ProMIS Neurosciences (PMN) rose 7.7% to $13.49 after its chief executive and chief medical officer presented interim data from a Phase 1b trial of its Alzheimer's antibody candidate PMN310 at the Moody Capital Disruptive Growth & Life Science Conference on Thursday.
The company reported zero cases of amyloid-related imaging abnormalities-edema (ARIA-E) across 136 patients evaluated in a six-month blinded interim safety analysis conducted July 28, including no ARIA-E in patients carrying the APOE4 gene variant, which carries the highest risk for the side effect.
"We saw zero cases of ARIA-E," said CEO Neil Warma. "We saw no treatment-related serious adverse events. We saw no treatment-related dropouts."
PMN310 is a second-generation monoclonal antibody that targets beta-amyloid toxic oligomers while sparing plaques and monomers. Warma said the design approach allows it to "avoid plaque, and it certainly avoids the monomers."
The trial enrolled 144 patients across three ascending dose cohorts in a placebo-controlled, double-blind study randomized three to one toward active treatment. Patients averaged about 73 years old and included early Alzheimer's individuals with mild cognitive impairment, including APOE4 carriers.
Beyond safety, ProMIS highlighted biomarker activity. P-tau217 levels fell 15% over six months, reversing the typical upward disease-progression slope, according to Warma. About 68% of evaluable patients showed declining p-tau217, while 31% showed increases — roughly tracking the randomization ratio.
MTBR-tau243, a downstream biomarker, moved in a favorable downward trend aligned with the randomization scheme, the company said.
Warma contrasted the safety profile with competing amyloid drugs. Eli Lilly's donanemab showed approximately a 24% ARIA-E rate at six months, while Eisai and Biogen's lecanemab showed about 12% overall and 30% in APOE4 carriers, according to the presentation.
The stock gained 11% over the prior week and has returned 110% year to date through Thursday, though it remains well below its 52-week high of $27.40 and above its low of $6.27.
ProMIS raised up to $175 million in February from institutional biotech investors. It expects final top-line Phase 1b unblinded results in Q1 2027 and a planned FDA meeting next year to discuss the Phase 3 registration path. The company also disclosed preclinical programs targeting misfolded TDP-43 for ALS and misfolded alpha-synuclein for Parkinson's disease and Lewy body dementia.
"The disconnect between where we're trading today versus the potential of where this could get to in Q1, Q2 next year with the results is quite significant," Warma said.
