West Coast Editor

Tibotec Pharmaceuticals Inc. submitted a new drug application for TMC114, its protease inhibitor for HIV, based on 24-week findings from two Phase IIb studies, thereby moving another compound officially nearer to the competitive space - though the drug has been available through an expanded-access program since October.

"You have a growing population of treatment failures, and the trial results here were pretty stunning," noted Andrew McDonald, analyst with ThinkEquity Partners LLC in San Francisco. "Half of the patients went undetectable' [in terms of viral load] as compared to 10 percent in the control arm."

Data from one of the studies, called POWER 1, were presented at the International AIDS Society (IAS) conference in Rio de Janeiro in July. POWER 2 data were offered earlier this month at the 45th Interscience Conference on Antimicrobial Agents and Chemotherapy in Washington, where "enthusiasm was very high," McDonald said.

Boosted with low-dose ritonavir, TMC114 is in Phase III trials in treatment-experienced and treatment-na ve HIV-1 infected patients. As of this fall, the compound is available through the expanded access program for patients who've failed therapy but are not eligible for trials.

Pending U.S. regulatory approval, Cork, Ireland-based Tibotec, a division of Ortho Biotech Products LP (a subsidiary of Johnson & Johnson) will commercialize the product in the U.S., but the trade name has not been determined.

In the months ahead, Tibotec plans regulatory moves overseas, too.

Although integrase inhibitors currently are the "hot" item in HIV therapy, TMC114 is "one of the more important agents" for patients whose disease has beaten other drugs, McDonald said.

"There's nothing to give them, once they get to this point," he said, and TMC114, though it does not boast a new mechanism of action, "is really a credit to the scientists at Tibotec. They're a very impressive group."

As for the market, McDonald estimates $200 million to $300 million in yearly sales, with "maybe double or triple that in 10 years, if everything goes right. There are a lot of factors that make forecasting second-line to salvage-line therapies fairly difficult."

Tibotec's main competitor for TMC114 is Aptivus (tipranavir), from Boehringer Ingelheim GmbH, of Ingelheim, Germany. Aptivus already is cleared for marketing in Europe.

"Right now, when you do these physician surveys, which ask which agents they would use for patients who've failed prior therapies, they're split equally," McDonald said. "As the years go by, that balance may shift over to TMC114."