West Coast Editor

Two days after the FDA rejected a separate partner's new drug application for their antibiotic, Forest Laboratories Inc. said the steering committee placed on hold the Phase IIb/III study with desmoteplase, the plasminogen activator for acute ischemic stroke in-licensed from Paion AG.

New York-based Forest's stock (NYSE:FRX) closed Wednesday at $48.08, down $1.34, after starting to recover from Monday's 5 percent haircut that left shares at $48.86.

"The market is saying they think this thing is gone," said analyst Megan Murphy with Lazard Capital Markets in New York, although she had not placed much overall value in the drug. "It's not of individual importance, but it's important in the macro sentiment of whether their pipeline will survive standard industry attrition rates," she told BioWorld Today.

The steering panel for the desmoteplase trial followed the advice of an independent data monitoring committee, which recommended that the study stop while researchers use more data to evaluate an undisclosed safety signal. No conclusions about the drug's safety or efficacy should be drawn as a result of the move, the committee said.

"You could speculate a million ways to Sunday what's going on," Murphy said, adding that the trial's monitors "supposedly have the data now and are convening to look at it." She expects a decision early next week on the next step. "They've had two successful safety looks [at the study] already," she added.

Stroke trials can fail because patients aren't well screened, or don't get enough drug, or get the drug too late.

"You can be too aggressive on your window," Murphy said. "From a marketing perspective, you want to get as much time as possible" from the point of stroke to the time the drug is administered. "They're going for three to nine hours [with desmoteplase]," she said, and that window has worked in Phase II trials.

Activase, the tissue plasminogen activator from South San Francisco-based Genentech Inc. that was cleared for stroke in 1996, must be given within three hours of an episode. Neurobiological Technologies Inc.'s Viprinex (ancrod), the Phase III defibrinogenating thrombin-like enzyme derived from the venom of the Malayan pit viper, has shown efficacy when given as long as six hours after a stroke. (See BioWorld Today, July 16, 2004.)

Forest at one point considered in-licensing Viprinex, and NTI sniffed out desmoteplase but chose Viprinex - gained through the buyout of Empire Pharmaceuticals Inc. for $23 million in 2004 - because the drug had been tested in more patients. NTI, a smaller company, didn't like desmoteplase's risk profile. (See BioWorld Today, July 16, 2004.)

Forest is paying clinical development costs for the drug as part of a 2004 deal with Aachen, Germany-based Paion. European and Asian marketing rights to the compound belong to H. Lundbeck A/S, through an arrangement made with Paion in 2005.

Word on desmoteplase, an engineered version of a clot-dissolving protein found in the saliva of the vampire bat Desmodus rotundus, followed news of a non-approvable letter from the FDA regarding the NDA for the antibiotic faropenem, partnered with Replidyne Inc. The agency wants further clinical studies, which means a delay of at least two years. (See BioWorld Today, Oct. 24, 2006.)

Faropenem's trouble was, "at a minimum, a big setback," Murphy said. "We're not sure that drug is capable of getting approved. The take-away is yet another reminder that you need a lot of products in the clinic to hope that a couple make it to the finish line."

In a research report this week, Murphy still is behind Forest.

"We wouldn't condemn the remaining portfolio on this [faropenem] news," she wrote, pointing to a pipeline that includes a filed NDA, two products in Phase III trials and three in Phase II.