Treatment patterns and outcomes in patients with multiple myeloma in second relapse in Colombia (freedomm): a multicenter observational study.

Introduction: Treatment selection for patients with relapsed Multiple Myeloma (MM) is highly individualized and characterized by diverse treatment patterns. While substantial evidence exists regarding relapsed MM in high-income settings, data on treatment patterns and clinical outcomes at second relapse in Latin American populations remain limited. This study describes the clinical characteristics, treatment patterns, effectiveness, and safety of third-line therapy in patients with MM experiencing a second relapse in routine clinical practice across five Colombian institutions. Methods: This multicenter retrospective observational study included medical records from five specialized institutions in Colombia. Patients with MM who experienced a second relapse and initiated third-line therapy between 2013 and 2022 were included. Baseline characteristics, treatment patterns, and the effectiveness and safety of third-line therapy were analyzed descriptively. Results: The study included 84 participants with multiple myeloma who experienced a documented second relapse. The median age at diagnosis was 63.5 years (IQR 57.0 - 70.0), 56% were male, and bone disease and anaemia were the most frequent presenting features. The median time from diagnosis to second relapse was 3.2 years (IQR 1.8 - 4.9). First-line therapy was mainly bortezomib-based, most frequently the combination of bortezomib, cyclophosphamide, and dexamethasone (36.9%). Second-line treatment shifted toward lenalidomide-based regimens, with lenalidomide plus dexamethasone administered to 29.8% of patients. Autologous stem cell transplantation was performed in 36.9% of patients. Third-line treatment patterns were diverse, with greater use of novel agent-based combinations, including regimens containing daratumumab and carfilzomib. In the third-line setting, the overall response rate was 47.1%. The median overall survival from initiation of treatment at second relapse was 27.5 months, while the median progression-free survival and time to treatment failure were 14.6 months and 5.94 months, respectively. Treatment-emergent adverse events (TEAEs) occurred in 11.9% of patients, mostly moderate. Conclusion: In this real-world study of patients with multiple myeloma treated in the third-line setting after second relapse, treatment patterns were heterogeneous, with increasing use of novel agent-based combinations. An objective response was achieved in nearly half of the patients, with a median overall survival of 27.5 months and a median progression-free survival of 14.6 months. Treatment-emergent adverse events were infrequently reported and predominantly hematologic. No health-related quality of life data were available, highlighting an important gap in routine clinical practice.