Leukemia is a cancer of the white blood cells and the acute forms of leukemia can manifest quickly and leave patients with limited treatment options. AML is the most common type of acute leukemia in adults. It occurs when a clone of leukemic progenitor white blood cells proliferates in the bone marrow suppressing the production of normal blood cells. The therapy of combining 2 chemotherapeutic drugs which always includes an anthracycline in inducing a CR or complete response has not improved since it was first used in the 1970’s and we estimate that it has the same cure rate of about 20% as then.
Currently, the only viable option for acute leukemia patients is a bone marrow transplant, which is successful in a significant number of patients. However, in order to qualify for a bone marrow transplant, the patient’s leukemia cells must be decreased to a sufficiently low level. Unfortunately, the current clinically approved anthracyclines are cardiotoxic, which can result in damage to the heart and limit the dosage amount that may be administered to patients. Additionally, the tumor cells often present de novo or developed resistance to the first line anthracycline, often through what is called “multidrug resistance” making them capable of purging themselves of the available anthracyclines.
Consequently, there remains no effective therapy for these patients and unfortunately most will succumb quickly to their leukemia. If a patient’s leukemia reappears before they can be prepared for a bone marrow transplant, they are considered to have “relapsed”. If a patient fails to achieve a sufficient response from the induction therapy to qualify for a bone marrow transplant, they are considered to be “refractory” (resistant to therapy). Together, this group of AML patients is our primary focus with Annamycin and our intent is to pursue approval for Annamycin as a second-line induction therapy for relapsed and refractory AML patients.
Of the estimated 18,860 U.S. cases of acute myeloid leukemia diagnosed in 2014, an estimated 97% were adult and although exact numbers are not available, we estimate that 70% to 80% (approximately 13,000 to 14,000 patients) were expected to relapse or be resistant to first-line therapy.