Idenix Inks HIV-Drug Deal with GSK Worth up to $450M

Shares of Idenix Pharmaceuticals (NASDAQ: [[ticker:IDIX]]) jumped in pre-market trading this morning on the news that the Cambridge, MA-based developer of treatments for infectious diseases has inked a deal with pharma giant GlaxoSmithKline potentially worth some $450 million.

GSK will pay Idenix $34 million upfront—half as cash and half via a purchase of its stock at $6.87 a share, a premium over yesterday’s close of $6.44—for exclusive worldwide rights to the Massachusetts firm’s HIV drug IDX899. The drug, a member of a class called non-nucleoside reverse transcriptase inhibitors, is in mid-stage trials as a once-a-day treatment for HIV/AIDS. Idenix is also poised to collect up to $416 million in milestone payments tied to the development, regulatory approval, and sales of the drug, and it will be entitled to “double-digit, tiered worldwide royalties” as well, according to a press release.

Idenix shared opened at $6.74, up 4.7%  from yesterday’s close. The upfront money from GSK represents a sizable addition to Idenix’s coffers, which held about with $45 million to $50 million at year’s end.

Author: Rebecca Zacks

Rebecca is Xconomy's co-founder. She was previously the managing editor of Physician's First Watch, a daily e-newsletter from the publishers of New England Journal of Medicine. Before helping launch First Watch, she spent a decade covering innovation for Technology Review, Scientific American, and Discover Magazine's TV show. In 2005-2006 she was a Knight Science Journalism Fellow at MIT. Rebecca holds a bachelor's degree in biology from Brown University and a master's in science journalism from Boston University.