BACKGROUND: Approvals of new agents have changed the treatment landscape for multiple myeloma (MM) in recent years, but real-world (RW) data on treatment patterns and clinical outcomes in patients with relapsed/refractory multiple myeloma (RRMM) outside of clinical trial settings remain limited.
AIMS: To assess RW treatment patterns and clinical outcomes of patients with RRMM in Canada, France, Spain, and UK. Methods: This retrospective, observational chart abstraction study recruited oncologists, hematologists and hemato-oncologists in Canada, France, Spain and the UK, who reviewed deidentified medical records from adult patients with a diagnosis of RRMM between Jan 1, 2012–Dec 31, 2016. RRMM was defined by disease progression during or after first-line (1L) therapy for MM (date of 1L MM progression was study index). Treatment regimens were described, and progression-free survival (PFS) and overall survival (OS) were assessed by Kaplan–Meier estimation from start of each line of therapy (LoT), 1L–3L.
RESULTS: A total of 412 patient records were included (Canada: n=101; France: n=101; Spain: n=104; UK: n=106). Mean (SD) age of patients at index was 65.4 (10.5) years, 59.2% of participants were male, median duration of follow-up from index was 37.7 months; and median number of LoT received was 3. At index, a higher proportion of patients in the UK (53.8%) had at least one gene translocation associated with high risk MM including del(17/17p), t(4;14), t(14;16), t(14;20), compared with other countries (34.6–39.6%). Median Charlson Comorbidity Index score at index was 1.0 in Canada, France and the UK, and 2.0 in Spain. Rates of MM-related symptoms were broadly comparable but with some country variation for some symptoms: proportion of patients with anaemia ranged from 24.8–51.9%, renal impairment from 5.9–24.0%, hypercalcemia 6.6–12.5%, and skeletal-related events 4.7–22.1%. Bortezomibbased regimens were most frequently used in 1L (Table), both in patients who did and who did not have stem cell transplant (SCT). Lenalidomide-based regimens were frequently used in 2L (particularly Rd, KRd, VRd, and NRd); carfilzomib (KRd, Kd) and daratumumab (DaraVd) were among the most frequently used regimens in 2L in France and Spain, but not Canada and the UK. In the 3L setting, pomalidomide (Pd, PCd), carfilzomib (Kd), and daratumumab (Dara monotherapy, DaraVd) were frequently used in most countries except the UK. Following 1st relapse, almost all patients received 2L therapy (>93% in all countries); while a lower proportion received 3L therapy following 2nd relapse (36.6%–64.2%). Median PFS ranged from 20.7 months (UK) to 33.9 months (Canada) in 2L, and from 12.0 months (France) to 22.5 months (UK) in 3L. Median OS was not reached for any LoT from 1L–3L. From start of 2L, 2-y OS rate ranged from 82% (Spain) to 92% (UK); from start of 3L, 2-y OS ranged from 65% (Spain) to 89% (UK).
SUMMARY/CONCLUSION: Newer therapies for RRMM began to be commonly used in 2L and became more frequent in 3L. Following first relapse, a substantial proportion of patients with RRMM received 2L but not 3L therapies. PFS in 2L and 3L was longer than in clinical trials but comparable with other RW studies, suggesting that patients with RRMM have longer than expected treatment-free interval instead of continuous treatment until disease progression. These findings also suggest there may be country variations in the implementation of approved new therapies in routine clinical practice.
