The US Food and Drug Administration has granted breakthrough therapy designation to Boehringer Ingelheim’s volasertib for acute myeloid leukaemia.
Volasertib is a polo-like kinase (Plk) inhibitor,and Boehringer’s head of medicine, Klaus Dugi, says that its "innovative mode of action offers a new approach and may potentially provide a new therapy option for AML patients who have a high unmet medical need”. AML accounts for about one-third of all adult leukaemias in the western world and has one of the lowest survival rates.
The average age of newly-diagnosed patients is 65 and Prof Dugi noted that the most common treatment approach for AML is intensive remission induction therapy but this involves high doses of chemotherapy which the elderly are often unable to tolerate. “These patients are in particular need of new treatments and we hope that volasertib may be able to fill this gap,” he added.
Breakthrough therapy designation is distinct from the FDA's other fast-track programmes, such as accelerated approval and priority review, as it involves more intensive guidance from the agency on putting together an efficient drug development programme. It is intended, the FDA says, for a treatment that “treats a serious or life-threatening condition and preliminary clinical evidence indicates that the drug may demonstrate substantial improvement on a clinically significant endpoint(s) over available therapies”.
The FDA is clearly impressed with volasertib data to date. A Phase II study in patients with previously untreated AML ineligible for intensive therapy compared volasertib in combination with the established therapy of low-dose cytarabine (LDAC) versus LDAC alone. Objective responses were observed in 31% of patients (13 of 42) treated with the combo compared to 13.3% (6 of 45) treated with LDAC alone.
Boehringer added that a trend for overall survival benefit (8.0 months for the volasertib combo compared to 5.2 months for LDAC alone) was seen, while median event-free survival was 5.6 months in the former group compared to 2.3 months in the chemotherapy-alone arm. The encouraging results led to the initiation of a Phase III study.