Cambridge, Massachusetts, Aug. 03, 2026 (GLOBE NEWSWIRE) -- ProMIS Neurosciences Inc. (Nasdaq: PMN), a clinical-stage biotechnology company developing antibody therapeutics and vaccines targeting toxic misfolded proteins in neurodegenerative diseases, today announced it will report financial results for the second quarter ended June 30, 2026, and provide corporate updates on August 13, 2026.

The company will host a conference call and webcast on the same day of August 13, 2026 at 4:30 p.m. ET.

Conference Call and Webcast Information: 

A replay of the webcast will be available in the Investors section of the ProMIS website following the completion of the call.

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 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).

For further information:
Visit us at www.promisneurosciences.com

Media Contact
Maggie Whitney
LifeSci Communications
mwhitney@lifescicomms.com

Investor Relations Contact
Carie Pierce
VP Investor Relations & External Affairs
IR@ProMISNeurosciences.com

ARIA-H tracking background rates

Early biomarker movement consistent with target engagement

12-month topline results expected in Q1 2027

Cambridge, Massachusetts, July 28, 2026 (GLOBE NEWSWIRE) -- ProMIS Neurosciences Inc. (Nasdaq: PMN), a clinical-stage biopharmaceutical company developing therapeutics that selectively target toxic misfolded proteins in neurodegenerative diseases, today announced positive blinded six-month interim safety and biomarker results from PRECISE-AD, the Phase 1b trial of its lead drug candidate, PMN310, in patients with mild cognitive impairment due to Alzheimer’s disease or mild Alzheimer’s disease (AD).

In the blinded interim analysis evaluating 136 AD patients, PMN310 was observed to have a favorable safety profile across all genotypes, with no cases of amyloid-related imaging abnormalities-edema (ARIA-E) reported as of the data cutoff date, and early, directionally consistent movement in disease-relevant biomarkers potentially reflective of the randomization pattern. The trial remains blinded and ongoing with topline 12-month results expected in the first quarter of 2027.

Interim Highlights

• Favorable safety profile across all genotypes: No ARIA-E and 4.4% 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.
  
  
• Same profile in high-risk APOE4 carriers: No ARIA-E observed in any genotype in a population that included 61% APOE4 carriers, of which 11% were homozygotes, a group underserved by approved amyloid-directed therapies.
  
  
• Early biomarker movement consistent with target engagement: On a blinded basis, a majority of patients showed reductions in disease-relevant biomarkers against expected increases in natural-history trajectories: 68.5% of patients had a decline from baseline (change ≤ 0) in plasma pTau217 and 62.5% had a decline in CSF MTBR-tau243, consistent with a potential beneficial drug effect and potentially reflective of the trial’s 3:1 active-to-placebo randomization. These are blinded interim biomarker observations, meaning treatment allocations between drug and placebo groups are not known at this time. These observed biomarker trends are not a determination of efficacy, and trends in biomarkers may not ultimately be reflective of clinical effects.
  
  
• Differentiated, oligomer-selective mechanism: PMN310 is designed to selectively bind toxic amyloid-beta oligomers while avoiding plaque, a mechanism intended to decouple potential efficacy from ARIA risk.
  
  
• Clear path forward: Unblinded 12-month topline data expected Q1 2027, including efficacy data.

“These interim data reinforce our central thesis: by selectively targeting toxic oligomers, PMN310 has the potential to deliver the benefits of amyloid-directed therapy without the ARIA burden that has constrained this class of drugs,” said Neil Warma, Chief Executive Officer of ProMIS Neurosciences. “The absence of ARIA-E, an overall favorable safety profile, and early biomarker movement together align with our expectations based on our prior studies. We look forward to our 12-month topline readout in the first quarter of 2027.”

Dr. Will Mantyh, a behavioral neurologist at the University of Minnesota, said, “In real-world practice, ARIA risk is the central prescribing barrier: clinicians, patients, and health systems must contend with the issues of safety monitoring, identification, and sometimes emergent neurological treatment of ARIA. A profile with low incidence of total ARIA, including no ARIA-E, would be a game-changer. Just as importantly, plasma pTau217 and CSF MTBR-tau243 are among the most informative fluid biomarkers we have for tracking Alzheimer’s biology; seeing early, coherent movement in both is highly encouraging before a definitive readout.”

ProMIS will host a live webinar today to discuss these results. 

Webinar Details

Date: July 28, 2026

Time: 8:00–9:00 a.m. ET

Speakers (ProMIS): Neil Warma, Chief Executive Officer, and Dr. Larry Altstiel, Chief Medical Officer

Featured Key Opinion Leaders: Dr. Will Mantyh and Dr. Michael Weiner

Registration: https://lifescievents.com/event/it38tlq/

About PMN310 and the PRECISE-AD Trial for Alzheimer’s Disease (AD)

PMN310, ProMIS’ lead product candidate for the treatment of AD, is a humanized IgG1 monoclonal antibody designed to selectively target only the toxic oligomers of amyloid-beta (AβOs), believed to be among the earliest and most damaging drivers of Alzheimer’s disease, while avoiding binding to amyloid plaques and vascular deposits. This selectivity may reduce or eliminate the risk of amyloid-related imaging abnormalities (ARIA), including brain swelling (ARIA-E) and microhemorrhages (ARIA-H), which are commonly associated with plaque-binding antibodies. PMN310 was granted Fast Track Designation by the U.S. Food and Drug Administration in July 2025.

Based on encouraging results from a Phase 1a trial (NCT06105528) in healthy volunteers, ProMIS initiated the PRECISE-AD Phase 1b trial to evaluate PMN310 in patients with mild cognitive impairment due to AD or mild AD. PRECISE-AD (NCT06750432) is a randomized, double-blind, placebo-controlled study evaluating the safety, tolerability, and pharmacokinetics of multiple ascending doses (5, 10, and 20 mg/kg) of intravenous PMN310. The study has completed enrollment of 144 participants across the three dosing cohorts who are being treated for twelve months. It is designed to provide meaningful insight into the effects of PMN310 on biomarkers and clinical outcomes.

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 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).

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 significance of the blinded six-month interim safety and biomarker data (including ARIA, pTau217, and MTBR-tau243 findings) described in this release, target engagement, the expected timing and nature of topline clinical data of PMN310, its mechanism of action and potential benefits, and the Company’s development plans. 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 early or interim results may not be indicative of future results and that blinded, pooled data may not reflect the effect of PMN310 once unblinded. 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

Media Contact
Maggie Whitney
LifeSci Communications
mwhitney@lifescicomms.com

Investor Relations Contact
Carie Pierce
VP Investor Relations & External Affairs
IR@ProMISNeurosciences.com

Webinar Details
Date: July 28, 2026
Time: 8:00-9:00 am ET
Speakers (ProMIS): Neil Warma, Chief Executive Officer, and Dr. Larry Altstiel, Chief Medical Officer
KOLs: Dr. Will Mantyh and Dr. Michael Weiner
Registration link: https://lifescievents.com/event/it38tlq/

About Dr. Will Mantyh

William G. Mantyh, M.D. is an Associate Professor with Tenure in Behavioral/Cognitive Neurology at the University of Minnesota, specializing in Alzheimer's disease and related neurodegenerative disorders. His research focuses on blood-based biomarkers, APOE genetics, and expanding equitable access to Alzheimer's diagnosis and treatment in underserved communities. He is the principal investigator of a $3.7 million NIH grant studying Alzheimer's blood tests in Native American communities and serves as M Health Fairview's Practice Leader for new biomarker and anti-amyloid infusion care models. Dr. Mantyh earned his M.D. from the University of Minnesota, completed his internship and neurology residency at Mayo Clinic, and finished a fellowship in Behavioral Neurology at the University of California, San Francisco. 

About Dr. Michael Weiner

Dr. Weiner is UCSF Professor Emeritus of Radiology and Biomedical Imaging, Medicine, Psychiatry, and Neurology, and the CEO of the AI voice company, Vaicro. He has conducted research for over 60 years and is Principal Investigator of the Alzheimer's Disease Neuroimaging Initiative (ADNI) and the BrainHealthRegistry.org. He was one of the first to perform nuclear magnetic resonance on an intact animal. He then pursued development of MRI/MRS as a clinical tool and established the Center for Imaging of Neurodegenerative Diseases at the San Francisco VAMC. Dr. Weiner has published over 1,030 peer-reviewed articles, trained dozens of postdoctoral fellows, and received numerous honors including the Alzheimer’s Association’s Nancy and Ronald Reagan Award, the Potamkin Prize of the American Academy of Neurology, a Docteur Honoris Causa Degree from Paul Sabatier University, Toulouse, France, and the Henry Wisniewski Lifetime Achievement Award in Alzheimer's Disease Research, from the Alzheimer's Association in 2021. His current interest is AI applications to ADRD research, especially development of AI-powered conversational voice agents to perform clinical and cognitive assessments.

About PMN310 and the PRECISE-AD Trial for Alzheimer’s Disease (AD)

PMN310, ProMIS’ lead product candidate for the treatment of AD, is a humanized IgG1 monoclonal antibody designed to selectively target only the toxic oligomers of amyloid-beta (AβOs), believed to be among the earliest and most damaging drivers of Alzheimer's disease, while avoiding binding to amyloid plaques and vascular deposits. This selectivity may reduce or eliminate the risk of amyloid-related imaging abnormalities (ARIA), including brain swelling (ARIA-E) and microhemorrhages (ARIA-H), which are commonly associated with plaque-binding antibodies. PMN310 was granted Fast Track Designation by the U.S. Food and Drug Administration in July 2025.

Based on encouraging results from a Phase 1a trial (NCT06105528) in healthy volunteers, ProMIS initiated the PRECISE-AD Phase 1b trial to evaluate PMN310 in patients with mild cognitive impairment due to AD or mild AD. PRECISE-AD (NCT06750432) is a randomized, double-blind, placebo-controlled study evaluating the safety, tolerability, and pharmacokinetics of multiple ascending doses (5, 10, and 20 mg/kg) of intravenous PMN310. The study has completed enrollment of 144 participants across the three dosing cohorts who are being treated for twelve months. It is designed to provide meaningful insight into the effects of PMN310 on biomarkers and clinical outcomes.

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 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).

For further information:
Visit us at www.promisneurosciences.com

Media Contact
Maggie Whitney
LifeSci Communications
mwhitney@lifescicomms.com

Investor Relations Contact
Carie Pierce
VP Investor Relations & External Affairs
IR@ProMISNeurosciences.com

Represents one of the first quantitative measures of treatment-related effects on oligomer levels in a clinical trial

Company on track to present six-month blinded interim data from its Phase 1b trial in the coming weeks

Poster to be presented today, July 14, at the 2026 Alzheimer’s Association International Conference® (AAIC)

Cambridge, Massachusetts, July 14, 2026 (GLOBE NEWSWIRE) -- ProMIS Neurosciences Inc. (Nasdaq: PMN), a clinical-stage biotechnology company developing antibody therapeutics and vaccines targeting toxic misfolded proteins in neurodegenerative diseases, today announced the first human evidence of dose-dependent amyloid-beta oligomer (AβO) reduction by its lead Alzheimer’s drug candidate, PMN310, presented at AAIC 2026.

The findings, drawn from analysis of samples collected during the Company's Phase 1a trial in healthy volunteers (NCT06105528), showed that individuals receiving PMN310 exhibited a dose-dependent reduction in detectable AβO in cerebrospinal fluid (CSF) at both three and 29 days after dosing. While healthy individuals carry lower oligomer burdens than Alzheimer's patients, amyloid-beta oligomers are detectable in CSF even in cognitively normal adults, making this a meaningful measure of target engagement. This represents one of the first quantitative demonstrations of treatment-related oligomer reduction in humans.

"These data represent an important milestone for PMN310 and offer evidence supporting our precision medicine approach in treating Alzheimer's disease," said Neil Warma, Chief Executive Officer of ProMIS Neurosciences. "Using CSF samples from our Phase 1a study, subjects receiving PMN310 showed a clear dose-dependent reduction in oligomer particles, which, we believe, represents direct evidence that PMN310 was able to reach the brain and engage its intended target. We are grateful to our partner, attyloid, for their contribution to the assay development that made this possible, and we intend to deploy this assay in our ongoing PRECISE-AD Phase 1b trial to directly measure oligomer burden in Alzheimer's patients before and after treatment."

Dr. Johanne Kaplan, Chief Development Officer, ProMIS Neurosciences said, "A large body of evidence in Alzheimer's disease research indicates that disease pathogenesis is not directly driven by plaque burden, but rather by soluble toxic amyloid-beta oligomers. Selectively targeting oligomers while avoiding plaque could have a meaningful impact on both the efficacy and safety of treatment, reducing off-target binding that limits effective dosing and potentially limiting the ARIA side effects associated with plaque-binding antibodies. We believe the data presented today provide pharmacodynamic evidence supportive of PMN310's differentiated mechanism of action."

Mr. Warma added, “Building on this evidence of target engagement, we look forward to sharing blinded six-month interim data from the PRECISE-AD Phase 1b trial in the coming weeks. This interim analysis will focus on blinded aggregate safety data and overall trends in selected biomarkers across study participants. Top line unblinded results are expected in early Q1 2027." 

Key Results Presented at AAIC
Amyloid-beta oligomers in CSF were measured using surface-based fluorescence intensity distribution analysis (sFIDA) developed by attyloid GmbH, an assay which enables direct quantification of oligomer particles with unprecedented sensitivity. While the assay is currently exploratory, it provides pharmacodynamic evidence of target engagement by PMN310.

• Oligomer reduction: Placebo-treated healthy volunteers (N=40) in the Phase 1a trial exhibited low levels of AβO in CSF.  PMN310 administration resulted in a dose-dependent reduction in detectable AβO particles in CSF.

• Strict oligomer selectivity: PMN310 demonstrated strong binding to AβO with no interaction with monomers by surface plasmon resonance (SPR), and no detectable reactivity with plaques or vascular deposits of Aβ in AD brain tissue sections, representing the potential for a differentiated clinical profile.

• Favorable pharmacokinetics and tolerability: PMN310 was generally well-tolerated, with CSF concentrations linearly dose-dependent, reaching 100–600 times the estimated molar concentration of AβO, and a CSF half-life of approximately 27 days.

• Preclinical memory preservation: In a transgenic AD mouse model, PMN310 preserved memory and learning performance in the Morris Water Maze task.

AAIC Presentation details

About PMN310 and the PRECISE-AD Trial for Alzheimer’s Disease (AD)

PMN310, ProMIS’ lead product candidate for the treatment of AD, is a humanized IgG1 monoclonal antibody designed to selectively target only the toxic oligomers of amyloid-beta (AβOs), believed to be among the earliest and most damaging drivers of Alzheimer's disease, while avoiding binding to amyloid plaques and vascular deposits. This selectivity may reduce or eliminate the risk of amyloid-related imaging abnormalities (ARIA), including brain swelling (ARIA-E) and microhemorrhages (ARIA-H), which are commonly associated with plaque-binding antibodies. PMN310 was granted Fast Track Designation by the U.S. Food and Drug Administration in July 2025.

Based on encouraging results from a Phase 1a trial (NCT06105528) in healthy volunteers, ProMIS initiated the PRECISE-AD Phase 1b trial to evaluate PMN310 in patients with mild cognitive impairment due to AD or mild AD. PRECISE-AD (NCT06750432) is a randomized, double-blind, placebo-controlled study evaluating the safety, tolerability, and pharmacokinetics of multiple ascending doses (5, 10, and 20 mg/kg) of intravenous PMN310. The study has completed enrollment of 144 participants across the three dosing cohorts who are being treated for twelve months. It is designed to provide meaningful insight into the effects of PMN310 on biomarkers and clinical outcomes.

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 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).

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 Phase 1a clinical trial, results of the use of the assay discussed in this release and intent to deploy such assay in the future, the PRECISE-AD Phase 1b clinical trial, target engagement and biomarker findings, the expected timing and nature of blinded interim and topline clinical data of PMN310, its mechanism of action and potential benefits and the Company’s development plans. 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. 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

Media Contact

Maggie Whitney
LifeSci Communications
mwhitney@lifescicomms.com

Investor Relations Contact

Carie Pierce
VP Investor Relations & External Affairs
IR@ProMISNeurosciences.com

Conference details below:

Jefferies Global Healthcare Conference, June 2-4, 2026
Location: New York, NY
Presentation: Thursday, June 4, 2026, from 11:40 a.m. to 12:10 p.m. ET
Webcast link: Click here.

Virtual Alzheimer’s R&D Day, organized by Wolfe Research, June 4, 2026
Presentation: Thursday, June 4, 2026, from 8:30 a.m. to 9:00 a.m. ET (invitation-only)
The event will feature leading companies and key opinion leaders in Alzheimer’s disease research, discussing the current treatment landscape, development of disease modifying therapies and symptom management.

Oppenheimer CNS Summit, June 10, 2026
Location: Miami, FL
One-on-one meetings only

H.C. Wainwright Neuro Perspectives Expert Summit, June 15-16, 2026
Location: New York, NY
Presentation: Monday, June 15, 2026
Webcast link:  Click here

BIO International Convention, June 22-25, 2026
Location: San Diego, CA
One-on-one meetings only

During these conferences, Neil Warma, CEO of ProMIS Neurosciences, will discuss the Company’s EpiSelect™ platform and differentiated approach to developing therapeutics for neurodegenerative diseases driven by toxic misfolded proteins, including its lead Alzheimer’s disease (AD) candidate, PMN310.

PMN310 is designed to selectively target toxic amyloid-beta oligomers believed to drive AD pathology while avoiding plaque binding, an approach intended to potentially reduce off-target effects associated with plaque-directed therapies.

ProMIS expects to report blinded 6-month interim data from its fully enrolled PRECISE-AD Phase 1b trial in patients with early AD in early Q3 2026, with 12-month topline data anticipated in early 2027.

Webcast replays of the presentations will be available in the Investors section of the ProMIS Neurosciences website at https://www.promisneurosciences.com/ under “News & Events”.

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).

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 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”, “expects”, “anticipates”, “believes”, or variations of such words and ‎phrases. 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 expected in early third quarter of 2026 and topline results by early 2027, statements relating to the Company's progress, including enrollment and dosing, the potential for PMN310 to positively benefit patients with AD, the targeting of toxic misfolded proteins, and the ability of the Company’s cash runway to fund operations through 2027. 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 and uncertainties, including the risk that preclinical results or early results may not be indicative of future results. Except as required by applicable securities laws, the Company undertakes no obligation to publicly update any forward-looking information.

Investor Relations Contact:
Carie Pierce VP, Investor Relations & External Affairs
IR@promisneurosciences.com

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.

EpiSelect^TM 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

IR@promisneurosciences.com

Presented on 4/21/2026

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.

EpiSelect^TM 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 info@promisneurosciences.com

For Investor Relations, please contact:
Carie Pierce carie.pierce@promisneurosciences.com

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)

• Two novel vaccine candidates unveiled for ALS and Parkinson's disease, targeting misfolded TDP-43 and alpha-synuclein proteins.
• EpiSelect™ platform used to design vaccines with "sniper-like precision," avoiding healthy proteins.
• PMN310, an Alzheimer's antibody developed using the same platform, received Fast Track designation by the FDA in 2025 and is in Phase 1b trials.

Expert Consensus (from BriefGlance.com)

Experts view ProMIS's precision immunotherapy approach as a promising and innovative strategy for targeting neurodegenerative diseases, with potential advantages in safety and efficacy over less-selective therapies.

SK
Sharon Kelly
Strategic Shifts & Business Growth

ProMIS Unveils Precision Vaccines for ALS and Parkinson's Disease

CAMBRIDGE, MA – March 18, 2026 – ProMIS Neurosciences, a clinical-stage biotechnology company, is expanding its fight against neurodegeneration, moving beyond its established Alzheimer's program to take aim at Amyotrophic Lateral Sclerosis (ALS) and Parkinson's disease. The company announced it is presenting promising preclinical data on two novel vaccine candidates at the prestigious Alzheimer’s & Parkinson’s Diseases Conference (AD/PD™ 2026) in Copenhagen this week, signaling a significant strategic broadening of its therapeutic pipeline.

The presentations highlight a highly precise approach to treating these devastating diseases by targeting the toxic, misfolded proteins believed to be their root cause. This move leverages the company's proprietary computational discovery engine, which has already produced a Fast Track-designated antibody for Alzheimer's disease currently in human trials.

A "Sniper Rifle" Approach to Brain Disease

At the heart of many neurodegenerative disorders, including ALS and Parkinson's, is a common culprit: proteins that misfold into toxic shapes. These misshapen proteins, or oligomers, clump together, spread through the brain like a slow-motion infection, and kill nerve cells. For decades, scientists have tried to clear these proteins, but a major challenge has been distinguishing the toxic culprits from their healthy, functional counterparts, which are essential for normal cellular activity.

ProMIS Neurosciences believes it has a solution with its proprietary discovery platform, EpiSelect™. The platform functions like a molecular detective, using advanced computational algorithms to identify unique structural features, or "Disease Specific Epitopes," that are only exposed on the surface of toxic, misfolded proteins. This allows the company to design vaccines and antibodies with what it calls "sniper-like precision."

This targeted strategy is designed to induce an immune response that attacks only the pathogenic protein clumps, leaving the vast quantities of healthy, properly folded proteins untouched. This selectivity is critical for developing safer and potentially more effective therapies, as it aims to avoid off-target effects that could interfere with normal biological functions and cause unintended side effects.

New Vaccine Candidates Take Center Stage

The two scientific posters being presented at the AD/PD™ conference provide the first public glimpse into how this precision technology is being applied to ALS and Parkinson's disease.

One presentation details the rational design of a vaccine targeting misfolded TDP-43, a protein whose pathology is a hallmark of nearly all cases of ALS and some forms of frontotemporal dementia (FTD). By generating an immune response specifically against the pathogenic form of TDP-43, the vaccine aims to halt the spread of the toxic protein and clear the aggregates that lead to motor neuron death, without affecting the protein's vital role in healthy cells.

The second presentation focuses on a vaccine designed to elicit an antibody response against toxic species of alpha-synuclein, the protein that aggregates to form Lewy bodies in the brains of Parkinson's disease patients. The field of alpha-synuclein immunotherapy is competitive, with several large pharmaceutical companies pursuing antibody treatments. However, ProMIS asserts its approach is different. Its vaccine is engineered to be highly selective for the most toxic oligomeric forms of alpha-synuclein, potentially offering a better safety and efficacy profile than less-targeted therapies.

“We are pleased to be invited to present at AD/PD™ 2026, a leading forum for the presentation and discussion of advances in neurodegenerative disease research,” said Neil Warma, Chief Executive Officer of ProMIS Neurosciences, in a statement. “These data highlight two of our pipeline candidates and underscore our focus on advancing novel therapeutic approaches for ALS and Parkinson’s disease, particularly through targeting misfolded protein species believed to drive disease pathology.”

Leveraging a Platform Proven in Alzheimer's

The confidence to pursue these new targets stems from the progress of the company's lead candidate, PMN310, for Alzheimer's disease. Developed using the same EpiSelect™ platform, PMN310 is a monoclonal antibody designed to selectively bind to toxic amyloid-beta oligomers—the species now widely considered the primary driver of neurodegeneration in Alzheimer's—while avoiding both single amyloid-beta molecules and the dense plaque deposits that have been the target of many previous therapies.

This non-plaque-binding approach is believed to be the reason for a potentially improved safety profile, specifically a lower risk of amyloid-related imaging abnormalities (ARIA), a form of brain swelling or microhemorrhages seen with plaque-clearing antibodies. PMN310 was granted Fast Track designation by the U.S. Food and Drug Administration in 2025 and is currently being evaluated in a Phase 1b clinical trial, known as PRECISE-AD, in patients with early-stage Alzheimer's disease.

The advancement of PMN310 into human trials provides crucial validation for the underlying EpiSelect™ platform, demonstrating its ability to translate a computational concept into a clinical-stage therapeutic. This track record provides a strong foundation for the company's expansion into other complex neurodegenerative diseases.

The Quest for Disease-Modifying Therapies

For patients with ALS and Parkinson's, the need for new treatments is urgent. Current therapies for both conditions primarily manage symptoms but do not stop or slow the relentless underlying progression of the disease. A therapy that could modify the disease course by targeting its root cause remains one of the most significant unmet needs in medicine.

ProMIS's immunotherapy strategy represents a promising avenue in this global quest. By activating the body's own immune system to precisely identify and eliminate the toxic proteins driving cell death, these vaccine candidates offer a fundamentally different approach from daily pills or infusions that may have broader, less-specific effects.

While the data presented in Copenhagen is from preclinical studies, it marks a critical step in validating the science and moving these programs toward human trials. The presentations will be closely watched by researchers, clinicians, and investors, all searching for the next breakthrough. For patients and families facing these devastating conditions, the promise of such a targeted approach represents a significant new direction in the long fight against neurodegenerative disease.

The posters will highlight ongoing research related to the Company’s proprietary discovery platform and its approach to selectively targeting toxic misfolded proteins in neurodegenerative diseases.

Oral Platform Presentation Details

Presentation #1
Title: Rational Design of a Vaccine Against TDP-43 Proteinopathies Using a Pathogenic Epitope of Misfolded TDP-43
Session: Mechanisms and Pathways to Therapy in AD, FTD, and ALS (Symposium)
Date, Time, & Location: Friday, March 20, 2026 | 13:50–15:50 | Auditorium 12
Presenter: Neil Cashman
Authors: N Cashman, E Scruten, K Verma, J Kaplan, S Napper

Presentation #2
Title: Vaccination with Conformational Epitopes Derived from Computational Modeling Elicits Active Antibody Response Selective for Toxic Alpha-Synuclein Species (ID 961)
Session: Translational Treatment Strategies and New Targets (Symposium)
Date, Time, & Location: Friday, March 20, 2026 | 16:20–18:20 | Hall A2
Presenter: Johanne Kaplan
Authors: J Kaplan, S Napper, E Gibbs, E Scruten, J Coutts, A Attaran, C Evangelista, M Prado, N Cashman

“We are pleased to be invited to present at AD/PD™ 2026, a leading forum for the presentation and discussion of advances in neurodegenerative disease research,” said Neil Warma, Chief Executive Officer of ProMIS Neurosciences. “These data highlight two of our pipeline candidates and underscore our focus on advancing novel therapeutic approaches for ALS and Parkinson’s disease, particularly through targeting misfolded protein species believed to drive disease pathology.”

Additional details, including poster abstracts, are available on the AD/PD™ 2026 conference website.  AD/PD™ 2026 Alzheimer's & Parkinson's Diseases Conference

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 and is designed to provide meaningful insight into the effects of PMN310 on biomarkers and clinical outcomes.

EpiSelect^TM 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 (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

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 preclinical data, novel vaccine approach to target toxic oligomers and the potential implications thereof, statements of reference to its preclinical studies, its proprietary discovery platform, two of its pipeline candidates and its focus on advancing novel therapeutic approaches for ALS and Parkinson’s disease, and to its lead product, PMN310, designed for the treatment of AD, statements related to the targeting of toxic misfolded proteins in neurodegenerative diseases and the belief that they 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, and therapeutic activity and preferential targeting of toxic soluble aggregates by Aß-directed antibodies and the potential implications thereof. 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, 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.

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Carie Pierce
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