Interneuron regulatory update

The Lexington, Mass., company submitted its formal response to the FDA's February action letter on IPIC's NDA for dexfenfluramine to treat obesity (see BioCentury Feb. 27). IPIC said the response includes data from two studies that address the principal issues raised by the FDA, including the risk of developing primary pulmonary hypertension (PPH) and the potential for neurotoxicity.

The PPH study, done by an independent European investigator, is an international case control study assessing the potential risk factors that may contribute to the cardio-pulmonary disorder. The investigators estimated that PPH occurs at an annual rate of one to two persons per million in the general population, and increased four-fold in the group of patients reviewed. ...