Bortezomib and the increased incidence of herpes zoster in patients with multiple myeloma

Bortezomib has significantly advanced the treatment of patients with multiple myeloma (MM). However, considering that most patients with MM are elderly, bortezomib-related morbidity should be thoroughly studied to ensure the safe use of this drug. Herpes zoster has been reported as a possible adverse event associated with bortezomib because a major target of bortezomib, nuclear factor-κB, is known to be involved with T-cell immunity. Patients and Methods: We performed a retrospective analysis of the incidence of herpes zoster among 282 patients treated with a bortezomib-containing regimen. Results: During the patients' pre-bortezomib treatment (median, 2.14 years), the incidence of herpes zoster was 11% (31 of 282 patients). However, after the patients were treated with bortezomib, the incidence increased to 22.3% (63 of 282 patients), of which almost all occurrences were within the first 3 cycles (median duration, 41 days). The time interval from diagnosis to bortezomib initiation date was shorter in herpes zoster-positive patients than in herpes zoster-negative patients (2.14 ± 1.87 years vs. 3.38 ± 2.95 years; P = .002). Disease duration, previous herpes zoster infection, disease stage and type of myeloma, and the type and intensity of previous treatments failed to show any relationship with herpes zoster. These findings suggest that longer history of disease and treatments did not affect the occurrence of herpes zoster, nor did the type of bortezomib regimens or their toxicities. Conclusion: Bortezomib can increase the incidence of herpes zoster regardless of disease duration, previous treatments, and concomitantly administered drugs. Thus, the occurrence of herpes zoster should be monitored during bortezomib treatment.