ProMIS Neurosciences — Third Quarter 2026 Earnings Summary

Financial Performance:

• Cash position was $44.1 million as of September 30, 2026, compared to $6.1 million as of December 31, 2025, driven by $70.1 million in net proceeds from a January 2026 private placement.
• Research and development expenses were $6.7 million for the three months ended September 30, 2026, a 32% decrease from $9.8 million in the same period of 2025, primarily due to a $3.6 million reduction in direct PMN310 expenses as the PRECISE-AD trial neared completion of patient visits.
• General and administrative expenses were $1.9 million for the three months ended September 30, 2026, compared to $2.0 million in the same period of 2025, with lower professional fees offset by higher employee salaries and benefits.
• Other income was $0.5 million for the three months ended September 30, 2026, compared to $0.2 million in the same period of 2025, attributed to higher interest income on increased cash balances.
• Net loss was $8.2 million ($0.89 per share) for the three months ended September 30, 2026, compared to $11.6 million ($5.93 per share) for the same period in 2025.
• For the nine months ended September 30, 2026, net loss was $28.1 million ($3.39 per share), compared to $29.0 million ($19.58 per share) for the same period in 2025.
• Total current assets were $47.2 million as of September 30, 2026, compared to $9.2 million as of December 31, 2025.
• Total liabilities decreased to $5.4 million as of September 30, 2026, from $10.4 million as of December 31, 2025.
• Shareholders' equity turned positive at $41.8 million as of September 30, 2026, compared to a deficit of $1.3 million as of December 31, 2025.

Guidance and Future Outlook:

• The PRECISE-AD Phase 1b clinical trial remains on track for unblinded 12-month topline data in the first quarter of 2027, including full safety, biomarker, and cognitive outcomes.
• Management expects existing cash resources to fund operations through 2027, extending well beyond the anticipated first quarter 2027 topline data readout.
• A subcutaneous formulation of PMN310 is under development to support patient convenience and is intended for incorporation into the next phase of clinical development.
• The Company plans to request a meeting with the FDA in 2027 after analyzing the full dataset from the PRECISE-AD trial.
• A registrational study for the subcutaneous formulation is anticipated to initiate toward the end of 2027, subject to FDA feedback.
• Completion of all PRECISE-AD patient visits is expected in the fourth quarter of 2026.

Business Segments and Product Lines:

• PMN310 (Alzheimer's Disease): The lead candidate is a humanized IgG1 monoclonal antibody designed to selectively bind toxic amyloid-beta oligomers while avoiding monomers, fibrils, and plaque. It has received Fast Track Designation from the FDA.
• PRECISE-AD Trial Results: Blinded six-month interim data from 136 patients showed no ARIA-E in any APOE genotype (including 11% APOE4 homozygotes), ARIA-H of 4.4% (all mild and asymptomatic), no drug-related discontinuations, and no treatment-related serious adverse events. Biomarkers showed a decrease of approximately 15% in plasma pTau217 and 13.3% in CSF MTBR-tau243.
• PMN267 (ALS): The program targeting misfolded TDP-43 is advancing a lead humanized monoclonal antibody for extracellular administration and an intrabody format for intracellular delivery.
• PMN442 (Synucleinopathies): The lead candidate for dementia with Lewy Bodies, Parkinson's Disease, and Multiple System Atrophy was selected for its selective binding against pathogenic alpha-synuclein and has been humanized in an IgG1 framework for IND-enabling studies.
• Vaccine Programs: Lead candidates include PMN311 (amyloid-beta oligomers in AD), PMN440 (pathogenic alpha-synuclein), and PMN260 (misfolded TDP-43). All have shown robust immunogenicity in mouse studies, with PMN440 demonstrating protective activity in synucleinopathy models.
• Corporate Appointments: Ivana Rubino, Ph.D., a former senior Biogen and Roche executive with over 15 years of neuroscience leadership experience, was appointed Chief Commercial Officer effective October 5, 2026.

Market and Competitive Landscape:

• Management states that PMN310 offers a differentiated approach by selectively targeting toxic amyloid-beta oligomers, whereas other antibodies have shown binding to multiple forms of amyloid-beta, including plaque, resulting in significant amyloid-related imaging abnormalities (ARIA).
• The Company believes PMN310 could achieve a leadership position in treating early AD and potentially asymptomatic (preclinical) AD patients if it demonstrates a benefit-risk profile with ARIA rates similar to placebo and efficacy comparable to existing standards of care.
• The PRECISE-AD trial is the first study to examine the effects of a monoclonal antibody directed solely against Aβ oligomers on biomarkers associated with AD pathology and clinical outcomes.

Risks and Challenges:

• Forward-looking statements include risks that early or interim results may not be indicative of final or topline results.
• The Company faces risks related to its accumulated deficit and expectations for continued losses.
• Actual results may differ materially from projections due to known and unknown risks, uncertainties, and assumptions regarding the interpretation of clinical data, FDA interactions, and development timelines.

Management Commentary and Tone:

• CEO Neil Warma described the third quarter of 2026 as productive, citing encouraging interim data from the PRECISE-AD trial.
• Management expressed confidence that PMN310's distinct clinical hypothesis, supported by its selectivity and IgG1 backbone, could lead to an improved benefit-risk profile compared to existing therapies.
• The tone is forward-looking and confident regarding the potential to shift the treatment paradigm for Alzheimer's disease by reducing ARIA liability associated with plaque binding.

Other Key Points:

• The PRECISE-AD six-month interim data was selected for poster presentation at the 2026 Clinical Trials in Alzheimer's Disease (CTAD) conference in Boston (November 16–19, 2026).
• Abstracts on the PRECISE-AD trial and PMN440 alpha-synuclein vaccine activity were selected for platform presentations at the 2027 AD/PD conference.
• Management participated in six healthcare investor conferences, including Cantor and H.C. Wainwright, and the CEO participated in the Lausanne XIII Workshop and a Nasdaq interview for World Alzheimer's Day.
• The Company utilizes the proprietary EpiSelect™ drug discovery engine to identify Disease Specific Epitopes (DSEs) on misfolded proteins.
• The Company has offices in Cambridge, Massachusetts, and Toronto, Ontario.