Development of Varicella-Zoster virus infection in patients with chronic myelogenous leukemia treated with imatinib mesylate.

PURPOSE Infection with Varicella-Zoster virus (VZV) is an exceptionally rare complication of chronic myelogenous leukemia (CML) without stem cell transplantation. We report 16 patients with CML who developed VZV infection during imatinib mesylate therapy. PATIENTS AND METHODS From July 1998 until February 2002, 771 patients were included in 11 imatinib mesylate studies for all CML phases in the Departments of Leukemia and Bioimmunotherapy at The University of Texas M. D. Anderson Cancer Center. Sixteen patients developed VZV infection. Charts and follow-up information of were reviewed and analyzed. RESULTS Sixteen patients (2%) developed a VZV infection [15 episodes of herpes zoster (HZ), 1 varicella]. The baseline characteristics of the 16 patients with infection do not differ significantly from those who did not develop VZV infection, except for time from diagnosis of CML to imatinib (median: 55 versus 25 months, P = 0.0056) and the number of prior therapies (3 versus 1, P < 0.001). All patients received therapy with antiviral agents with good response. Six patients developed postherpetic neuralgia. CONCLUSIONS Our results suggest that imatinib therapy in CML is associated with low incidence of HZ infection. VZV infection is more frequent with longer duration of CML disease and with prior therapy, does not disseminate, responds well to therapy, and does not mandate a recommendation for HZ prophylaxis in such patients.