Cellectar Biosciences presents data from DLBCL cohort of Phase 2 CLOVER-1 study
Cellectar Biosciences announced Jarrod Longcor, CBO of Cellectar, presented data from the diffuse large B cell lymphoma cohort in the company's Phase 2 CLOVER-1 study of CLR 131 in relapsed or refractory select B-cell malignancies at the European Society for Medical Oncology Congress 2019. The oral presentation, entitled: "Interim Evaluation of a Targeted Radiotherapeutic, CLR 131, in Relapsed/Refractory Diffuse Large B-Cell Lymphoma Patients," featured data from 6 subjects who received a single 30-minute intravenous dose of 25mCi/m2 of CLR 131. Data showed durable responses, including a 33% overall response rate, a 16.6% complete response rate and a 50% clinical benefit rate. All patients enrolled in the study received an average of 3 prior lines of systemic therapy, 5 of 6 patients were refractory to at least one prior line of therapy. Importantly, CLR 131 showed activity against both germinal center and activated DLBCL. In a patient for whom cytogenetics was available, CLR 131 showed activity against c-Myc and BCL-2 mutation positive patients. As required by the Lugano Criteria for Response, the patient who experienced a CR had a total reduction in tumor volume of greater than 99% and continues to be a CR at 510+ days post dosing. This patient was refractory to two prior treatment lines, which included the combination regimen RICE. Analysis of dosing showed that the disease control rate and progression free survival were markedly improved in patients receiving a dosing ratio of 1.2% or greater versus those receiving below a 1.2% dosing ratio. Finally, the most frequent adverse events in DLBCL patients were consistent with prior studies of CLR 131; the majority of AEs being hematologic in nature and predominately Grades 1 and 2. CLOVER-1 is a Phase 2 study of CLR 131 being conducted in approximately 10 leading cancer centers in the United States in patients with relapsed or refractory B-cell hematologic cancers. The hematologic cancers being studied in the trial include multiple myeloma, chronic lymphocytic leukemia/small lymphocytic lymphoma, lymphoplasmacytic lymphoma, marginal zone lymphoma, mantle cell lymphoma, and diffuse large B-cell lymphoma. The study will enroll up to 80 patients. Its primary endpoint is clinical benefit response, with additional endpoints of overall response rate, progression free survival, median overall survival and other markers of efficacy following a fractionated dose of 37.575mCi/m2 of CLR 131 administered in two 30-minute infusions of 18.75mCi/m2 of CLR 131 administered on day 1 and day 8, with the option for a second dose cycle approximately 75-180 days later. The company expects to report topline data in 2019.