Nelfinavir, combined with lenalidomide and dexamethasone, showed promise in treatment of multiple myeloma (MM) in patients who were refractory to lenalidomide, according to results from a phase 1/2 trial published in Blood Cancer Journal.

This phase 1/2 trial based in Switzerland (SAKK 39/10; ClinicalTrials.gov Identifier: NCT01555281) included 29 patients with lenalidomide-refractory MM. The study treatment was nelfinavir (2500 mg/day) for 4 cycles, in combination with lenalidomide and dexamethasone.

Of the patients in this study, 93% had received at least 2 lines of prior therapy. A total of 34% of patients were refractory to both lenalidomide and bortezomib, and 31% showed high-risk cytogenetic abnormalities.

The median study follow-up occurred at 24.9 months, and 15 patients received all 4 cycles of treatment. The median overall survival (OS) time was 21.6 months (95% CI, 13.0-50.1), with a 24-month OS rate of 45% (25%-63%). The median progression-free survival (PFS) time was 3.4 months (95% CI, 2.0-4.9), with a 12-month PFS rate of 8% (95% CI, 1%-22%).

The rate of minor response or better on this treatment combination was 55% (95% CI, 36%-74%). A partial response was achieved by 21% of patients, with 10% achieving a very good partial response. Patients who were refractory to both lenalidomide and bortezomib had a 40% rate of minor response or better.

The most common grade 3 or higher adverse events (AEs) reported on this study were anemia (n=7), neutropenia (n=7), and thrombocytopenia (n=6). Grade 1 gastrointestinal and metabolic AEs were the most common AEs overall, occurring in 9 patients each.

Treatment using nelfinavir with lenalidomide and dexamethasone, the researchers stated in their report, “was found to be active in patients with lenalidomide-refractory myeloma, including those with lenalidomide–bortezomib double-refractory and high-risk disease.”

Reference

Hitz F, Kraus M, Pabst T, et al. Nelfinavir and lenalidomide/dexamethasone in patients with lenalidomide-refractory multiple myeloma. A phase I/II Trial (SAKK 39/10). Blood Cancer J. 2019;9(9):70.