Tolerability and safety of real-world use of pomalidomide in patients with relapsed/refractory multiple myeloma.

Pomalidomide (POM) is a second-generation immunomodulatory agent with proven efficacy in patients with relapsed/refractory multiple myeloma (RRMM) proven to be refractory to previous treatment with lenalidomide (LEN) and bortezomib. We herein conducted a retrospective analysis of 14 RRMM patients receiving POM to determine its tolerability and safety in the clinical setting. The median age of the patients was 72 years (range, 58-84 years), and 85.7% of the patients were aged >70 years. The most frequent treatment dose was 3 mg/day. POM dose reductions were required in 54.5% (6/11) of the patients. The patient data were compared among three age groups (<70, 70-75 and >75 years) and there was only significant difference in daily POM treatment dose. The tolerability of POM must be confirmed, particularly in elderly patients. Dose reduction from 4 to 3 mg occurred during the second cycle in 83.3% (5/6) of the patients. It is important to determine the tolerability of POM in the early phases of treatment. The most frequently reported grade 3/4 hematological adverse events were neutropenia (64.3%), anemia (64.3%) and thrombocytopenia (57.1%). Although the median number of treatment cycles was 4 (range, 1-13), 21.4% (3/14) of the patients with a performance status (PS) of 3 were administered only 1 treatment cycle. The tolerability of POM was low among patients with poor PS and an aggressive treatment introduction should be avoided. However, 21.4% (3/14) of the patients were able to continue treatment for >1 year and some patients received long-term therapy. POM does not require dose modification for renal function, and multiple capsule doses are available, which is an advantage of POM compared with LEN. POM may be administered to late-stage RRMM patients in a real-world clinical setting, but elderly patients or those with poor PS must be treated with caution. In this manner, the treatment options for RRMM patients may be expanded by assessing the tolerability and safety of POM.