A phase II study of older patients with untreated acute myeloid leukemia showed that treatment with volasertib and low-dose cytarabine more than doubled the objective response rate compared to cytarabine chemotherapy alone.
The study data were published in the American Society of Hematology journal Blood. Volasertib, sponsored by Boehringer Ingelheim, has not been approved by the FDA, and its safety and efficacy have not been established.
The rate of objective response, either complete remission or complete remission with incomplete blood count recovery, was 31 percent for patients receiving volasertib and LDAC, compared to 13.3 percent for LDAC alone (p=0.052).
The secondary endpoints of the study were overall survival, event-free survival, relapse-free survival and safety.
Patients treated with volasertib combined with LDAC had a median overall survival of 8 months compared to 5.2 months in patients treated with LDAC (p=0.047).
Median event-free survival was prolonged in patients receiving volasertib and LDAC versus LDAC: 5.6 months versus 2.3 months, respectively (p=0.021). Relapse-free survival for volasertib and LDAC versus LDAC was 18.5 months versus 10 months.
The open-label study enrolled 87 adult patients, with a median age of 75 years, with AML considered unsuitable for intensive induction therapy.
Patients were randomized in a 1:1 ratio to receive the combination of LDAC plus volasertib 350 mg intravenously over one hour on days 1 and 15 versus LDAC 20 mg twice daily subcutaneously on days 1-10 alone. Cycles were scheduled every four weeks until progression, relapse, intolerance, or requested discontinuation.
Volasertib is an investigational compound that inhibits enzymes called Polo-like kinase. Plk1, the best understood of the five known Plks, has an important role in cell division. This inhibition can result in prolonged cell cycle arrest, ultimately leading to cell death.
Volasertib is currently being evaluated in clinical trials for various solid tumors and hematological cancers. FDA has granted volasertib Breakthrough Therapy and Orphan Drug designations.
