Efficacy and Safety of Modified BLd Therapy for Japanese Patients with Transplant-Ineligible Multiple Myeloma

The BLd regimen, which is a triplet regimen of bortezomib (Bor), lenalidomide (Len), and dexamethasone (Dex), is effective against newly diagnosed multiple myeloma (NDMM). However, non-hematological toxicities, such as peripheral neuropathy (PN), often hamper long-term continuation of the regimen, particularly in older adult patients. In this study, we examined the efficacy and safety of the modified BLd regimen with reduced-intensity Bor and standard-dose Len. The chemotherapy regimen consisted of 1.3 mg/m2 Bor administered subcutaneously on days 1 and 8, 25 mg Len administered on days 1–14, and 20 mg Dex on days 1–2 and 8–9 of a 3 week cycle for 8 cycles, followed by a 4 week cycle of Dex (40 mg weekly). Among the 30 patients enrolled, 60.0% (95% CI 40.6–77.3) had a very good partial response or better, and the best overall response rate was 96.7% (95% CI 82.8–99.9). Eight patients (26.7%) achieved a complete response. Grade 3 or higher PN was not observed and hematological toxicity was the most common adverse event. The modified BLd regimen showed favorable efficacy with a manageable safety profile, which suggests it could be a treatment option for transplant-ineligible NDMM.