Licensor, Medarex, lost 16.84% of its value.

The halt of Phase III melanoma compound tremelimumab spells Pfizer’s second late-stage disappointment in recent past and sent Medarex’ stock crashing. Pfizer licensed the compound from Medarex for development in multiple indications. Interim analyses of the Phase III trial in melanoma concluded that the molecule would be no better than standard chemotherapy.

Medarex opened at $7.75, about 16.84% down from the previous day’s closing price. Besides today’s failed investigation, part of the lost value may be attributed to a decreased confidence in the company’s second melanoma drug candidate, which is partnered with Bristol-Myers Squibb.

All is not lost for Medarex, however, who may still earn significant milestones and eventually royalties on other allied development programs.

Pfizer, on the other hand, has been marred by recent letdowns. In October 2007, the company said that it would stop making inhaled insulin product, Exubera, which tanked in commercialization. In late 2006, Pfizer axed development of cholesterol medication, Torcetrapib, another potential blockbuster. The company did, however, recently gain approval for anti-HIV agent, maraviroc.

Previous articleGenta Cuts More Jobs in the Aftermath of Failed Drug