Why Is Genetic Disease Focused Reneo Pharmaceuticals Stock Plummeting Today?

Reneo Pharmaceuticals Inc RPHM shares are sinking after the company released data from its pivotal STRIDE Phase 2b study of mavodelpar in adult patients with primary mitochondrial myopathies (PMM), a group of mitochondrial diseases that cause prominent muscular problems.

The study did not meet its primary efficacy or secondary efficacy endpoint. 

The trial's primary efficacy endpoint was the change from baseline in the distance walked during the 12-minute walk test (12MWT) at week 24. 

The secondary efficacy endpoint was the change from baseline in the PROMIS Short Form Fatigue 13a score.

The company intends to implement immediate cost savings initiatives, including suspension of the ongoing STRIDE AHEAD study and all other mavodelpar development activities and a workforce reduction of approximately 70%. 

The STRIDE AHEAD study was an open-label extension (OLE) trial being conducted outside of the United States in adult patients with PMM due to mtDNA defects who participated in the STRIDE study, the mavodelpar Phase 1b study, and mavodelpar-naïve patients with PMM due to nuclear DNA (nDNA) defects. 

The study was designed to evaluate the long-term safety and tolerability of 100 mg mavodelpar administered once-daily over 24 months.

The company has over $100 million in cash, cash equivalents, and short-term investments.

Price Action: RPHM shares are down 87% at $1.01 on the last check Thursday.