Low dose venetoclax in combination with bortezomib, daratumumab, and dexamethasone for the treatment of relapsed/refractory multiple myeloma patients-a single-center retrospective study.

Venetoclax is a BCL-2 inhibitor currently indicated for use in treating hematologic malignancies with recommended doses ranging from 400 to 600 mg/day. Although currently not FDA-approved to treat multiple myeloma (MM) patients, there is a growing number of reports indicating its efficacy as a salvage therapy for these patients, especially for those with the t(11;14) chromosomal marker. These studies, however, have also indicated that venetoclax given at doses ≥ 400 mg/day can cause serious adverse events (SAEs) especially when administered with bortezomib, commonly related to infections. The purpose of this single-center retrospective study was to determine the efficacy of low dose venetoclax (defined as ≤ 250 mg/day) in combination with low dose bortezomib (defined as 1.0 mg/m2 per dose), daratumumab, and dexamethasone (Dvvd) as a salvage therapy for relapsed/refractory myeloma (RRMM) patients. Twenty-two RRMM patients were given venetoclax orally at doses ranging from 100 to 250 mg daily using this four-drug regimen. While the low doses resulted in reduced venetoclax efficacy among those lacking t(11;14) (overall response rate [ORR] = 31%), those harboring the t(11;14) marker exhibited an ORR of 80%. Notably, this response was without frequent infection-related SAEs as reported in previous studies. Together, the results of this study demonstrate that treatment of t(11;14) positive RRMM patients with Dvvd is both effective and well-tolerated.