Background and importance The overall survival of patients with multiple myeloma (MM) has changed dramatically in the last decade. Immunotherapy has emerged as a promising treatment, such as daratumumab. This human monoclonal IgG kappa antibody that targets CD38 is used in monotherapy or in combination, and has demonstrated durable responses. But good clinical management of toxicities is needed to reach the goal of therapy.

Aim and objectives To assess the safety of daratumumab in monotherapy and in combination with other agents used in our institution, and to review the clinical management of toxicities.

Material and methods A retrospective observational study was conducted in a second level hospital. We reviewed the medical records of all patients diagnosed with MM who received at least one cycle of daratumumab as monotherapy or as combination therapy in our hospital until August 2020. Collected data were: sex, age, cytogenetic risk, prior line of therapy, prior autologous stem cell transplantation (ASCT), daratumumab monotherapy or combination therapy, adverse drug reactions (ADRs), grade and clinical management (supportive treatments, temporary interruptions and permanent discontinuations).

Results 33 patients received at least one cycle of daratumumab and were included (26% men). Median age was 64 (42–77) years, 26% (8) had high cytogenetic risk abnormalities, median number of prior lines of therapy was 2 (0–6) and 74% (23) of patients received daratumumab in combination therapy. Average number of cycles received was 8 (1–38). 39% (13) of patients had infusion reactions (IRs) but the majority (92%) occurred during the first infusion and were grades 1–2. We registered 22 haematological severe ADRs (grades 3–4) and the most common was thrombocytopenia (60%), followed by neutropenia (22%), all requiring supportive treatment, and in 32% temporary interruption of treatment was necessary. 28 non-haematological severe ADRs (grades 3–4) were registered, 50% were severe infections, most of them respiratory that required temporary interruption to therapy, and 10 (71%) needed hospital admission. Almost one in three patients experienced permanent discontinuation of daratumumab related to toxicity (90% receiving combination therapy).

Conclusion and relevance Most adverse reactions related to daratumumab therapy were clinically manageable, but the incidence of severe haematological toxicity and severe respiratory infections makes close monitoring of side effects necessary, along with practical management strategies to reach the maximal benefit.

Conflict of interest No conflict of interest