Another FDA hurdle for Orexigen obesity drug candidate

It might seem to some that the US Food and Drug Administration has no intentions of approving any new prescription drugs to treat obesity or manage weight loss, having so far put stumbling blocks in the way of all current candidates, the latest being another setback for Orexigen Therapeutics (Nasdaq: OREX) Contrave (naltrexone SR and bupropion SR), which is partnered with Japan’s Takeda (TYO: 4502). The agency has not cleared a new weight-loss drug since 1999.

Orexigen says it has received a Complete Response Letter to its New Drug Application noting a single approval deficiency related to cardiovascular safety, requiring Orexigen to conduct a randomized, double-blind, placebo-controlled cardiovascular outcomes trial prior to approval. The objective of the trial is to demonstrate that Contrave does not unacceptably increase the risk of major adverse cardiovascular events (MACE). The company plans to initiate the Contrave outcomes trial late in the second quarter of this year.

Other potential obesity drugs that have hit the FDA buffers include Arena and Eisai’s Lorquess (lorcaserin) and Vivus’ Qnexa (phentermine/topiramate), although the latter looks the most likely to gain first approval (The Pharma Letter January 11), while Amylin Pharmaceuticals and Japan’s Takeda Pharmaceutical have discontinued development of pramlintide/metreleptin for obesity (TPL August 8, 2011).