Gilead to acquire Calistoga Pharma for $375m

Calistoga could earn up to an additional $225m if certain milestones are achieved.

Calistoga’s lead product candidate, CAL-101, is a first-in-class specific inhibitor of the PI3K delta isoform.

PI3K delta is preferentially expressed in leukocytes involved in a variety of inflammatory and autoimmune diseases and hematological cancers.

In addition to CAL-101, Calistoga’s product development pipeline includes other selective PI3K inhibitors that are in preclinical development, and may have application in both oncology and inflammatory diseases.

Gilead EVP and chief scientific officer of R&D Norbert Bischofberger said they are very encouraged by emerging clinical data for CAL-101, and this compound could represent an advance for the treatment of certain hematological cancers.

"Building on the recent acquisitions of CGI Pharmaceuticals and Arresto Biosciences, this acquisition serves to further broaden Gilead’s pipeline and expertise in the areas of oncology and inflammation. We look forward to working with the team from Calistoga as we move these programs forward," Bischofberger said.

Calistoga president and CEO Carol Gallagher said their team at the company was the first to demonstrate the clinical benefit of targeting the delta isoform of PI3K as a novel treatment approach for patients with CLL and iNHL.

Gilead anticipates that the deal will close in the second quarter of 2011, subject to satisfaction of certain closing conditions, and plans to finance the acquisition through available cash on hand.