The efficacy and safety of triplet regimens based on pomalidomide and dexamethasone for treatment of relapsed/refractory multiple myeloma: a systematic review and meta-analysis.

Objective: Triplet regimens based on pomalidomide and dexamethasone have been applied to treat relapsed/refractory multiple myeloma, but the safety and efficacy are not yet very clear. This meta-analysis aimed at comparing the safety and efficacy of different triplet therapies and analyzing the best therapy regimen.

Materials And Methods: A comprehensive literature search identified a total of 615 studies, and 22 studies assessing 1,889 subjects met the inclusion criteria of this meta: phase II/III trial, over 2 median lines of prior therapy, and detailed efficacy outcomes like overall response rate (ORR), overall survival, and progression-free survival (PFS). All statistical analyses were performed by Revman version 5.3, and the heterogeneity was tested by I2 (25% indicating low heterogeneity, 50% moderate, and 75% high). For those with less heterogeneity, fixed-effect model was used. With a significant high heterogeneity, a random-effect model was used.

Results: Pooled analysis showed ORR 66.2% across all triplet regimens based on pomalidomide and dexamethasone. Among all triplet regimens, therapy containing bortezomib showed the highest ORR (90.3%), and the one containing elotuzumab showed the lowest ORR (41.2%). The pooled ORRs for the remaining treatment regimens are as follows: cyclophosphamide (70.1%), isatuximab (66.3%), daratumumab (61.2%), clarithromycin (60.0%), pembrolizumab (47.3%). A total of 21 adverse events appeared in the included studies, with neutropenia being the highest incidence of hematologic adverse events (32.1%) and cough being the highest incidence of non-hematologic adverse events (43.3.%).

Conclusions: Three-drug regimens based on pomalidomide and dexamethasone could yield excellent overall response rate to relapsed/refractory multiple myeloma, but there are still various adverse events; therefore, consequent studies should address these adverse events.