Comparative efficacy of treatments for previously treated multiple myeloma

Maiese, E. M., Ainsworth, C., Le Moine, J-G., Ahdesmäki, O., Bell, J., & Hawe, E. (2018). Comparative efficacy of treatments for previously treated multiple myeloma: A systematic literature review and network meta-analysis. Clinical Therapeutics. DOI: 10.1016/j.clinthera.2018.01.014

PURPOSE: New therapies, including daratumumab plus lenalidomide plus dexamethasone (DRd) and daratumumab plus bortezomib plus dexamethasone (DVd), have recently been approved in the United States for patients with multiple myeloma (MM) who have received at least 1 prior line of therapy. However, few treatments have been compared in head-to-head clinical trials to determine the most efficacious therapy. In an update of the POLLUX (Phase 3 Study Comparing DRd Versus Rd in Subjects with Relapsed or Refractory Multiple Myeloma [RRMM]) trial, median progression-free survival (PFS) for DRd was not reached; the hazard ratio compared with Rd was 0.41. In an update of the CASTOR (Phase 3 Study Comparing DVd Versus Vd in Subjects with RRMM) trial, median PFS for DVd was 16.7 months, compared with 7.1 months for Vd with a PFS hazard ratio of 0.31. A systematic literature review and network meta-analysis (NMA) was performed to estimate the relative efficacy of treatments for previously treated patients with MM.

METHODS: A systematic search of MEDLINE, EMBASE, BioSciences Information Service, and the Cochrane Library databases was conducted from initiation to September 2016. Abstracts published by international congresses (2014-2016) and bibliographies of pertinent systematic reviews and meta-analyses were also searched. Eligible studies consisted of randomized controlled trials (RCTs) or long-term follow-up studies with >1 treatment arm assessing the efficacy or safety of MM therapies. An NMA was conducted by using Bayesian fixed effect mixed-treatment comparisons. Outcomes considered were hazard ratios for PFS and odds ratios for overall response rate (ORR).

FINDINGS: In total, 108 articles reporting 27 RCTs were included in the NMA. Data formed 2 evidence networks: RCTs with DRd and RCTs with DVd. Primary analysis of PFS found that DRd and DVd had a higher probability of being the best treatments (probability, 0.997 and 0.999, respectively) and had the lowest risk of progression or death than other treatments approved by the US Food and Drug Administration for the treatment of MM. Results from sensitivity analyses using time to progression as a proxy for missing PFS data were consistent. DRd and DVd also showed improved ORR compared with other treatments. Subgroup analyses of PFS in patients treated with only 1 prior therapy were like the results of the primary analyses.

IMPLICATIONS: This NMA provides comparative efficacy for MM treatments not studied in head-to-head RCTs. The NMA suggests that, compared with other approved MM treatments in the United States, DRd and DVd have a higher probability of providing the longest PFS in patients who have received at least 1 prior therapy and in patients who have received only 1 prior therapy.