A Glimmer of Hope for Beloranib

The folks at Zafgen released a glimmer of hope for beloranib this week. On Wednesday, Zafgen announced that this investigational new drug met its two primary efficacy endpoints in the pivotal clinical trial for treating Prader-Willi syndrome (PWS). In December, that trial was halted after a second patient suffered a fatal blood clot in the trial. Zafgen has been developing beloranib for treating severe forms of obesity since its founding in 2005.

Patients with PWS who received beloranib lost significantly more weight than patients on placebo (p<0.0001) and had significantly less (p=0.0003) of the abnormal hunger that PWS causes. This randomized controlled trial tested two doses of the drug against placebo and efficacy was seen at both doses. CEO Thomas Hughes commented, saying:

This clear efficacy outcome is a crucial first step in moving discussions forward with the Food and Drug Administration regarding continued development of beloranib. While we take the previously reported adverse events very seriously, we now have the robust data to provide greater perspective on the benefit/risk relationship of beloranib in this high-risk patient population. We thank our investigators, and the patients and their families for participating in the clinical trial.

Zafgen stock rebounded on this good news, but not all the way back to its previous value before the two patient deaths. Much work remains to sort out the safety issues, but these results give both Zafgen and the families of people with PWS a shot at gaining access to an effective new therapy.

PWS is a life-threatening form of obesity caused by a genetic defect that leads to an uncontrollable urge to eat, along with other physical and developmental problems. Zafgen is hard at work to understand how much of the clotting risk was due to beloranib and how that risk can be reduced. A principal investigator for the study at the University of Kansas Medical Center, Merlin Butler, offers perspective:

The efficacy of Beloranib looks very promising. We’ve seen individuals who have lost significant amounts of weight in the six-month period. We think the drug must at least diminish the food-seeking drive, which correlates to an increased caloric intake in patients.

If Zafgen can find a way forward, beloranib could become an important advance. Stay tuned.

Click here for more from Reuters and here for more details from Zafgen. For more about PWS, click here.

Glimmering Edifice, photograph © Ted Kyle

Subscribe by email to follow the accumulating evidence and observations that shape our view of health, obesity, and policy.

January 23, 2016