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Antimicrobial Agents and Chemotherapy Sep 2022Maribavir was approved by the U.S. Food and Drug Administration in November 2021 for the treatment of adult and pediatric patients with post-transplant cytomegalovirus... (Review)
Review
Maribavir was approved by the U.S. Food and Drug Administration in November 2021 for the treatment of adult and pediatric patients with post-transplant cytomegalovirus (CMV) infection/disease that is refractory to treatment (with or without genotypic resistance) with ganciclovir, valganciclovir, cidofovir, or foscarnet. Maribavir is an oral benzimidazole riboside with potent and selective multimodal anti-CMV activity. It utilizes a novel mechanism of action which confers activity against CMV strains that are resistant to traditional anti-CMV agents, and also offers a more favorable safety profile relative to the dose-limiting side effects of previously available therapies. Maribavir was initially studied as an agent for CMV prophylaxis in solid organ and hematopoietic stem cell recipients, but initial phase III trials failed to meet clinical efficacy endpoints. It has been more recently studied as a therapeutic agent at higher doses for refractory-resistant (R-R) CMV infections with favorable outcomes. After an overview of maribavir's chemistry and clinical pharmacology, this review will summarize clinical efficacy, safety, tolerability, and resistance data associated with maribavir therapy.
Topics: Adult; Anti-Infective Agents; Antiviral Agents; Benzimidazoles; Child; Cidofovir; Cytomegalovirus Infections; Dichlororibofuranosylbenzimidazole; Drug Resistance, Viral; Foscarnet; Ganciclovir; Humans; Valganciclovir
PubMed: 35916518
DOI: 10.1128/aac.02405-21 -
Clinical Microbiology and Infection :... Jan 2023The burden that cytomegalovirus (CMV) portends for haematopoietic and solid-organ transplant recipients cannot be understated. Valganciclovir and ganciclovir have... (Review)
Review
BACKGROUND
The burden that cytomegalovirus (CMV) portends for haematopoietic and solid-organ transplant recipients cannot be understated. Valganciclovir and ganciclovir have successfully been used for prevention and treatment of CMV infections, although with serious side effects such as leucopenia and some development of resistance. Until recently, available therapies for ganciclovir-resistant CMV have significant toxicities. Although advances have been made in the field, the unmet medical needs for effective and well-tolerated therapies are significant.
OBJECTIVES
This review aims to summarise the current and emerging CMV antiviral drugs and discusses future perspectives in the field.
SOURCES
We searched for relevant articles with pertinent keywords: "Cytomegalovirus OR CMV", "Transplant" and "Antiviral". Articles published after 2019 were given preference. Articles were reviewed by the authors for relevance and impact to the subject of interest.
CONTENT
We outline in this review current advances in prophylaxis of CMV infection with letermovir, breakthrough CMV infections while on or after prophylaxis, the development of resistant and refractory CMV infections, and the newly approved anti-CMV agent, maribavir, in haematopoietic and solid-organ transplant recipients.
IMPLICATIONS
Prevention of CMV infections after transplant has improved greatly over the past few years. Despite major advancements, breakthrough CMV infections and development of refractory and resistant CMV infections remain major complications post transplantation. We highlight emerging therapeutics that tolerably and effectively prevent and treat CMV infections, especially refractory and resistant cases.
Topics: Humans; Transplant Recipients; Cytomegalovirus Infections; Antiviral Agents; Ganciclovir; Cytomegalovirus
PubMed: 35843567
DOI: 10.1016/j.cmi.2022.07.001 -
Clinical Infectious Diseases : An... Feb 2023The immune response to COVID-19 vaccination is inferior in kidney transplant recipients (KTRs) and to a lesser extent in patients on dialysis or with chronic kidney... (Clinical Trial)
Clinical Trial
Antibody and T-Cell Responses 6 Months After Coronavirus Disease 2019 Messenger RNA-1273 Vaccination in Patients With Chronic Kidney Disease, on Dialysis, or Living With a Kidney Transplant.
BACKGROUND
The immune response to COVID-19 vaccination is inferior in kidney transplant recipients (KTRs) and to a lesser extent in patients on dialysis or with chronic kidney disease (CKD). We assessed the immune response 6 months after mRNA-1273 vaccination in kidney patients and compared this to controls.
METHODS
A total of 152 participants with CKD stages G4/5 (eGFR <30 mL/min/1.73 m2), 145 participants on dialysis, 267 KTRs, and 181 controls were included. SARS-CoV-2 Spike S1 specific IgG antibodies were measured using fluorescent bead-based multiplex-immunoassay, neutralizing antibodies to ancestral, Delta, and Omicron (BA.1) variants by plaque reduction, and T-cell responses by interferon-γ release assay.
RESULTS
At 6 months after vaccination, S1-specific antibodies were detected in 100% of controls, 98.7% of CKD G4/5 patients, 95.1% of dialysis patients, and 56.6% of KTRs. These figures were comparable to the response rates at 28 days, but antibody levels waned significantly. Neutralization of the ancestral and Delta variants was detected in most participants, whereas neutralization of Omicron was mostly absent. S-specific T-cell responses were detected at 6 months in 75.0% of controls, 69.4% of CKD G4/5 patients, 52.6% of dialysis patients, and 12.9% of KTRs. T-cell responses at 6 months were significantly lower than responses at 28 days.
CONCLUSIONS
Although seropositivity rates at 6 months were comparable to rates at 28 days after vaccination, significantly decreased antibody levels and T-cell responses were observed. The combination of low antibody levels, reduced T-cell responses, and absent neutralization of the newly emerging variants indicates the need for additional boosts or alternative vaccination strategies in KTRs.
CLINICAL TRIALS REGISTRATION
NCT04741386.
Topics: Humans; Antibodies, Neutralizing; Antibodies, Viral; COVID-19; COVID-19 Vaccines; Immunoglobulin G; Kidney Transplantation; Renal Dialysis; Renal Insufficiency, Chronic; SARS-CoV-2; T-Lymphocytes; Vaccination
PubMed: 35796536
DOI: 10.1093/cid/ciac557 -
Transplantation and Cellular Therapy Jul 2022Outcomes of refractory (Rf) cytomegalovirus (CMV) infection (CMVi) after hematopoietic cell transplantation (HCT) are poor owing to limited treatment options and...
Outcomes of refractory (Rf) cytomegalovirus (CMV) infection (CMVi) after hematopoietic cell transplantation (HCT) are poor owing to limited treatment options and treatment related toxicities. Maribavir, an orally bioavailable CMV antiviral, was recently approved for treatment of Rf-CMVi. Real-world studies quantifying the burden of Rf-CMVi prior to maribavir provide a benchmark for evaluating the net value of novel treatments. Here we report the incidence, clinical outcomes, and healthcare resource utilization (HRU) associated with Rf-CMVi in the first year post-HCT in a cohort of CMV-seropositive HCT recipients (R+) who underwent HCT between January 1, 2014, and December 31, 2017, at Memorial Sloan Kettering Cancer Center and were managed exclusively by preemptive therapy. CMVi was defined as CMV viremia treated preemptively. Rf-CMVi was defined as a <1 log decrease and CMV viral load >1000 U/mL after ≥14 days of appropriately dosed therapy. Welldays were defined as alive days not hospitalized and off CMV antivirals by 1 year post-HCT. The impact of Rf-CMVi on mortality and HRU was examined in multivariable models. Of the 286 R+ patients, 145 (50.7%) developed CMVi (99 no Rf-CMVi and 46 Rf-CMVi). Compared with the no Rf-CMVi group, the Rf-CMVi group had higher rates of CMV EOD (23.9% versus 10.1%; P = .030), CMV-related mortality (9.5% versus .0%; P = .002), and all-cause mortality (33.3% versus 15.6%; adjusted P = .049). Rf-CMVi was an independent predictor for readmission (adjusted odds ratio [aOR], 3.24; 95% confidence interval [CI], 2.19 to 4.87; P < .0001); CMV-related readmission (aOR, 9.48; 95% CI, 5.83 to 15.80; P < .0001), and decreased well days (adjusted arithmetic mean ratio, .72; 95% CI, .58 to .89; P = .001) in the first year post-HCT. Rf-CMVi is associated with increased mortality and increased HRU at 1 year after HCT. Improved therapies for Rf-CMVi have the potential of improving HCT outcomes and reducing HRU.
Topics: Antiviral Agents; Cytomegalovirus; Cytomegalovirus Infections; Hematopoietic Stem Cell Transplantation; Humans; Transplant Recipients; Viremia
PubMed: 35476955
DOI: 10.1016/j.jtct.2022.04.016 -
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 -
Microbiology Spectrum Apr 2022mutations in the terminase subunit and its associated phenotypes were studied in the context of cytomegalovirus (CMV) transplant recipients clinically resistant to...
mutations in the terminase subunit and its associated phenotypes were studied in the context of cytomegalovirus (CMV) transplant recipients clinically resistant to DNA-polymerase inhibitors, naive to letermovir. R246C was the only variant detected by standard and deep sequencing, located within the letermovir-resistance-associated region (residues 230-370). R246C emerged in 2/80 transplant recipients (1 hematopoietic and 1 heart) since first cytomegalovirus replication and responded transiently to various alternative antiviral treatments . Recombinant phenotyping showed R246C conferred an advanced viral fitness and was sensitive to ganciclovir, cidofovir, foscarnet, maribavir, and letermovir. These results demonstrate a low rate (2.5%) of natural occurring polymorphisms within the letermovir-resistant-associated region before its administration. Identification of high replicative capacity variants in patients not responding to treatment or experiencing relapses could be helpful to guide further therapy and dosing of antiviral molecules. We provide comprehensive data on the clinical correlates of both CMV genotypic follow-up by standard and deep sequencing and the clinical outcomes, as well as recombinant phenotypic results of this novel mutation. Our study emphasizes that the clinical follow-up in combination with genotypic and phenotypic studies is essential for the assessment and optimization of patients experiencing HCMV relapses or not responding to antiviral therapy. This information may be important for other researchers and clinicians working in the field to improve the care of transplant patients since drug-resistant CMV infections are an important emerging problem even with the new antiviral development.
Topics: Acetates; Antiviral Agents; Cytomegalovirus; Cytomegalovirus Infections; Drug Resistance, Viral; Humans; Mutation; Quinazolines; Recurrence; Transplant Recipients
PubMed: 35343771
DOI: 10.1128/spectrum.00191-22 -
Therapeutics and Clinical Risk... 2022Cytomegalovirus (CMV) infections are a common complication in solid organ (SOT) and hematopoietic stem cell transplant (HSCT) recipients, leading to increased morbidity... (Review)
Review
PURPOSE OF REVIEW
Cytomegalovirus (CMV) infections are a common complication in solid organ (SOT) and hematopoietic stem cell transplant (HSCT) recipients, leading to increased morbidity and mortality. Currently available treatment options have reduced the burden of infection, but utilization of these agents can be limited by toxicities such as nephrotoxicity and/or myelosuppression as well as emergence of resistance. The expansion of our current armamentarium towards CMV infection is crucial. Here, we review an emerging therapy, maribavir, and the safety and efficacy of this potential new agent for the prophylaxis and treatment of CMV infections including resistant/refractory disease.
RECENT FINDINGS
Maribavir is a novel agent with CMV activity approved by Federal Food and Drug Administration (FDA) in December 2021 for resistant/refractory disease. Compared to currently available treatment for CMV infection, maribavir has a unique mechanism of action, retains activity against most (val)ganciclovir resistant strains, provides a more predictable pharmacokinetic profile, and fewer severe toxicities. Maribavir has been studied in phase 2 and 3 studies with ongoing phase 3 studies. While maribavir failed to meet the primary endpoints in the initial phase 3 study for prophylaxis therapy in allogeneic-HSCT and liver transplant recipients, results from the phase 2 study when used for pre-emptive therapy after HSCT show similar efficacy to valganciclovir, and results from the phase 3 study examining resistant/refractory disease demonstrate superiority to investigator-initiated therapy of (val)ganciclovir, foscarnet, or cidofovir.
SUMMARY
Maribavir provides a new agent for the management of resistant/refractory CMV infection. Results of the recently published phase 3 study provide further insight into the role of this novel therapy.
PubMed: 35308097
DOI: 10.2147/TCRM.S303052 -
Clinical Infectious Diseases : An... Feb 2022Most studies of solid organ transplant (SOT) recipients with COVID-19 focus on outcomes within one month of illness onset. Delayed mortality in SOT recipients...
INTRODUCTION
Most studies of solid organ transplant (SOT) recipients with COVID-19 focus on outcomes within one month of illness onset. Delayed mortality in SOT recipients hospitalized for COVID-19 has not been fully examined.
METHODS
We used data from a multicenter registry to calculate mortality by 90 days following initial SARS-CoV-2 detection in SOT recipients hospitalized for COVID-19 and developed multivariable Cox proportional-hazards models to compare risk factors for death by days 28 and 90.
RESULTS
Vital status at day 90 was available for 936 of 1117 (84%) SOT recipients hospitalized for COVID-19: 190 of 936 (20%) died by 28 days and an additional 56 of 246 deaths (23%) occurred between days 29 and 90. Factors associated with mortality by day 90 included: age > 65 years [aHR 1.8 (1.3-2.4), p =<0.001], lung transplant (vs. non-lung transplant) [aHR 1.5 (1.0-2.3), p=0.05], heart failure [aHR 1.9 (1.2-2.9), p=0.006], chronic lung disease [aHR 2.3 (1.5-3.6), p<0.001] and body mass index ≥ 30 kg/m 2 [aHR 1.5 (1.1-2.0), p=0.02]. These associations were similar for mortality by day 28. Compared to diagnosis during early 2020 (March 1-June 19, 2020), diagnosis during late 2020 (June 20-December 31, 2020) was associated with lower mortality by day 28 [aHR 0.7 (0.5-1.0, p=0.04] but not by day 90 [aHR 0.9 (0.7-1.3), p=0.61].
CONCLUSIONS
In SOT recipients hospitalized for COVID-19, >20% of deaths occurred between 28 and 90 days following SARS-CoV-2 diagnosis. Future investigations should consider extending follow-up duration to 90 days for more complete mortality assessment.
PubMed: 35212363
DOI: 10.1093/cid/ciac159 -
Clinical Infectious Diseases : An... Sep 2022Therapies for refractory cytomegalovirus infections (with or without resistance [R/R]) in transplant recipients are limited by toxicities. Maribavir has multimodal... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Therapies for refractory cytomegalovirus infections (with or without resistance [R/R]) in transplant recipients are limited by toxicities. Maribavir has multimodal anti-cytomegalovirus activity through the inhibition of UL97 protein kinase.
METHODS
In this phase 3, open-label study, hematopoietic-cell and solid-organ transplant recipients with R/R cytomegalovirus were randomized 2:1 to maribavir 400 mg twice daily or investigator-assigned therapy (IAT; valganciclovir/ganciclovir, foscarnet, or cidofovir) for 8 weeks, with 12 weeks of follow-up. The primary endpoint was confirmed cytomegalovirus clearance at end of week 8. The key secondary endpoint was achievement of cytomegalovirus clearance and symptom control at end of week 8, maintained through week 16.
RESULTS
352 patients were randomized (235 maribavir; 117 IAT). Significantly more patients in the maribavir versus IAT group achieved the primary endpoint (55.7% vs 23.9%; adjusted difference [95% confidence interval (CI)]: 32.8% [22.80-42.74]; P < .001) and key secondary endpoint (18.7% vs 10.3%; adjusted difference [95% CI]: 9.5% [2.02-16.88]; P = .01). Rates of treatment-emergent adverse events (TEAEs) were similar between groups (maribavir, 97.4%; IAT, 91.4%). Maribavir was associated with less acute kidney injury versus foscarnet (8.5% vs 21.3%) and neutropenia versus valganciclovir/ganciclovir (9.4% vs 33.9%). Fewer patients discontinued treatment due to TEAEs with maribavir (13.2%) than IAT (31.9%). One patient per group had fatal treatment-related TEAEs.
CONCLUSIONS
Maribavir was superior to IAT for cytomegalovirus viremia clearance and viremia clearance plus symptom control maintained post-therapy in transplant recipients with R/R cytomegalovirus. Maribavir had fewer treatment discontinuations due to TEAEs than IAT. Clinical Trials Registration. NCT02931539 (SOLSTICE).
Topics: Antiviral Agents; Cytomegalovirus; Cytomegalovirus Infections; Dichlororibofuranosylbenzimidazole; Drug Resistance, Viral; Foscarnet; Ganciclovir; Humans; Valganciclovir; Viremia
PubMed: 34864943
DOI: 10.1093/cid/ciab988 -
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