A Noninterventional, Observational, European Post-Authorization Safety Study of Patients With Relapsed/Refractory Multiple Myeloma Treated With Lenalidomide

Introduction: Lenalidomide plus dexamethasone is effective and well tolerated in relapsed/refractory multiple myeloma (RRMM). In this observational, noninterventional European post-authorization safety study, the safety profile of lenalidomide plus dexamethasone was investigated and compared with that of other agents in the treatment of RRMM in a real-world setting. Patients and Methods: Patients had received ≥ 1 prior antimyeloma therapy; prior lenalidomide was excluded. Treatment was per investigator's routine practice. Adverse events were analyzed by incidence rates per 100 person-years to account for differences in observation length and treatment duration. Results: In total, 2150 patients initiated lenalidomide, and 1479 initiated any other antimyeloma therapy, predominately bortezomib (80.3%), which was primarily administered intravenously (74.3%). The incidence rate of neuropathy was lower with lenalidomide (10.5) than with bortezomib (78.9) or thalidomide (38.7). Lenalidomide also had a lower incidence rate of infections (68.7) versus bortezomib (95.9) and thalidomide (76.0). Conversely, the incidence rate of neutropenia was higher with lenalidomide (38.0) than with bortezomib (18.2) or thalidomide (25.7). The incidence rates of thrombocytopenia were 24.4, 40.4, and 14.4 with lenalidomide, bortezomib, and thalidomide, respectively. Conclusion: No new safety signals for lenalidomide were identified in this study, which is the largest prospective real-world European study of lenalidomide in patients with RRMM to date. These results confirm that the safety profile of lenalidomide plus dexamethasone in RRMM in a real-world setting is comparable to that reported in clinical trials. © 2020 The AuthorsGiven the key role of lenalidomide in the treatment of relapsed/refractory multiple myeloma, it is important to evaluate the safety of lenalidomide in real-world populations of patients who may not qualify for clinical trial participation. This noninterventional, European post-authorization safety study confirms that the real-world safety profile of lenalidomide is similar to what has been reported in clinical trials. © 2020 The Authors