ProJenX Announces Removal of Partial Clinical Hold for Prosetin Program by FDA

NEW YORK, NY, March 28, 2024 – ProJenX, a clinical-stage biotechnology company developing novel, brain-penetrant therapies targeting biologically-defined pathways for the treatment of amyotrophic lateral sclerosis (ALS) and other debilitating brain diseases, today announced that the United States Food and Drug Administration (FDA) has removed a partial clinical hold on Study PRO-101, a hybrid Phase 1 clinical trial evaluating prosetin—a first-in-class MAP4 kinase (MAP4K) inhibitor—in healthy volunteers and participants with ALS. The healthy volunteer portions of the trial have been completed, and the company is initiating Part 1c of PRO-101, designed to evaluate the safety, tolerability, pharmacokinetics, and pharmacodynamics of prosetin in participants with ALS.

Stan Abel, President and Chief Executive Officer at ProJenX, commented, “Recent clinical trial results in ALS have further demonstrated the urgent need for meaningful therapies that can alter the course of this devastating disease. Our Columbia University and Project ALS co-founders have invested over two decades in scientific research that shows a critical role for MAP4K inhibition on ALS motor neuron survival, and we are thrilled to be advancing prosetin to people living with ALS in the coming months.”

“Following recent Clinical Trial Application authorizations in Canada and Europe, we are very pleased that FDA has lifted this partial clinical hold, which previously limited prosetin dose levels in Study PRO-101 in the United States,” added Erin Fleming, Co-Founder and Chief Operating Officer at ProJenX. “The FDA’s decision allows us to fully pursue a global strategy to bring this promising investigational treatment to people with ALS and other neurodegenerative diseases.”

Prosetin is a selective, oral, brain-penetrant, MAP4K inhibitor developed by ProJenX co- founders at Columbia University for the treatment of ALS. Following the discovery that MAP4K inhibition confers potent motor neuron protection across multiple patient stem cell-derived models of ALS, prosetin was optimized for potency against MAP4Ks, efficacy in motor neuron rescue, and preferential distribution to the CNS.

“There is an immense unmet need for safe and effective treatment options for ALS, and prosetin is an exciting investigational therapy option in the current clinical trial landscape,” said Jinsy Andrews, MD, MSc, Associate Professor of Neurology and Director of Neuromuscular Clinical Trials at Columbia University. “I am encouraged by prosetin’s compelling preclinical efficacy data and by its consistent safety and tolerability profile in healthy volunteers and chronic toxicology studies, and look forward to working with the ProJenX team to bring Study PRO-101 to people living with ALS in the United States.”

About PRO-101

PRO-101 is a three-part Phase 1 clinical trial designed to evaluate the safety, tolerability, pharmacokinetics, and pharmacodynamics of prosetin in healthy volunteers and patients with ALS. Parts 1a and 1b, which have been completed, consisted of a randomized, double-blind, placebo-controlled, dose-escalating study to evaluate the safety, tolerability, and pharmacokinetics of single ascending and multiple doses of prosetin in healthy volunteers. Based on favorable safety, tolerability, and pharmacokinetic data from this portion of the study, Part 1c will evaluate the safety, tolerability, pharmacokinetics, and pharmacodynamics of prosetin in ALS patients. For more information about PRO-101, contact [email protected].

About ProJenX

ProJenX is a clinical-stage biotechnology company developing novel, brain-penetrant, targeted therapies to address untreatable brain diseases, with an initial focus on ALS. ProJenX was created out of a long-term research collaboration between Project ALS and researchers at Columbia University to rapidly develop and commercialize its lead therapy candidate, prosetin, for people living with ALS. At the heart of ProJenX’s approach is an innovative, patient-specific, cell-based drug discovery platform that can be leveraged for research and drug development for ALS and other debilitating brain diseases. For more information, visit

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Margot Shanahan
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