Subcutaneous bortezomib in newly diagnosed patients with multiple myeloma nontransplant eligible: Retrospective evaluation.

Bortezomib-melphalan-prednisone combination is one of the standards of care for nontransplant eligible patients with newly diagnosed multiple myeloma. However, bortezomib intravenous (twice weekly for 4 cycles then weekly for 5 cycles) results in ~13% of patients with grade 3-4 peripheral neuropathy. Bortezomib subcutaneous (SQ) and weekly delivery, improves tolerability without impairment of efficacy. The aim of this study was to evaluate the safety and effectiveness of SQ bortezomib-based combinations in nontransplant eligible patients with newly diagnosed myeloma in a real-world setting. A total of 135 patients (median age [range] = 76 [58-89], International Staging System-III = 54%, median follow-up = 14.8 months [1-40], Intensive group [twice weekly bortezomib] = 65%, Optimized group [weekly bortezomib] = 35%) were included and evaluable for safety, whereas 121 were evaluable for effectiveness. Overall response rate (95% CI) was 61% (53%, 71%) (complete response = 27%, very good partial response = 13%, and partial response = 21%) and median progression-free survival was 22.2 months (95% CI: 16.1-not reached). The 3-year overall survival was 75%. The most frequent grade 3-4 adverse events were thrombocytopenia (18%), neutropenia (17%), and anemia (11%). Peripheral neuropathy of any grade was observed in 44% of patients (2% with grade 3). Comparison between regimens (Intensive vs Optimized) showed similar overall response rate (57% vs 70%) and PFS (25 vs 19 months). A similar safety profile was observed between regimens. Thus, SQ bortezomib showed similar effectiveness and better tolerability as compared with results from intravenous bortezomib studies, and showing no differences either in effectiveness or safety in different bortezomib-based combinations.