Clene submits NDA for ALS drug CNM-Au8, banking on a biomarker. Clene has filed a New Drug Application with the FDA seeking accelerated approval of CNM-Au8 for ALS, using reductions in plasma neurofilament light chain (NfL) as a surrogate endpoint. The submission comes despite two missed primary trial endpoints, with survival signals from open-label extensions helping build the regulatory case.
Clene files for FDA accelerated approval of ALS drug CNM-Au8 after years of mixed trial results
Clene has submitted a New Drug Application (NDA) to the FDA seeking accelerated approval of CNM-Au8 for amyotrophic lateral sclerosis (ALS). The filing is anchored on reductions in plasma neurofilament light chain (NfL) — a blood-based biomarker of neuronal injury — as a surrogate endpoint, alongside clinical outcomes data. The company is simultaneously planning a confirmatory phase 3 trial set to begin in Q1 2027.
The road to this filing was anything but smooth. CNM-Au8 missed its primary endpoint in both the RESCUE-ALS phase 2 trial and the HEALEY ALS Platform Trial. However, open-label extension data from both studies showed roughly 60% reductions in long-term mortality risk and meaningful NfL reductions, which ultimately shaped Clene's regulatory strategy. The FDA's accelerated approval pathway here mirrors its 2023 approval of tofersen (Qalsody) for SOD1-mutated ALS — the first ALS therapy cleared on NfL reduction as a surrogate biomarker.
By the Numbers
Why it matters: ALS remains a devastating disease with very few treatment options. If approved, CNM-Au8 would offer a new mechanism of action for patients, and its NfL-based approval pathway could further validate biomarker-driven drug development in neurodegenerative diseases.
