Safety, Tolerability and Response Rates of Daratumumab in Patients with Relapsed Light Chain (AL) Amyloidosis: Results of a Phase II Study

Daratumumab is a human IgG1k monoclonal antibody targeting the CD38 surface antigen on plasma cells with proven efficacy in multiple myeloma. While biology of clonal plasma cells in AL amyloidosis is distinct from myeloma, clonal plasma cells in AL amyloidosis express surface CD38, providing a rationale for using daratumumab. Infusion-related reactions (IR) of 48% were reported in patients who had daratumumab as monotherapy for relapsed multiple myeloma. Therefore, we designed a clinical trial to study tolerability of daratumumab in those with relapsed AL amyloidosis (clinicaltrials.gov identifier: NCT02841033). The primary objective was to determine the safety and tolerability of infusion of daratumumab, with respect to IR. The secondary objectives were to assess hematologic response, clinical response and time to next treatment.Accrual began in April 2017. Patients with AL amyloidosis after ≥1 prior therapy, and involvement of at least 1 vital organ , eGFR of >20 mL/min, AST/ALT < 3xULN, NT-proBNP ≤8500 pg/mL, LVEF ≥30%, FEV1 ≥50% in patients with COPD or chronic smokers, and ECOG performance status of <3, received daratumumab at 16 mg/kg IV infusion weekly for weeks 1-8, followed by every 2 weeks for weeks 9-24 and every 4 weeks thereafter until progression or unacceptable toxicity, for up to 24 months. The first infusion of daratumumab was given in 1000 mL, the second infusion in 500 mL if no grade 1 or greater reactions occurred, and subsequent doses...
Source: Blood - Category: Hematology Authors: Tags: 653. Myeloma: Therapy, excluding Transplantation: Poster I Source Type: research