Arena stands by plan to short-circuit rat study for lorcaserin

Disregarding the harsh reviews Arena Pharmaceuticals earned after the FDA rejected its closely-watched obesity drug lorcaserin, the biotech's CEO is telling investors that the developer is zeroing in on a three-month rat study to satisfy the FDA's concerns about evidence of cancer seen in its early research work on the drug. When the agency rejected Arena's marketing application, it suggested a 12-month rat study to satisfy its questions outlined in a CRL.

"We have talked with the (FDA), and the discussion was just on the shorter study," CEO Jack Lief told analysts, according to a report in the San Diego Union-Tribune. If the agency accepts the three-month study, he added, Arena expects to resubmit its application by the end of this year, sticking with a controversial timeline laid out after the rejection. In a release Arena noted that "Arena and Eisai (its partner)  believe that prolactin studies of three months and shorter duration will be sufficient to test the hypothesis that lorcaserin causes mammary tumors in rats by increasing prolactin effects on the mammary gland, and currently do not anticipate initiating a 12-month study in female rats."

When lorcaserin was rejected last fall a number of industry analysts hooted at the biotech company's insistence that it might not have to complete the agency's suggested 12-month animal study. Forbes' Matthew Herper went so far as to call on Lief to stand down, saying that he had lost sight of what was needed to get an approval. "Executives at Arena probably believe so passionately in lorcaserin that they can't believe anyone could doubt it," Herper noted in January. "Belief and faith are what have gotten Arena this far, but they are not what is needed now. It's time to figure out how to get the drug approved, and that could require a fresh set of eyes."

Arena lost close to $40 million in the first quarter, which was far worse than analysts had expected. Company officials said that its fundraising deal with Deerfield forced them to retire debt ahead of schedule, altering the expected three-month outcome. Arena is still racing two other companies to what it hopes will be an eventual approval for a new obesity drug, something not seen in more than a decade. Regulators and agency experts have raised a high bar on safety for any obesity drug intended for a mass market. 

- check out the release from Arena
- see the report from the San Diego Union-Tribune