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Expert Opinion on Pharmacotherapy Apr 2024Cytomegalovirus (CMV) remains a serious opportunistic infection in hematopoietic cell transplant (HCT) and solid-organ transplant (SOT) recipients. Traditional anti-CMV... (Review)
Review Comparative Study
INTRODUCTION
Cytomegalovirus (CMV) remains a serious opportunistic infection in hematopoietic cell transplant (HCT) and solid-organ transplant (SOT) recipients. Traditional anti-CMV drugs are limited by toxicities and the development of resistance. Letermovir and maribavir are newly approved antivirals for the prevention and treatment of CMV.
AREAS COVERED
Prior reviews have discussed use of letermovir for prevention of CMV after HCT and maribavir for resistant or refractory (R/R) CMV post HCT or SOT. Subsequent data have expanded their use including letermovir for primary CMV prophylaxis in high-risk renal transplant recipients and new recommendations for extending prophylaxis through day + 200 in certain HCT patients. Data on the use of maribavir for first asymptomatic CMV infection post-HCT has also been published. This review compares the pharmacology of anti-CMV agents and discusses the updated literature of these new drugs in the prevention and treatment of CMV.
EXPERT OPINION
Letermovir and maribavir are much needed tools that spare toxicities of ganciclovir, foscarnet, and cidofovir. High cost is a challenge preventing their integration into clinical practice in resource-limited countries. Transplant centers need to exercise restraint in overuse to avoid resistance, particularly in the setting of high viral loads.
Topics: Humans; Acetates; Antiviral Agents; Benzimidazoles; Cytomegalovirus Infections; Dichlororibofuranosylbenzimidazole; Drug Resistance, Viral; Hematopoietic Stem Cell Transplantation; Opportunistic Infections; Organ Transplantation; Quinazolines; Ribonucleosides; Viral Load
PubMed: 38717943
DOI: 10.1080/14656566.2024.2353627 -
Clinical and Translational Science Jan 2024Maribavir is an oral benzimidazole riboside for treatment of post-transplant cytomegalovirus (CMV) infection/disease that is refractory to prior antiviral treatment... (Review)
Review
Maribavir is an oral benzimidazole riboside for treatment of post-transplant cytomegalovirus (CMV) infection/disease that is refractory to prior antiviral treatment (with or without resistance). Through competitive inhibition of adenosine triphosphate, maribavir prevents the phosphorylation actions of UL97 to inhibit CMV DNA replication, encapsidation, and nuclear egress. Maribavir is active against CMV strains with viral DNA polymerase mutations that confer resistance to other CMV antivirals. After oral administration, maribavir is rapidly and highly absorbed (fraction absorbed >90%). The approved dose of 400 mg twice daily (b.i.d.) achieves a steady-state area under the curve per dosing interval of 128 h*μg/mL and trough concentration of 4.90 μg/mL (13.0 μM). Maribavir is highly bound to human plasma proteins (98%) with a small apparent volume of distribution of 27.3 L. Maribavir is primarily cleared by hepatic CYP3A4 metabolism; its major metabolite, VP44669 (pharmacologically inactive), is excreted in the urine and feces. There is no clinically relevant impact on maribavir pharmacokinetics by age, sex, race/ethnicity, body weight, transplant type, or hepatic/renal impairment status. In phase II dose-ranging studies, maribavir showed similar rates of CMV viral clearance across 400, 800, or 1200 mg b.i.d. groups, ranging from 62.5-70% in study 202 (NCT01611974) and 74-83% in study 203 (EudraCT 2010-024247-32). In the phase III SOLSTICE trial (NCT02931539), maribavir 400 mg b.i.d. demonstrated superior CMV viremia clearance at week 8 versus investigator-assigned treatments, with lower treatment discontinuation rates. Dysgeusia, nausea, vomiting, and diarrhea were commonly experienced adverse events among patients treated with maribavir in clinical trials.
Topics: Humans; Antiviral Agents; Translational Science, Biomedical; Cytomegalovirus Infections; Benzimidazoles; Dichlororibofuranosylbenzimidazole
PubMed: 38071422
DOI: 10.1111/cts.13696 -
Infectious Disease Reports Jan 2024Cytomegalovirus (CMV) infections may increase morbidity and mortality in immunocompromised patients. Until recently, standard antiviral drugs against CMV were limited to... (Review)
Review
Cytomegalovirus (CMV) infections may increase morbidity and mortality in immunocompromised patients. Until recently, standard antiviral drugs against CMV were limited to viral DNA polymerase inhibitors (val)ganciclovir, foscarnet and cidofovir with a risk for cross-resistance. These drugs may also cause serious side effects. This narrative review provides an update on new antiviral agents that were approved for the prevention and treatment of CMV infections in transplant recipients. Letermovir was approved in 2017 for CMV prophylaxis in CMV-seropositive adults who received an allogeneic hematopoietic stem cell transplant. Maribavir followed four years later, with an indication in the treatment of adult and pediatric transplant patients with refractory/resistant CMV disease. The target of letermovir is the CMV terminase complex (constituted of pUL56, pUL89 and pUL51 subunits). Letermovir prevents the cleavage of viral DNA and its packaging into capsids. Maribavir is a pUL97 kinase inhibitor, which interferes with the assembly of capsids and the egress of virions from the nucleus. Both drugs have activity against most CMV strains resistant to standard drugs and exhibit favorable safety profiles. However, high-level resistance mutations may arise more rapidly in the gene under letermovir than low-grade resistance mutations. Some mutations emerging in the gene under maribavir can be cross-resistant with ganciclovir. Thus, letermovir and maribavir now extend the drug arsenal available for the management of CMV infections and their respective niches are currently defined.
PubMed: 38247977
DOI: 10.3390/idr16010005 -
Current Opinion in Pulmonary Medicine Jul 2024Infections in lung transplant recipients remain a major challenge and can affect lung allograft function and cause significant morbidity and mortality. New strategies... (Review)
Review
PURPOSE OF REVIEW
Infections in lung transplant recipients remain a major challenge and can affect lung allograft function and cause significant morbidity and mortality. New strategies for the prevention and treatment of infection in lung transplantation have emerged and are reviewed.
RECENT FINDINGS
For important vaccine preventable infections (VPIs), guidance has been updated for at risk solid organ transplant (SOT) recipients. However, data on the efficacy of newer vaccines in lung transplant, including the respiratory syncytial virus (RSV) vaccine, are limited. Studies demonstrate improved vaccination rate with Infectious Diseases consultation during pretransplant evaluation. Two new antiviral agents for the treatment and prevention of cytomegalovirus (CMV) in SOT, letermovir and maribavir, are being incorporated into clinical care. CMV-specific cell-mediated immune function assays are more widely available. Antibiotics for the management of multidrug resistant pathogens and Burkholderia cepacia complex have been described in case series and case reports in lung transplant.
SUMMARY
Although new vaccines and novel therapies for preventing and treating infections are available, larger studies evaluating efficacy in lung transplant recipients are needed.
Topics: Humans; Lung Transplantation; Antiviral Agents; Transplant Recipients; Cytomegalovirus Infections; Anti-Bacterial Agents
PubMed: 38411211
DOI: 10.1097/MCP.0000000000001060 -
The Annals of Pharmacotherapy Mar 2024The article reviews the safety and efficacy of treatments for cytomegalovirus (CMV) in solid organ transplantation. (Review)
Review
OBJECTIVE
The article reviews the safety and efficacy of treatments for cytomegalovirus (CMV) in solid organ transplantation.
DATA SOURCES
A literature review was conducted in PubMed, MEDLINE, and Clinicaltrials.gov from database inception through January 2024, using terms CMV, therapy, and solid organ transplantation.
STUDY SELECTION AND DATA EXTRACTION
Clinical trials, meta-analyses, cohort studies, case reports, and guidelines were included. Letters to the editor, reviews, and commentaries were excluded.
DATA SYNTHESIS
After abstract screening and full-text review of 728 citations for eligibility, 53 were included. Valganciclovir and intravenous ganciclovir are drugs of choice for CMV management and, until recently, the availability of alternative options has been restricted due to toxicity. For instance, foscarnet and cidofovir serve as second-line agents due to potential bone marrow and renal toxicity. In patients with refractory or resistant CMV, maribavir, a novel oral agent, has proven efficacy and a lower adverse effect profile. However, in refractory or resistant CMV, foscarnet and cidofovir are preferred in invasive disease (CMV gastritis, CMV retinitis, and CMV encephalitis), high viral loads, and inability to tolerate oral preparations.
RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE
Consensus guidelines have not been revised since approval of novel antivirals in solid organ transplantation. Valganciclovir and ganciclovir remain drugs of choice for initial CMV therapy. Foscarnet, cidofovir, and maribavir are treatments for refractory or resistant-CMV.
CONCLUSIONS
Selection of CMV antiviral treatment should be determined by patient-specific factors, including severity of illness, resistant or refractory disease, dose-limiting adverse effects, and the preferred route of administration.
PubMed: 38501850
DOI: 10.1177/10600280241237534 -
Viruses Jul 2023Solid organ transplant recipients (SOTRs) are at high risk of human herpesvirus (HHV)-related morbidity and mortality due to the use of immunosuppressive therapy. We aim... (Review)
Review
Solid organ transplant recipients (SOTRs) are at high risk of human herpesvirus (HHV)-related morbidity and mortality due to the use of immunosuppressive therapy. We aim to increase awareness and understanding of HHV disease burden in SOTRs by providing an overview of current prevention and management strategies as described in the literature and guidelines. We discuss challenges in both prevention and treatment as well as future perspectives.
Topics: Humans; Organ Transplantation; Herpesviridae Infections; Herpesvirus 6, Human; Herpes Simplex; Transplant Recipients
PubMed: 37515280
DOI: 10.3390/v15071595 -
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 -
Current Opinion in Organ Transplantation Apr 2024Human cytomegalovirus (CMV) continues to be the most important infectious complication following solid organ transplantation (SOT). (Review)
Review
PURPOSE OF REVIEW
Human cytomegalovirus (CMV) continues to be the most important infectious complication following solid organ transplantation (SOT).
RECENT FINDINGS
Universal prophylaxis and preemptive therapy are the most adopted strategies for prevention of CMV disease globally. Prophylaxis with valganciclovir is the most widely used approach to CMV prevention, however leukopenia and late onset CMV disease after discontinuation of prophylaxis requires new strategies to prevent this complication. The use of assays detecting CMV-specific T cell-mediated immunity may individualize the duration of antiviral prophylaxis after transplantation. Letermovir has been recently approved for prophylaxis in kidney transplant recipients. CMV-RNAemia used together with CMV-DNAemia in the viral surveillance of CMV infection provides accurate information on viral load kinetics, mostly in patients receiving letermovir prophylaxis/therapy. The development of refractory and resistant CMV infection remains a major challenge and a new treatment with maribavir is currently available. In the present paper we will review the most recent advances in prevention and treatment of CMV diseases in SOT recipients.
SUMMARY
Recent findings, summarized in the present paper, may be useful to optimize prevention and treatment of CMV infection in SOT.
Topics: Humans; Antiviral Agents; Cytomegalovirus Infections; Valganciclovir; Transplant Recipients; Organ Transplantation; Acetates; Quinazolines
PubMed: 38288947
DOI: 10.1097/MOT.0000000000001139 -
Antiviral Research Jul 2023Cytomegalovirus (CMV) is a significant human pathogen, especially for immunocompromised patients, often treated with one or more antiviral drugs. Although the prevalence...
Cytomegalovirus (CMV) is a significant human pathogen, especially for immunocompromised patients, often treated with one or more antiviral drugs. Although the prevalence of resistance is low, the impact of drug resistant CMV infections on patient outcomes is high and genotypic testing is recommended when resistance is suspected. To assess the prevalence of CMV drug resistance mutations among samples submitted for genotypic testing, 2750 patient sample results were analyzed. Testing was performed by sequencing for ganciclovir (GCV), cidofovir (CDV), foscarnet (FOS), maribavir (MBV) and/or letermovir (LMV) resistance conferring mutations. Of the 2750 patient samples, 826 (30.04%) had resistance to one or more anti-CMV drug. Resistance mutations were most common in UL97, with 27.64% and 9.96% of samples having GCV and MBV mutations, respectively. Resistance mutations in UL54 were less common, with 6.11%, 5.98% and 1.76% of samples having GCV, CDV and FOS mutations, respectively. For LMV, resistance mutations in UL56 were present in 7.17% of samples, with mutations at codon 325 representing 80.95% of the observed LMV resistance mutations. Resistance to two drugs was identified in 215 samples and to 3 or more drugs in 35 samples. While a high prevalence of CMV resistance mutations was identified, this must be taken in the context of healthcare providers submitting samples from patients with suspected resistant CMV strains. For these patients, rapid monitoring for resistance allows treatment modifications based on objective results rather than empiric drug selection, which is particularly relevant given the presence of mutations conferring resistance to more than one drug.
Topics: Humans; Cytomegalovirus; Prevalence; Transplant Recipients; DNA-Directed DNA Polymerase; Viral Proteins; Antiviral Agents; Ganciclovir; Foscarnet; Cidofovir; Drug Resistance, Viral; Mutation; Benzimidazoles
PubMed: 37150409
DOI: 10.1016/j.antiviral.2023.105623 -
Antiviral Research Feb 2024Therapeutic use of maribavir for human cytomegalovirus infection has renewed attention to the extent of cross-resistance with ganciclovir as the existing standard...
Therapeutic use of maribavir for human cytomegalovirus infection has renewed attention to the extent of cross-resistance with ganciclovir as the existing standard therapy. Each drug selects in vivo for a characteristic set of resistance mutations in the viral UL97 kinase gene. To improve the calibration of relative susceptibilities to each drug, genetic variants at relevant UL97 codons were extensively phenotyped using the same baseline viral clone, cell culture conditions and growth readout. Ganciclovir-selected mutations at codons 460, 520, 592, 594, 595 and 603 conferred 2.8-fold (C603Y) to 12-fold (M460I) increases in ganciclovir 50% inhibitory concentrations (EC50) over wild type baseline, while conferring maribavir EC50 fold changes ranging from 0.21-fold (M460I) to 1.9-fold (A594V). Maribavir-selected mutations at codons 409, 411 and 480 conferred maribavir EC50 fold changes ranging from 17 (H411Y) to 210 (C480F), while conferring ganciclovir EC50 fold changes ranging from 0.7 (H411Y) to 2.3 (C480F). The P-loop substitution F342Y, selected by either drug, is confirmed to confer 4.7-fold and 6-fold increases in maribavir and ganciclovir EC50s respectively, and suggests this part of the ATP-binding domain of UL97 to be involved in moderate resistance to both drugs. The maribavir hypersensitivity of M460I and M460V may be advantageous.
Topics: Humans; Ganciclovir; Cytomegalovirus; Antiviral Agents; Mutation; Codon; Drug Resistance, Viral; Phosphotransferases (Alcohol Group Acceptor); Dichlororibofuranosylbenzimidazole
PubMed: 38163624
DOI: 10.1016/j.antiviral.2023.105792