Antiviral prophylaxis in haematological patients: Systematic review and meta-analysis

Purpose: Antiviral prophylaxis is commonly prescribed to haematological cancer patients. We conducted a systematic review and meta-analysis to quantify its overall benefit in specific clinical scenarios. Methods: Randomised controlled trials assessing antiviral prophylaxis versus placebo, no treatment, pre-emptive treatment or another antiviral drug were included. Patients undergoing haematopoietic stem cell transplantation (HSCT) or intensive chemotherapy for acute leukaemia or high-grade lymphoma were included. No restrictions on language, year or publication status were applied. Overall mortality, herpes simplex virus (HSV) and cyto-megalovirus (CMV) diseases were assessed as primary outcomes. Pooled relative risks (RRs) and numbers needed to treat (NNT) with 95% confidence intervals (CI) are reported. Results: HSCT was the condition assessed in 22 trials and intensive chemotherapy in 5 trials. In the pre-engraftment setting of autologous or allogeneic HSCT, antiviral prophylaxis (mainly acyclovir for HSV seropositive recipients) significantly reduced HSV (NNT 2, 2-2, control event rate (CER) 61.9%) and CMV disease, with no effect on overall mortality. In the allogeneic post-engraftment setting (mainly CMV-seropositive recipients/donors), antiviral prophylaxis resulted in a significant reduction in overall mortality, RR 0.79 (0.65-0.95), NNT 12 (7-50, CER 39.4%) and all viral-related outcomes. In this setting, acyclovir significantly reduced overall mortality (RR 0.71, 0.53-0.96, 4 trials) and ganciclovir/maribavir significantly reduced CMV disease (RR 0.26, 0.14-0.48, 5 trials). During chemotherapy, acyclovir significantly decreased HSV disease (NNT 3, 2-4, CER 37.4%) and infection rates, with no effect on mortality. Conclusions: Antiviral prophylaxis reduced mortality with a small NNT in the post-engraftment setting of allogeneic HSCT. In the pre-engraftment phase and during chemotherapy only viral-related morbidity was reduced. (C) 2009 Elsevier Ltd. All rights reserved.