Clinical Study Finds Continuous Lenalidomide Delivery Effective and Well Tolerated in RRMM

Administration of lenalidomide continuously for six or more cycles shows meaningful efficacy in patients with relapsed or refractory multiple myeloma (RRMM) without serious toxicity, according to a phase 1b study.

Results were presented at the AACR Annual Meeting 2025. No drug-related grade 3 or 4 hematologic toxicities were observed, all nonhematologic toxicities were below grade 2, and no significant increase in immune checkpoints was associated with T-cell exhaustion. Moreover, all patients achieved an objective response to treatment.

In the study, six patients were receiving their second line of therapy for relapsed or refractory multiple myeloma. All patients in the cohort were White, and the male-to-female ratio was 1:1. At baseline, two patients in the cohort had refractory disease, and the remaining four patients had experienced relapse during their prior therapy. Four patients had been exposed to lenalidomide, and all six patients had previously received bortezomib. The cohort received bortezomib 1.3 mg/m² and dexamethasone 20-40 mg weekly for 28 days. Lenalidomide was administered by subcutaneous infusion at a rate of 400 μg/h for 28 days.

As of data cutoff, five patients are continuing treatment with lenalidomide with a median progression-free survival (PFS) of more than 10 months. The best response was a complete response in a patient who had only one prior line of therapy, and the PFS in this patient was 11 months. In the patients with the most prior therapies (n=4), the response was partial with PFS of 9 months.

The most frequently occurring treatment-emergent adverse events were fatigue, diarrhea, injection site erythema, and injection site reaction.

These data suggest that low-dose lenalidomide, administered on a continuous basis, improves the therapeutic index in comparison with oral lenalidomide. Furthermore, it may result in avoidance the hematologic toxicity of more than 22%  observed in a literature-based report on oral lenalidomide as second-line therapy for RRMM.

Reference:

116th Annual Meeting of the American Association for Cancer Research. Abstract No. LB207 / 4.