Ambit Biosciences, a privately held biopharmaceutical company based in San Diego, has closed the first $25 million tranche of a new $50 million preferred stock financing to support continued advancement of its lead drug candidate, quizartinib, for the treatment of acute myeloid leukemia (AML).

Existing investor OrbiMed Advisors led the financing with participation from other existing Ambit investors including Aisling Capital, Apposite Healthcare, Roche Ventures, GrowthWorks, MedImmune Ventures, Forward Ventures, GIMV and Radius Ventures.

"2012 has been a pivotal year of progress for Ambit, and this financing is a reflection of that progress and the momentum we have built as a team. We've received the data from our large, 333-patient phase II trial of quizartinib in patients with relapsed/refractory AML,” said Michael Martino, president and CEO of Ambit. “We've refocused and prioritized our work on earlier stage pipeline assets, including our oral JAK2 and CSF1R inhibitor programs, and re-energized the team. This financing, with OrbiMed Advisors leading a round in which all existing investors participated, is a strong vote of confidence in our direction and provides the resources to accelerate our progress in 2013.”

In conjunction with the financing, David Bonita, M.D, of OrbiMed Advisors will join Ambit's board of directors.