Rare disease setbacks for Ultragenyx, mid-stage win for Rhythm

It’s been a tough week for Ultragenyx, with its stock price taking a hit after announcing two program delays. Fellow rare disease company Rhythm Pharmaceuticals posted the only notable data-driven gain in the last seven days, based on Phase II results in acquired hypothalamic obesity.

Shares of Ultragenyx Pharmaceutical Inc. (NASDAQ:RARE) fell 25% last Thursday, translating to $940 million lost market cap, after data from its Phase II Orbit trial in patients with osteogenesis imperfecta failed to clear a second interim threshold of p=0.01, which would have triggered stopping the trial early for efficacy. The study is instead proceeding to the trial to final analysis, which has a threshold of p<0.04. ...