Clene Inc. (Nasdaq: CLNN) announced post hoc biomarker analyses from two completed Phase 2 ALS trials that will be included in a planned New Drug Application (NDA) seeking accelerated approval for its investigational drug CNM-Au8, according to a company statement.

The analyses examined clinical outcomes among CNM-Au8-treated patients whose neurofilament light chain (NfL) levels declined or stabilized. In the HEALEY ALS Platform Trial, participants in the CNM-Au8 30 mg group whose NfL declined or stabilized showed a 38% lower risk of death than concurrently randomized controls over the full follow-up period, with a survival gain of nearly six months at four years of follow-up. The 30 mg group overall showed a 74% lower risk of death after 12 months compared with concurrently randomized controls.

A principal stratum causal analysis, which classified patients using pre-treatment characteristics only, found a 41% lower risk of death in the predicted NfL-responder group on CNM-Au8 30 mg versus controls. No statistically significant difference was observed among those predicted not to respond.

In the separate RESCUE-ALS trial, participants whose NfL declined or stabilized had a 76% lower adjusted risk of death compared with those whose NfL increased, and a 69% lower risk versus propensity-matched real-world ALS controls.

Analyses of more than 2,000 ALS patients who never received CNM-Au8, drawn from the APST and ANSWER ALS observational cohorts, found that a 10% NfL decline was associated with a 6% to 10% lower risk of death.

The company noted that neither Phase 2 trial met its prespecified primary efficacy endpoint, and that all biomarker analyses are post hoc and exploratory, with no adjustment made for multiple comparisons. The FDA has not determined whether NfL reduction is an acceptable surrogate endpoint for CNM-Au8.

Clene said it plans to file the NDA in early Q4 and intends the submission to address questions raised during a March 2026 FDA Type C meeting. The company also plans a Phase 3 confirmatory trial, RESTORE-ALS, which will prospectively evaluate the NfL biomarker relationship.