Bortezomib-associated peripheral neuropathy requiring medical treatment is decreased by administering the medication by subcutaneous injection in Korean multiple myeloma patients.

Abstract

Bortezomib-induced peripheral neuropathy (BIPN) is a significant neurotoxicity, requiring dose reduction or the delay of treatment. In a multicentre trial including 97 % Caucasians and 3 % Asians, BIPN was shown to occur less frequently in cases in which bortezomib was administered subcutaneously. Considering the different pharmacokinetics between Caucasians and Asians, we analysed BIPN according to the administration route, specifically in Korean myeloma patients. We surveyed the prescribed anticonvulsants for the treatment of BIPN and analysed the data after stratifying the results by the cumulative dose of bortezomib. Exclusion criteria were as follows: treated with <2 doses of bortezomib, change in the administration route during the treatment, or receiving anticonvulsants for other reasons prior to bortezomib administration. A total of 101 patients were enrolled; 60 were treated with bortezomib and dexamethasone, and 37 were treated with bortezomib, melphalan, and prednisolone. The median number of treatment courses was four for each regimens. The median exposure to bortezomib for all patients was 19 mg/m(2). Progression-free survival (PFS) and overall survival rates were not statistically different between the groups. There was no difference in the proportion of patients requiring medical treatment (p = 0.388). After stratifying the results, BIPN developed less frequently when bortezomib was administered subcutaneously rather than intravenously in patients receiving more than 23.4 mg/m(2) of bortezomib (p < 0.05). Since the responses were potent regardless of administration route, the subcutaneous injection of bortezomib should be considered in Asian myeloma patients who are expected to achieve a longer PFS with bortezomib.