The Experts below are selected from a list of 438 Experts worldwide ranked by ideXlab platform
Karl S Peggs - One of the best experts on this subject based on the ideXlab platform.
-
in vitro comparison of currently available and investigational antiviral agents against pathogenic human double stranded dna viruses a systematic literature review
Antiviral Research, 2019Co-Authors: Roy F. Chemaly, Joshua A Hill, Sebastian Voigt, Karl S PeggsAbstract:Abstract Background Double-stranded (ds) DNA virus infections often occur concomitantly in immunocompromised patients. We performed a systematic search of published in vitro activity for nine approved and investigational antivirals to understand the spectrum of in vitro activity against dsDNA viruses. Methods A literature search was performed (PubMed and the WoS Core Collection) using keywords related to: 1) targeted approved/developmental antivirals (acyclovir, artesunate, Brincidofovir, cidofovir, cyclopropavir (filociclovir), foscarnet, ganciclovir, letermovir, and maribavir); 2) pathogenic dsDNA viruses; 3) in vitro activity. We summarized data from 210 publications. Results Activity against ≤3 viruses was documented for maribavir (cytomegalovirus, Epstein-Barr virus), and letermovir, while activity against > 3 viruses was shown for ganciclovir, cidofovir, acyclovir, foscarnet, cyclopropavir, artesunate, and Brincidofovir. The EC 50 values of Brincidofovir were the lowest, ranging from 0.001 to 0.27 μM, for all viruses except papillomaviruses. The next most potent agents included cidofovir, ganciclovir, foscarnet, and acyclovir with EC 50 values between 0.1 μM and >10 μM for cytomegalovirus, herpes simplex virus, and adenovirus. Conclusion Most of the identified antivirals had in vitro activity against more than one dsDNA virus. Brincidofovir and cidofovir have broad-spectrum activity, and Brincidofovir has the lowest EC 50 values. These findings could assist clinical practice and developmental research.
-
in vitro comparison of currently available and investigational antiviral agents against pathogenic human double stranded dna viruses a systematic literature review
Antiviral Research, 2019Co-Authors: Roy F. Chemaly, Joshua A Hill, Sebastian Voigt, Karl S PeggsAbstract:Abstract Background Double-stranded (ds) DNA virus infections often occur concomitantly in immunocompromised patients. We performed a systematic search of published in vitro activity for nine approved and investigational antivirals to understand the spectrum of in vitro activity against dsDNA viruses. Methods A literature search was performed (PubMed and the WoS Core Collection) using keywords related to: 1) targeted approved/developmental antivirals (acyclovir, artesunate, Brincidofovir, cidofovir, cyclopropavir (filociclovir), foscarnet, ganciclovir, letermovir, and maribavir); 2) pathogenic dsDNA viruses; 3) in vitro activity. We summarized data from 210 publications. Results Activity against ≤3 viruses was documented for maribavir (cytomegalovirus, Epstein-Barr virus), and letermovir, while activity against > 3 viruses was shown for ganciclovir, cidofovir, acyclovir, foscarnet, cyclopropavir, artesunate, and Brincidofovir. The EC 50 values of Brincidofovir were the lowest, ranging from 0.001 to 0.27 μM, for all viruses except papillomaviruses. The next most potent agents included cidofovir, ganciclovir, foscarnet, and acyclovir with EC 50 values between 0.1 μM and >10 μM for cytomegalovirus, herpes simplex virus, and adenovirus. Conclusion Most of the identified antivirals had in vitro activity against more than one dsDNA virus. Brincidofovir and cidofovir have broad-spectrum activity, and Brincidofovir has the lowest EC 50 values. These findings could assist clinical practice and developmental research.
Roy F. Chemaly - One of the best experts on this subject based on the ideXlab platform.
-
Brincidofovir: understanding its unique profile and potential role against adenovirus and other viral infections.
Future Microbiology, 2020Co-Authors: Julio J. Alvarez-cardona, Laura K. Whited, Roy F. ChemalyAbstract:Brincidofovir (BCV) is a lipid conjugate of cidofovir with good oral bioavailability, enabling optimal intracellular levels of the active drug. Lower rates of nephrotoxicity and myelotoxicity make it a favorable alternative. Despite a greater safety profile among pediatric hematopoietic cell transplant recipients, the oral formulation has been associated with increased gastrointestinal toxicity in adult hematopoietic cell transplant recipients. Oral BCV continues to be developed as a countermeasure against smallpox, while a potentially safer intravenous preparation has been out licensed to another company. BCV has demonstrated great in vitro potency against double-stranded DNA viruses, especially adenovirus. Because of its importance for immunocompromised patients, this review aims to evaluate BCV's clinical and safety profile to support its continued development.
-
in vitro comparison of currently available and investigational antiviral agents against pathogenic human double stranded dna viruses a systematic literature review
Antiviral Research, 2019Co-Authors: Roy F. Chemaly, Joshua A Hill, Sebastian Voigt, Karl S PeggsAbstract:Abstract Background Double-stranded (ds) DNA virus infections often occur concomitantly in immunocompromised patients. We performed a systematic search of published in vitro activity for nine approved and investigational antivirals to understand the spectrum of in vitro activity against dsDNA viruses. Methods A literature search was performed (PubMed and the WoS Core Collection) using keywords related to: 1) targeted approved/developmental antivirals (acyclovir, artesunate, Brincidofovir, cidofovir, cyclopropavir (filociclovir), foscarnet, ganciclovir, letermovir, and maribavir); 2) pathogenic dsDNA viruses; 3) in vitro activity. We summarized data from 210 publications. Results Activity against ≤3 viruses was documented for maribavir (cytomegalovirus, Epstein-Barr virus), and letermovir, while activity against > 3 viruses was shown for ganciclovir, cidofovir, acyclovir, foscarnet, cyclopropavir, artesunate, and Brincidofovir. The EC 50 values of Brincidofovir were the lowest, ranging from 0.001 to 0.27 μM, for all viruses except papillomaviruses. The next most potent agents included cidofovir, ganciclovir, foscarnet, and acyclovir with EC 50 values between 0.1 μM and >10 μM for cytomegalovirus, herpes simplex virus, and adenovirus. Conclusion Most of the identified antivirals had in vitro activity against more than one dsDNA virus. Brincidofovir and cidofovir have broad-spectrum activity, and Brincidofovir has the lowest EC 50 values. These findings could assist clinical practice and developmental research.
-
in vitro comparison of currently available and investigational antiviral agents against pathogenic human double stranded dna viruses a systematic literature review
Antiviral Research, 2019Co-Authors: Roy F. Chemaly, Joshua A Hill, Sebastian Voigt, Karl S PeggsAbstract:Abstract Background Double-stranded (ds) DNA virus infections often occur concomitantly in immunocompromised patients. We performed a systematic search of published in vitro activity for nine approved and investigational antivirals to understand the spectrum of in vitro activity against dsDNA viruses. Methods A literature search was performed (PubMed and the WoS Core Collection) using keywords related to: 1) targeted approved/developmental antivirals (acyclovir, artesunate, Brincidofovir, cidofovir, cyclopropavir (filociclovir), foscarnet, ganciclovir, letermovir, and maribavir); 2) pathogenic dsDNA viruses; 3) in vitro activity. We summarized data from 210 publications. Results Activity against ≤3 viruses was documented for maribavir (cytomegalovirus, Epstein-Barr virus), and letermovir, while activity against > 3 viruses was shown for ganciclovir, cidofovir, acyclovir, foscarnet, cyclopropavir, artesunate, and Brincidofovir. The EC 50 values of Brincidofovir were the lowest, ranging from 0.001 to 0.27 μM, for all viruses except papillomaviruses. The next most potent agents included cidofovir, ganciclovir, foscarnet, and acyclovir with EC 50 values between 0.1 μM and >10 μM for cytomegalovirus, herpes simplex virus, and adenovirus. Conclusion Most of the identified antivirals had in vitro activity against more than one dsDNA virus. Brincidofovir and cidofovir have broad-spectrum activity, and Brincidofovir has the lowest EC 50 values. These findings could assist clinical practice and developmental research.
-
A Randomized, Double-Blind, Placebo-Controlled Phase 3 Trial of Oral Brincidofovir for Cytomegalovirus Prophylaxis in Allogeneic Hematopoietic Cell Transplantation.
Biology of Blood and Marrow Transplantation, 2018Co-Authors: Francisco M. Marty, Roy F. Chemaly, Chad Wilson, Genovefa A. Papanicolaou, Thomas M. Brundage, Drew J. Winston, Kathleen M. Mullane, Tsiporah B. Shore, Greg Chittick, Marion E. MorrisonAbstract:Cytomegalovirus (CMV) infection is a common complication of allogeneic hematopoietic cell transplantation (HCT). In this trial, we randomized adult CMV-seropositive HCT recipients without CMV viremia at screening 2:1 to receive Brincidofovir or placebo until week 14 post-HCT. Randomization was stratified by center and risk of CMV infection. Patients were assessed weekly through week 15 and every third week thereafter through week 24 post-HCT. Patients who developed clinically significant CMV infection (CS-CMVi; CMV viremia requiring preemptive therapy or CMV disease) discontinued the study drug and began anti-CMV treatment. The primary endpoint was the proportion of patients with CS-CMVi through week 24 post-HCT; patients who discontinued the trial or with missing data were imputed as primary endpoint events. Between August 2013 and June 2015, 452 patients were randomized at a median of 15 days after HCT and received study drug. The proportion of patients who developed CS-CMVi or were imputed as having a primary endpoint event through week 24 was similar between Brincidofovir-treated patients and placebo recipients (155 of 303 [51.2%] versus 78 of 149 [52.3%]; odds ratio, .95 [95% confidence interval, .64 to 1.41]; P = .805); fewer Brincidofovir recipients developed CMV viremia through week 14 compared with placebo recipients (41.6%; P < .001). Serious adverse events were more frequent among Brincidofovir recipients (57.1% versus 37.6%), driven by acute graft-versus-host disease (32.3% versus 6.0%) and diarrhea (6.9% versus 2.7%). Week 24 all-cause mortality was 15.5% among Brincidofovir recipients and 10.1% among placebo recipients. Brincidofovir did not reduce CS-CMVi by week 24 post-HCT and was associated with gastrointestinal toxicity.
-
Brincidofovir for Asymptomatic Adenovirus Viremia in Pediatric and Adult Allogeneic Hematopoietic Cell Transplant Recipients: A Randomized Placebo-Controlled Phase II Trial
Biology of Blood and Marrow Transplantation, 2017Co-Authors: Michael Grimley, Roy F. Chemaly, Thomas M. Brundage, Marion E. Morrison, Gregory E. Chittick, Janet A. Englund, Joanne Kurtzberg, Andrew Bae, Vinod K. PrasadAbstract:Adenovirus infection in immunocompromised patients contributes to significant morbidity and mortality, especially after allogeneic hematopoietic cell transplantation (HCT). Brincidofovir (BCV, CMX001) is an orally bioavailable lipid conjugate of cidofovir that has in vitro activity against adenoviruses and other double-stranded DNA viruses. This randomized placebo-controlled phase II trial evaluated pre-emptive treatment with BCV for the prevention of adenovirus disease in pediatric and adult allogeneic HCT recipients with asymptomatic adenovirus viremia. Allogeneic HCT recipients with adenovirus viremia were randomized 1:1:1 to receive oral BCV 100 mg (2 mg/kg if
M. Leruez-ville - One of the best experts on this subject based on the ideXlab platform.
-
Traitements antiviraux de l’infection sévère à cytomégalovirus – état des lieux et perspectives
Réanimation, 2016Co-Authors: P. Frange, M. Leruez-villeAbstract:L’infection a cytomegalovirus (CMV) est une cause majeure de morbidite et de mortalite chez les patients immunodeprimes, notamment apres greffe de cellules souches hematopoietiques ou d’organe solide. Les traitements antiviraux actuellement disponibles ([val]ganciclovir, foscarnet, cidofovir) sont en nombre tres limite, exposent a un risque de toxicite non negligeable, voire de selection de virus CMVresistants en cas de replication virale prolongee sous traitement. Des progres recents ont ete faits dans le developpement de nouvelles molecules antivirales (en particulier le letermovir et le Brincidofovir), qui entrent actuellement dans leur derniere phase de developpement clinique et qui pourraient etre particulierement interessantes du fait de leur profil de tolerance et de leur activite preservee vis-a-vis de certains CMV resistant aux molecules actuelles. Nous presentons ici les donnees concernant les molecules antivirales actuellement disponibles et leurs modalites d’utilisation, ainsi que les perspectives therapeutiques pour le traitement des infections a CMV.
-
Traitements antiviraux de l’infection sévère à cytomégalovirus – état des lieux et perspectives
Réanimation, 2016Co-Authors: Pierre Frange, M. Leruez-villeAbstract:L’infection à cytomégalovirus (CMV) est une cause majeure de morbidité et de mortalité chez les patients immunodéprimés, notamment après greffe de cellules souches hématopoïétiques ou d’organe solide. Les traitements antiviraux actuellement disponibles ([val]ganciclovir, foscarnet, cidofovir) sont en nombre très limité, exposent à un risque de toxicité non négligeable, voire de sélection de virus CMVrésistants en cas de réplication virale prolongée sous traitement. Des progrès récents ont été faits dans le développement de nouvelles molécules antivirales (en particulier le letermovir et le Brincidofovir), qui entrent actuellement dans leur dernière phase de développement clinique et qui pourraient être particulièrement intéressantes du fait de leur profil de tolérance et de leur activité préservée vis-à-vis de certains CMV résistant aux molécules actuelles. Nous présentons ici les données concernant les molécules antivirales actuellement disponibles et leurs modalités d’utilisation, ainsi que les perspectives thérapeutiques pour le traitement des infections à CMV. Cytomegalovirus (CMV) infection is a common complication in immunodeficient patients, especially after haematopoietic stem cell or solid organ transplantation, and it is associated with multiple direct and indirect effects. Universal antiviral prophylaxis and a pre-emptive treatment strategy are options for prevention. However, therapeutic options ([val]ganciclovir, foscarnet, cidofovir) are still limited and could expose to severe toxicities. Moreover, drug-resistant CMV infection is now increasing in incidence. After many years during which we have seen few tangible advances in terms of new antiviral drugs, we are now experiencing an exciting period of late-stage drug development, characterized by a series of phase III trials incorporating a variety of novel agents (especially letermovirir and Brincidofovir).This article reviews the current state of treatment of severe CMV infections and summarizes the data on investigational drugs in clinical development.
Sebastian Voigt - One of the best experts on this subject based on the ideXlab platform.
-
in vitro comparison of currently available and investigational antiviral agents against pathogenic human double stranded dna viruses a systematic literature review
Antiviral Research, 2019Co-Authors: Roy F. Chemaly, Joshua A Hill, Sebastian Voigt, Karl S PeggsAbstract:Abstract Background Double-stranded (ds) DNA virus infections often occur concomitantly in immunocompromised patients. We performed a systematic search of published in vitro activity for nine approved and investigational antivirals to understand the spectrum of in vitro activity against dsDNA viruses. Methods A literature search was performed (PubMed and the WoS Core Collection) using keywords related to: 1) targeted approved/developmental antivirals (acyclovir, artesunate, Brincidofovir, cidofovir, cyclopropavir (filociclovir), foscarnet, ganciclovir, letermovir, and maribavir); 2) pathogenic dsDNA viruses; 3) in vitro activity. We summarized data from 210 publications. Results Activity against ≤3 viruses was documented for maribavir (cytomegalovirus, Epstein-Barr virus), and letermovir, while activity against > 3 viruses was shown for ganciclovir, cidofovir, acyclovir, foscarnet, cyclopropavir, artesunate, and Brincidofovir. The EC 50 values of Brincidofovir were the lowest, ranging from 0.001 to 0.27 μM, for all viruses except papillomaviruses. The next most potent agents included cidofovir, ganciclovir, foscarnet, and acyclovir with EC 50 values between 0.1 μM and >10 μM for cytomegalovirus, herpes simplex virus, and adenovirus. Conclusion Most of the identified antivirals had in vitro activity against more than one dsDNA virus. Brincidofovir and cidofovir have broad-spectrum activity, and Brincidofovir has the lowest EC 50 values. These findings could assist clinical practice and developmental research.
-
in vitro comparison of currently available and investigational antiviral agents against pathogenic human double stranded dna viruses a systematic literature review
Antiviral Research, 2019Co-Authors: Roy F. Chemaly, Joshua A Hill, Sebastian Voigt, Karl S PeggsAbstract:Abstract Background Double-stranded (ds) DNA virus infections often occur concomitantly in immunocompromised patients. We performed a systematic search of published in vitro activity for nine approved and investigational antivirals to understand the spectrum of in vitro activity against dsDNA viruses. Methods A literature search was performed (PubMed and the WoS Core Collection) using keywords related to: 1) targeted approved/developmental antivirals (acyclovir, artesunate, Brincidofovir, cidofovir, cyclopropavir (filociclovir), foscarnet, ganciclovir, letermovir, and maribavir); 2) pathogenic dsDNA viruses; 3) in vitro activity. We summarized data from 210 publications. Results Activity against ≤3 viruses was documented for maribavir (cytomegalovirus, Epstein-Barr virus), and letermovir, while activity against > 3 viruses was shown for ganciclovir, cidofovir, acyclovir, foscarnet, cyclopropavir, artesunate, and Brincidofovir. The EC 50 values of Brincidofovir were the lowest, ranging from 0.001 to 0.27 μM, for all viruses except papillomaviruses. The next most potent agents included cidofovir, ganciclovir, foscarnet, and acyclovir with EC 50 values between 0.1 μM and >10 μM for cytomegalovirus, herpes simplex virus, and adenovirus. Conclusion Most of the identified antivirals had in vitro activity against more than one dsDNA virus. Brincidofovir and cidofovir have broad-spectrum activity, and Brincidofovir has the lowest EC 50 values. These findings could assist clinical practice and developmental research.
-
Brincidofovir clearance of acyclovir-resistant herpes simplex virus-1 and adenovirus infection after stem cell transplantation
Transplant Infectious Disease, 2016Co-Authors: Sebastian Voigt, Jörg Hofmann, Anke Edelmann, Andreas Sauerbrei, Jörn-sven KühlAbstract:Infections with adenovirus (AdV) and herpesviruses can result in considerable morbidity and mortality in pediatric hematopoietic stem cell transplant (SCT) recipients. Herpes simplex virus (HSV) reactivations are usually prevented by acyclovir (ACV) prophylaxis, whereas cidofovir (CDV) has been used off indication to manage AdV infections. We report a child with myelodysplastic syndrome undergoing multiple SCT, who experienced HSV-1 disease including severe mucositis and herpetic whitlow, as well as high viral load AdV DNAemia. Both ACV and CDV were ineffective; however, viral loads were decreased with Brincidofovir, resulting in viral clearance. A subsequent Epstein–Barr virus disease with relevant meningoencephalitis responded to rituximab.
Joshua A Hill - One of the best experts on this subject based on the ideXlab platform.
-
Oral Brincidofovir decreases the incidence of HHV-6B viremia after allogeneic HCT.
Blood, 2020Co-Authors: Joshua A Hill, W. Garrett Nichols, Francisco M. Marty, Genovefa A. Papanicolaou, Thomas M. Brundage, Randall Lanier, Danielle M. Zerr, Michael BoeckhAbstract: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 with placebo (32.4%; log-rank, 0.019). In an adjusted Cox model, Brincidofovir exposure remained associated with a lower hazard for HHV-6B plasma detection (hazard ratio, 0.40; 95% confidence interval, 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.
-
in vitro comparison of currently available and investigational antiviral agents against pathogenic human double stranded dna viruses a systematic literature review
Antiviral Research, 2019Co-Authors: Roy F. Chemaly, Joshua A Hill, Sebastian Voigt, Karl S PeggsAbstract:Abstract Background Double-stranded (ds) DNA virus infections often occur concomitantly in immunocompromised patients. We performed a systematic search of published in vitro activity for nine approved and investigational antivirals to understand the spectrum of in vitro activity against dsDNA viruses. Methods A literature search was performed (PubMed and the WoS Core Collection) using keywords related to: 1) targeted approved/developmental antivirals (acyclovir, artesunate, Brincidofovir, cidofovir, cyclopropavir (filociclovir), foscarnet, ganciclovir, letermovir, and maribavir); 2) pathogenic dsDNA viruses; 3) in vitro activity. We summarized data from 210 publications. Results Activity against ≤3 viruses was documented for maribavir (cytomegalovirus, Epstein-Barr virus), and letermovir, while activity against > 3 viruses was shown for ganciclovir, cidofovir, acyclovir, foscarnet, cyclopropavir, artesunate, and Brincidofovir. The EC 50 values of Brincidofovir were the lowest, ranging from 0.001 to 0.27 μM, for all viruses except papillomaviruses. The next most potent agents included cidofovir, ganciclovir, foscarnet, and acyclovir with EC 50 values between 0.1 μM and >10 μM for cytomegalovirus, herpes simplex virus, and adenovirus. Conclusion Most of the identified antivirals had in vitro activity against more than one dsDNA virus. Brincidofovir and cidofovir have broad-spectrum activity, and Brincidofovir has the lowest EC 50 values. These findings could assist clinical practice and developmental research.
-
in vitro comparison of currently available and investigational antiviral agents against pathogenic human double stranded dna viruses a systematic literature review
Antiviral Research, 2019Co-Authors: Roy F. Chemaly, Joshua A Hill, Sebastian Voigt, Karl S PeggsAbstract:Abstract Background Double-stranded (ds) DNA virus infections often occur concomitantly in immunocompromised patients. We performed a systematic search of published in vitro activity for nine approved and investigational antivirals to understand the spectrum of in vitro activity against dsDNA viruses. Methods A literature search was performed (PubMed and the WoS Core Collection) using keywords related to: 1) targeted approved/developmental antivirals (acyclovir, artesunate, Brincidofovir, cidofovir, cyclopropavir (filociclovir), foscarnet, ganciclovir, letermovir, and maribavir); 2) pathogenic dsDNA viruses; 3) in vitro activity. We summarized data from 210 publications. Results Activity against ≤3 viruses was documented for maribavir (cytomegalovirus, Epstein-Barr virus), and letermovir, while activity against > 3 viruses was shown for ganciclovir, cidofovir, acyclovir, foscarnet, cyclopropavir, artesunate, and Brincidofovir. The EC 50 values of Brincidofovir were the lowest, ranging from 0.001 to 0.27 μM, for all viruses except papillomaviruses. The next most potent agents included cidofovir, ganciclovir, foscarnet, and acyclovir with EC 50 values between 0.1 μM and >10 μM for cytomegalovirus, herpes simplex virus, and adenovirus. Conclusion Most of the identified antivirals had in vitro activity against more than one dsDNA virus. Brincidofovir and cidofovir have broad-spectrum activity, and Brincidofovir has the lowest EC 50 values. These findings could assist clinical practice and developmental research.
-
Oral Brincidofovir Decreased HHV-6 Viremia in Hematopoietic Cell Transplant Recipients: Results from the Suppress Study
Biology of Blood and Marrow Transplantation, 2019Co-Authors: Joshua A Hill, Thomas M. Brundage, Randall Lanier, Danielle M. Zerr, Garrett Nichols, Michael BoeckhAbstract:Introduction Human herpesvirus 6B (HHV-6) is detected in plasma in ∼40% of allogeneic hematopoietic cell transplant (HCT) recipients and ∼75% of cord blood recipients. HHV-6 viremia, particularly at levels >104 copies/mL, is associated with increased risk for HHV-6 encephalitis. Ganciclovir and foscarnet have antiviral activity against HHV-6, but studies of pre-emptive or prophylactic treatment have not been successful in preventing HHV-6 encephalitis. Prophylaxis for HHV-6 has never been studied in a randomized trial. Brincidofovir (BCV, CMX001) has potent in vitro activity against HHV-6 (EC50=0.007 µM), and unlike cidofovir, has good CNS penetration. Objectives In vivo activity of BCV against HHV-6 has not been demonstrated. We tested plasma from participants in the SUPPRESS clinical trial to explore the potential of BCV to prevent HHV-6 viremia. Methods SUPPRESS was a randomized, double-blind, placebo (PBO)-controlled trial of oral BCV for cytomegalovirus (CMV) prophylaxis after allo-HCT. 452 adult CMV-seropositive HCT recipients without CMV viremia at screening were randomized 2:1 to receive BCV or PBO twice-weekly until week 14 post-HCT. We selected subjects who were randomized within 2 weeks of allo-HCT, who did not have HHV-6 viremia at baseline, and who received at least 6 doses of BCV or PBO within the first 3 weeks of randomization for HHV-6 testing. Plasma samples from the first six weeks post-HCT were tested for HHV-6 with quantitative PCR (Viracor Eurofins, Lee's Summit, MO). We compared HHV-6 viremia between subjects who received BCV and those who received PBO using the Kaplan-Meier method, log rank test, and Cox proportional hazards model. Results 92 subjects in the BCV group and 61 in the PBO group met criteria for inclusion: 64% were male, 84% were white, and median age was 57 years (range: 18-76). 6% of subjects received cord blood grafts, 5% had haploidentical donors, and 8% had mismatched donors. 41% had ex vivo T-cell depletion or received serotherapy with antithymocyte globulin or alemtuzumab. Baseline characteristics were balanced between groups. 15% of BCV subjects vs. 31% of PBO subjects had detectable HHV-6 viremia within 6 weeks after HCT. The cumulative incidence of HHV-6 viremia was significantly lower in BCV subjects (Figure 1). Two subjects (2%) in the BCV group had HHV-6 viremia >103 copies/mL compared to 7 (11%) in the PBO group (Figure 2). In the study overall, no subjects in the BCV group and one in the PBO group developed HHV-6 encephalitis. Conclusion BCV reduced the incidence of detectable HHV-6 viremia in HCT recipients enrolled in a randomized, placebo-controlled clinical trial. BCV prophylaxis could prevent the morbidity and mortality associated with HHV-6 in HCT recipients.