Epirium surfaced Dec. 18 with an $85 million series A round to develop programs aimed at rare muscular disorders.

The San Diego biotech said its scientists discovered a hormone pathway that can tweak mitochondria creation, which plays a critical role in muscle function.

Epirium conducted proof-of-concept studies in orphan diseases such as Becker muscular dystrophy, Duchenne muscular dystrophy and Friedreich’s ataxia. Its lead drug will start a clinical trial in the former disease next year.

“Epirium has discovered a novel class of therapeutics addressing not only the loss of muscle structure, but also the underlying mitochondrial dysfunction, which represents another major progression factor in diseases of muscle failure,” said Craig McDonald with the University of California at Davis, and a principal investigator of Epirium’s first company-sponsored study, in a statement.

The company has ambitions beyond muscle disease.

“In addition to orphan neuromuscular diseases, the technology is also relevant to diseases of aging, which are believed to share a common mechanism of progressive mitochondrial loss,” Epirium said in a statement.

Participating in the funding round were Longitude Capital, Arch Venture Partners, Bluebird Ventures, Adams Street Partners, Vertex Ventures HC, and The Longevity Fund.

Epirium’s CEO is Russell Cox, the former CEO of Vital Therapies and COO of Jazz Pharmaceuticals.