BiParFollowing through on its plans to buy up small and mid-sized drug developers, Sanofi-Aventis struck a deal to buy the U.S. cancer specialist BiPar Sciences for up to $500 million.

The money is being invested in a company that has been squarely focused on advancing new therapies that use PARP inhibitors to stop cancer cells from being able to repair DNA damage, triggering their death. Brisbane, CA-based BiPar's lead drug–BSI-201–is in four mid-stage trials for ovarian and breast cancer. Interestingly, the release included no breakdown in the upfront fee or milestone payments.

Sanofi CEO "Chris Viehbacher is putting his money where his mouth is," BiPar board member Wende Hutton  said. "He was very aggressive about pursuing BiPar." Viehbacher was quick to catch on to the therapeutic potential of PARP inhibitors, along with the market potential it would have following an approval. The BiPar deal is a "landmark transaction for 2009," adds Hutton, a partner at Canaan Partners. And it underscores the importance of later-stage therapeutics that address important unmet medical needs. This is a tough environment for anyone advancing me-too drugs, she says.

"The acquisition of BiPar, one of the pioneer for novel tumor-selective therapies, is a further step in our company's goal to focus on new approaches to strengthen our oncology R&D portfolio," said  Viehbacher, who's been on a buying spree lately. Analysts say that today's deal is a long-term gamble.

"Although this acquisition strengthens its oncology pipeline in the mid term, the result will not show up in its accounts before 2012-2013 in the best case," analyst Arsene Guekam informed.