Reneo Pharmaceuticals Inc. is halting development of its only asset, mavodelpar, after a phase IIb study missed its primary and secondary efficacy endpoints. The selective peroxisome proliferator-activated receptor (PPAR)-delta agonist was being developed to treat to rare genetic mitochondrial diseases.

Stealth Biotherapeutics Corp.’s refusal to file (RTF) letter from the FDA regarding the NDA for elamipretide, a candidate that targets mitochondria in the treatment of Barth syndrome, hardly knocked the stock, as investors likely saw the bad news coming.