11 October 2019 - - US-based biopharmaceutical company Verastem, Inc. (NASDAQ: VSTM) partner Yakult Honsha Co., Ltd. (Yakult) has dosed the first patient in a Phase 1b Japanese bridging study evaluating Copiktra (duvelisib) in patients with relapsed or refractory chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) following at least one prior therapy.

Copiktra is an oral inhibitor of phosphoinositide 3-kinase, and the first approved dual inhibitor of PI3K-delta and PI3K-gamma in the United States.

Verastem and Yakult entered into an exclusive licensing agreement in June 2018 for Yakult to develop and commercialize Copiktra for the treatment, prevention or diagnosis of all oncology indications in Japan.

Yakult's Phase 1b, multicenter, open-label study is expected to enroll approximately 10 patients with relapsed or refractory CLL/SLL after at least one prior therapy. The primary endpoint of the study is objective response rate.

Secondary endpoints of the study include overall survival, progression free survival and safety.

This Phase 1b study is expected to serve as a bridging study based on the efficacy and safety observed in Verastem Oncology's Phase 3 DUO study.

The results of the Phase 1b bridging study are expected to form the basis of a regulatory submission for Copiktra for the treatment of relapsed or refractory CLL/SLL in Japan.

Copiktra was approved in September 2018 by the US Food and Drug Administration for the treatment of adult patients with relapsed or refractory CLL/SLL after at least two prior therapies.

In addition, Copiktra has been granted accelerated approval by the FDA for the treatment of adult patients with relapsed or refractory follicular lymphoma after at least two prior systemic therapies.

Accelerated approval in FL was based on overall response rate and continued approval may be contingent upon verification and description of clinical benefit in confirmatory trials.

Copiktra is an oral inhibitor of phosphoinositide 3-kinase, and the first approved dual inhibitor of PI3K-delta and PI3K-gamma, two enzymes known to help support the growth and survival of malignant B-cells.

PI3K signaling may lead to the proliferation of malignant B-cells and is thought to play a role in the formation and maintenance of the supportive tumor microenvironment.

Copiktra is indicated for the treatment of adult patients with relapsed or refractory chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) after at least two prior therapies and relapsed or refractory follicular lymphoma after at least two prior systemic therapies.

Copiktra is also being developed by Verastem Oncology for the treatment of peripheral T-cell lymphoma, for which it has received Fast Track status, and is being investigated in combination with other agents through investigator-sponsored studies.

Verastem Oncology (NASDAQ: VSTM) is a commercial biopharmaceutical company committed to the development and commercialisation of medicines to improve the lives of patients diagnosed with cancer.