Human herpesvirus 6B (HHV-6B) frequently reactivates after allogeneic hematopoietic cell transplantation (HCT). There are no randomized studies of antiviral treatments to prevent HHV-6B reactivation. Brincidofovir has high in vitro activity against HHV-6B and other DNA viruses, but its in vivo activity for HHV-6B has not been demonstrated. We performed a post hoc analysis of a randomized controlled trial of twice-weekly oral brincidofovir for cytomegalovirus prophylaxis after allogeneic HCT to study the effect of brincidofovir on HHV-6B reactivation. We included patients randomized within 2 weeks of HCT and who received at least 6 consecutive doses of study drug after randomization. We tested plasma for HHV-6B through week 6 post-HCT. The cohort consisted of 92 patients receiving brincidofovir and 61 receiving placebo. The cumulative incidence of HHV-6B plasma detection through day 42 post-HCT was significantly lower among patients receiving brincidofovir (14.2%) compared to placebo (32.4%; log-rank 0.02). In an adjusted Cox model, brincidofovir exposure remained associated with a lower hazard for HHV-6B plasma detection (hazard ratio, 0.40; 95% CI, 0.20-0.80). In conclusion, brincidofovir prophylaxis reduced HHV-6B reactivation after allogeneic HCT in a post hoc analysis of a randomized controlled trial. These data support the study of intravenous brincidofovir for HHV-6B prophylaxis.

中文翻译：

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口服布林西多福韦降低异基因 HCT 后 HHV-6B 病毒血症的发生率

人类疱疹病毒 6B (HHV-6B) 经常在同种异体造血细胞移植 (HCT) 后重新激活。没有关于预防 HHV-6B 再激活的抗病毒治疗的随机研究。Brincidofovir 对 HHV-6B 和其他 DNA 病毒具有高体外活性，但其对 HHV-6B 的体内活性尚未得到证实。我们对每周两次口服 brincidofovir 预防异基因 HCT 后巨细胞病毒预防的随机对照试验进行了事后分析，以研究 brincidofovir 对 HHV-6B 再激活的影响。我们纳入了在 HCT 后 2 周内随机分组且在随机分组后接受至少连续 6 剂研究药物的患者。我们在 HCT 后第 6 周测试了血浆中的 HHV-6B。该队列由 92 名接受布西多福韦治疗的患者和 61 名接受安慰剂的患者组成。与安慰剂（32.4%；log-rank 0.02）相比，接受布西多福韦治疗的患者在 HCT 后第 42 天 HHV-6B 血浆检测的累积发生率（14.2%）显着降低。在调整后的 Cox 模型中，溴西多福韦暴露仍然与 HHV-6B 血浆检测的较低风险相关（风险比，0.40；95% CI，0.20-0.80）。总之，在一项随机对照试验的事后分析中，brincidofovir 预防减少了异基因 HCT 后 HHV-6B 的再激活。这些数据支持静脉注射布西多福韦用于 HHV-6B 预防的研究。溴西多福韦暴露仍与 HHV-6B 血浆检测的较低风险相关（风险比，0.40；95% CI，0.20-0.80）。总之，在一项随机对照试验的事后分析中，brincidofovir 预防减少了异基因 HCT 后 HHV-6B 的再激活。这些数据支持静脉注射布西多福韦用于 HHV-6B 预防的研究。溴西多福韦暴露仍与 HHV-6B 血浆检测的较低风险相关（风险比，0.40；95% CI，0.20-0.80）。总之，在一项随机对照试验的事后分析中，brincidofovir 预防减少了异基因 HCT 后 HHV-6B 的再激活。这些数据支持静脉注射布西多福韦用于 HHV-6B 预防的研究。