Expanded approval for daratumumab in multiple myeloma

Abstract

THE JOURNAL OF COMMUNITY AND SUPPORTIVE ONCOLOGY 65 Volume 15/Number 2 In November 2016, the US Food and Drug Administration expanded the approval of daratumumab for patients with multiple myeloma. The monoclonal antibody, which targets CD38, a protein that is highly expressed on the surface of multiple myeloma cells, was previously granted approval by the agency as a single agent for the treatment of patients who had received at least three previous therapies. The current approval was for the use of daratumumab in two different combination regimens for the treatment of patients who have received one previous line of treatment. On the basis of improved progression-free survival (PFS), demonstrated in two randomized, open-label, phase 3 trials, daratumumab can now be used in combination with the immunomodulatory agent lenalidomide and dexamethasone, or the proteasome inhibitor bortezomib and dexamethasone, both standard therapies for the treatment of multiple myeloma. In the POLLUX trial, 569 patients with relapsed/refractory multiple myeloma were randomized 1:1 to receive daratumumab in combination with lenalidomide-dexamethasone or lenalidomide-dexamethasone alone. The CASTOR trial randomized 498 patients with relapsed/ refractory multiple myeloma 1:1 to daratumumab in combination with bortezomib-dexamethasone, or bortezomibdexamethasone alone. The eligibility and exclusion criteria for both trials were similar; patients had received at least one previous line of therapy, had documented progressive disease according to International Myeloma Working Group criteria, and had measurable disease on the basis of urine and/or serum assessments or serum-free, light-chain assay. Patients with a neutrophil count of ≤1,000 cells/mm3, hemoglobin level of ≤7.5 g/dL, platelet count of <75,000 cells/mm3, creatinine clearance of ≤20 mL/min per 1.73m2 body surface area (or <30 mL/min in the POLLUX trial), alanine aminotransferase or aspartate aminotransferase level ≥2.5 times the upper limit of normal (ULN) range, bilirubin level of ≥1.5 or more times the ULN range, disease refractory to bortezomib or lenalidomide, and unacceptable side effects from bortezomib or lenalidomide, were ineligible for these studies. In addition, patients with grade 2 or higher peripheral neuropathy or neuropathic pain, were excluded from the CASTOR study. Randomization was stratified according to International Staging System disease stage at the time of screening (stage I, II or III, with higher stage indicating more severe disease), number of previous lines of therapy (1 vs 2, or 3 vs >3), and previous receipt of lenalidomide or bortezomib. In the CASTOR trial, patients received up to eight 21-day cycles of bortezomib, administered subcutaneously at a dose of 1.3 mg/m2 on days 1, 4, 8, and 11 of cycles 1-8, and dexamethasone, administered orally or intravenously at a dose of 20 mg on days 1, 2, 4, 5, 8, 9, 11, and 12 for a total Expanded approval for daratumumab in multiple myeloma