Outcomes of transplant recipients treated with cidofovir for resistant or refractory cytomegalovirus infection

Approaches and Challenges in the Current Management of Cytomegalovirus in Transplant Recipients: Highlighting the Role of Advanced Practice Providers (Nurse Practitioners and Physician Assistants)

Cytomegalovirus (CMV) infection is associated with increased morbidity and mortality in hematopoietic cell transplant (HCT) and solid organ transplant (SOT) recipients, with traditional anti-CMV therapies limited by their associated toxicities and the development of resistance. Clinical providers are often faced with challenging and complicated CMV infections that require multiple courses of antiviral therapies. Increasingly, advanced practice providers (APPs) are playing an important role in the day-to-day management of transplant recipients with CMV infection, including resistant/refractory CMV and other complex CMV syndromes. Here, we provide an overview of current preventative and treatment strategies for CMV infection in HCT and SOT recipients, highlighting the challenging aspects of current management and the potential utility of newer antiviral agents. This article also focuses on how a multidisciplinary team, orchestrated by APPs, can improve CMV-associated patient outcomes. Protocols using antiviral agents for the prevention or treatment of CMV infections require carefully designed and meticulously implemented strategies to ensure the best clinical outcomes for patients. APPs, who have increasingly become the frontline providers of outpatient care for transplant recipients, are ideally positioned to design and carry out these protocols.

What's New: Updates on Cytomegalovirus in Solid Organ Transplantation

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.

Adoptive therapy with cytomegalovirus-specific cytotoxic T lymphocytes for refractory cytomegalovirus DNAemia and disease after allogeneic haematopoietic stem cell transplantation

Cytomegalovirus (CMV) DNAemia and disease are common complications in patients undergoing allogeneic haematopoietic stem cell transplantation (allo-HSCT). Few studies have compared the efficacy and safety of the HSCT donor and third-party CMV-specific cytotoxic T lymphocytes (CMV-CTLs) in the treatment of CMV DNAemia and disease. In this study, we retrospectively compared the efficacy and safety of HSCT donor and third-party CMV-CTLs in patients with refractory CMV DNAemia or disease after allo-HSCT at our centre from January 2017 to September 2021. Fifty-three patients who received CMV-CTL therapy were enrolled, including 40 in the donor group and 13 in the third-party group, and they were adults aged 18 years or older. Within 6 weeks of treatment, 26 (65.0%) and 9 (69.2%) patients achieved complete response in the donor and third-party groups (p = 1.000). The 2-year overall survival was 59.6% (95% CI 46.1%-77.1%) and 53.8% (32.6%-89.1%) in the donor and third-party groups (p = 0.860). Four (10.0%) patients in the donor group and two (15.4%) patients in the third-party group developed acute graft-versus-host disease within 3 months after CMV-CTL infusions. In conclusion, our data suggest that donor and third-party CMV-CTLs have comparable efficacy and safety for refractory CMV DNAemia and disease.

Treatment for First Cytomegalovirus Infection Post-Hematopoietic Cell Transplant in the AURORA Trial: A Multicenter, Double-Blind, Randomized, Phase 3 Trial Comparing Maribavir With Valganciclovir

BACKGROUND

Neutropenia may limit the use of valganciclovir treatment for cytomegalovirus (CMV) infection following hematopoietic cell transplant (HCT). A phase 2 study indicated efficacy of maribavir with fewer treatment-limiting toxicities than valganciclovir.

METHODS

In this multicenter, double-blind, phase 3 study, patients with first asymptomatic CMV infection post-HCT were stratified and randomized 1:1 to maribavir 400 mg twice daily or valganciclovir (dose-adjusted for renal clearance) for 8 weeks with 12 weeks of follow-up. The primary endpoint was confirmed CMV viremia clearance at week 8 (primary hypothesis of noninferiority margin of 7.0%). The key secondary endpoint was a composite of the primary endpoint with no findings of CMV tissue-invasive disease at week 8 through week 16. Treatment-emergent adverse events (TEAEs) were assessed.

RESULTS

Among patients treated (273 maribavir; 274 valganciclovir), the primary endpoint of noninferiority of maribavir was not met (maribavir, 69.6%; valganciclovir, 77.4%; adjusted difference: -7.7%; 95% confidence interval [CI]: -14.98, -.36; lower limit of 95% CI of treatment difference exceeded -7.0%). At week 16, 52.7% and 48.5% of patients treated (maribavir and valganciclovir, respectively) maintained CMV viremia clearance without tissue-invasive disease (adjusted difference: 4.4%; 95% CI: -3.91, 12.76). With maribavir (vs valganciclovir), fewer patients experienced neutropenia (16.1% and 52.9%) or discontinued due to TEAEs (27.8% and 41.2%). Discontinuations were mostly due to neutropenia (maribavir, 4.0%; valganciclovir, 17.5%).

CONCLUSIONS

Although noninferiority of maribavir to valganciclovir for the primary endpoint was not achieved based on the prespecified noninferiority margin, maribavir demonstrated comparable CMV viremia clearance during post-treatment follow-up, with fewer discontinuations due to neutropenia. Clinical Trials Registration. NCT02927067 [AURORA].

Cytomegalovirus Treatment in Solid Organ Transplantation: An Update on Current Approaches

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.

A Multicenter Assessment of the Outcomes and Toxicities of Foscarnet for Treatment of Acyclovir-Resistant Mucocutaneous Herpes Simplex in Immunocompromised Patients

Background

Acyclovir-resistant mucocutaneous herpes simplex virus (HSV) infection is an uncommon problem typically seen in immunocompromised hosts. Systemic treatment options are limited. The performance of foscarnet and its toxicities in this population are poorly characterized.

Methods

This was a multicenter retrospective study of adults treated with foscarnet for HSV infection between January 2012 and December 2017. Relevant data were collected including demographics, baseline conditions, previous anti-HSV medications, concomitant medications, HSV outcomes, and adverse events. Acyclovir-resistant HSV infection was defined based on genotypic or phenotypic testing results; refractory infection was defined as infection not improving after 5 days of treatment-dosed antiviral therapy in those not tested for resistance.

Results

Twenty-nine patients had 31 episodes of HSV (15/18 resistant; among episodes without resistance testing, 7/10 refractory; 3 not evaluable) treated with foscarnet. All patients were immunocompromised including 19 (66%) with hematologic malignancy and 9 (31%) with HIV. Median duration of foscarnet was 16 days (range, 6-85 days). Fifteen episodes (48%) healed by the end of or after foscarnet. Median time to healing among those with resolution was 38 days (range, 9-1088 days). At least 1 adverse event during therapy was reported in 26 (84%) treatment episodes including 23 (74%) that were considered drug related. Common adverse events were electrolyte disturbance (20 [65%]) and kidney dysfunction (13 [42%]). Foscarnet was discontinued in 10 episodes (32%) due to an adverse event, including 6 due to kidney dysfunction.

Conclusions

Among 31 episodes of HSV treated with foscarnet, only half resolved with treatment, and adverse events were common.

Slaying the "Troll of Transplantation"-new frontiers in cytomegalovirus management: A report from the CMV International Symposium 2023

The 2023 International CMV Symposium took place in Barcelona in May 2023. During the 2-day meeting, delegates and faculty discussed the ongoing challenge of managing the risk of cytomegalovirus infection (the Troll of Transplantation) after solid organ or hematopoietic cell transplantation. Opportunities to improve outcomes of transplant recipients by applying advances in antiviral prophylaxis or pre-emptive therapy, immunotherapy, and monitoring of cell-mediated immunity to routine clinical practice were debated and relevant educational clinical cases presented. This review summarizes the presentations, cases, and discussions from the meeting and describes how further advances are needed before the Troll of Transplantation is slain.

Management of Cytomegalovirus Infections in the Era of the Novel Antiviral Players, Letermovir and Maribavir

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 UL56 gene under letermovir than low-grade resistance mutations. Some mutations emerging in the UL97 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.

Retrospective chart review of transplant recipients with cytomegalovirus infection who received maribavir in the Phase 3 SOLSTICE trial: Data at 52 weeks post-maribavir treatment initiation

BACKGROUND

Cytomegalovirus (CMV) infection is a frequent complication in haematopoietic cell/solid organ transplant (HCT/SOT) recipients. Previous studies report all-cause mortality rates of 31% and 50% in HCT/SOT recipients post-treatment initiation with conventional anti-CMV therapies for refractory or resistant CMV.

METHODS

This was a multi-country, retrospective medical chart review study of HCT/SOT recipients with refractory CMV infection with or without resistance (R/R) who were randomized to the maribavir arm in the open-label Phase 3 SOLSTICE trial. Patients came from 21 SOLSTICE sites across 6 countries; each site randomized ≥3 patients to the maribavir arm. Patients were followed for 52 weeks (SOLSTICE trial period: 20 weeks; follow-up chart review period: 32 weeks). The primary outcomes were mortality and graft status.

RESULTS

Of 234 patients who were randomized and received maribavir in SOLSTICE, chart abstraction was completed for all 109 patients enrolled across 21 trial sites (SOT, 68/142; HCT, 41/92). At 52 weeks, overall mortality was 15.6% (17/109) and survival probability was 0.84. Among SOT recipients, survival probability was 0.96, and 3 (4.4%) deaths occurred during the chart review period. For the HCT recipients, survival probability was 0.65 with 14 (34.1%) deaths; 8 occurred during SOLSTICE and 6 during the chart review period. No new graft loss or re-transplantation occurred during the chart review period.

CONCLUSIONS

Overall mortality at 52 weeks post-maribavir treatment initiation in this sub-cohort of patients from the SOLSTICE trial was lower than that previously reported for similar populations treated with conventional therapies for R/R cytomegalovirus infection.

Cytomegalovirus in children undergoing haematopoietic stem cell transplantation: a diagnostic and therapeutic approach to antiviral resistance

Cytomegalovirus (CMV) is a ubiquitous virus which causes a mild illness in healthy individuals. In immunocompromised individuals, such as children receiving haematopoietic stem cell transplantation, CMV can reactivate, causing serious disease and increasing the risk of death. CMV can be effectively treated with antiviral drugs, but antiviral resistance is an increasingly common complication. Available therapies are associated with adverse effects such as bone marrow suppression and renal impairment, making the choice of appropriate treatment challenging. New agents are emerging and require evaluation in children to establish their role. This review will discuss established and emerging diagnostic tools and treatment options for CMV, including antiviral resistant CMV, in children undergoing haematopoietic stem cell transplant.

New Perspectives on Antimicrobial Agents: Maribavir

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.

Features of Epstein–Barr Virus and Cytomegalovirus Reactivation in Acute Leukemia Patients After Haplo-HCT With Myeloablative ATG-Containing Conditioning Regimen

Background

Haploidentical donor hematopoietic cell transplantation (haplo-HCT) has become a preferred option for patients without HLA-matched donors, but it increases the risk of viral reactivations. Epstein–Barr virus (EBV) and cytomegalovirus (CMV) are common viruses post-HCT, but limited data have been reported in the setting of haplo-HCT.

Methods

We conducted a retrospective study enrolling acute leukemia patients who received haplo-HCT with myeloablative conditioning regimen employing ATG in our center from July 2014 to July 2017. All the patients enrolled were EBV-IgM and EBV-DNA negative but EBV-IgG positive, and so were their donors. The same went for CMV as well.

Results

In total, 602 patients were recruited consisting of 331 with acute myeloid leukemia (AML) and 271 with acute lymphoblastic leukemia (ALL). One-year cumulative incidences of EBV (22.9% ± 2.4% vs. 27.4% ± 2.8%, P = 0.169) and CMV (24.7% ± 2.4% vs. 29.4% ± 2.8%, P = 0.190) reactivation were comparable between AML and ALL. EBV and CMV were independent risk factors for each other. In the AML group, male recipients [HR = 1.275, 95% CI (1.001–1.624), P = 0.049] and acute graft-versus-host disease [HR = 1.592, 95% CI (1.001–2.533), P = 0.049] were independent risk factors for EBV reactivation and CMV reactivation, respectively. CMV rather than EBV reactivation was related to a trend of worsened treatment-related mortality (TRM) (15.6% ± 0.1% vs. 10.2% ± 0.0%, P = 0.067) and progression-free survival (PFS) (60.6% ± 4.1% vs. 70.3% ± 2.3%, P = 0.073), while significant impacts were revealed only in the subgroup analysis. CMV reactivation resulted in a remarkable inferior 2-year overall survival (OS) (64.2% ± 5.7% vs. 77.6% ± 3.2%, P = 0.038) and PFS (55.0% ± 5.9% vs. 71.9% ± 3.4%, P = 0.042) in ALL patients. On the other hand, in the EBV+/CMV− subgroup, relapse was lower in ALL patients (8.2% ± 0.2% vs. 32.4% ± 0.8%, P = 0.010) compared with AML patients, which led to a superior 2-year OS (82.0% ± 6.2% vs. 60.3% ± 8.8%, P = 0.016) and PFS (74.5% ± 7.0% vs. 57.5% ± 8.4%, P = 0.036).

Conclusion

We concluded that EBV and CMV reactivations were frequent in acute leukemia patients after haplo-HCT, with possibly distinctive risk factors from HLA-matched HCT. There could be a potential interaction between EBV and CMV, but impacts on transplant outcomes remained complex.

Evaluation of treatment patterns, healthcare resource utilization, and costs among patients receiving treatment for cytomegalovirus following allogeneic hematopoietic cell or solid organ transplantation

AIM

Management of cytomegalovirus (CMV) infection/disease in transplant recipients may be complicated by toxicities and resistance to conventional antivirals, adding to the overall healthcare burden. We characterized treatment patterns, healthcare resource utilization (HCRU), and costs to elucidate the healthcare burden associated with CMV therapies post-transplant.

MATERIALS AND METHODS

A retrospective, longitudinal cohort study of transplant recipients using data from a US commercial insurance claims database (2013-2017) was conducted. Patients with a claim for post-transplant CMV diagnosis and anti-CMV treatment (ganciclovir, valganciclovir, foscarnet, or cidofovir) were identified (Treated CMV cohort) and compared with patients with neither a claim for CMV diagnosis nor anti-CMV treatment (No CMV cohort) for outcomes including HCRU and associated costs. Allogeneic hematopoietic cell transplantation (HCT) or solid organ transplantation (SOT) recipients were analyzed separately. Anti-CMV treatment patterns were assessed in the Treated CMV cohort. Costs were evaluated among subgroups with myelosuppression or nephrotoxicity.

RESULTS

Overall, 412 allogeneic HCT and 899 SOT patients were included in the Treated CMV cohorts, of which 41.7% and 52.5%, respectively, received multiple antiviral courses. Treated CMV cohorts compared with No CMV cohorts had higher mean monthly healthcare visits per patient (allogeneic HCT: 8.83 vs 6.61, SOT: 5.61 vs 4.45) and had an incremental adjusted mean monthly cost per patient differences of $8,157 (allogeneic HCT, p < .004) and $2,182 (SOT, p < .004). Among Treated CMV cohorts, HCRU and costs increased with additional CMV antiviral treatment courses. Mean monthly costs were higher for patients with than without myelosuppression or nephrotoxicity.

LIMITATIONS

Results may not be generalizable to patients covered by government insurance or outside the USA.

CONCLUSIONS

CMV post-transplant managed with conventional treatment is associated with substantial HCRU and costs. The burden remains particularly high for patients requiring multiple treatment courses for post-transplant CMV or for transplant recipients who develop myelosuppression or nephrotoxicity.

Maribavir for Refractory Cytomegalovirus Infections With or Without Resistance Post-Transplant: Results From a Phase 3 Randomized Clinical 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).

Development and Dynamics of Cytomegalovirus UL97 Ganciclovir Resistance Mutations in Transplant Recipients Detected by Next-Generation Sequencing

Background

(Val)ganciclovir resistance mutations in CMV UL97 (UL97-GCV-R) complicate anti-CMV therapy in recipients of solid organ and hematopoietic stem cell transplants, but comprehensive data on prevalence, emergence, and outcome are scarce.

Methods

Using next-generation sequencing (NGS; Illumina MiSeq platform), we analyzed UL97-GCV-R in patients with available plasma samples and refractory CMV replication/DNAemia (n = 87) containing viral loads ≥910 IU/mL. Twenty-one patients with CMV DNAemia resolving under antiviral therapy were analyzed as controls. Detected mutations were considered induced and of potential clinical significance if they increased by ≥10% compared with the first detected frequency or if they had a maximum frequency ≥25%.

Results

Nineteen of 87 (21.8%) with refractory CMV replication had ≥1 UL97-GCV-R detected by NGS, in comparison to 0/21 of the controls (P = .02). One-third of the recipients had 2 or more induced UL97-GCV-R mutations. The most frequently induced mutations affected codons 595 (42% [8/19]), 594 (32% [6/19]), and 603 (32% [6/19]). C592G was present in all episodes of both cases and controls at frequencies <15%, but never induced. UL97-GCV-R tended to be more frequent in donor/recipient CMV immunoglobulin G mismatch or following failure to complete primary prophylaxis, and many developed invasive CMV disease.

Conclusions

UL97-GCV-R is common among transplant patients with refractory CMV replication. Early testing by NGS allows for identification of major mutations at codons 595, 594, and 603 and excludes a major role of C592G in ganciclovir resistance. Large prospective studies on UL97-GCV-R are warranted.

Safety and efficacy of intravenously administered cidofovir in adult haematopoietic cell transplant recipients: a retrospective multicentre cohort study

OBJECTIVES

To evaluate the safety and efficacy of cidofovir for the treatment of double-stranded DNA (dsDNA) viral infections following allogeneic haematopoietic cell transplant (HCT).

METHODS

This was a retrospective multicentre cohort study including adult HCT recipients who received ≥1 dose of IV-administered cidofovir for any dsDNA viral infection from 2006 to 2019. The objectives were to describe the rate of and risk factors for nephrotoxicity and virological response by the end of treatment (EOT).

RESULTS

We included 165 patients from nine centres. Cidofovir was administered at 5 mg/kg/week (N = 115; 69.7%), 1 mg/kg/week (18; 10.9%), 3 mg/kg/week (12; 7.3%) or 1 mg/kg three times/week (11; 6.7%). Cidofovir was administered for adenovirus, cytomegalovirus (CMV) and BK virus infection in 75 (45.5%), 64 (38.8%) and 51 (30.9%) patients, respectively. Among 158 patients with renal function data at baseline and EOT, 40 (25.3%) developed nephrotoxicity. In multivariable analyses, age (OR 1.04; P = 0.05), weight (OR 1.05; P = 0.01), CMV infection (OR 3.6; P = 0.02), liposomal amphotericin B (OR 8.06; P = 0.05) and IV voriconazole/posaconazole (OR 13.0; P = 0.003) were predictors of nephrotoxicity. Creatinine concentration was significantly higher at EOT (1.16 ± 0.95 mg/dL) compared with baseline (0.91 ± 0.39 mg/dL; P < 0.001), but improved by 2 weeks (0.91 ± 0.84 mg/dL; P = 0.007) and 4 weeks (0.96 ± 0.89 mg/dL; P = 0.03) post-EOT. Median viral load significantly declined for patients with adenovirus DNAaemia by EOT (P < 0.0001) and for patients with CMV DNAaemia by EOT + 4 weeks (P = 0.003), but not for patients with BK virus DNAaemia.

CONCLUSIONS

One in four HCT recipients treated with IV cidofovir developed largely reversible nephrotoxicity. Careful selection of patients and close follow-up of renal function may minimize toxicity.