New York – October 29, 2026 -- ProJenX will present long-term Phase 1b data at the 2026 NEALS Annual Meeting showing that its ALS candidate prosetin reached target therapeutic exposures and kept a favorable safety profile over extended dosing. The meeting runs Oct. 27-30 in Clearwater, Florida, and online.
PRO-101 data show target engagement tracking with prosetin exposure
Prosetin is an oral, CNS-penetrant MAP4K inhibitor being tested in people with ALS in the Phase 1b PRO-101 study. The trial is evaluating safety, tolerability, pharmacokinetics and pharmacodynamics. According to CEO Stan Abel, target engagement in PRO-101 tracked with exposure.
Abel said the results show for the first time that CNS-penetrant MAP4K inhibition is "a viable clinical strategy." The company has not disclosed participant numbers, dosing levels or efficacy endpoints in this announcement.
Preclinical work shows prosetin corrects TDP-43 mis-splicing in human motor neurons
New in vitro data show that prosetin broadly corrects TDP-43-related mis-splicing in human stem cell-derived motor neurons. ProJenX says internal and independent data also show MAP4K inhibition has neuroprotective effects across diverse preclinical ALS models, including significant rescue of TDP-43 pathology in vitro.
MAP4K was first identified as a regulator of proteotoxic stress-mediated motor neuron loss on a human stem cell-based discovery platform. ProJenX's scientific founders developed the platform at Columbia University.
Three NEALS presentations are scheduled for Oct. 28-29
- Oct. 28, 4:50 pm ET, Poster #56: preclinical characterization of prosetin.
- Oct. 29, 9:50 am ET, oral presentation: early incorporation of lived experience in the prosetin program, in the session "A Collaborative Ecosystem for Clinical Trial Innovation."
- Oct. 29, 4:50 pm ET, Poster #207: PRO-101 Phase 1b results.
The oral presentation will cover the role of ProJenX's Community Advisory Board across the development program. Prosetin is an investigational new drug and has not been approved by the FDA.