Analysis of Herpes Zoster Events Among Bortezomib-Treated Patients in the Phase III APEX Study

Purpose The aim of this subset analysis was to determine if bortezomib treatment is associated with increased incidence of varicella-zoster virus (VZV) reactivation in patients with relapsed multiple myeloma (MM). Patients and Methods Incidence of herpes zoster was evaluated in 663 patients with relapsed MM from the phase III APEX trial comparing single-agent bortezomib with high-dose dexamethasone. Results Bortezomib was associated with a significantly higher incidence of herpes zoster compared with dexamethasone treatment (13%, 42 of 331 v 5%, 15 of 332; P = .0002). Most herpes zoster infections were grade 1/2; incidences of grade 3/4 events (1.8% v 1.5%) and infections considered serious adverse events (1.5% v 0.9%) were similar between treatment arms, and no herpes zoster–related deaths occurred. Neither the time to onset of the herpes event nor the patients’ absolute lymphocyte counts at baseline differed significantly between arms. VZV reactivation was the only herpes viral event noted to be signifi...