Treatment with Verastem’s duvelisib has shown sustained efficacy and safety in a trial with indolent non-Hodgkin’s lymphoma (iNHL) patients who had not responded well to Rituxan (rituximab) and chemotherapy or radioimmunotherapy.
These findings come from the DYNAMO Phase 2 study (NCT01882803). Dr. Pier Luigi Zinani presented the study, “DYNAMO: A Phase 2 Study Demonstrating the Clinical Activity of Duvelisib in Patients with Double-Refractory Indolent Non-Hodgkin Lymphoma,” at the 14th International Conference on Malignant Lymphoma (ICML), held June 14-17 in Lugano, Switzerland.
“The data we are presenting at ICML help fill in the clinical picture for those patients who receive duvelisib over a longer period,” Zinzani said in a news release. “Not only did duvelisib monotherapy continue to show robust and durable responses in double-refractory iNHL, but longer-term exposure to duvelisib did not reveal any unexpected safety findings. These results suggest duvelisib has favorable benefit-risk in double-refractory iNHL, and may provide an important new treatment option for a population in need of new targeted therapies.”
Duvelisib is an experimental drug that inhibits both the PI3K-delta and PI3K-gamma proteins, which are involved in various blood cancers including iNHL, chronic lymphocytic leukemia and T-cell lymphoma.
The Phase 2 DYNAMO trial evaluated the safety and efficacy of duvelisib in 129 patients with double-refractory iNHL, including follicular lymphoma (83 patients), small lymphocytic lymphoma (28 patients) and marginal zone lymphoma (18 patients). Patients had received a median of three prior regimens before enrolling in the trial.
In this group of patients, 47 percent (61 patients) responded to treatment. The overall response rate in each lymphoma subgroup was 43 percent in the follicular lymphoma subgroup, 68 percent among small lymphocytic lymphoma patients, and 33 percent in the marginal zone lymphoma subgroup. Response to duvelisib occurred within a median of two months.
Importantly, 88 percent of duvelisib-treated patients experienced a decrease in the size of their target lymph nodes. Their median duration of response was 10 months, median time to disease progression was nine months, and median overall survival was 27.8 months.
During a median follow-up of 18 months, duvelisib was considered safe and manageable. The most common severe side effects were low levels of neutrophils, a type of immune cells, and platelets, anemia and diarrhea. Patients also reported infections of all types and severity (56 percent).
“The clinical activity and durability of responses observed in the DYNAMO study seen across a range of highly refractory disease subtypes, together with the well-characterized and manageable safety profile, highlight the potential of this drug in lymphoid malignancies,” sai Dr. Hagop Youssoufian, Verastem’s head of hematology and oncology development. “What I find really encouraging is that we saw these results in patients refractory to both rituximab and chemotherapy, a specific population with unmet medical need.”