After patient deaths, new Zafgen obesity med data revives approval hopes
- Zafgen shares continued to rise in Thursday morning trading after closing up about double its Tuesday closing price on Wednesday thanks to promising new clinical trial data for the firm's embattled lead product, beloranib.
- Belonarib is intended for the treatment of obesity linked to compulsive overeating by patients with a rare genetic disorder called Prader-Willi syndrome. The condition affects approximately 1 in 13,000 people.
- The investigational candidate attempts to shift the manner in which the body metabolizes fat. But its run into several significant clinical problems, including the deaths of two study participants in October and December, respectively, from blood clots. That second death led to a complete clinical hold being placed on belonarib trials by the FDA.
The data that was released on Wednesday stems from 74 patients who had completed the phase 3 trial before the FDA's hold and another 27 who had completed at least three-quarters of the trial. Specifically, the data showed significant body weight reductions (9.45% weight loss at a 2.4 mg dose and 8.2% loss at 1.8 mg) and reduced the urge to overeat associated with Prader-Willi syndrome.
"The fact that our drug is impacting both of the major issues that confront these patients is clearly a path forward," Zafgen CEO Thomas Hughes told Reuters in an interview.
Zafgen is by no means out of the woods. The firm argues that with a robust screening and risk mitigation process, the treatment can be targeted towards those who can truly benefit from it without the elevated adverse event risk.
But the fact that the second death in December occurred in a patient who had gone through the study's screening procedure may leave lingering doubts in regulators' minds, meaning the company will have to convince the FDA that the screens and risk mitigation strategies are stringent enough to ensure patient safety.
Despite the stock rise on Wednesday and Thursday, Zafgen is still substantially off from its pre-patient death October high of $35.18.