Impact of dose modification on intravenous bortezomib-induced peripheral neuropathy in multiple myeloma patients

Patients discontinue bortezomib treatment despite good response to the therapy because of bortezomib-induced neuropathy. Early and active dose reduction is recommended for efficacy of treatment. This study evaluates patterns of bortezomib-associated neuropathy and examines the effectiveness of dose modification on symptom management and treatment compliance.

This is a retrospective cohort study of multiple myeloma patients who received bortezomib intravenously from 2009 to 2012 at Samsung Medical Center, Seoul, Korea. Peripheral neuropathy was assessed using neurotoxicity subscale of the FACT/GOG-Ntx at daily clinical practice; physicians modified the dosage and schedule of bortezomib treatment. Mixed-effect models were used for evaluating changes of neuropathy symptoms over time. Linear spline models and multivariate logistic regression were used for testing the effectiveness of interventions.

There were 1,060 visits of 55 multiple myeloma patients during the study period. Patients were most likely to have numbness of feet, painful burning in feet, muscle weakness, and the symptoms worsened over time (P < 0.05). For patients who received intervention (n = 32, 58.1 %), neuropathy symptoms were significantly decreased after the intervention (coefficient, -0.1 (95 % confidence interval (CI), -0.8, 0.6)). The intervention group had on average 5.19 (95 % CI, 3.79, 6.59) more bortezomib administrations and was 1.4 times more likely to complete the treatment (odds ratio, 1.40 (95 % CI, 0.31, 6.32)) than the nonintervention group.

Close monitoring of peripheral neuropathy in patients receiving bortezomib is a feasible and useful way to manage neuropathy in the real world.