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.

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

The fireside chat will be held at 9:30am Eastern Time on Wednesday, February 11th and a live webcast of the presentation may be accessed by visiting the Events page of the Company’s website at www.promisneurosciences.com. The webcast will be available for at least 30 days following the event.

About ProMIS Neurosciences Inc.

ProMIS Neurosciences is a clinical-stage biotechnology company committed to the discovery and development of therapeutic antibodies and vaccines selective for toxic oligomers associated with the development and progression of neurodegenerative and other misfolded protein diseases. The Company’s proprietary target discovery engine, EpiSelect™, has been shown to predict novel targets known as Disease Specific Epitopes (DSEs) on the molecular surface of misfolded proteins that cause neurodegenerative and other misfolded protein diseases, including Alzheimer’s disease (AD), amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), multiple system atrophy (MSA), and Parkinson’s Disease (PD). ProMIS has offices in Cambridge, Massachusetts (USA) and Toronto, Ontario (CAN).

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

PMN310, the Company’s lead product candidate for the treatment of AD, is a humanized monoclonal antibody that has been designed to selectively target only the toxic oligomers, avoiding plaque, thereby potentially reducing, or eliminating amyloid-related imaging abnormalities (ARIA) liability. In addition, because PMN310 may not be limited by off-target binding or side effects, PMN310 could potentially offer an improved efficacy profile over other amyloid-directed antibody therapeutics. PMN310 was granted Fast Track designation by the U.S. Food and Drug Administration in July 2025.

Based on the encouraging results from the Phase 1a trial (NCT06105528) of PMN310, ProMIS initiated PRECISE-AD, a Phase 1b clinical trial in AD patients. PRECISE-AD (NCT06750432) is a randomized, double-blind, placebo-controlled study to evaluate the safety, tolerability and pharmacokinetics (PK) of multiple ascending doses (5, 10, 20 mg/kg) of intravenous PMN310 in patients with Mild Cognitive Impairment due to AD and mild AD (Stage 3 and Stage 4 AD).  PRECISE-AD will be the first study to examine the effects of a monoclonal antibody directed solely against AβO on biomarkers associated with AD pathology and clinical outcomes. Safety will be a primary outcome of the study with particular emphasis on assessing whether, as a non-plaque binder, PMN310 may have a reduced risk of ARIA. The study is powered to provide 95% confidence for detection of ARIA. The study has been designed with a sample size intended to provide sufficient power to provide meaningful insight into effects of PMN310 on biomarkers and clinical outcomes.

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^TM) 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.

For further information:

Visit us at www.promisneurosciences.com

Please submit media inquiries to info@promisneurosciences.com

For Investor Relations, please contact:
Kaytee Bock Zafereo
katherine.bock@promisneurosciences.com

Proceeds expected to enable completion of ProMIS’ landmark  Phase 1b AD study and support execution of key clinical milestones

Blinded 6-month top-line data expected mid-2026; 12-month top-line data expected toward end of 2026

CAMBRIDGE, Massachusetts , Jan. 30, 2026 (GLOBE NEWSWIRE) -- ProMIS Neurosciences Inc. (Nasdaq: PMN) (“ProMIS” or the “Company”), a clinical-stage biotechnology company focused on the generation and development of antibody therapeutics and vaccines targeting toxic misfolded proteins in neurodegenerative diseases, such as Alzheimer’s disease (AD), amyotrophic lateral sclerosis (ALS) and Parkinson’s disease (PD), today announced that it has entered into a securities purchase agreement with certain new and existing institutional and accredited investors to issue and sell up to an aggregate of approximately $175 million comprised of (i)  6,815,296 common shares, no par value (the “Common Shares”),  (ii) Common Share Warrants to purchase 6,915,296 Common Shares or Pre-Funded Warrants in lieu thereof (the “Common Share Warrants”), and (iii) Pre-Funded Warrants to purchase 100,000 Common Shares (the “Pre-Funded Warrants”, and the Common Shares issuable upon exercise of the Common Share Warrants and Pre-Funded Warrants, the “Warrant Shares”).

6,090,075 Common Shares were sold at a price of $10.77 per Common Share, 100,000 Pre-Funded Warrants were sold at a price of $10.77 less an exercise price $0.0001 per Warrant Share and 725,221 Common Shares were sold at a price of $12.13 per Common Share to certain affiliates and insiders of the Company. The Common Share Warrants have an exercise price of $14.40, are exercisable immediately and will expire upon the earlier of (i) within 60 days of the Milestone Event (as defined below) or (ii) February 3, 2031. The Pre-Funded Warrants are immediately exercisable and will expire when exercised in full. For purposes of the foregoing, the “Milestone Event” means the public announcement via press release or the filing of a Current Report on Form 8-K of topline data from the cohorts treated with single ascending doses of PMN310.

The private investment in public equity (“PIPE”) financing is being co-led by Janus Henderson and Ally Bridge Group, with participation from new and existing investors, including Deep Track Capital, Great Point Partners, LLC, Trails Edge Capital Partners, Wellington Management, and Woodline Partners LP. The ProMIS CEO and members of the management team and Board of Directors are also participating.

“We are pleased to have the support of such a high-caliber group of sophisticated healthcare investors in this transformational financing” said Neil Warma, Chief Executive Officer of ProMIS. “We expect the proceeds to enable the anticipated completion of our landmark Phase 1b Alzheimer’s disease clinical study and accelerate development of the subcutaneous formulation of PMN310. We believe we remain on track to report blinded top-line data in mid-2026 and 12-month top-line data toward the end of 2026.”

ProMIS anticipates the upfront gross proceeds from the PIPE financing to be approximately $75 million, before deducting fees to the placement agents and other offering expenses payable by the Company, and up to an additional approximately $100 million in gross proceeds if the Common Share Warrants and Pre-Funded Warrants are fully exercised for cash. The financing is expected to close on February 3, 2026, subject to customary closing conditions.

Guggenheim Securities acted as lead placement agent and Ceros Financial Services, Inc. and Leede Financial Inc. acted as placement agents in the PIPE financing.

The offer and sale of the foregoing securities are being made in a transaction not involving a public offering and have not been registered under the Securities Act of 1933, as amended (“Securities Act”), or any state or other applicable jurisdiction’s securities laws, and may not be offered or sold in the United States absent registration or an applicable exemption from the registration requirements of the Securities Act and applicable state or other jurisdictions’ securities laws. ProMIS Neurosciences has agreed to file a registration statement with the SEC registering the resale of the Common Shares and the Common Shares issuable upon the exercise of the Common Share Warrants and Pre-Funded Warrants issued in the PIPE financing.

This press release shall not constitute an offer to sell or the solicitation of an offer to buy these securities, nor shall there be any sale of these securities in any state or jurisdiction in which such offer, solicitation or sale would be unlawful prior to the registration or qualification under the securities law of any such state or other jurisdiction.

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 (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”, “excited to”, “targets”, “expects” or “does not expect”, “is expected”, “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 expected timing for the closing of the PIPE financing, the anticipated use of proceeds from the PIPE financing, the potential exercise of the Common Share Warrants and anticipated proceeds therefrom, and planned timing to report blinded top-line data and 12-month top-line data. 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 Company’s ability to fund its operations and continue as a going concern, its accumulated deficit and the expectation for continued losses and future financial results. Important factors that could cause actual results to differ materially from those indicated in the forward-looking information include, among others, the factors discussed throughout the “Risk Factors” section of the Company’s most recently Annual Report on Form 10-K for the year ended December 31, 2024, as filed with the Securities and Exchange Commission, and subsequent quarterly reports. 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.

Please submit media inquiries to info@promisneurosciences.com.

For Investor Relations, please contact:
Kaytee Bock Zafereo
katherine.bock@promisneurosciences.com

Clear and near-term value inflection points, with blinded 6-month interim data expected in Q2 2026 and final unblinded top-line results anticipated in Q4 2026

Cambridge, Massachusetts, Dec. 18, 2025 (GLOBE NEWSWIRE) -- ProMIS Neurosciences Inc. (Nasdaq: PMN), a clinical-stage biotechnology company focused on the generation and development of antibody therapeutics and vaccines targeting toxic misfolded proteins in neurodegenerative diseases, such as Alzheimer’s disease (AD), amyotrophic lateral sclerosis (ALS) and Parkinson’s disease (PD), today announced completion of enrollment of 144 patients in its PRECISE-AD Phase 1b clinical trial, evaluating PMN310, the Company’s lead therapeutic antibody candidate for the treatment of AD.

PRECISE-AD is a randomized, double-blind, placebo-controlled study in patients with mild cognitive impairment or early AD. The 12-month trial was designed to assess the safety, tolerability, pharmacokinetics, biomarker and clinical effects of PMN310, an antibody designed to be uniquely selective for toxic soluble amyloid-beta oligomers, widely believed to be the primary drivers of synaptic dysfunction and neurodegeneration in AD.

To date, PMN310 has demonstrated a favorable safety profile, with limited patient discontinuations and no treatment-related serious adverse events (SAEs) reported during the trial.

The Company remains on track to conduct a blinded 6-month interim analysis in Q2 2026, including an evaluation of key plasma and cerebrospinal fluid biomarkers, followed by final unblinded 12-month top-line analysis expected in Q4 2026.

“This is a major execution milestone for ProMIS and a potentially pivotal moment for the Alzheimer’s field” said Neil Warma, Chief Executive Officer of ProMIS Neurosciences. “Completing enrollment and above our target in a rigorously designed, biomarker-rich study of this scale positions us to potentially confirm, clinically and biologically, for the first time the central role of toxic amyloid-beta oligomers in Alzheimer’s disease. The safety profile we have observed thus far, with no treatment-related SAEs and minimal dropouts, reinforces our belief that PMN310 may offer a fundamentally differentiated approach that has the potential to significantly reduce the ARIA liability that has limited broader use of current therapies. We believe the over-enrollment of PRECISE-AD may reflect strong enthusiasm among both patients and trial physicians for PMN310’s differentiated mechanism and its potential for improved safety, underscoring the importance of the upcoming blinded interim analysis expected in Q2 2026 and final unblinded top-line results expected in Q4 2026.”

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 designed to selectively target only amyloid-beta 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 with targeted enrollment of 128 AD patients. PRECISE-AD (NCT06750432) is a randomized, double-blind, placebo-controlled study to evaluate the safety, tolerability and pharmacokinetics of multiple ascending doses (5, 10, 20 mg/kg) of intravenous PMN310 in patients with Mild Cognitive Impairment due to AD 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 toxic amyloid-beta 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. The study has been designed with a sample size intended to provide sufficient power to provide meaningful insight into effects of PMN310 on biomarkers and clinical outcomes. A blinded 6-month interim analysis is expected in Q2 2026 with final top line data expected in Q4 2026.

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 progress and expectations for  its Phase 1b clinical trial in AD patients, including the number of participants enrolled, planned timing for completion and anticipated data readout of interim and full results in the second and fourth quarters of 2026, respectively, the potential for such studies to provide the first proof-of-concept data for PMN310, the potential for PMN310 to positively benefit patients with AD and to be a more effective and well-tolerated option, 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 amyloid-beta oligomers are a major driver of AD) and have greater therapeutic potential due to reduction of off-target activity. 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 interim or early clinical data or other early preclinical data may not be indicative of future results from ongoing and planned clinical trials, the Company’s ability to fund its operations and continue as a going concern, its accumulated deficit and the expectation for continued losses and future financial results. Important factors that could cause actual results to differ materially from those indicated in the forward-looking information include, among others, the factors discussed throughout the “Risk Factors” section of the Company's most recently filed Annual Report on Form 10-K for the year ended December 31, 2024 and in its subsequent filings filed with the United States Securities and Exchange Commission. Except as required by applicable securities laws, the Company undertakes no obligation to publicly update any forward-looking information, whether written or oral, that may be made from time to time, whether as a result of new information, future developments or otherwise.

For further information:

Visit us at www.promisneurosciences.com

Please submit media inquiries to info@promisneurosciences.com

For Investor Relations, please contact:
Kaytee Bock Zafereo
katherine.bock@promisneurosciences.com

ProMIS on track to complete enrollment in PRECISE-AD trial in Alzheimer’s disease by end of 2025 with planned Q2 2026 interim readout

Cambridge, Massachusetts, Dec. 10, 2025 (GLOBE NEWSWIRE) -- ProMIS Neurosciences Inc. (Nasdaq: PMN), a clinical-stage biotechnology company focused on the generation and development of antibody therapeutics and vaccines targeting toxic misfolded proteins in neurodegenerative diseases, such as Alzheimer’s disease (AD), amyotrophic lateral sclerosis (ALS) and Parkinson’s disease (PD), today announced a publication in the peer-reviewed journal Alzheimer’s & Dementia: Translational Research & Clinical Interventions. entitled, “Relationship between efficacy and preferential targeting of soluble Aβ aggregates.” The paper can be accessed at the following link: http://dx.doi.org/10.1002/trc2.70184.

Amyloid beta (Aβ) is known to play a role in the pathogenesis of AD, and certain approved and marketed Aβ-directed antibodies have achieved slowing of cognitive decline in AD. The results and analysis from the study announced today highlight the importance of targeting soluble toxic Aβ aggregates as supported by the observed retrospective correlation between selectivity for soluble toxic oligomers and reported clinical efficacy and the potential for attenuation of amyloid-related imaging abnormalities (ARIA), an adverse side effect of current anti-amyloid antibody therapies.

“This new publication reinforces the critical importance of selectively targeting toxic Aβ oligomers, believed to be the hallmark drivers of Alzheimer’s pathology,” said Neil Warma, Chief Executive Officer of ProMIS Neurosciences. “We believe PMN310 has the potential to deliver a meaningful advance in both clinical outcomes and quality of life for patients and caregivers, and with our 6-month interim readout from our ongoing PRECISE-AD clinical trial expected in Q2 2026 and top-line results expected in Q4 2026, we look forward to providing clinical data evaluating our approach next year.”

In this study, a side-by-side comparison of the binding profile of various Aβ-targeted antibodies to Aβ species, including monomers, low- and high-molecular-weight AD brain oligomers, and plaque was conducted and compared with known clinical outcomes.

1. Key Findings and Implications for PMN310: Antibody Specificity for Toxic Oligomers May Provide Greater Potency

• In the studies conducted, clinical efficacy across Aβ antibodies correlated strongly with the ability to bind toxic oligomers even in the presence of overwhelming monomer concentrations, which otherwise divert antibody activity away from pathogenic species.

• PMN310 showed the highest resistance to monomer competition among all antibodies tested, preserving oligomer binding while pan-Aβ antibodies lost activity in in vitro models. This suggests that a higher proportion of each dose of PMN310 could be available to reach the relevant toxic targets, which could potentially translate into clinical benefit in patients.

• In AD mouse studies, this oligomer selectivity translated into complete protection of spatial memory, restoring performance to normal wild-type levels, reinforcing the mechanistic rationale.

2. PMN310’s Lack of Plaque or Vascular Deposit Binding Suggests a Possible Lower Risk of ARIA

• ARIA is strongly associated with antibody binding to insoluble plaque and vascular amyloid deposits. Antibodies such as donanemab, aducanumab, and lecanemab showed significant plaque binding and correspondingly increased ARIA rates. In contrast, PMN310 exhibited no detectable plaque binding across concentrations tested, aligning with its engineered specificity for misfolded, soluble oligomers, not fibrils.

• Consistent with this mechanism, high-dose chronic administration of PMN310 in plaque-bearing mice (800 mg/kg for 26 weeks) produced no microhemorrhages on microscopic examination of brain tissue.

• Together, these findings provide preclinical evidence supporting a possible reduced ARIA risk.

3. PMN310 Is Positioned to Test the Oligomer Hypothesis Without Confounding Cross-Reactivity

• All other antibodies tested in the study appeared to bind monomers and/or plaque to varying degrees. PMN310 was the only antibody in the study showing strict specificity for toxic soluble oligomers while avoiding monomers and plaque.

• This positions the ongoing PRECISE-AD study to potentially become the first clinical test of oligomer-only targeting, which may clarify the relative contributions of oligomers vs plaque to cognitive decline, an important scientific inflection point for the field.

“This publication provides further evidence, supported experimentally and clinically, that selective targeting of toxic Aβ oligomers has the potential to increase efficacy by focusing the dose of antibody on the most relevant toxic Aβ species and improve safety by reducing the risk of ARIA associated with plaque binding which has been a significant side effect of current Aβ-directed antibodies,” said Johanne Kaplan, PhD, Chief Development Officer of ProMIS Neurosciences.

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 with targeted enrollment of 128 AD patients. PRECISE-AD (NCT06750432) is a randomized, double-blind, placebo-controlled study to evaluate the safety, tolerability and pharmacokinetics  of multiple ascending doses (5, 10, 20 mg/kg) of intravenous PMN310 in patients with Mild Cognitive Impairment due to AD 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 toxic amyloid-beta 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. The study has been designed with a sample size intended to provide sufficient power to provide meaningful insight into effects of PMN310 on biomarkers and clinical outcomes. A blinded 6-month interim analysis is expected in Q2 2026 with final top line data expected in Q4 2026.

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 and retrospective clinical analysis, the Company’s progress and expectations for  its Phase 1b clinical trial in AD patients, including planned timing for completion and anticipated data readout of interim results in the second quarter of 2026, the potential for such studies to provide the first proof-of-concept data for PMN310, the potential for PMN310 to positively benefit patients with AD and to be a more effective and well-tolerated option, 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 amyloid-beta oligomers are a major driver of AD) and have greater therapeutic potential due to reduction of off-target activity. 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 and retrospective clinical analyses described in the Alzheimer’s & Dementia: Translational Research & Clinical Interventions publication will not be predictive of clinical results for PMN310, the risk that enrollment may not continue at the current rate, that clinical results or early results may not be indicative of future results, the Company’s ability to retain and recognize the incentives conferred by Fast Track Designation for PMN310, the Company’s ability to fund its operations and continue as a going concern, its accumulated deficit and the expectation for continued losses and future financial results. Important factors that could cause actual results to differ materially from those indicated in the forward-looking information include, among others, the factors discussed throughout the “Risk Factors” section of the Company's most recently filed Annual Report on Form 10-K for the year ended December 31, 2024 and in its subsequent filings filed with the United States Securities and Exchange Commission. Except as required by applicable securities laws, the Company undertakes no obligation to publicly update any forward-looking information, whether written or oral, that may be made from time to time, whether as a result of new information, future developments or otherwise.

For further information:

Visit us at www.promisneurosciences.com

Please submit media inquiries to info@promisneurosciences.com

For Investor Relations, please contact:
Kaytee Bock Zafereo
katherine.bock@promisneurosciences.com

ProMIS on track to leverage new plasma pTau insights with planned Q2 2026 interim readout

Cambridge, Massachusetts, Dec. 01, 2025 (GLOBE NEWSWIRE) -- ProMIS Neurosciences Inc. (Nasdaq: PMN), a clinical-stage biotechnology company focused on the generation and development of antibody therapeutics and vaccines targeting toxic misfolded proteins in neurodegenerative diseases, such as Alzheimer’s disease (AD), amyotrophic lateral sclerosis (ALS) and Parkinson’s disease (PD), today announced a publication in the peer-reviewed journal Alzheimer’s & Dementia: Translational Research & Clinical Interventions. entitled, “Leveraging recent advances in plasma biomarkers to optimize early proof of concept trials in Alzheimer’s disease.” The paper can be accessed at the following link: http://dx.doi.org/10.1002/trc2.70183.

The analysis, conducted by Pentara Corporation in collaboration with scientists from ProMIS, provides important new evidence that plasma phosphorylated tau (pTau181 and pTau217) can serve as a meaningful primary endpoint in early-stage AD clinical trials, with potential to predict subsequent clinical benefit.

Key Findings from the Publication

Using summary data from several large monoclonal antibody (mAb) trials in early AD, the analysis showed:

• Strong predictive relationship: Group level treatment effects on plasma pTau at 6 months were strongly correlated with treatment effects on the Clinical Dementia Rating Sum of Boxes (CDR-SB) at 12 months (correlation ≈ 0.78; statistically significant).

• Amplified signal, earlier readout compared to clinical outcomes: The effect size on plasma pTau was ~2.6 times larger than the effect size on CDR-SB, indicating that biomarker changes can be detected earlier and more robustly than clinical changes.

• Potential for smaller, more efficient trials: Simulations suggest that, for drugs with effect sizes similar to those seen with one of the leading mAbs, well-powered proof-of-concept (POC) trials using plasma pTau as a primary endpoint may require as few as ~100 participants.

Together, these findings support the use of plasma pTau as a primary endpoint in early clinical development and as a quantitative bridge to predict future clinical outcomes.

Implications for ProMIS, PMN310, and the PRECISE-AD Trial

ProMIS is currently conducting PRECISE-AD, an ongoing Phase 1b clinical trial of PMN310, its lead amyloid-beta targeting antibody, in patients with early Alzheimer’s disease (AD). PMN310 is designed to selectively target toxic amyloid-beta oligomers, the species believed to be a primary driver of synaptic dysfunction and downstream disease pathology, while avoiding binding to monomers or plaque which is associated with higher rates of amyloid-related imaging abnormalities.

The newly published analysis is directly aligned with, and supportive of, key elements of the PRECISE-AD design:

• Biomarker-centric strategy: PRECISE-AD incorporates plasma pTau (including pTau217) as a central biomarker endpoint at 6 and 12 months, consistent with the timing and methodology highlighted in the publication.

• Early readout with potentially predictive value: By assessing plasma pTau changes as early as 6 months, PRECISE-AD is positioned to generate an early, quantitative signal of disease modification that can be used to model and predict future clinical outcomes.

• Efficient, de-risking design: The publication’s simulations reinforce that a biomarker-driven Phase 1b trial can be both smaller and faster, while still providing robust information to guide dose selection and go/no-go decisions for future trials including a pivotal Phase 3 trial.

• Mechanistic fit for PMN310: Because PMN310 is designed to neutralize toxic oligomers upstream of tau phosphorylation, meaningful reductions in plasma pTau could be expected if PMN310 successfully interrupts this pathogenic cascade.

“This publication provides important validation of the strategy we have adopted at ProMIS which is to use highly sensitive plasma pTau biomarkers as a central pillar of our ongoing Phase 1b AD clinical trial,” said Neil Warma Chief Executive Officer of ProMIS Neurosciences. “The ability to link a 6-month plasma readout to later clinical benefit means we can make smarter, earlier decisions about PMN310’s development path, while using capital more efficiently. Importantly, we remain on track to assess blinded 6-month biomarker data, including plasma pTau217, from our PRECISE-AD trial in Q2 2026, which we believe will offer an early and meaningful look at PMN310’s potential to modify disease biology. This publication significantly strengthens the scientific and investment thesis behind our approach.”

“For years, the field has discussed the promise of blood-based biomarkers, but they are now transitioning into practical tools for trial optimization,” added Larry D. Altstiel, M.D., Ph.D., Chief Medical Officer of ProMIS and a co-author on the paper. “Our analysis shows that plasma pTau not only tracks disease biology, but also robustly predicts clinical outcomes across multiple monoclonal antibody trials. For PMN310, which is designed to selectively target the toxic amyloid-beta oligomers that trigger tau phosphorylation, we believe plasma pTau offers a sensitive, biologically aligned readout of drug effect that can inform both dose selection and future Phase 3 planning.”

“By combining data across several large, well-characterized AD trials, we were able to quantify how strongly early plasma pTau changes predicted later clinical outcomes,” said Suzanne Hendrix, Ph.D., CEO of Pentara Corporation and a co-author on the paper. “The magnitude of this relationship, and the fact that the biomarker signal is easier to detect than the clinical signal, make plasma pTau a highly attractive primary endpoint for early proof-of-concept studies. This approach has the potential to reduce trial size and duration while increasing confidence in the decisions sponsors must make as they advance into Phase 3 pivotal studies.”

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 with targeted enrollment of 128 AD patients. PRECISE-AD (NCT06750432) is a randomized, double-blind, placebo-controlled study to evaluate the safety, tolerability and pharmacokinetics  of multiple ascending doses (5, 10, 20 mg/kg) of intravenous PMN310 in patients with Mild Cognitive Impairment due to AD 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 toxic amyloid-beta 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. The study has been designed with a sample size intended to provide sufficient power to provide meaningful insight into effects of PMN310 on biomarkers and clinical outcomes. A blinded 6-month interim analysis is expected in Q2 2026 with final top line data expected in Q4 2026.

About Pentara

Pentara Corporation provides statistical expertise and is a leader in the neurodegenerative space. Pentara offers clinical data analysis services to the pharmaceutical and biotechnology industries, including ProMIS. The teams at Pentara have decades of experience in clinical trial experiences, regulatory interactions, and Alzheimer’s Disease research. Pentara is headquartered in Salt Lake City, Utah.

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 progress and expectations for  its Phase 1b clinical trial in AD patients, including planned timing for completion and anticipated data readout of interim and full results in the second and fourth quarters of 2026, respectively, the potential for such studies to provide the first proof-of-concept data for PMN310, the potential for PMN310 to positively benefit patients with AD and to be a more effective and well-tolerated option, 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 amyloid-beta oligomers are a major driver of AD) and have greater therapeutic potential due to reduction of off-target activity. 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 enrollment may not continue at the current rate, that clinical results or early results may not be indicative of future results, the Company’s ability to retain and recognize the incentives conferred by Fast Track Designation for PMN310, the Company’s ability to fund its operations and continue as a going concern, its accumulated deficit and the expectation for continued losses and future financial results. Important factors that could cause actual results to differ materially from those indicated in the forward-looking information include, among others, the factors discussed throughout the “Risk Factors” section of the Company's most recently filed Annual Report on Form 10-K for the year ended December 31, 2024 and in its subsequent filings filed with the United States Securities and Exchange Commission. Except as required by applicable securities laws, the Company undertakes no obligation to publicly update any forward-looking information, whether written or oral, that may be made from time to time, whether as a result of new information, future developments or otherwise.

For further information:

Visit us at www.promisneurosciences.com

Please submit media inquiries to info@promisneurosciences.com

For Investor Relations, please contact:
Kaytee Bock Zafereo
katherine.bock@promisneurosciences.com

The fireside chat will be held at 3:25pm Eastern Time and a live webcast of the presentation may be accessed by visiting the Events page of the Company’s website at www.promisneurosciences.com. The webcast will be available for at least 30 days following the event.

About ProMIS Neurosciences Inc.

ProMIS Neurosciences is a clinical-stage biotechnology company committed to the discovery and development of therapeutic antibodies and vaccines selective for toxic oligomers associated with the development and progression of neurodegenerative and other misfolded protein diseases. The Company’s proprietary target discovery engine, EpiSelect™, has been shown to predict novel targets known as Disease Specific Epitopes (DSEs) on the molecular surface of misfolded proteins that cause neurodegenerative and other misfolded protein diseases, including Alzheimer’s disease (AD), amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), multiple system atrophy (MSA), and Parkinson’s Disease (PD). ProMIS has offices in Cambridge, Massachusetts (USA) and Toronto, Ontario (CAN).

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

PMN310, the Company’s lead product candidate for the treatment of AD, is a humanized monoclonal antibody that has been designed to selectively target only the toxic oligomers, avoiding plaque, thereby potentially reducing or eliminating amyloid-related imaging abnormalities (ARIA) liability. In addition, because PMN310 may not be limited by off-target binding or side effects, PMN310 could potentially offer an improved efficacy profile over other amyloid-directed antibody therapeutics. PMN310 was granted Fast Track designation by the U.S. Food and Drug Administration in July 2025.

Based on the encouraging results from the Phase 1a trial (NCT06105528) of PMN310, ProMIS initiated PRECISE-AD, a Phase 1b clinical trial in AD patients. PRECISE-AD (NCT06750432) is a randomized, double-blind, placebo-controlled study to evaluate the safety, tolerability and pharmacokinetics (PK) of multiple ascending doses (5, 10, 20 mg/kg) of intravenous PMN310 in patients with Mild Cognitive Impairment due to AD and mild AD (Stage 3 and Stage 4 AD).  PRECISE-AD will be the first study to examine the effects of a monoclonal antibody directed solely against AβO on biomarkers associated with AD pathology and clinical outcomes. Safety will be a primary outcome of the study with particular emphasis on assessing whether, as a non-plaque binder, PMN310 may have a reduced risk of ARIA. The study is powered to provide 95% confidence for detection of ARIA. The study has been designed with a sample size intended to provide sufficient power to provide meaningful insight into effects of PMN310 on biomarkers and clinical outcomes.

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^TM) 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.

For further information:

Visit us at www.promisneurosciences.com

Please submit media inquiries to info@promisneurosciences.com

For Investor Relations, please contact:
Kaytee Bock Zafereo
katherine.bock@promisneurosciences.com

The reverse stock split will take effect at 12:01 a.m. Eastern Time on November 28, 2025, and the Common Shares will begin trading on a split-adjusted basis on The Nasdaq Capital Market as of the opening of trading on November 28, 2025. The CUSIP number of 74346M505 will be assigned to the Common Shares when the reverse stock split becomes effective.

When the reverse stock split becomes effective, every twenty-five issued Common Shares will be combined into one issued Common Share, without any change to the par value per share. This will reduce the number of outstanding Common Shares from approximately 53,811,110 million shares to approximately 2,152,444 million shares.

Proportional adjustments will also be made to the number of Common Shares awarded and available for issuance under the company’s equity incentive plans, as well as the exercise price and the number of shares issuable upon the exercise or conversion of the company’s outstanding stock options and other equity securities under the company’s equity incentive plans. All outstanding warrants will also be adjusted in accordance with their terms, which will, among other changes to the warrant terms, result in proportionate adjustments being made to the number of shares issuable upon exercise of such warrants and to the exercise and redemption prices of such warrants, as applicable.

No fractional shares will be issued in connection with the reverse stock split. Stockholders who would otherwise be entitled to receive fractional shares will automatically be entitled to receive cash in lieu of such fractional share.

Stockholders with shares held in book-entry form or through a bank, broker, or other nominee are not required to take any action and will see the consequence of the reverse stock split reflected in their accounts on or after November 28, 2025. Such beneficial holders may contact their bank, broker, or nominee for more information.

The reverse stock split ratio approved by the board of directors is within the previously disclosed range of ratios for a reverse stock split authorized by the stockholders of the company at the 2025 Special Meeting of Stockholders of the Company held on November 17, 2025.

On January 8, 2025, ProMIS received a deficiency letter from The Nasdaq Stock Market LLC (Nasdaq) notifying the Company that, for the last 30 consecutive business days, the closing bid price of the Common Shares had not been maintained at the minimum required closing bid price of at least $1.00 per share, as required for continued listing on the Nasdaq Capital Market pursuant to Nasdaq Listing Rule 5550(a)(2) (Bid Price Rule).

In accordance with Nasdaq Listing Rule 5810(c)(3), ProMIS had 180 calendar days, or until July 2, 2025, to regain compliance with the Bid Price Rule. During such compliance period, if the Common Shares had a closing bid price of $0.10 or less for ten consecutive trading days, Nasdaq would have been entitled to issue a Staff Delisting Determination, with the potential opportunity for the Company to appeal such determination.

Subsequently, the Company received written notice from Nasdaq indicating that although the Company was not in compliance with the Bid Price Rule, Nasdaq determined that the company is eligible for an additional 180 calendar day compliance period, or until December 29, 2025. Nasdaq’s determination was based on the Company meeting the continued listing requirement for market value of publicly held shares and all other initial listing standards for the Nasdaq Capital Market with the exception of the Bid Price Rule, and the Company provided written notice of its confirmation to cure the deficiency during the additional compliance period, by effecting a reverse stock split, if necessary.

ProMIS believes that the reverse stock split will increase the market price for its Common Shares and cure the deficiency in the Bid Price Rule.

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 (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 “anticipate,” “believe,” “continue,” “could,” “estimate,” “expect,” “intend,” “may,” “might,” “plan,” “possible,” “potential,” “predict,” “project,” “should,” “strive,” “would” and similar expressions may identify forward-looking statements, but the absence of these words does not mean that a statement is not forward-looking. Specifically, this news release contains forward-looking information relating to the timing and completion of the Company’s reverse stock split, the intended effects of the reverse stock split and the acceptance and implementation of its proposed plan of compliance with Nasdaq continued listing standards. 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 clinical results or early results may not be indicative of future results,  the Company’s ability to fund its operations and continue as a going concern, its accumulated deficit and the expectation for continued losses and future financial results. Important factors that could cause actual results to differ materially from those indicated in the forward-looking information include, among others, the factors discussed throughout the “Risk Factors” section of the Company's most recently filed Annual Report on Form 10-K for the year ended December 31, 2024 and in its subsequent filings filed with the United States Securities and Exchange Commission. Except as required by applicable securities laws, the Company undertakes no obligation to publicly update any forward-looking information, whether written or oral, that may be made from time to time, whether as a result of new information, future developments or otherwise.

For further information:

Visit us at www.promisneurosciences.com

Please submit media inquiries to info@promisneurosciences.com

For Investor Relations, please contact:
Kaytee Bock Zafereo
Katherine.Bock@promisneurosciences.com