Reneo Pharmaceuticals Inc.’s $93.8 million IPO last month brought renewed attention to primary mitochondrial myopathy (PMM), a genetic disorder that impairs oxidative phosphorylation, affecting mainly muscles. The San Diego-based firm sold about 6.2 million shares at $15 each, but the stock (NASDAQ:RPHM) has since taken a dive, closing May 19 at $8.83.