ProMIS Neurosciences (NASDAQ:PMN) expects to report unblinded 12-month data from its Phase 1b Alzheimer’s disease trial in the first quarter of 2027, a milestone that management says will help determine whether its lead antibody, PMN310, can offer a better balance of safety and efficacy than existing treatments.
All patient visits in the PRECISE-AD study are expected to conclude in the fourth quarter of 2026, President and Chief Executive Officer Neil Warma said on the company’s November 12 earnings call. The company ended the third quarter with $44.1 million in cash and expects that funding to last through 2027.
What Management Wants to See in the Data
PMN310 is designed to selectively bind and clear toxic amyloid-beta oligomers, which ProMIS believes contribute to neurodegeneration in Alzheimer’s disease. Warma said the company’s goal is to maintain efficacy comparable to approved therapies while reducing the risk of amyloid-related imaging abnormalities, or ARIA.
Management will assess safety, clinical outcomes, biomarkers and changes in oligomer levels when the trial data become available. Warma said the company wants to see a directional slowing of cognitive decline versus placebo on either the iADRS or CDR Sum of Boxes measures.
During the question-and-answer session, Warma said a slowing of decline in the approximate range of 15% to 20%, accompanied by a substantially improved safety profile, would be a significant win. He cautioned against direct comparisons between ProMIS’ roughly 140-patient, 12-month study and larger studies conducted over 18 months. His estimate was an extrapolation from results of those longer studies, not a forecast of PMN310’s results.
Warma also discussed a separate company’s recent Phase 2 trial of an antibody described as oligomer-selective, which did not meet its primary or secondary endpoints. He argued that plaque reductions and cases of brain swelling in that trial suggested the antibody engaged plaque and fibrillar amyloid. That interpretation reflects ProMIS management’s assessment; Warma said the disclosed data were limited.
Interim Findings Remain Blinded
In a six-month interim analysis reported in July, ProMIS said there were no cases of ARIA-E, a form of brain swelling, among 136 safety-evaluable patients across APOE genotypes. ARIA-H, which involves bleeding-related abnormalities, occurred at a rate of 4.4%; all cases were mild and asymptomatic. The company also reported no drug-related discontinuations or treatment-related serious adverse events.
The pooled analysis showed plasma p-tau217 decreased approximately 15% from baseline and cerebrospinal fluid MTBR-tau243 decreased approximately 13%. Warma emphasized that the observations were blinded and pooled across treatment and placebo groups, so they do not establish efficacy. He also said ProMIS did not disclose the number of patient samples used for each biomarker at the interim analysis.
ProMIS has not conducted head-to-head studies comparing PMN310 with approved therapies. Chief Medical Officer Dr. Larry Altstiel said any reduction in MRI monitoring requirements would need to be discussed with the Food and Drug Administration as safety evidence accumulates.
The company plans to use an assay in PRECISE-AD to measure changes in oligomer levels before and after treatment. Altstiel said the assay measures absolute oligomer concentrations in cerebrospinal fluid, while Warma said the results could help test the drug’s proposed mechanism of action.
Planning for a Potential Registration Study
PMN310 has received fast-track designation, and ProMIS intends to request an FDA meeting after analyzing the full trial data. Warma said the company is preparing for a potential registration-quality study that could begin toward the end of 2027, subject to regulatory feedback.
The company is also developing a subcutaneous formulation. Warma said the goal is to bring PMN310 to market in that form and potentially include a subcutaneous arm in a larger study without delaying development of the intravenous formulation. The final design, size and cost of a registration study remain under consideration.
Warma said ProMIS will present its previously disclosed interim findings at the upcoming CTAD conference but does not expect to present new data there. He also noted that Dr. Ivana Rubino joined as chief commercial officer in October.
Third-Quarter Financial Results
Research and development expenses fell 32% to approximately $6.7 million from $9.8 million a year earlier. The decline was primarily driven by lower direct PMN310 costs as PRECISE-AD approached completion, partly offset by increased activity in the company’s ALS and other pipeline programs.
General and administrative expenses were approximately $1.9 million, compared with $2 million a year earlier. Other income rose to about $0.5 million from $0.2 million, reflecting higher interest income.
ProMIS reported a third-quarter net loss of $8.2 million, or $0.89 per share, compared with a loss of $11.6 million, or $5.93 per share, a year earlier. For the first nine months of 2026, its net loss was approximately $28.1 million, or $3.39 per share, compared with $29 million, or $19.58 per share, in the same period of 2025.
About Promis Neurosciences (NASDAQ:PMN)
ProMIS Neurosciences Inc. (NASDAQ: PMN) is a clinical-stage biotechnology company developing precision medicines for neurodegenerative diseases. The company’s research focuses on misfolded proteins, which can form toxic structures associated with conditions such as Alzheimer’s disease, amyotrophic lateral sclerosis and other neurological disorders. ProMIS uses its proprietary target-discovery platform to identify disease-specific toxic protein conformations and develop antibodies intended to selectively bind and neutralize them while avoiding healthy forms of the same proteins.
