The Food and Drug Administration has approved duvelisib (Copiktra), a dual PI3K delta/gamma inhibitor, for the treatment of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) and follicular lymphoma.
who have received at least two prior therapies. Duvelisib also has accelerated approval to treat adults with relapsed or refractory follicular lymphoma (FL) who have received at least two prior systemic therapies.
Accelerated approval is based on a surrogate or intermediate endpoint – in this case, overall response rate – that is reasonably likely to predict clinical benefit. Continued approval of duvelisib in FL may be contingent upon results of confirmatory trials verifying that the drug provides a clinical benefit.
Duvelisib will be available in the U.S. immediately, according to Verastem, the company marketing the drug. The prescribing information for duvelisib includes a boxed warning detailing four fatal and/or serious toxicities associated with the drug – infections, diarrhea or colitis, cutaneous reactions, and pneumonitis. Verastem said it is implementing an informational risk evaluation and mitigation strategy to provide appropriate dosing and safety information for duvelisib.
The recommended dose of duvelisib is 25 mg orally twice daily, taken continuously in 28-day treatment cycles.
The FDA’s approval of duvelisib is supported by data from the phase 3 DUO trial and the phase 2 DYNAMO trial. The DUO trial included 319 patients with CLL (n=312) or SLL (n=7) who had received at least one prior therapy. They were randomized to receive either duvelisib (25 mg orally twice daily) or ofatumumab (initial infusion of 300 mg followed by 7 weekly infusions and 4 monthly infusions of 2,000 mg).
Efficacy results are based on patients who had received at least two prior therapies, including 95 patients in the duvelisib arm and 101 in the ofatumumab arm. The overall response rate was 78% in the duvelisib arm and 39% in the ofatumumab arm. All responses in both arms were partial responses.
The median progression-free survival was 16.4 months with duvelisib and 9.1 months with ofatumumab.
The safety results include all patients treated with duvelisib or ofatumumab in this trial. In the duvelisib arm, 12% of patients had fatal adverse events (AEs) within 30 days of the last dose. The same was true of 4% of patients treated with ofatumumab. Serious AEs occurred in 73% of patients treated with duvelisib. The most common were infection and diarrhea/colitis. The DYNAMO trial enrolled patients with indolent non-Hodgkin lymphoma whose disease was refractory to both rituximab and chemotherapy or radioimmunotherapy. There were 83 patients with FL.
Patients received duvelisib at 25 mg orally twice daily until disease progression or unacceptable toxicity.
The overall response rate was 42%. One patient achieved a complete response, and 34 had a partial response.
Forty-three percent of responders maintained their response at 6 months, and 17% maintained their response at 12 months.
Serious AEs occurred in 58% of FL patients. The most common were diarrhea/colitis, pneumonia, renal insufficiency, rash, and sepsis.