Ambit Biosciences (Nasdaq: AMBI), a biopharmaceutical company focused on discovery and development of drugs targeting unmet needs in oncology, autoimmune and inflammatory disease, today announced the initiation of the QUANTUM-R Phase 3 clinical trial comparing quizartinib as monotherapy to chemotherapy regimens in relapsed/refractory acute myeloid leukemia (AML) patients with the FMS-like tyrosine kinase-3 (FLT3)-ITD mutation.
"Initiation of QUANTUM-R is an important step in the development of quizartinib, and the trial will continue to be a central focus for our team going forward. We believe quizartinib has the potential to help patients with relapsed/refractory FLT3-ITD positive AML. Importantly, the trial design allows for patients in the quizartinib arm to continue to receive quizartinib as a continuous maintenance therapy following a transplant, which has the potential to increase duration of remission and overall survival," said Mike Martino, CEO of Ambit.
The trial will be conducted in FLT3-ITD positive AML patients over the age of 18 who have relapsed from, or are refractory to, frontline chemotherapy, including those patients relapsing following hematopoietic stem cell transplantation (HSCT). Patients will be dosed continually until disease progression or intolerable toxicity. Patients who proceed to HSCT after quizartinib treatment will be able to reinitiate treatment with quizartinib following the transplant.
The trial is expected to enroll approximately 326 patients in the United States, Western Europe, Canada and Australia. The primary endpoint for the Phase 3 clinical trial will be overall survival. An interim analysis will be conducted and will include an adaptive design component that will allow the Data Safety Monitoring Board (DSMB) to increase the number of patients, if warranted. Enrollment is expected to be completed in the second half of 2015, assuming there is no increase in the number of patients following the interim analysis.
"We are excited about starting the Phase 3 trial," said Athena Countouriotis, Chief Medical Officer at Ambit. "Based on the survival data with quizartinib in over 400 patients in two Phase 2 trials, as well as data collected from historical databases and recently published data from a similar Phase 3 study, we believe QUANTUM-R is designed to highlight the clinical benefits of quizartinib, and support its worldwide approval."
The Phase 3 trial follows completion of the Phase 2 and Phase 2b clinical trials, which demonstrated the key clinical benefits of quizartinib as a monotherapy, including a high response rate in relapsed/refractory FLT3-ITD positive patients; a substantial number of patients who were bridged to a potentially curative HSCT; and median overall survival in FLT3-ITD positive patients which compared favorably to historical survival data reported for FLT3-ITD positive and negative AML patients. Results from these studies were presented at medical conferences in 2012 and 2013.