gw-257406x and letermovir

The prevention and treatment of human cytomegalovirus (HCMV) infections is based on the use of antiviral agents that currently target the viral DNA polymerase and that may cause serious side effects. The search for novel inhibitors against HCMV infection led to the discovery of new molecular targets, the viral terminase complex and the viral pUL97 kinase. The most advanced compounds consist of letermovir (LMV) and maribavir (MBV). LMV inhibits the cleavage of viral DNA and its packaging into capsids by targeting the HCMV terminase complex. LMV is safe and well tolerated and exhibits pharmacokinetic properties that allow once daily dosing. LMV showed efficacy in a phase III prophylaxis study in hematopoietic stem cell transplant (HSCT) recipients seropositive for HCMV. LMV was recently approved under the trade name Prevymis

Topics: Acetates; Animals; Antiviral Agents; Benzimidazoles; Clinical Trials as Topic; Cytomegalovirus; Cytomegalovirus Infections; DNA, Viral; Drug Development; Drug Resistance, Viral; Humans; Quinazolines; Ribonucleosides; Viral Proteins; Virus Replication

Cytomegalovirus (CMV) infection is a common complication in immunocompromised patients, especially after hematopoietic stem cell or solid organ transplantation. Therapeutic antiviral options [(val)ganciclovir, foscarnet, cidofovir] are still limited and can expose to severe toxicities. Moreover, prolonged antiviral drug exposure and ongoing viral replication are key factors in the development of antiviral drug resistance. After many years of few tangible advances in terms of new antiviral drugs, we are now experiencing an exciting period characterized by a series of phase III clinical trials incorporating three novel agents: maribavir, brincidofovir, and letermovir. This article summarizes the current state of the prevention and treatment of CMV infections as well as data of investigational drugs in clinical development.

Topics: Acetates; Antiviral Agents; Benzimidazoles; Cytomegalovirus Infections; Cytosine; Ganciclovir; Humans; Organophosphonates; Quinazolines; Ribonucleosides

Over the past 25 years, several randomized controlled trials have investigated the efficacy of different antiviral agents for cytomegalovirus (CMV) prophylaxis in allogeneic hematopoietic cell transplantation. We performed a systematic literature review, conventional meta-analysis, and network meta-analysis using a random-effects model and risk ratios (RRs) with corresponding 95% confidence intervals (CIs) as effect estimates. Fifteen randomized controlled trials were identified, including 7 different antiviral agents: acyclovir, ganciclovir, maribavir, brincidofovir, letermovir, valacyclovir, and vaccine. Twelve trials used placebo as comparator while 3 trials compared different antiviral agents. We found evidence for CMV disease and infection being significantly reduced by antiviral prophylaxis, with an RR of .66 (95% CI, .48 to .90) and .63 (95% CI, .50 to .79). Across the network, ganciclovir showed the best relative efficacy for CMV disease while letermovir provided first rank of being the best option for CMV infection. The risk for death was not significantly influenced by antiviral prophylaxis in the meta-analysis, with an RR of .92 (95% CI, .78 to 1.08), as well as in the network meta-analysis. In terms of safety, letermovir was at least similar in comparison with placebo and most agents while both letermovir and acyclovir showed significantly reduced risk for serious adverse events compared with ganciclovir, with RRs of .55 (95% CI, .30 to 1.00) for letermovir and .63 (95% CI, .42 to .93) for acyclovir. With a probability of 81%, letermovir appears to be the best option in terms of safety. Future randomized head-to-head comparisons are needed to evaluate the definite efficacy and safety of different prophylactic strategies.

Topics: Acetates; Acyclovir; Allografts; Antiviral Agents; Benzimidazoles; Cytomegalovirus; Cytomegalovirus Infections; Female; Ganciclovir; Hematopoietic Stem Cell Transplantation; Humans; Male; Quinazolines; Ribonucleosides; Risk Factors; Valacyclovir

Human cytomegalovirus (HCMV) represents the major viral complication after hematopoietic stem cell transplantation. HCMV infection may be controlled by the reconstituting immune system and remain subclinical or can lead to severe systemic and/or organ disease (mainly pneumonia and gastroenteritis) when immune reconstitution is delayed or impaired. In order to prevent the occurrence of HCMV disease, a prompt diagnosis of HCMV infection is mandatory. The adoption of pre-emptive therapy strategies guided by virological monitoring dramatically reduced the occurrence of HCMV disease. However, late-onset end-organ disease may occur in some patients with apparent immune reconstitution. In the near future, introduction of immunological monitoring and immunotherapies could markedly improve management of HCMV infection.

Topics: Acetates; Adult; Animals; Antiviral Agents; Asymptomatic Diseases; Benzimidazoles; Clinical Trials as Topic; Cytomegalovirus; Cytomegalovirus Infections; Cytosine; Disease Management; Gastroenteritis; Hematopoietic Stem Cell Transplantation; Humans; Immunotherapy; Monitoring, Immunologic; Organophosphonates; Pneumonia; Postoperative Complications; Quinazolines; Ribonucleosides

The 2015 Tandem American Society for Blood and Marrow Transplantation/Center for International Blood and Marrow Transplant Meetings provide an opportunity to review the current status and future perspectives on therapy for cytomegalovirus (CMV) infection in the setting of hematopoietic stem cell transplantation (HSCT). 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. These trials have the potential to shift our current standard therapeutic strategies, which generally involve pre-emptive therapy based on sensitive molecular surveillance, towards the prophylactic approaches we see more generally with other herpes viruses such as herpes simplex and varicella zoster. This comes at a time when the promise of extensive preclinical research has been translated into encouraging clinical responses with several cellular immunotherapy strategies, which have also been moved towards definitive late-stage clinical trials. How these approaches will be integrated with the new wave of antiviral drugs remains open to conjecture. Although most of the focus of these cellular immunotherapy studies has been on adaptive immunity, and in particular T cells, an increasing awareness of the possible role of other cellular subsets in controlling CMV infection has developed. In particular, the role of natural killer (NK) cells is being revisited, along with that of γδ T cells. Depletion of NK cells in mice results in higher titers of murine CMV in tissues and increased mortality, whereas NK cell deficiency in humans has been linked to severe CMV disease. We will review recent progress in these areas.

Topics: Acetates; Adoptive Transfer; Animals; Antiviral Agents; Benzimidazoles; Cell- and Tissue-Based Therapy; Clinical Trials, Phase III as Topic; Cytomegalovirus; Cytomegalovirus Infections; Cytosine; Hematopoietic Stem Cell Transplantation; Humans; Isoxazoles; Killer Cells, Natural; Leflunomide; Mice; Organophosphonates; Quinazolines; Ribonucleosides; T-Lymphocytes

Cytomegalovirus (CMV) remains a significant cause of morbidity and mortality in immunocompromised patients, particularly following allogeneic haematopoietic transplantation. One of the principal factors leading to this increased risk is the loss of T-cell immunity.. In a recent review, we assessed the treatment strategies for prophylaxis and pre-emptive treatment of CMV, particularly where relevant to the high-risk patient populations following allogeneic haematopoietic transplantation. This review is a focused update to our previous article and presents a more detailed analysis of the developments in drugs, vaccines and adoptive T-cell therapies since that time. Relevant studies were selected from PubMed and clinicaltrials.gov. The search terms include allogeneic transplant, cytomegalovirus, multidrug-resistant virus and adoptive T-cell therapy.. The current randomised controlled studies evaluating pharmacological agents for CMV should inform as to whether these provide significant clinical benefits. Adoptive cell therapy provides a more physiological approach to the problem of lack of CMV-specific immunity. Recent reports add to the evidence that culture-based techniques can create cellular products that are safe and efficacious, although without Phase III data to definitively support their routine application and the difficulty of satisfying GMP standards.

Topics: Acetates; Antiviral Agents; Benzimidazoles; Cytomegalovirus; Cytomegalovirus Infections; Cytosine; Hematologic Neoplasms; Hematopoietic Stem Cell Transplantation; Humans; Immunotherapy, Adoptive; Organophosphonates; Quinazolines; Ribonucleosides; T-Lymphocytes; Transplant Recipients; Transplantation, Homologous

To consider new treatment options for cytomegalovirus (CMV) infection, review recent trials, and anticipate their use in clinical practice, focussing on bone marrow transplantation, congenital infection, and intervention during pregnancy.. Three double-blind randomized placebo-controlled phase 2 proof-of-concept studies have each identified a novel antiviral drug with activity against CMV infection in bone marrow transplant patients. One of these (brincidofovir) inhibits the DNA polymerase that is the target of the currently licensed drug ganciclovir. Another new drug (maribavir) inhibits a protein kinase which, coincidentally, is the enzyme responsible for activating ganciclovir through phosphorylation. The third drug (letermovir) inhibits the terminase enzyme complex responsible for packaging unit length DNA into assembling virions.In addition, in a double-blind randomized placebo-controlled trial in neonates with symptomatic congenital CMV infection, a 6-month course of valganciclovir was superior to the standard 6-week course of the same drug. In pregnant women with primary CMV infection, administration of hyperimmune immunoglobulin did not significantly reduce transmission of CMV across the placenta.. The ability to diagnose CMV infections reliably in different clinical settings through application of molecular laboratory methods has ushered in new ways of evaluating potential new treatments for CMV. Several of these may help control the diseases caused by this important human pathogen.

Topics: Acetates; Antiviral Agents; Benzimidazoles; Bone Marrow Transplantation; Cytomegalovirus; Cytomegalovirus Infections; Cytosine; Disease Transmission, Infectious; Double-Blind Method; Female; Ganciclovir; Humans; Male; Organ Transplantation; Organophosphonates; Practice Guidelines as Topic; Pregnancy; Pregnancy Complications, Infectious; Quinazolines; Randomized Controlled Trials as Topic; Ribonucleosides

Management of pan-resistant cytomegalovirus infection (CMVi) requires a multifaceted approach, including host defence optimization by reducing immunosuppression, and standard or experimental antiviral therapy.. A 36-year-old man with anaplastic lymphoma kinase (ALK)-negative anaplastic large cell lymphoma, who underwent allogeneic haematopoietic stem cell transplant (alloHCT) with resultant graft-versus-host disease treated with immunosuppressive therapy, developed pan-resistant CMVi. He was successfully treated with combination therapy of maribavir and letermovir.. Combination therapy, used for other infections to prevent cross-resistant, may apply for CMVi.

Topics: Acetates; Adult; Antiviral Agents; Benzimidazoles; Cytomegalovirus; Cytomegalovirus Infections; Hematologic Neoplasms; Hematopoietic Stem Cell Transplantation; Humans; Male; Quinazolines; Ribonucleosides

Until recently, available drugs for cytomegalovirus (CMV) prevention and treatment in transplant patients included (val)ganciclovir, foscarnet, and cidofovir. Use of these drugs is limited by toxicity and the development of resistance. The 2017 approval of letermovir for prevention of CMV after stem cell transplant marked the first approval of an anti-CMV agent since 2003. The role of letermovir in treatment of established CMV infection or disease remains largely unstudied, although early reports suggest that a low barrier to resistance will likely limit efficacy as primary therapy for patients with refractory or resistant disease. The investigational agent maribavir has shown promise as preemptive treatment; in patients with refractory or resistant disease the emergence of resistance while on treatment has been observed and ongoing studies will define efficacy in this population. Both agents have unique mechanisms of action limiting cross resistance, and neither exhibit myelotoxicity or nephrotoxicity.

Topics: Acetates; Antiviral Agents; Benzimidazoles; Cytomegalovirus Infections; Drug Resistance, Viral; Hematopoietic Stem Cell Transplantation; Humans; Quinazolines; Ribonucleosides; Transplant Recipients

Congenital cytomegalovirus infection can lead to severe sequelae. When fetal infection is confirmed, we hypothesize that fetal treatment could improve the outcome. Maternal oral administration of an effective drug crossing the placenta could allow fetal treatment. Letermovir (LMV) and Maribavir (MBV) are new CMV antivirals, and potential candidates for fetal treatment.. The objective was to investigate the placental transfer of LMV and MBV in the ex vivo method of the human perfused cotyledon. Term placentas were perfused, in an open-circuit model, with LMV or MBV at concentrations in the range of clinical peak plasma concentrations. Concentrations were measured using ultraperformance liquid chromatography coupled with tandem mass spectrometry. Mean fetal transfer rate (FTR) (fetal (FC) /maternal concentration), clearance index (CLI), accumulation index (AI) (retention of each drug in the cotyledon tissue) were measured. Mean FC were compared with half maximal effective concentrations of the drugs (EC50(LMV) and EC50(MBV)).. For LMV, the mean FC was (± standard deviation) 1.1 ± 0.2 mg/L, 1,000-fold above the EC50(LMV). Mean FTR, CLI and AI were 9 ± 1%, 35 ± 6% and 4 ± 2% respectively. For MBV, the mean FC was 1.4 ± 0.2 mg/L, 28-fold above the EC50(MBV). Mean FTR, CLI and AI were 10 ± 1%, 50 ± 7% and 2 ± 1% respectively.. Drugs' concentrations in the fetal side should be in the range for in utero treatment of fetuses infected with CMV as the mean FC was superior to the EC50 for both molecules.

Topics: Acetates; Adult; Antiviral Agents; Benzimidazoles; Chromatography, Liquid; Cytomegalovirus Infections; Female; Humans; Kinetics; Maternal-Fetal Exchange; Models, Biological; Perfusion; Placenta; Pregnancy; Quinazolines; Ribonucleosides; Tandem Mass Spectrometry

We have recently shown that the artemisinin derivative artemisone, which was screened against malaria in human clinical studies, is a potent inhibitor of human cytomegalovirus (HCMV). Here we evaluated the antiviral effect of artemisone when employed in 2-drug combinations with approved and experimental anti-HCMV agents. Using the Chou-Talalay method, we found that in-vitro combination of artemisone with cidofovir, brincidofovir, or with the HCMV UL97 inhibitor maribavir resulted in antiviral synergism and the combination of artemisone with ganciclovir or with the viral terminase inhibitors letermovir and BDCRB resulted in moderate synergism. Importantly, the combination of artemisone with maribavir demonstrated synergistic antiviral activity ex-vivo, in a clinically-relevant multicellular model of human placental tissues maintained in organ culture. Our findings provide the basis for the use of artemisone in synergistically acting drug combinations, to enhance viral control and reduce antiviral drug toxicities.

Topics: Acetates; Antiviral Agents; Artemisinins; Benzimidazoles; Cidofovir; Cytomegalovirus; Cytomegalovirus Infections; Cytosine; Drug Interactions; Drug Synergism; Drugs, Investigational; Female; Ganciclovir; Humans; Organ Culture Techniques; Organophosphonates; Placenta; Pregnancy; Quinazolines; Ribonucleosides