcutaneous (SC) and intravenous (IV) administration, Alector selected AL137 as the lead molecule for its anti-amyloid beta (Aβ) antibody program for AD, with AL037 retained as a backup candidate. The company is targeting an IND submission in Q1 2027 and first-in-human dosing in Australia no later than April 2027. AL137 combines Alector’s proprietary high-affinity fully human anti-Aβ antibody which selectively binds pyroglutamate-3 (PyroGlu3-Aβ), a validated and pathogenic form of Aβ enriched in amyloid plaques, with the company’s proprietary ABC platform. Based on preclinical studies, AL137 is designed to be delivered SC and to combine several differentiated attributes intended to optimize efficacy, safety, convenience, and manufacturability, including: ABC-Enabled siRNA Platform Alector continues to advance its ABC-enabled siRNA platform, designed for peripheral dosing and offering the potential for more convenient administration compared with traditional intrathecal delivery, as well as the potential for homogeneous drug distribution throughout the brain. AL064/AL164 Alector’s lead siRNA program, AL064/AL164, is a tau siRNA program for AD and other tauopathies and aims to reduce toxic tau protein expression and slowing of cognitive decline in AD. AL064 demonstrated robust tau mRNA knockdown and durable reduction of phospho-Tau 217 in non-human primate brains. AL064 was modified to incorporate a well-validated chemical modification intended to further optimize siRNA stability, and this modified form is advancing into IND-enabling studies as AL164. Early-Stage siRNA Programs Earlier-stage siRNA programs advancing toward lead candidate selection include ADP062-ABC, an alpha-synuclein siRNA for PD, and ADP065-ABC, an NLRP3 siRNA for multiple neurodegenerative conditions, reflecting the broad applicability of the ABC platform across disease mechanisms. Alector continues to evaluate development plans and timing for its ABC-enabled siRNA programs. AL050 AL050, Alector’s ABC-enabled engineered glucocerebrosidase (GCase) enzyme replacement therapy (ERT), is in preclinical development for PD. AL050 is engineered to overcome the central challenges of delivering enzyme therapy to the brain, combining an engineered GCase with enhanced activity and stability, a silenced effector function for safety, and Alector's tunable ABC technology. To date, preclinical data have demonstrated increased GCase activity in both rodents and NHPs and reduced toxic substrate accumulation in a rodent GBA disease model with no apparent hematologic findings, supporting continued development as a potential therapy for PD and Lewy body dementia (LBD) associated with GBA loss-of-function mutations and subsequently for idiopathic PD and LBD. Second Quarter 2026 Financial Results Revenue. Collaboration revenue for the quarter ended June 30, 2026, was $3.3 million, compared to $7.9 million for the same period in 2025. The decrease was primarily due to lower revenue recognized for the AL101 AD program. R&D Expenses. Total research and development expenses for the quarter ended June 30, 2026, were $19.5 million, compared to $27.6 million for the quarter ended June 30, 2025. The decrease was mainly due to a decrease in personnel-related costs as a result of the reductions in force as well as a decrease in facilities and other expenses. G&A Expenses. Total general and administrative expenses for the quarter ended June 30, 2026, were $8.3 million, compared to $14.4 million for the quarter ended June 30, 2025. The decrease was mainly driven by a decrease in personnel-related costs as a result of the reductions in force. Net Loss. For the quarter ended June 30, 2026, Alector reported a net loss of $23.0 million, or $0.21 net loss per share, compared to a net loss of $30.5 million, or $0.30 net loss per share, for the same period in 2025. Cash Position. Cash, cash equivalents, and investments were $172.8 million as of June 30, 2026. Management anticipates that this will be sufficient to fund Alector’s operations at least through 2027. About Alector Alector is a biotechnology company focused on developing therapies to counteract the devastating progression of neurodegenerative diseases. Leveraging the principles of genetics, immunology, and neuroscience, the company is advancing a portfolio of programs that aim to remove toxic proteins, replace missing proteins, and restore immune and nerve cell function. Supported by biomarkers, Alector’s product candidates seek to treat a range of indications, such as Alzheimer’s disease and Parkinson's disease. The company is also developing Alector Brain Carrier (ABC), a proprietary blood-brain barrier platform, which is being applied to its preclinical and research pipeline. ABC aims to enhance the delivery of therapeutics, achieve deeper brain penetration and efficacy at lower doses, and ultimately improve patient outcomes while reducing costs. Alector is headquartered in South San Francisco, California. For more information, please visit www.alector.com. Forward-Looking Statements This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Forward-looking statements in this press release include, but are not limited to, statements regarding our business plans, business strategy, product candidates, research and preclinical pipeline, blood-brain barrier technology platform, planned and ongoing preclinical studies, planned clinical trials, expected milestones, and financial and cash guidance. Such statements are subject to numerous risks and uncertainties, including but not limited to risks and uncertainties as set forth in Alector’s Annual Reports on Form 10-K and Quarterly Reports on Form 10-Q, with the Securities and Exchange Commission (“SEC”), as well as the other documents Alector files from time to time with the SEC. These documents contain and identify important factors that could cause the actual results for Alector to differ materially from those contained in Alector’s forward-looking statements. Any forward-looking statements contained in this press release speak only as of the date hereof, and Alector specifically disclaims any obligation to update any forward-looking statement, except as required by law.

Advancing the Alector Brain Carrier (ABC) platform across multiple therapeutic modalities, including antibodies, enzymes, and siRNA, with continued progress across AL037/AL137 (ABC-enabled antibody for Alzheimer’s disease (AD)), AL050 (ABC-enabled GCase Enzyme Replacement Therapy for Parkinson’s disease (PD)), and AL064/AL164 (ABC-enabled Tau siRNA for AD and other tauopathies) $206.5 million in cash, cash equivalents and investments provide runway at least through 2027 SOUTH SAN FRANCISCO, Calif., May 07, 2026 (GLOBE NEWSWIRE) -- Alector, Inc. (Nasdaq: ALEC), a biotechnology company focused on developing therapies to counteract the devasting progression of neurodegeneration, today reported first quarter 2026 financial results and recent portfolio and business updates. As of March 31, 2026, Alector’s cash, cash equivalents, and investments totaled $206.5 million. “Over the past seven years, we have built a highly differentiated blood-brain barrier platform with the versatility to deliver antibodies, enzymes, proteins, and siRNA to the brain,” said Arnon Rosenthal, Ph.D., Chief Executive Officer of Alector. “We have a rich and growing pipeline of ABC-enabled programs, and we remain deeply committed to developing therapies that can make a meaningful difference for patients living with neurodegenerative diseases.” Recent Program Updates Alector Brain Carrier (ABC): Preclinical and Research Pipeline At the core of Alector’s strategy is the Alector Brain Carrier (ABC), the company’s proprietary platform designed to enhance the delivery of therapeutics to the brain. ABC is intended for peripheral dosing and is adaptable across multiple drug modalities, including antibodies, enzymes, and siRNA. The platform is built on core design principles of versatility, optimized binding properties, and translatability, with the goal of achieving efficient and targeted brain delivery while maintaining a favorable safety profile. Across multiple ABC-enabled programs, preclinical studies have demonstrated robust brain penetration, supporting the advancement of a broad pipeline aimed at addressing the underlying drivers of neurodegenerative diseases. AL037/AL137 Alector continues to advance AL037/AL137, its ABC-enabled anti-amyloid beta (Aβ) antibody program for the treatment of AD, through investigational new drug (IND)-enabling studies. The company is targeting an IND submission in Q1 2027. Both of our AL037 and AL137 candidates are engineered for optimal brain uptake, potency, safety, and convenience. Both candidates comprise the same high-affinity, fully human antibody that selectively binds PyroGlu3, a validated epitope on toxic amyloid beta found in plaques and retain an active effector function intended to facilitate myeloid-mediated plaque clearance. AL037 and AL137 each incorporates Alector’s proprietary ABC technology with TfR binding domains that bind the same epitope on TfR, but with different affinities and binding kinetics, to balance brain penetration and plaque removal with minimized hematologic adverse effects. AL050 Alector continues to progress AL050, its ABC-enabled engineered glucocerebrosidase (GCase) enzyme replacement therapy (ERT) for PD, through preclinical development. AL050 is designed to address key challenges associated with enzyme delivery to the brain, featuring an engineered GCase with improved activity and stability and a silenced effector function to maximize safety, paired with Alector’s tunable ABC technology. Preclinical studies to date have demonstrated increased GCase activity and reduced toxic substrate accumulation, supporting its continued preclinical development as a potential therapy for PD and Lewy body dementia (LBD) associated with GBA loss-of-function mutations and subsequently for idiopathic PD and LBD. We continue to evaluate our timeline to the clinic. ABC siRNA Platform Alector is advancing its ABC-enabled siRNA platform with the goal of making treatment more accessible by enabling peripheral dosing as a potential alternative to traditional intrathecal delivery. Alector continues to advance AL064/AL164, its ABC-enabled tau siRNA program for the treatment of AD and other tauopathies. AL064 demonstrated robust tau mRNA knockdown and durable reduction of phospho-Tau 217 in non-human primate studies, and it was subsequently modified to further optimize siRNA stability. This modified form is advancing into IND-enabling studies as AL164. In addition to AL164, the company is advancing early-stage siRNA programs toward lead candidate selection, including ADP062-ABC, an alpha-synuclein siRNA for PD and ADP065-ABC, an NLRP3 siRNA for multiple neurodegenerative conditions, reflecting the broad applicability of the ABC platform across disease mechanisms. Progranulin Program (nivisnebart (AL101/GSK4527226) The global, randomized, double-blind, placebo-controlled PROGRESS-AD Phase 2 clinical trial of nivisnebart (AL101/GSK4527226) in early AD has been discontinued following a pre-specified interim futility analysis. An independent data monitoring committee concluded that the trial was unlikely to meet its primary endpoint of slowing disease progression at completion. As the company’s platform and pipeline have continued to evolve, Alector remains focused on the significant opportunities ahead across its ABC-enabled programs. First Quarter 2026 Financial Results Revenue. Collaboration revenue for the quarter ended March 31, 2026, was $1.0 million, compared to $3.7 million for the same period in 2025. The decrease in year-over-year collaborative revenue was primarily due to lower manufacturing-related activity to support the Nivisnebart Phase 2 study in early Alzheimer’s disease. R&D Expenses. Total research and development expenses for the quarter ended March 31, 2026, were $17.9 million, compared to $33.6 million for the quarter ended March 31, 2025. The decrease was mainly due to a decrease in personnel-related costs as a result of the reductions in force as well as a decrease in research and development expenses for the AL002 program. G&A Expenses. Total general and administrative expenses for the quarter ended March 31, 2026, were $8.1 million, compared to $14.7 million for the quarter ended March 31, 2025. The decrease was mainly driven by a decrease in personnel-related costs as a result of the reductions in force. Net Loss. For the quarter ended March 31, 2026, Alector reported a net loss of $22.9 million, or $0.21 per share, compared to a net loss of $40.5 million, or $0.41 net loss per share, for the same period in 2025. Cash Position. Cash, cash equivalents, and investments were $206.5 million as of March 31, 2026. Management anticipates that this will be sufficient to fund Alector’s operations at least through 2027. About Alector Alector is a biotechnology company focused on developing therapies to counteract the devastating progression of neurodegenerative diseases. Leveraging the principles of genetics, immunology, and neuroscience, the company is advancing a portfolio of programs that aim to remove toxic proteins, replace missing proteins, and restore immune and nerve cell function. Supported by biomarkers, Alector’s product candidates seek to treat a range of indications, such as Alzheimer’s disease and Parkinson's disease. The company is also developing Alector Brain Carrier (ABC), a proprietary blood-brain barrier platform, which is being applied to its preclinical and research pipeline. ABC aims to enhance the delivery of therapeutics, achieve deeper brain penetration and efficacy at lower doses, and ultimately improve patient outcomes while reducing costs. Alector is headquartered in South San Francisco, California. For more information, please visit www.alector.com. Forward-Looking Statements This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Forward-looking statements in this press release include, but are not limited to, statements regarding our business plans, business strategy, product candidates, research and preclinical pipeline, blood-brain barrier technology platform, planned and ongoing preclinical studies, expected milestones, and financial and cash guidance. Such statements are subject to numerous risks and uncertainties, including but not limited to risks and uncertainties as set forth in Alector’s Annual Reports on Form 10-K and Quarterly Reports on Form 10-Q, with the Securities and Exchange Commission (“SEC”), as well as the other documents Alector files from time to time with the SEC. These documents contain and identify important factors that could cause the actual results for Alector to differ materially from those contained in Alector’s forward-looking statements. Any forward-looking statements contained in this press release speak only as of the date hereof, and Alector specifically disclaims any obligation to update any forward-looking statement, except as required by law. Selected Consolidated Balance Sheet Data (in thousands) Condensed Consolidated Statement of Operations Data (in thousands, except share and per share data) Alector Contacts: Argot Partners (media) David Rosen (646) 461-6387 [email protected] Argot Partners (investors) Laura Perry (212) 600-1902 [email protected]

The market expects Alector (ALEC) to deliver a year-over-year increase in earnings on lower revenues when it reports results for the quarter ended March 2026. This widely-known consensus outlook is important in assessing the company's earnings picture, but a powerful factor that might influence its near-term stock price is how the actual results compare to these estimates. The earnings report might help the stock move higher if these key numbers are better than expectations. On the other hand, if they miss, the stock may move lower. While management's discussion of business conditions on the earnings call will mostly determine the sustainability of the immediate price change and future earnings expectations, it's worth having a handicapping insight into the odds of a positive EPS surprise. This biotechnology company is expected to post quarterly loss of $0.35 per share in its upcoming report, which represents a year-over-year change of +14.6%. Revenues are expected to be $3 million, down 18.3% from the year-ago quarter. The consensus EPS estimate for the quarter has been revised 7.96% lower over the last 30 days to the current level. This is essentially a reflection of how the covering analysts have collectively reassessed their initial estimates over this period. Investors should keep in mind that the direction of estimate revisions by each of the covering analysts may not always get reflected in the aggregate change. Price, Consensus and EPS Surprise Estimate revisions ahead of a company's earnings release offer clues to the business conditions for the period whose results are coming out. This insight is at the core of our proprietary surprise prediction model -- the Zacks Earnings ESP (Expected Surprise Prediction). The Zacks Earnings ESP compares the Most Accurate Estimate to the Zacks Consensus Estimate for the quarter; the Most Accurate Estimate is a more recent version of the Zacks Consensus EPS estimate. The idea here is that analysts revising their estimates right before an earnings release have the latest information, which could potentially be more accurate than what they and others contributing to the consensus had predicted earlier. Thus, a positive or negative Earnings ESP reading theoretically indicates the likely deviation of the actual earnings from the consensus estimate. However, the model's predictive power is significant for positive ESP readings only. A positive Earnings ESP is a strong predictor of an earnings beat, particularly when combined with a Zacks Rank #1 (Strong Buy), 2 (Buy) or 3 (Hold). Our research shows that stocks with this combination produce a positive surprise nearly 70% of the time, and a solid Zacks Rank actually increases the predictive power of Earnings ESP. Please note that a negative Earnings ESP reading is not indicative of an earnings miss. Our research shows that it is difficult to predict an earnings beat with any degree of confidence for stocks with negative Earnings ESP readings and/or Zacks Rank of 4 (Sell) or 5 (Strong Sell). For Alector, the Most Accurate Estimate is lower than the Zacks Consensus Estimate, suggesting that analysts have recently become bearish on the company's earnings prospects. This has resulted in an Earnings ESP of -18.57%. On the other hand, the stock currently carries a Zacks Rank of #4. So, this combination makes it difficult to conclusively predict that Alector will beat the consensus EPS estimate. While calculating estimates for a company's future earnings, analysts often consider to what extent it has been able to match past consensus estimates. So, it's worth taking a look at the surprise history for gauging its influence on the upcoming number. For the last reported quarter, it was expected that Alector would post a loss of$0.39 per share when it actually produced a loss of -$0.34, delivering a surprise of +12.82%. Over the last four quarters, the company has beaten consensus EPS estimates four times. An earnings beat or miss may not be the sole basis for a stock moving higher or lower. Many stocks end up losing ground despite an earnings beat due to other factors that disappoint investors. Similarly, unforeseen catalysts help a number of stocks gain despite an earnings miss. That said, betting on stocks that are expected to beat earnings expectations does increase the odds of success. This is why it's worth checking a company's Earnings ESP and Zacks Rank ahead of its quarterly release. Make sure to utilize our Earnings ESP Filter to uncover the best stocks to buy or sell before they've reported. Alector doesn't appear a compelling earnings-beat candidate. However, investors should pay attention to other factors too for betting on this stock or staying away from it ahead of its earnings release. Among the stocks in the Zacks Medical - Biomedical and Genetics industry, MeiraGTx Holdings PLC (MGTX), is soon expected to post loss of $0.43 per share for the quarter ended March 2026. This estimate indicates a year-over-year change of +15.7%. This quarter's revenue is expected to be $1.55 million, down 19.7% from the year-ago quarter. The consensus EPS estimate for MeiraGTx has been revised 6.5% higher over the last 30 days to the current level. However, a lower Most Accurate Estimate has resulted in an Earnings ESP of -48.84%. When combined with a Zacks Rank of #3 (Hold), this Earnings ESP makes it difficult to conclusively predict that MeiraGTx will beat the consensus EPS estimate. Over the last four quarters, the company surpassed consensus EPS estimates two times. Stay on top of upcoming earnings announcements with the Zacks Earnings Calendar. Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report Alector, Inc. (ALEC) : Free Stock Analysis Report MeiraGTx Holdings PLC (MGTX) : Free Stock Analysis Report This article originally published on Zacks Investment Research (zacks.com). Zacks Investment Research

Advancing the Alector Brain Carrier (ABC) platform across multiple therapeutic modalities, including antibodies, enzymes, and siRNA, with continued progress across AL137 (ABC-enabled anti-amyloid antibody for Alzheimer’s Disease), AL050 (ABC-enabled GCase Enzyme Replacement Therapy for Parkinson’s Disease) and AL064 (ABC-enabled Tau siRNA for Alzheimer’s Disease) Independent interim futility analysis of the PROGRESS-AD Phase 2 trial of nivisnebart (AL101) in early Alzheimer’s disease expected in the first half of 2026 $256.0 million in cash, cash equivalents and investments provide runway at least through 2027 SOUTH SAN FRANCISCO, Calif., Feb. 25, 2026 (GLOBE NEWSWIRE) -- Alector, Inc. (Nasdaq: ALEC), a clinical-stage biotechnology company focused on developing therapies to counteract the devastating progression of neurodegeneration, today reported fourth quarter and full year 2025 financial results and recent portfolio and business updates. As of December 31, 2025, Alector’s cash, cash equivalents, and investments totaled $256.0 million. “Alector’s strength lies in the combination of a highly differentiated blood-brain barrier platform and a team with deep experience executing complex neurodegenerative programs,” said Arnon Rosenthal, Ph.D., Chief Executive Officer of Alector. “Following more than six years of focused investment in our ABC technology, we believe the breadth, flexibility, and tunability of our ABC platform position us to translate scientific innovation into exciting clinical-stage assets. At the same time, we continue to advance the PROGRESS-AD Phase 2 trial of nivisnebart (AL101) in early Alzheimer’s disease, together with GSK, toward an independent interim futility analysis in the first half of 2026.” Recent Program Updates Alector Brain Carrier (ABC): Preclinical and Research Pipeline Alector’s pipeline leverages its proprietary blood-brain barrier platform, Alector Brain Carrier (ABC), which has been developed to enhance the delivery of therapeutics to the brain. ABC is designed to enable peripheral dosing and is adaptable across multiple drug modalities, including antibodies, enzymes, and siRNA. Built on core design principles of versatility, optimized binding properties, and translatability, ABC is intended to enable targeted brain delivery with improved safety and efficacy. ABC-enabled candidates have demonstrated robust brain penetration in preclinical studies, providing the basis for advancing multiple programs targeting neurodegenerative diseases. AL137 Alector continues to advance AL137, its lead ABC-enabled anti-amyloid beta (Aβ) antibody for the treatment of AD, through investigational new drug (IND)-enabling studies. The company expects to file an IND application in Q4 2026 / Q1 2027, based on the timing of GMP clinical supply production. AL137 is engineered for optimal brain uptake, potency, safety, and convenience. The candidate comprises a high-affinity, fully human antibody that selectively binds PyroGlu3, a validated epitope on toxic amyloid beta found in plaques and retains an active effector function intended to facilitate myeloid-mediated plaque clearance. AL137 incorporates Alector’s proprietary ABC technology with tuned transferrin receptor binding, designed to facilitate brain penetration and plaque removal while minimizing hematologic effects. In preclinical studies to date, AL137 has demonstrated robust brain uptake at low doses, supporting further advancement and the potential for low-dose, subcutaneous administration. AL050 Alector continues to progress AL050, its ABC-enabled engineered glucocerebrosidase (GCase) enzyme replacement therapy (ERT) for PD, through preclinical development. The company is targeting submission of an IND application in 2027. AL050 is designed to address key challenges associated with enzyme delivery to the brain, featuring an engineered GCase with improved activity and stability and a silenced effector function to maximize safety, paired with Alector’s tunable ABC technology. Preclinical studies to date have demonstrated increased GCase activity and reduced toxic substrate accumulation, supporting its continued preclinical development as a potential therapy for PD and Lewy body dementia associated with GBA loss-of-function mutations. ABC siRNA Platform Alector continues to advance its ABC-enabled siRNA platform, which is designed to enable peripheral dosing, offering the potential for more convenient administration compared with traditional intrathecal delivery. Alector has selected lead candidate, AL064 for its ABC-enabled tau siRNA program for the treatment of AD and other tauopathies and is advancing it to IND-enabling studies. In addition to AL064, the company is advancing early-stage siRNA programs toward lead candidate selection, including ADP062-ABC (PD), an alpha-synuclein siRNA, and ADP065-ABC (multiple neurodegenerative conditions), an NLRP3 siRNA, reflecting the broad applicability of the ABC platform across disease mechanisms. Progranulin Programs (nivisnebart (AL101/GSK4527226) and latozinemab (AL001)) in Collaboration with GSK Nivisnebart (AL101/GSK4527226) The global, randomized, double blind, placebo-controlled PROGRESS-AD Phase 2 clinical trial of nivisnebart (AL101/GSK4527226) in early AD remains ongoing. An independent interim futility analysis for the PROGRESS-AD trial is planned for the first half of 2026. Nivisnebart is an investigational human monoclonal antibody designed to block and internalize the sortilin receptor, leading to increased levels of progranulin (PGRN) in the brain. It has pharmacokinetic and pharmacodynamic properties that may make it suitable for the potential treatment of more prevalent neurodegenerative diseases. Latozinemab (AL001) Alector plans to present the results from the INFRONT-3 Phase 3 clinical trial at an upcoming scientific meeting in 1H 2026. Fourth Quarter 2025 Financial Results Revenue. Collaboration revenue for the quarter ended December 31, 2025, was $6.2 million, compared to $54.2 million for the same period in 2024. Collaboration revenue for the year ended December 31, 2025, was $21.0 million, compared to $100.6 million for the same period in 2024. The decrease in year-over-year collaborative revenue was primarily due to the satisfaction of the performance obligations associated with the AL002 program and the latozinemab FTD-C9orf72 Phase 2 trial in the fourth quarter of 2024, resulting in lower revenue recognized in 2025. R&D Expenses. Total research and development expenses for the quarter ended December 31, 2025, were $32.5 million, compared to $46.5 million for the same period in 2024. Total research and development expenses for the year ended December 31, 2025, were $123.1 million compared to $185.9 million for the same period in 2024. The decrease in year-over-year R&D expenses was mainly due to a decrease in research and development expenses for the AL002 program as well as a decrease in personnel related costs as a result of the reductions in force. G&A Expenses. Total general and administrative expenses for the quarter ended December 31, 2025, were $13.3 million compared to $15.0 million for the same period in 2024. Total general and administrative expenses for the year ended December 31, 2025, were $54.0 million compared to $59.6 million for the same period in 2024. The decrease in year-over-year G&A expenses was primarily due to a decrease in personnel related costs as a result of the reductions in force. Net Loss. For the quarter ended December 31, 2025, Alector reported a net loss of $37.3 million, or $0.34 net loss per share, compared to a net loss of $2.1 million, or $0.02 net loss per share, for the same period in 2024. For the year ended December 31, 2025, Alector reported a net loss of $142.9 million or $1.39 net loss per share, compared to a net loss of $119.0 million or $1.23 net loss per share, for the same period in 2024. Cash Position. Cash, cash equivalents, and investments were $256.0 million as of December 31, 2025. Management expects that this will be sufficient to fund current operations at least through 2027. About Alector Alector is a clinical-stage biotechnology company focused on developing therapies to counteract the devastating progression of neurodegenerative diseases. Leveraging the principles of genetics, immunology, and neuroscience, the company is advancing a portfolio of programs that aim to remove toxic proteins, replace missing proteins, and restore immune and nerve cell function. Supported by biomarkers, Alector’s product candidates seek to treat a range of indications, such as Alzheimer’s disease, Parkinson's disease, and frontotemporal dementia. The company is also developing Alector Brain Carrier (ABC), a proprietary blood-brain barrier platform, which is being applied to its preclinical and research pipeline. ABC aims to enhance the delivery of therapeutics, achieve deeper brain penetration and efficacy at lower doses, and ultimately improve patient outcomes while reducing costs. Alector is headquartered in South San Francisco, California. For more information, please visit www.alector.com. Forward-Looking Statements This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Forward-looking statements in this press release include, but are not limited to, statements regarding our business plans, business strategy, product candidates, research and preclinical pipeline, blood-brain barrier technology platform, planned and ongoing preclinical studies and clinical trials, anticipated timing of and detail regarding release of data for PROGRESS-AD, expected milestones, expectations of our collaborations and financial and cash guidance. Such statements are subject to numerous risks and uncertainties, including but not limited to risks and uncertainties as set forth in Alector’s Annual Reports on Form 10-K and Quarterly Reports on Form 10-Q, with the Securities and Exchange Commission (“SEC”), as well as the other documents Alector files from time to time with the SEC. These documents contain and identify important factors that could cause the actual results for Alector to differ materially from those contained in Alector’s forward-looking statements. Any forward-looking statements contained in this press release speak only as of the date hereof, and Alector specifically disclaims any obligation to update any forward-looking statement, except as required by law. Alector Contacts: Argot Partners (media) David Rosen (212) 600-1494 [email protected] Argot Partners (investors) Laura Perry (212) 600-1902 [email protected]

Selected lead candidates AL137 for the company’s Alector Brain Carrier (ABC)-enabled anti-amyloid beta antibody in Alzheimer's disease, and AL050 for its ABC-enabled GCase enzyme replacement therapy in Parkinson’s disease; both advancing toward IND-enabling studies Advancing ABC-enabled Tau, Alpha Synuclein and NLRP3 siRNA programs targeting peripheral delivery of novel therapies for neurodegenerative disorders Independent interim analysis for the PROGRESS-AD Phase 2 clinical trial of nivisnebart (AL101) in early Alzheimer’s disease planned for 1H 2026 $291.1 million in cash, cash equivalents, and investments provides runway through 2027 SOUTH SAN FRANCISCO, Calif., Nov. 06, 2025 (GLOBE NEWSWIRE) -- Alector, Inc. (Nasdaq: ALEC), a clinical-stage biotechnology company focused on developing therapies to counteract the devastating progression of neurodegeneration, today reported third quarter 2025 financial results and recent portfolio and business updates. As of September 30, 2025, Alector’s cash, cash equivalents, and investments totaled $291.1 million. “We are well-resourced to advance our portfolio of innovative drug candidates for the treatment of neurodegenerative diseases, with a sharpened focus on our differentiated Alector Brain Carrier (ABC) platform,” said Arnon Rosenthal, Ph.D., Chief Executive Officer of Alector. “ABC represents an important driver of innovation, with the versatility to deliver antibodies, enzymes and nucleic acid to the brain. Our ABC-enabled programs have demonstrated robust brain penetration through peripheral dosing, favorable safety, and good pharmacokinetics. We are advancing AL137, our ABC-enabled anti-amyloid beta antibody, AL050, our ABC-enabled GCase enzyme replacement therapy, and ADP064, our ABC-enabled Tau siRNA, toward IND-enabling studies, with IND submissions targeted in 2026 and 2027.” Dr. Rosenthal continued, “Additionally, together with GSK, we continue to advance the Phase 2 PROGRESS-AD trial for nivisnebart (AL101), an investigational monoclonal antibody being studied for the treatment of Alzheimer’s disease. We remain on track for an independent interim analysis planned for the first half of 2026.” Recent Program Updates Alector Brain Carrier: Preclinical and Research Pipeline A key pillar of Alector’s focus is its proprietary blood-brain barrier (BBB) technology platform, Alector Brain Carrier (ABC). Built on the core design principles of versatility, tunability, and differentiated binding to a distinct region of the transferrin receptor (TfR), ABC is intended to support the targeted delivery of therapeutics to the brain and to optimize safety and efficacy. The platform’s tunable TfR binding affinities allow adjustment of binding strength and drug configuration to align with the needs of diverse therapeutic cargos, including antibodies, enzymes, and siRNA, aiming to achieve efficient transport across the BBB with the goal of balancing brain uptake and safety. AL137 Alector has selected lead candidate AL137 for its ABC-enabled anti-amyloid beta (Aβ) antibody in Alzheimer’s disease (AD) and is advancing it toward investigational new drug (IND)-enabling studies. The company is targeting an IND filing for AL137 in 2026. AL137 is engineered for optimal brain uptake, potency, safety, and convenience. This candidate features a high-affinity, humanized antibody that selectively binds PyroGlu3, a validated epitope on the toxic form of Aβ found in plaques, a fully active effector function that enables maximal recruitment of myeloid cells to remove plaques, and Alector’s proprietary ABC with tuned affinity and binding epitope designed to facilitate brain penetration and plaque removal while minimizing hematologic adverse effects. In preclinical studies to date, AL137 has demonstrated robust brain penetration at low doses, supporting the potential for low dose, subcutaneous administration. AL050 Alector has selected lead candidate AL050 for its ABC-enabled glucocerebrosidase (GCase) enzyme replacement therapy (ERT) in Parkinson’s disease (PD) and is advancing the candidate toward IND-enabling studies. The company is targeting submission of an IND application for AL050 in 2027. AL050 is an ABC-enabled GCase ERT engineered to address the key challenges of enzyme replacement for the brain. It features an engineered GCase with improved activity and stability, a silenced effector function to maximize safety, and Alector’s tunable ABC with a TfR epitope and affinity designed to enhance delivery across the BBB. In preclinical studies to date, AL050 increased GCase activity in both rodents and NHPs and reduced toxic substrate accumulation in a rodent GBA disease model with no apparent hematologic findings, supporting its potential as a therapy for Parkinson’s disease and Lewy body dementia associated with GBA loss-of-function mutations. ABC siRNA Platform The company also continues to advance its ABC-enabled siRNA platform. The platform is designed for peripheral dosing, offering the potential for more convenient administration compared with traditional intrathecal or intracerebroventricular delivery, as well as homogeneous drug distribution throughout the brain. Current programs include Alector’s lead siRNA program, ADP064-ABC, an anti-tau siRNA for AD and other tauopathies, as well as ADP062-ABC, an alpha-synuclein siRNA for PD and eventually Lewy body dementia; and ADP065-ABC, an NLRP3 siRNA, for a range of neurodegenerative diseases. Progranulin Programs (nivisnebart (AL101/GSK4527226) and latozinemab (AL001)) in Collaboration with GSK Nivisnebart (AL101/GSK4527226) The 76-week, global, randomized, double-blind, placebo-controlled PROGRESS-AD Phase 2 clinical trial of nivisnebart (AL101/GSK4527226) in early AD is ongoing, with enrollment completed in April 2025. An independent interim analysis is planned for the first half of 2026. Nivisnebart is an investigational human monoclonal antibody (mAb) designed to block and internalize the sortilin receptor to elevate the concentrations of progranulin (PGRN) in the brain. It is distinct from latozinemab, with differentiated pharmacokinetic and pharmacodynamic properties that may make it suitable for the potential treatment of more prevalent neurodegenerative diseases. Latozinemab In October 2025, Alector and GSK announced topline results from the INFRONT-3 Phase 3 clinical trial of latozinemab for the potential treatment of frontotemporal dementia due to a GRN gene mutation (FTD-GRN). The study did not demonstrate clinical benefit. Based on these results, the open-label extension portion of the INFRONT-3 trial and the continuation study for latozinemab will be discontinued. Corporate News In October 2025, the company implemented a reduction in force of approximately 47% intended to focus the company’s resources on its highest-priority programs, to ensure continued progress across its portfolio, and extend cash runway through 2027. Third Quarter 2025 Financial Results Revenue. Collaboration revenue for the quarter ended September 30, 2025, was $3.3 million, compared to $15.3 million for the same period in 2024. The decrease was mainly due to the satisfaction of the performance obligation associated with the AL002 program and the latozinemab FTD-C9orf72 Phase 2 trial in the fourth quarter of 2024. R&D Expenses. Total research and development expenses for the quarter ended September 30, 2025, were $29.4 million, compared to $48.0 million for the quarter ended September 30, 2024. The decrease was mainly due to a decrease in research and development expenses for the AL002 program as well as a decrease in personnel related costs as a result of the reductions in force. G&A Expenses. Total general and administrative expenses for the quarter ended September 30, 2025, were $11.5 million, compared to $15.8 million for the quarter ended September 30, 2024. The decrease was mainly driven by the absence of impairment charges related to the right-of-use asset and leasehold improvements recognized in the third quarter of 2024. No comparable impairment occurred in the current period. Additionally, personnel-related costs declined as a result of the reductions in force. Net Loss. For the quarter ended September 30, 2025, Alector reported a net loss of $34.7 million, or $0.34 per share, compared to a net loss of $42.2 million, or $0.43 net loss per share, for the same period in 2024. Cash Position. Cash, cash equivalents, and investments were $291.1 million as of September 30, 2025. This includes approximately $14.7 million in net proceeds raised through the company’s at-the-market (ATM) equity offering in September. In October 2025, the company raised $5.3 million in ATM equity offerings. Management anticipates that its current cash position will be sufficient to fund Alector’s operations through 2027. 2025 Guidance. The company continues to anticipate collaboration revenue to be between $13 million and $18 million, total research and development expenses to be between $130 million and $140 million, and total general and administrative expenses to be between $55 million and $65 million. About Alector Alector is a clinical-stage biotechnology company focused on developing therapies to counteract the devastating progression of neurodegenerative diseases. Leveraging the principles of genetics, immunology, and neuroscience, the company is advancing a portfolio of programs that aim to remove toxic proteins, replace missing proteins, and restore immune and nerve cell function. Supported by biomarkers, Alector’s product candidates seek to treat a range of indications, such as Alzheimer’s disease, Parkinson's disease, and frontotemporal dementia. The company is also developing Alector Brain Carrier (ABC), a proprietary blood-brain barrier platform, which is being selectively applied to its preclinical and research pipeline. ABC aims to enhance the delivery of therapeutics, achieve deeper brain penetration and efficacy at lower doses, and ultimately improve patient outcomes while reducing costs. Alector is headquartered in South San Francisco, California. For more information, please visit www.alector.com. Forward-Looking Statements This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Forward-looking statements in this press release include, but are not limited to, statements regarding our business plans, business strategy, workforce reduction, product candidates, research and preclinical pipeline, blood-brain barrier technology platform, planned and ongoing preclinical studies and clinical trials, anticipated timing of and detail regarding release of data for PROGRESS-AD, expected milestones, expectations of our collaborations and financial and cash guidance. Such statements are subject to numerous risks and uncertainties, including but not limited to risks and uncertainties as set forth in Alector’s Annual Reports on Form 10-K and Quarterly Reports on Form 10-Q, with the Securities and Exchange Commission (“SEC”), as well as the other documents Alector files from time to time with the SEC. These documents contain and identify important factors that could cause the actual results for Alector to differ materially from those contained in Alector’s forward-looking statements. Any forward-looking statements contained in this press release speak only as of the date hereof, and Alector specifically disclaims any obligation to update any forward-looking statement, except as required by law. Alector Contacts: Argot Partners (media) David Rosen 646-461-6387 [email protected] Argot Partners (investors) Laura Perry 212-600-1902 [email protected]

The market expects Alector (ALEC) to deliver a year-over-year increase in earnings on lower revenues when it reports results for the quarter ended September 2025. This widely-known consensus outlook is important in assessing the company's earnings picture, but a powerful factor that might influence its near-term stock price is how the actual results compare to these estimates. The earnings report might help the stock move higher if these key numbers are better than expectations. On the other hand, if they miss, the stock may move lower. While management's discussion of business conditions on the earnings call will mostly determine the sustainability of the immediate price change and future earnings expectations, it's worth having a handicapping insight into the odds of a positive EPS surprise. This biotechnology company is expected to post quarterly loss of $0.42 per share in its upcoming report, which represents a year-over-year change of +2.3%. Revenues are expected to be $2.63 million, down 82.9% from the year-ago quarter. The consensus EPS estimate for the quarter has been revised 3.13% lower over the last 30 days to the current level. This is essentially a reflection of how the covering analysts have collectively reassessed their initial estimates over this period. Investors should keep in mind that the direction of estimate revisions by each of the covering analysts may not always get reflected in the aggregate change. Price, Consensus and EPS Surprise Estimate revisions ahead of a company's earnings release offer clues to the business conditions for the period whose results are coming out. Our proprietary surprise prediction model -- the Zacks Earnings ESP (Expected Surprise Prediction) -- has this insight at its core. The Zacks Earnings ESP compares the Most Accurate Estimate to the Zacks Consensus Estimate for the quarter; the Most Accurate Estimate is a more recent version of the Zacks Consensus EPS estimate. The idea here is that analysts revising their estimates right before an earnings release have the latest information, which could potentially be more accurate than what they and others contributing to the consensus had predicted earlier. Thus, a positive or negative Earnings ESP reading theoretically indicates the likely deviation of the actual earnings from the consensus estimate. However, the model's predictive power is significant for positive ESP readings only. A positive Earnings ESP is a strong predictor of an earnings beat, particularly when combined with a Zacks Rank #1 (Strong Buy), 2 (Buy) or 3 (Hold). Our research shows that stocks with this combination produce a positive surprise nearly 70% of the time, and a solid Zacks Rank actually increases the predictive power of Earnings ESP. Please note that a negative Earnings ESP reading is not indicative of an earnings miss. Our research shows that it is difficult to predict an earnings beat with any degree of confidence for stocks with negative Earnings ESP readings and/or Zacks Rank of 4 (Sell) or 5 (Strong Sell). For Alector, the Most Accurate Estimate is lower than the Zacks Consensus Estimate, suggesting that analysts have recently become bearish on the company's earnings prospects. This has resulted in an Earnings ESP of -5.77%. On the other hand, the stock currently carries a Zacks Rank of #3. So, this combination makes it difficult to conclusively predict that Alector will beat the consensus EPS estimate. While calculating estimates for a company's future earnings, analysts often consider to what extent it has been able to match past consensus estimates. So, it's worth taking a look at the surprise history for gauging its influence on the upcoming number. For the last reported quarter, it was expected that Alector would post a loss of$0.45 per share when it actually produced a loss of -$0.30, delivering a surprise of +33.33%. Over the last four quarters, the company has beaten consensus EPS estimates four times. An earnings beat or miss may not be the sole basis for a stock moving higher or lower. Many stocks end up losing ground despite an earnings beat due to other factors that disappoint investors. Similarly, unforeseen catalysts help a number of stocks gain despite an earnings miss. That said, betting on stocks that are expected to beat earnings expectations does increase the odds of success. This is why it's worth checking a company's Earnings ESP and Zacks Rank ahead of its quarterly release. Make sure to utilize our Earnings ESP Filter to uncover the best stocks to buy or sell before they've reported. Alector doesn't appear a compelling earnings-beat candidate. However, investors should pay attention to other factors too for betting on this stock or staying away from it ahead of its earnings release. Another stock from the Zacks Medical - Biomedical and Genetics industry, AC Immune (ACIU), is soon expected to post loss of $0.22 per share for the quarter ended September 2025. This estimate indicates a year-over-year change of -466.7%. Revenues for the quarter are expected to be $1.52 million, down 94.8% from the year-ago quarter. The consensus EPS estimate for AC Immune has been revised 4.3% higher over the last 30 days to the current level. However, a lower Most Accurate Estimate has resulted in an Earnings ESP of -4.55%. When combined with a Zacks Rank of #3 (Hold), this Earnings ESP makes it difficult to conclusively predict that AC Immune will beat the consensus EPS estimate. Over the last four quarters, the company surpassed consensus EPS estimates three times. Stay on top of upcoming earnings announcements with the Zacks Earnings Calendar. Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report Alector, Inc. (ALEC) : Free Stock Analysis Report AC Immune (ACIU) : Free Stock Analysis Report This article originally published on Zacks Investment Research (zacks.com). Zacks Investment Research

SOUTH SAN FRANCISCO, Calif., Oct. 21, 2025 (GLOBE NEWSWIRE) -- Alector, Inc. (Nasdaq: ALEC), a clinical-stage biotechnology company focused on developing therapies to counteract the devastating progression of neurodegeneration, today announced results from the Phase 3 INFRONT-3 clinical trial evaluating latozinemab (AL001) in individuals with frontotemporal dementia due to a progranulin gene mutation (FTD-GRN). In the 96-week, double-blind INFRONT-3 trial, latozinemab, developed in collaboration with GSK, did not meet the clinical co-primary endpoint of slowing FTD-GRN progression, as measured by the Clinical Dementia Rating® plus National Alzheimer’s Coordinating Center Frontotemporal Lobar Degeneration Sum of Boxes (CDR® plus NACC FTLD-SB). Although treatment resulted in a statistically significant effect on the biomarker co-primary endpoint of plasma progranulin (PGRN) concentrations, the secondary and exploratory endpoints, such as fluid biomarkers and volumetric magnetic resonance imaging (vMRI), demonstrated no treatment-related effects on FTD-GRN. Preliminary safety data have not highlighted any major safety concerns at present. More in-depth analysis of the data is ongoing. “While latozinemab did not demonstrate a clinical benefit in INFRONT-3, the insights gained are invaluable for understanding progranulin-related neurodegeneration," said Giacomo Salvadore, M.D., Chief Medical Officer of Alector. "We extend our deepest gratitude to the patients, caregivers, and investigators who made this trial possible, and we plan to share the results with the scientific community to support continued progress in understanding progranulin biology and FTD pathophysiology.” Based on these results, the open-label extension portion of the INFRONT-3 trial and the continuation study for latozinemab will be discontinued. The INFRONT-3 trial results will be presented at an upcoming medical congress. Alector Pipeline Outlook Alector remains focused on advancing a pipeline of programs designed to treat neurodegenerative diseases through mechanisms that remove toxic proteins, replace deficient proteins, and restore immune and neuronal function. In the ongoing collaboration with GSK, nivisnebart (AL101/GSK4527226) is being evaluated in PROGRESS-AD, a global, 76-week Phase 2 clinical trial in individuals with early Alzheimer’s disease (AD). Enrollment was completed in April 2025, and trial completion is expected in 2026. An independent interim analysis is planned for the first half of 2026. A key pillar of Alector’s focus is its proprietary blood-brain barrier (BBB) technology platform, Alector Brain Carrier (ABC). Built on the core design principles of versatility, tunability, and differentiated binding to a distinct region of the transferrin receptor (TfR), ABC is intended to support the targeted delivery of therapeutics to the brain and to optimize safety and efficacy at lower doses. The platform’s tunable TfR binding affinities allow adjustment of binding strength to align with the needs of diverse therapeutic cargos, including antibodies, enzymes, proteins, and siRNA, aiming to achieve efficient transport across the BBB with the goal of balancing brain uptake, potency, and safety. Alector is progressing multiple preclinical programs enabled by ABC and has selected lead candidate AL137 for its ABC-enabled anti-amyloid beta (Aβ) antibody program in AD, and AL050 for its ABC-enabled glucocerebrosidase (GCase) enzyme replacement therapy program in Parkinson’s disease (PD). The company is targeting submission of investigational new drug (IND) applications for AL137 in 2026 and for AL050 in 2027. Alector is also continuing to advance its ABC-enabled siRNA platform. The platform is being designed for peripheral dosing, offering the potential for more convenient administration compared with traditional intrathecal or intracerebroventricular delivery. The most advanced siRNA program is ADP064-ABC, targeting tau for the potential treatment of AD and FTD. Collectively, these programs reflect Alector’s continued commitment to advancing innovative approaches to treat neurodegenerative diseases. Alector Executive Leadership and Business Update To align resources with these strategic priorities, Alector is reducing its workforce by approximately 49%. This is intended to focus the company’s resources on its highest-priority programs and to ensure continued progress across its portfolio. Alector thanks all employees affected by these measures for their dedication and contributions to the company’s mission. In parallel, Sara Kenkare-Mitra, Ph.D., President and Head of Research and Development (R&D), has resigned from her role, effective December 22, 2025, to pursue new leadership opportunities. She will remain with Alector until then to ensure a smooth transition and continuity across the R&D organization. The company is deeply appreciative of Dr. Kenkare-Mitra for her leadership and impactful contributions to Alector. “Sara has been an extraordinary builder and operator who transformed Alector into a mature, fully integrated R&D organization,” said Arnon Rosenthal, Ph.D., Chief Executive Officer of Alector. “Her sage leadership has been critical for the successful execution of our preclinical and clinical pipeline programs. Sara’s integrity and vision have left a lasting mark on the science, culture, and people at Alector, and we wish her continued success in her next chapter.” Alector estimates that it had approximately $291.1 million in cash, cash equivalents, and short-term investments as of September 30, 2025, which the company expects will provide runway through 2027. Alector plans to issue guidance for 2026 when it reports fourth quarter and full year 2025 financial results. About INFRONT-3 INFRONT-3 (ClinicalTrials.gov identifier NCT04374136) was a pivotal, randomized, double-blind, placebo-controlled Phase 3 clinical trial evaluating the safety and efficacy of latozinemab (AL001) in slowing disease progression in individuals with frontotemporal dementia due to a progranulin gene mutation (FTD-GRN). The trial enrolled symptomatic and at-risk FTD-GRN participants at multiple sites across North America, Europe, Argentina, and the Asia-Pacific region. The primary analysis was conducted in symptomatic participants only, in alignment with regulatory guidance from the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA). Based on the FDA’s recommendation, Alector and GSK amended the statistical analysis plan in the U.S. to include plasma progranulin (PGRN) concentration as a co-primary endpoint along with the Clinical Dementia Rating® plus National Alzheimer’s Coordinating Center Frontotemporal Lobar Degeneration Sum of Boxes (CDR® plus NACC FTLD-SB). This designation of plasma PGRN as a co-primary endpoint does not apply outside the United States. Participants were randomized to receive 60 mg/kg of latozinemab or placebo intravenously every four weeks over the 96-week treatment period (Part 1, the double-blind period). Following completion of Part 1, participants could either enter a 10-week safety follow-up or roll over into a 96-week open-label extension (OLE) study. Those who completed the OLE had the option to roll over into a continuation study (ClinicalTrials.gov identifier NCT06111014). About Alector Alector is a clinical-stage biotechnology company focused on developing therapies to counteract the devastating progression of neurodegenerative diseases. Leveraging the principles of genetics, immunology, and neuroscience, the company is advancing a portfolio of programs that aim to remove toxic proteins, replace missing proteins, and restore immune and nerve cell function. Supported by biomarkers, Alector’s product candidates seek to treat a range of indications, such as Alzheimer’s disease, Parkinson's disease, and frontotemporal dementia. The company is also developing Alector Brain Carrier (ABC), a proprietary blood-brain barrier platform, which is being selectively applied to its preclinical and research pipeline. ABC aims to enhance the delivery of therapeutics, achieve deeper brain penetration and efficacy at lower doses, and ultimately improve patient outcomes while reducing costs. Alector is headquartered in South San Francisco, California. For more information, please visit www.alector.com. Forward-Looking Statements This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Forward-looking statements in this press release include, but are not limited to, statements regarding our business plans, business strategy, workforce reduction, product candidates, research and preclinical pipeline, blood-brain barrier technology platform, planned and ongoing preclinical studies and clinical trials, anticipated timing of and detail regarding release of data for PROGRESS-AD, expected milestones, expectations of our collaborations and financial and cash guidance. Such statements are subject to numerous risks and uncertainties, including but not limited to risks and uncertainties as set forth in Alector’s Annual Reports on Form 10-K and Quarterly Reports on Form 10-Q, with the Securities and Exchange Commission (“SEC”), as well as the other documents Alector files from time to time with the SEC. These documents contain and identify important factors that could cause the actual results for Alector to differ materially from those contained in Alector’s forward-looking statements. Any forward-looking statements contained in this press release speak only as of the date hereof, and Alector specifically disclaims any obligation to update any forward-looking statement, except as required by law. Alector Contacts: Alector Katie Hogan 202-549-0557 [email protected] Argot Partners (media) David Rosen 646-461-6387 [email protected] Argot Partners (investors) Laura Perry 212-600-1902 [email protected]