1902. A Survey of Pediatric Bone Marrow Transplant Centers Regarding Local Cytomegalovirus Prophylaxis Management Practices and Interest in a Future Randomized Trial

BACKGROUND: Cytomegalovirus (CMV) is a major source of morbidity and mortality after hematopoietic cell transplantation (HCT). A recent adult trial comparing letermovir to placebo, found this agent to be efficacious in preventing CMV reactivation with limited toxicity. Additional investigation of letermovir in pediatric HCT recipients is needed. To inform the feasibility of a pediatric trial, we surveyed bone marrow transplant (BMT) centers registered with the Children’s Oncology Group (COG) regarding their CMV management practices and interest in a pediatric trial for CMV prevention. METHODS: A brief 6-item questionnaire was created using REDCap™ and distributed by email to all COG-approved BMT Centers. The initial email request was sent on March 26, 2018 to the BMT physician representative listed in the COG member roster. A follow-up request was sent on April 2, 2018. The questionnaire requested information about CMV prophylaxis strategies, including antiviral agent(s) employed, and interest in a pediatric trial of CMV prophylaxis. RESULTS: The questionnaire was emailed to 89 BMT centers and was completed at 57 (64%). Of these, 23 (40%) reported giving prophylaxis to all or a subset of allogeneic/haploidentical HCT recipients. The most common indication for CMV prophylaxis (21/23) was a CMV recipient-positive, donor-negative allogeneic/haploidentical HCT recipient. Two centers provided prophylaxis to all cord blood recipients regardless of CMV status. Among these 23 prophylaxis centers, there were 10 different reported prophylaxis regimens. Fifty-one (89%) respondents confirmed an interest in a randomized trial to assess the efficacy of letermovir prophylaxis against CMV reactivation. The preferred comparator for such a trial was placebo/nothing (55%) followed by high dose acyclovir (24%). CONCLUSION: A significant proportion (40%) of pediatric BMT centers in the United States administer CMV prophylaxis to at least a subset of their HCT recipients. The variation in prophylaxis regimens highlights the lack of comparative effectiveness data to guide clinical decisions. Nearly all centers, regardless of whether they currently provide prophylaxis, reported an interest in a trial assessing the utility of letermovir prophylaxis in children. DISCLOSURES: B. T. Fisher, Merck: Grant Investigator, Grant recipient and Research grant. C. L. K. Boge, Merck: Grant Investigator, Research grant.