Bortezomib administered subcutaneously is well tolerated in bortezomib-based combination regimens used in patients with multiple myeloma.

Objective: Bortezomib (Btz) has emerged as a standard of care in the treatment of patients with multiple myeloma (MM), but Btz-induced peripheral neuropathy (PNP) has a particularly negative impact on patients' quality of life. According to a recent study, PNP was significantly less frequent with subcutaneous administration of Btz. Here, we report our experience regarding the efficacy and tolerability of standard combination regimens in MM with subcutaneous Btz.

Methods: 14 consecutive patients with newly diagnosed MM were included in this analysis. Btz was used in different combination regimens (Btz with dexamethasone with/without thalidomide or Btz combined with melphalan and prednisone). Standard criteria were applied to evaluate response and toxicity.

Results: Hematological toxicities occurred only at grades 1-2 and included anemia (71%) and thrombocytopenia (21%). Nonhematologic side effects at grades 1-2 were local skin reactions at the subcutaneous injection site, which were self-limited. No notable gastrointestinal toxicity was observed with subcutaneous Btz, and therefore routine use of intravenous hydration and antiemetics was abandoned. Overall response rate for transplant-eligible patients was 86%.

Conclusions: Our results confirm the improved toxicity profile of the subcutaneous administration of Btz in various standard Btz-based combination regimens. In addition, patient management with subcutaneous administration has been markedly ameliorated at our center.