Astellas dumps $390M pact with Ambit on eve of IPO

Talk about bad timing. Just days after San Diego-based Ambit Biosciences stepped up to confidently announce its second try at an IPO, its partner Astellas unceremoniously dumped its $390 million partnership on a portfolio that includes the biotech's lead development program.

Astellas announced that it has decided to drop all rights for quizartinib (AC220) and all other FLT-3 inhibitors covered by their 2009 pact. The Japanese pharma company had been committed to pushing quizartinib into Phase III later this year. Now Ambit is on its own, for now. Astellas walked away from its $40 million upfront and a promise to pay up to $350 million in pre-commercialization milestones. 

"With the Phase II study results for quizartinib that were presented at the ASH Annual Meeting last December, we and members of the medical community continue to be excited about quizartinib and its potential to meet a significant, unmet need in acute myeloid leukemia patients," said Ambit CEO Michael Martino in a statement. "We are fully committed to moving forward with the Phase III clinical trial plan and look forward to advancing this important drug candidate toward approval."

At the end of 2012 Ambit, a 2006 Fierce 15 company, reported that two cohorts of relapsed AML patients who were FLT3-ITD positive demonstrated signs of a response to the drug. About half of each group had a "composite complete response" and one in three "FLT3-ITD positive patients who had relapsed or were refractory after two prior lines of treatment or after a prior hematopoietic stem cell transplant received a potentially curative HSCT following treatment with quizartinib." There was no control arm in the study.

Ambit has had significant VC backing to date. Just last November a consortium of venture outfits put up the first half of a $50 million round. That followed a $30 million round announced in 2011, when its first try at an $86 million IPO had to be yanked in the face of investor indifference. OrbiMed Advisors joined Aisling Capital, Apposite Healthcare, GIMV, GrowthWorks, Forward Ventures, MedImmune Ventures, Radius Ventures and Roche Ventures in the round.

- here's the press release

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