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Clinical Microbiology and Infection :... Sep 2023Cytomegalovirus (CMV) is an opportunistic pathogen responsible for substantial morbidity after solid organ transplantation and haematopoietic stem cell transplantation.... (Review)
Review
BACKGROUND
Cytomegalovirus (CMV) is an opportunistic pathogen responsible for substantial morbidity after solid organ transplantation and haematopoietic stem cell transplantation. Treatment of CMV disease involves a two-pronged approach with antiviral drug treatment coupled with strategies to minimize the intensity of immune suppression.
OBJECTIVES
This narrative review examines the evidence for the current treatment of CMV disease in transplant recipients, including the use of oral antiviral drugs.
SOURCES
Literature search was performed on PubMed with keywords cytomegalovirus, transplantation, ganciclovir, valganciclovir, maribavir, letermovir, cidofovir, and foscarnet.
CONTENT
Intravenous and oral valganciclovir are the standard first-line treatment of cytomegalovirus disease after transplantation. Oral maribavir has demonstrated superior efficacy and safety over CMV DNA polymerase inhibitors for the treatment of refractory or resistant CMV infection. Transplant patients with severe and life-threatening CMV disease, those with very high viral load, and patients with impaired gastrointestinal absorption should still be treated initially with intravenous antiviral drugs, including ganciclovir and foscarnet. Criteria for the safe transition from intravenous therapies to oral antiviral drugs include achieving clinical improvement and satisfactory decline in viral load. Recurrence of CMV viremia and disease is common, particularly among transplant patients who are lymphopenic and have impaired CMV-specific immunity.
IMPLICATIONS
Oral antiviral drugs for the treatment of CMV infection and disease in transplant recipients have improved the CMV landscape, because they reduce the cost and mitigate the inconvenience and risks related to prolonged hospitalization and the need for long-term intravascular access. However, their antiviral efficacy should be complemented by an intentional strategy of reducing the degree of immune suppression to allow for immunologic recovery that ensures durable control of CMV infection.
Topics: Humans; Antiviral Agents; Cytomegalovirus; Valganciclovir; Foscarnet; Transplant Recipients; Ganciclovir; Cytomegalovirus Infections
PubMed: 36963566
DOI: 10.1016/j.cmi.2023.03.020 -
Journal of Clinical Pharmacology May 2024Maribavir, an orally available antiviral agent, has been approved in multiple countries for the treatment of patients with refractory post-transplant cytomegalovirus...
Maribavir, an orally available antiviral agent, has been approved in multiple countries for the treatment of patients with refractory post-transplant cytomegalovirus (CMV) infection and/or disease. Maribavir is primarily metabolized by CYP3A4; coadministration with CYP3A4 inducers and inhibitors may significantly alter maribavir exposure, thereby affecting its efficacy and safety. The effect of CYP3A4 inducers and inhibitors on maribavir exposure was evaluated based on a drug-drug interaction (DDI) study and physiologically-based pharmacokinetic (PBPK) modeling. The effect of rifampin (a strong inducer of CYP3A4 and moderate inducer of CYP1A2), administered at a 600 mg dose once daily, on maribavir pharmacokinetics was assessed in a clinical phase 1 DDI study in healthy participants. A full PBPK model for maribavir was developed and verified using in vitro and clinical pharmacokinetic data from phase 1 studies. The verified PBPK model was then used to simulate maribavir DDI interactions with various CYP3A4 inducers and inhibitors. The DDI study results showed that coadministration with rifampin decreased the maribavir maximum plasma concentration (C), area under the plasma concentration-time curve (AUC), and trough concentration (C) by 39%, 60%, and 82%, respectively. Based on the results from the clinical DDI study, the coadministration of maribavir with rifampin is not recommended. The PBPK model did not predict a clinically significant effect of CYP3A4 inhibitors on maribavir exposure; however, it predicted that strong or moderate CYP3A4 inducers, including carbamazepine, efavirenz, phenobarbital, and phenytoin, may reduce maribavir exposure to a clinically significant extent, and may prompt the consideration of a maribavir dosing increase, in accordance with local approved labels and/or regulations.
Topics: Humans; Drug Interactions; Cytochrome P-450 CYP3A Inducers; Cytochrome P-450 CYP3A Inhibitors; Rifampin; Models, Biological; Male; Adult; Benzimidazoles; Cytochrome P-450 CYP3A; Antiviral Agents; Female; Young Adult; Middle Aged; Area Under Curve; Dichlororibofuranosylbenzimidazole
PubMed: 38009271
DOI: 10.1002/jcph.2385 -
International Journal of Antimicrobial... Aug 2023Cytomegalovirus (CMV) is a common infection encountered in immunocompromised patients. It is associated with high morbidity and mortality, particularly in patients... (Review)
Review
Cytomegalovirus (CMV) is a common infection encountered in immunocompromised patients. It is associated with high morbidity and mortality, particularly in patients undergoing allogeneic (allo-) haematopoietic stem cell transplantation (HSCT). This review presents the most recent management strategies for CMV infection in allo-HSCT recipients. Pre-emptive treatment (PET) consists of frequent monitoring of CMV polymerase chain reaction (PCR) after HSCT; this has been the standard of care for prevention of CMV for many years, given the potential drug toxicity associated with the traditional drugs used as prophylaxis. However, letermovir, recently approved as a chemoprophylactic agent for prevention of CMV, has shown great efficacy in randomized clinical trials and real-world data. Treatment of CMV disease is becoming increasingly difficult, and must take into account the patient's risk profile and the potential for CMV drug resistance. Different treatment strategies exist for refractory and resistant CMV disease. Maribavir is a new drug that showed promising results in the treatment of refractory and resistant CMV disease. Other alternative treatments, such as cellular adoptive immunotherapy, artesunate and leflunomide, may play an adjunctive role in the treatment of challenging cases; however, further investigation is warranted.
Topics: Humans; Antiviral Agents; Cytomegalovirus Infections; Cytomegalovirus; Transplantation, Homologous; Hematopoietic Stem Cell Transplantation
PubMed: 37220849
DOI: 10.1016/j.ijantimicag.2023.106860 -
Current Treatment Options in Infectious... 2021Cytomegalovirus (CMV) remains a major cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (Allo-HSCT). New strategies and methods... (Review)
Review
PURPOSE OF REVIEW
Cytomegalovirus (CMV) remains a major cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (Allo-HSCT). New strategies and methods for prevention and management of CMV infection are urgently needed. We aim to review the new developments in diagnostics, prevention, and management strategies of CMV infection in Allo-HSCT recipients.
RECENT FINDINGS
The approval of the novel anti-CMV drug letermovir in 2017 has led to an increase in the use of antiviral prophylaxis as a preferred approach for prevention in many centers. Real-world studies have shown efficacy similar to the clinical trial. CMV-specific T cell-mediated immunity assays identify patients with immune reconstitution and predict disease progression. Phase 2 trials of maribavir have shown its efficacy as preemptive therapy and treatment of resistant and refractory CMV infections. Adoptive T cell therapy is an emerging option for treatment of refractory and resistant CMV. Of the different CMV vaccine trials, PepVax has shown promising results in a phase 1 trial.
SUMMARY
CMV cell-mediated immunity assays have potential to be used as an adjunctive test to develop individualized management plan by identifying the patients who develop immune reconstitution; however, further prospective interventional studies are needed. Maribavir and adoptive T cell therapy are promising new therapies for treatment of CMV infections. CMV vaccine trials for prevention are also under way.
PubMed: 34305463
DOI: 10.1007/s40506-021-00253-w -
International Journal of Molecular... Mar 2022Herpes simplex virus types 1 and 2 HSV1 and 2, namely varicella-zoster VZV and cytomegalovirus CMV, are among the most common pathogens worldwide. They remain in the... (Review)
Review
Herpes simplex virus types 1 and 2 HSV1 and 2, namely varicella-zoster VZV and cytomegalovirus CMV, are among the most common pathogens worldwide. They remain in the host body for life. The course of infection with these viruses is often asymptomatic or mild and self-limiting, but in immunocompromised patients, such as solid organ or bone marrow transplant recipients, the course can be very severe or even life-threatening. Unfortunately, in the latter group, the highest percentage of infections with strains resistant to routinely used drugs is observed. On the other hand, frequent recurrences of genital herpes can be a problem even in people with normal immunity. Genital herpes also increases the risk of acquiring sexually transmitted diseases, including HIV infection and, if present in pregnant women, poses a risk to the fetus and newborn. Even more frequently than herpes simplex, congenital infections can be caused by cytomegalovirus. We present the most important anti-herpesviral agents, the mechanisms of resistance to these drugs, and the associated mutations in the viral genome. Special emphasis was placed on newly introduced drugs such as maribavir and brincidofovir. We also briefly discuss the most promising substances in preclinical testing as well as immunotherapy options and vaccines currently in use and under investigation.
Topics: Acyclovir; Antiviral Agents; Cytomegalovirus; Female; HIV Infections; Herpes Genitalis; Herpes Simplex; Herpes Zoster; Herpesviridae Infections; Humans; Infant, Newborn; Pregnancy
PubMed: 35408788
DOI: 10.3390/ijms23073431 -
Reviews in Medical Virology 2008Mutations in the human CMV UL97 kinase gene are a major mechanism of viral resistance to two anti-CMV drugs, ganciclovir (GCV) and maribavir (MBV). GCV, the most widely... (Review)
Review
Mutations in the human CMV UL97 kinase gene are a major mechanism of viral resistance to two anti-CMV drugs, ganciclovir (GCV) and maribavir (MBV). GCV, the most widely used and established therapy for CMV, is a substrate for the UL97 kinase. Well-characterised GCV-resistance mutations at UL97 codons 460, 520 and 590-607 impair the phosphorylation of GCV that is necessary for its antiviral activity, presumably by altering substrate recognition. In contrast, MBV is an inhibitor of the UL97 kinase and is the first new CMV therapy to reach later stage clinical trials in many years. No MBV-resistant CMV isolates have yet been detected in clinical trials, but after culture propagation under drug, UL97 mutations that confer moderate to high-level MBV resistance have been identified at codons 353, 397, 409 and 411. These mutations are located upstream of the GCV-resistance mutations and are close to the ATP-binding and catalytic domains common to all kinases, consistent with MBV acting as a small molecule ATP-competitive kinase inhibitor. So far, no UL97 mutations are known to confer resistance to both GCV and MBV.
Topics: Antiviral Agents; Benzimidazoles; Cytomegalovirus; Drug Resistance, Viral; Ganciclovir; Humans; Mutation, Missense; Phosphotransferases (Alcohol Group Acceptor); Ribonucleosides
PubMed: 18383425
DOI: 10.1002/rmv.574 -
Journal of Clinical Virology : the... Feb 2017
Review
Topics: Administration, Oral; Antiviral Agents; Benzimidazoles; Blood; Cytomegalovirus; Cytomegalovirus Infections; Drug Resistance, Viral; Ganciclovir; Humans; Immunosuppressive Agents; Isoxazoles; Leflunomide; Male; Middle Aged; Ribonucleosides; Sputum; Time Factors
PubMed: 27987421
DOI: 10.1016/j.jcv.2016.12.006 -
The Lancet. Infectious Diseases Apr 2011Available drugs against cytomegalovirus have adverse effects that compromise their prophylactic use in recipients of allogeneic stem-cell transplants. We assessed the... (Randomized Controlled Trial)
Randomized Controlled Trial
Maribavir prophylaxis for prevention of cytomegalovirus disease in recipients of allogeneic stem-cell transplants: a phase 3, double-blind, placebo-controlled, randomised trial.
BACKGROUND
Available drugs against cytomegalovirus have adverse effects that compromise their prophylactic use in recipients of allogeneic stem-cell transplants. We assessed the safety, tolerability, and antiviral activity of oral maribavir in such patients.
METHODS
In this placebo-controlled, randomised, double-blind, multicentre phase 3 study, we enrolled adult patients recipient-seropositive or donor-seropositive for cytomegalovirus who had undergone allogeneic stem-cell transplantation. Patients were recruited from 90 centres in Canada, Europe, and the USA. After engraftment, patients were stratified by recipient cytomegalovirus serostatus and conditioning regimen (myeloablative or reduced-intensity) and assigned (2:1) by masked computer-generated randomisation sequence to receive maribavir 100 mg twice daily or placebo for up to 12 weeks, with weekly blood cytomegalovirus surveillance. If the virus was detected, administration of study drug was stopped and pre-emptive anticytomegalovirus treatment started. The primary endpoint was cytomegalovirus disease within 6 months of transplantation. Analysis was by intention-to-treat. This study is registered with ClinicalTrials.gov, NCT00411645.
FINDINGS
Between December, 2006, and May, 2008, 681 patients were enrolled and assigned to receive maribavir (454) or placebo (227). The incidence of cytomegalovirus disease within 6 months was 20 of 454 (4%) for the maribavir group and 11 of 227 (5%) for the placebo group (OR 0.90; 95% CI 0.42-1.92). During the 100 days following transplantation, cytomegalovirus infection rates as measured by pp65 antigenaemia were lower in the maribavir group (26.4%) than in the placebo group (34.8%; OR 0.67; 0.47-0.95), but not when measured by plasma cytomegalovirus DNA PCR (27.8%vs 30.4%; OR 0·88; 0.62-1.25), nor by initiation of treatment against cytomegalovirus (30.6%vs 37.4%; OR 0.73, 0.52-1.03). Maribavir was well tolerated: most adverse events, including incident acute graft-versus-host disease and neutropenia, affected both groups equally, except for taste disturbance (15% maribavir, 6% placebo).
INTERPRETATION
Compared with placebo, maribavir prophylaxis did not prevent cytomegalovirus disease when started after engraftment. Cytomegalovirus disease as a primary endpoint might not be sufficient to show improvements in cytomegalovirus prevention in recipients of allogeneic stem-cell transplants in the setting of pre-emptive antiviral treatment. Clinical and virological composite endpoints should be used in future trials.
FUNDING
ViroPharma Incorporated.
Topics: Administration, Oral; Adolescent; Adult; Aged; Antiviral Agents; Benzimidazoles; Canada; Chemoprevention; Cytomegalovirus Infections; Double-Blind Method; Europe; Female; Humans; Male; Middle Aged; Placebos; Ribonucleosides; Stem Cell Transplantation; Transplantation; Treatment Outcome; United States; Young Adult
PubMed: 21414843
DOI: 10.1016/S1473-3099(11)70024-X -
Transplantation Apr 2024Cytomegalovirus (CMV) is one of the most common infections occurring after solid organ transplantation. This high burden of disease, which incurs sizeable morbidity, may... (Review)
Review
Cytomegalovirus (CMV) is one of the most common infections occurring after solid organ transplantation. This high burden of disease, which incurs sizeable morbidity, may be worsening with the proportion of high-risk D+/R- solid organ transplantation recipients increasing in some regions globally. Cohort studies continue to support either universal prophylaxis or preemptive therapy as effective prevention strategies. Letermovir prophylaxis was noninferior to valganciclovir in adult high-risk D+/R- kidney transplant recipients with fewer drug-related adverse events in a recent clinical trial and has now been approved for such use in some regions. Maribavir preemptive therapy failed to demonstrate noninferiority when compared with valganciclovir in hematopoietic stem cell transplant recipients but looked promising for safety. Donor matching could be useful in prevention CMV disease with a survival advantage demonstrated in seronegative recipients waiting up to 30 mo for a seronegative kidney. Immune-guided prophylaxis resulted in fewer CMV infection episodes in lung transplant recipients when compared with fixed-duration prophylaxis in a recent clinical trial. For treatment of refractory or resistant CMV infection, maribavir was more efficacious and better tolerated when compared with investigator-initiated therapy in its registration trial for this condition. Further research regarding best treatment and prophylaxis of resistant or refractory CMV infection is needed to reflect best clinical practice choices. Optimal use of immune globulin or CMV-specific T cells for prevention or treatment of CMV disease remains undefined. Standardized definitions for the design of CMV clinical trials have been developed. In this review, we highlight recent updates in the field from data published since 2018.
Topics: Adult; Humans; Antiviral Agents; Cytomegalovirus; Cytomegalovirus Infections; Organ Transplantation; Valganciclovir; Clinical Trials as Topic
PubMed: 37899366
DOI: 10.1097/TP.0000000000004855 -
Drug Metabolism and Disposition: the... Nov 2021Maribavir is in phase 3 clinical development for treatment of cytomegalovirus infection/disease in transplant recipients. Previous research conducted using only intact...
Maribavir is in phase 3 clinical development for treatment of cytomegalovirus infection/disease in transplant recipients. Previous research conducted using only intact cynomolgus monkeys indicated biliary secretion as the primary elimination pathway for maribavir and that maribavir undergoes enterohepatic recirculation (EHR). To clarify the exact mechanisms of maribavir's EHR behavior, we studied its clearance pathways using intravenously administered C-labeled maribavir in intact and bile duct-cannulated (BDC) monkeys and constructed a semi-physiologically based pharmacokinetic (PBPK) model. Total radioactivity metabolite profiles in plasma and excreta were quantitatively determined along with plasma maribavir concentrations. Intact animals showed significantly lower clearance and longer half-lives in both total radioactivity and parent concentration in plasma than BDC monkeys. The primary in vitro and in vivo metabolic pathway for maribavir in monkey is direct glucuronidation; -dealkylation and renal clearance are minor pathways. In BDC monkeys, 73% of dose was recovered as maribavir glucuronides in bile, and 3% of dose was recovered as parent in bile and feces; in intact animals' feces, 58% of dose was recovered as parent, and no glucuronides were detected. Therefore, EHR of maribavir occurs through biliary secretion of maribavir glucuronides, and this is followed by hydrolysis of glucuronides in the gut lumen and subsequent reabsorption of parent. A semi-PBPK model constructed from physiologic, in vitro, and in vivo BDC monkey data is capable of projecting maribavir's pharmacokinetic and EHR behavior in intact animals after intravenous or oral dosing and could be applied to modeling other xenobiotics that are subject to similar EHR processes. SIGNIFICANCE STATEMENT: Through both mass balance and semi-physiologically based pharmacokinetic (semi-PBPK) modeling approaches, this study mechanistically and quantitatively elucidates maribavir's enterohepatic recirculation (EHR) behavior in monkeys, which occurs via extensive direct glucuronidation, biliary secretion of these glucuronides, luminal hydrolysis of glucuronides to parent, and subsequent reabsorption of the parent. The study also identifies important drug- and animal-specific parameters that determine the EHR kinetics, and the semi-PBPK model is readily applicable to other drugs that undergo similar metabolic and recirculation mechanisms.
Topics: Animals; Antiviral Agents; Benzimidazoles; Bile; Biotransformation; Caco-2 Cells; Dealkylation; Feces; Gastrointestinal Transit; Glucuronides; Half-Life; Humans; Hydrolysis; Kidney; Macaca fascicularis; Male; Models, Biological; Ribonucleosides
PubMed: 34462268
DOI: 10.1124/dmd.121.000493