FDA throws up a tricky roadblock for Arena's lorcaserin

The FDA has issued a Complete Response Letter to Arena Pharmaceuticals rejecting an immediate approval for the weight drug lorcaserin.

The FDA has issued a Complete Response Letter to Arena Pharmaceuticals rejecting an immediate approval for the weight drug lorcaserin and pointing the developer down a very narrow regulatory path that just might let the developer skirt the need for new clinical studies. Arena eagerly announced plans to meet with the FDA as soon as possible to address its concerns, hopeful that it won't have to wait very long to get a thumb's up. Some analysts, though, sounded distinctly doubtful that any quick resolution is in the offing and at least one thought the delay could stretch out as much as five years.

Arena announced the CRL on Saturday, a day after the agency's PDUFA date for one of the most closely watched decisions of the year. In it, the developer said, the FDA detailed its concerns about signs of tumors found during an animal study and voiced concerns that the weight-loss experienced by non-diabetics in its clinical trials was marginal. Regulators asked for new data from a on