Ambit Biosciences, Inc. is engaged in the discovery and development of small-molecule kinase inhibitors for the treatment of cancer.
Ambit’s lead product candidate, AC220, is an oral, small molecule FMS-like tyrosine kinase-3 (FLT3) inhibitor being developed for the treatment of Acute Myeloid Leukemia (AML), the most common type of blood cancer in adults. FLT3 is mutated and activated in 25-40% of AML patients, causing poor prognosis and decreased response to existing treatments including chemotherapy and stem cell treatments. AC220 has entered a Phase 2 pivotal trial after obtaining concurrence from the FDA for its co-primary endpoint as a single, open-label trial which may be eligible to support registration (marketing approval), depending on the results it will generate. Called the ACE trial (AC220 monotherapy Efficacy study), this clinical trial will enroll a total of 180 patients who have refractory or relapsed AML with a mutated FLT3 kinase called internal tandem duplication (FLT3-ITD), which has negative prognostic implications.
Ambit’s second clinical candidate, AC480, is a pan-HER (human epidermal growth factor receptor) small molecule tyrosine kinase inhibitor; HER kinases (e.g., HER-1 or EGFR, HER-2, HER-3, HER-4) and the attendant signaling transduction pathway have been found to correlate with, and contribute to, a variety of human malignancies, including breast, gastric, lung, head and neck, and colorectal cancer. AC480, licensed from Bristol-Myers Squibb, has shown unique and promising results in pre-clinical animal cancer and human xenograft model (e.g., synergistic effects with paclitaxel, another widely-used chemotherapeutic drug), including the ability to cross the blood-brain barrier, a characteristic that would be useful in the treatment of brain tumors and metastases.