Hubert Chen resigns as Pfenex CMO ahead of NDA

Hubert Chen, M.D., has resigned as CMO of Pfenex. The imminent departure leaves Pfenex without a CMO as it gears up to file a new drug application (NDA), although Chen will continue to advise the biotech as it interacts with the FDA.

Chen spent the past four years at Pfenex, guiding the biotech through a period in which it generated pivotal data on its lead asset, PF708. The drug performed comparably to the product it is based on, Eli Lilly’s Forteo, in osteoporosis patients, setting Pfenex up to file for approval later this year. Chen stuck around for the pre-NDA meeting but will leave Pfenex on Sept. 2.

Pfenex is looking for a successor for Chen—who has also held the CSO post for the past year—but in the interim thinks it is equipped to prosper without a full-time CMO. That optimism is underpinned by Chen’s ongoing involvement in the regulatory process. 

“We believe the U.S. Food and Drug Administration supports our strategy for filing the new drug application for PF708, and will not request additional clinical, nonclinical or analytical comparability studies. As we have concluded the clinical development of the program, we are pleased that Dr. Chen will support upcoming FDA interactions,” Pfenex CEO Eef Schimmelpennink said in a statement.

Schimmelpennink expects to file for approval in the fourth quarter and, if all goes to plan, bring the drug to market in the U.S. in the third quarter of 2019. Alvogen is handling manufacturing and commercialization of PF708 under the terms of an agreement it struck with Pfenex in June.

Pfenex’s plan to win approval is based on data from the aforementioned 181-person trial. The rate of immunogenicity and change in bone formation biomarkers were comparable among the cohorts that received PF708 and Forteo. Pfenex hopes that will result in PF708 being rated as therapeutic equivalent.