FDA Slaps Clinical Hold on Zafgen’s Lead Product Over Safety Concerns

Shares of Boston-based Zafgen, Inc. plunged more than 32 percent in pre-market trading after the company announced the U.S. Food and Drug Administration has slapped a clinical hold on its plans to launch a clinical trial in the United States for an experimental diabetes medicine due to safety concerns.

Shares of Boston-based Zafgen plunged more than 32 percent in pre-market trading after the company announced the U.S. Food and Drug Administration (FDA) has slapped a clinical hold on its plans to launch a clinical trial in the United States for an experimental diabetes medicine due to safety concerns.

This morning Zafgen said the FDA placed a hold on the Investigational New Drug Application filed for its first U.S. trial of ZGN-1061, the company’s second-generation, investigational MetAP2 inhibitor currently in development for the treatment of type 2 diabetes. The FDA placed the hold on the planned trial over the possibility of cardiovascular risks. Zafgen said those risks cited by the FDA were based on its prior compound. The FDA outlined several paths forward for ZGN-1061, including nonclinical or clinical options in order to address those concerns. Zafgen said it intends to assess the options and request a meeting with the FDA in order to discuss the next steps for the program.

This is a position that Zafgen is familiar with. Two years ago the company halted development of its obesity drug beloranib following a lengthy clinical hold placed by the FDA. In 2016 the company decided to scrap the development of beloranib following the death of two patients in a clinical trial and focus its resources on the development of ZGN-1061. Beloranib was being developed for the treatment of the genetic disorder Prader-Willi Syndrome, which is typically associated with an insatiable appetite that leads to excessive eating and obesity, as well as cognitive issues.

In the meantime, Zafgen said it will advance its ongoing Phase II trials of ZGN-1061, which are being conducted outside of the United States. Although that trial is blinded, Zafgen said no cardiovascular issues have so far been observed. Top-line results from this trial are expected in early 2019. Zafgen previously reported positive 12-week results for its initial cohort of this Phase II proof-of-concept clinical trial. The company said in that initial cohort, ZGN-1061 met all primary endpoints, demonstrating proof-of-concept efficacy with robust A1C lowering effects. Additionally, the company said that initial data showed a favorable safety and tolerability profile that was generally comparable to placebo. No treatment-related serious adverse events and no CV safety signals had been observed, the company added.

As a treatment for Type 2 diabetes, ZGN-1061 is anticipated to improve glycemic control while also helping to restore balance to fat metabolism, enabling calories to once again be used as a productive energy source, leading to improved metabolic control and long-term weight loss, according to company information.

With the new delay in the development of ZGN-1061, Zafgen expects its cash runway will extend through 2020, with sufficient capital through multiple milestones, the company said.

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