High-risk Kidney Transplant Recipients Research Articles

Real-life use of letermovir prophylaxis for cytomegalovirus in heart transplant recipients.

Cytomegalovirus (CMV) remains the predominant opportunistic infection following solid organ transplantation (SOT). While valganciclovir is the drug of choice for CMV prophylaxis, its utility can be compromised due to the risk of cytopenia. Letermovir, a novel agent approved for CMV prophylaxis in allogeneic hematopoietic stem cell transplant recipients and high-risk kidney transplant recipients, exhibits reduced toxicity. This study aims to present the practical application of letermovir as both primary and secondary prophylaxis against CMV in heart transplant recipients (HTR). In this observational, retrospective, single-center study, we included all consecutive adult HTRs from June 2020 to January 2022 who were administered letermovir for CMV prophylaxis. We documented instances of CMV breakthrough infections, side effects related to letermovir, changes in neutropenia following the switch from valganciclovir to letermovir, and any drug interactions with the immunosuppressive regimen. The study comprised 10 patients: two received primary prophylaxis with letermovir due to a high risk of CMV infection (donor-positive, recipient-negative serostatus), and eight received it as secondary prophylaxis following a CMV infection. The median duration of letermovir administration was 8 months (range 3-12 months). No CMV breakthrough infections were reported while on prophylaxis. However, three patients experienced CMV breakthrough infections after discontinuing letermovir prophylaxis (30%). No significant side effects were observed, although one patient reported digestive intolerance. Among the nine patients on tacrolimus, six needed reduced doses after switching to letermovir. This real-life study appears to support the effectiveness of letermovir prophylaxis in HTR. Nonetheless, the risk of CMV infection post-treatment cessation is notable. Further drug monitoring and research on the efficacy of letermovir for CMV prophylaxis in SOT patients is warranted.

Letermovir safety and efficacy for cytomegalovirus prophylaxis in adult Japanese kidney transplant recipients: a multicenter, open-label, noncomparative Phase 3 study.

Letermovir is approved for cytomegalovirus (CMV) prophylaxis in adult allogeneic hematopoietic cell transplantation recipients worldwide and is also approved in the United States for CMV prophylaxis in adult high-risk (D+/R-) kidney transplant recipients (KTRs). The safety and efficacy of letermovir for CMV prophylaxis in adult Japanese KTRs are reported here. In this Phase 3, single-arm, open-label study, adult Japanese KTRs with CMV serostatuses D+/R-, D+/R+, and D-/R+ received letermovir 480mg daily orally within 7days post-transplant through Week 28. Participants were followed through Week 52. The primary objective was to evaluate letermovir safety and tolerability. Efficacy was a secondary objective, measured by CMV disease, CMV disease or infection requiring intervention, and quantifiable CMV DNAemia. All CMV disease cases were confirmed by an independent adjudication committee. Among 22 participants (12 were D+/R-) who received letermovir prophylaxis, 20 (90.9%) experienced ≥ 1 AE through Week 28. Most AEs were mild to moderate in severity; no deaths were reported. During the prophylaxis period through Week 28, one transient case of quantifiable CMV DNAemia was detected, but no CMV disease or infection requiring intervention was reported. Through Week 52, four D+/R- participants met the endpoint of CMV disease or infection requiring intervention, of whom two had committee-confirmed CMV syndrome; all recovered with CMV therapy. A total of 5 participants had quantifiable CMV DNAemia through Week 52. Letermovir was generally well tolerated, and the data support its use for the prevention of CMV disease/infection in adult Japanese KTRs. ClinicalTrials.gov NCT04129398.

Risk factors and outcomes of bloodstream infection from a urinary source in kidney transplant recipients.

Bacteriuria is common among kidney transplant recipients (KTR). Risk factors and outcomes associated with bloodstream infection due to a urinary source (BSIU) in KTR are poorly understood. This single center case-control study from 2010 to 2022 compared KTR with BSIU to those with bacteria without bloodstream infection (BU). Multivariable logistic regression identified BSIU risk factors, and Cox models assessed its impact on graft failure. Among 3435 patients, who underwent kidney transplantation at Emory Hospital, 757 (22%) developed bacteriuria, among whom 142 (18.8%) were BSIU. Male sex, presence of Escherichia coli, Klebsiella pneumoniae, or Pseudomonas species in urine culture, urethral stricture, neuromuscular bladder disorder, and history of diabetes-induced renal failure were independently associated with increased odds of BSIU (Male sex: aOR 2.29, 95% CI 1.52, 3.47, E. coli: aOR 5.14, 95% CI 3.02, 9.13; K. pneumoniae aOR 3.19, 95% CI 1.65, 6.27, Pseudomonas spp aOR 3.06, 95% CI 1.25, 7.18; urethral stricture: 4.10, 95% CI 1.63, 10.3, neuromuscular bladder disorder aOR 1.98, 95% CI 1.09, 3.53, diabetes: aOR 1.64, 95% CI 1.08, 2.49). BSIU was associated with increased hazard of graft failure (HR 1.52, 95% CI 1.05, 2.20). Close monitoring is warranted for male KTR with bacteriuria, those with urine cultures positive for Pseudomonas spp, K. pneumoniae, or E. coli, as well as KTR with a history of diabetes-induced renal failure, urethral stricture, or neuromuscular bladder disorder due to their risk for developing BSIU. Future research should explore strategies to mitigate BSIU risk in these high-risk KTR and reduce the associated risk of long-term graft failure.

Imlifidase in kidney transplantation.

Kidney transplantation, the gold-standard therapeutic approach for patients with end-stage kidney disease, offers improvement in patient survival and quality of life. However, broad sensitization against human leukocyte antigens often resulting in a positive crossmatch against the patient's living donor or the majority of potential deceased donors in the allocation system represents a major obstacle due to a high risk for antibody-mediated rejection, delayed graft function and allograft loss. Kidney-paired donation and desensitization protocols have been established to overcome this obstacle, with limited success. Imlifidase, a novel immunoglobulin G (IgG)-degrading enzyme derived from Streptococcus pyogenes and recombinantly produced in Escherichia coli, is a promising agent for recipients with a positive crossmatch against their organ donor with high specificity towards IgG, rapid action and high efficacy in early pre-clinical and clinical studies. However, the rebound of IgG after a few days can lead to antibody-mediated rejection, making the administration of potent immunosuppressive regimens in the early post-transplant phase necessary. There is currently no comparative study evaluating the efficiency of imlifidase therapy compared with conventional desensitization protocols along with the lack of randomized control trials, indicating the clear need for future large-scale clinical studies in this field. Besides providing a practical framework for the clinical use of the agent, our aim in this article is to evaluate the underlying mechanism of action, efficiency and safety of imlifidase therapy in immunologically high-risk kidney transplant recipients.

Single-dose antithymocyte globulin in standard immunological risk kidney transplant recipients: efficacy and kinetics of peripheral blood CD3+ T lymphocyte modulation.

Polyclonal anti-T cell antibodies (ATG or thymoglobulin®) are used as induction therapy in kidney transplant recipients. This study evaluates the safety, efficacy, and CD3+T lymphocyte modulation of two ATG regimens. The trial included two cohorts of kidney transplant recipients that were followed for one year. The study group, including standard immunological risk recipients, received one 3mg/kg dose of ATG. The comparator group, including standard and high immunological risk kidney transplant recipients, received a fractionated dose regimen (up to four 1.5mg/kg doses). Patient and graft outcomes and the kinetics of CD3+T lymphocyte modulation in the peripheral blood were evaluated. One hundred kidney transplant recipients were included in each group. The one-year incidence of treated acute rejection, and patient and graft survival did not differ between groups. Bacterial infections were significantly more frequent in fractionated-dose group patients (66%versus 5%; P = 0.0001). At one-year follow-up, there was no difference in the incidence of cytomegalovirus infection (P = 0.152) or malignancies (P = 0.312). CD3+T lymphocyte immunomodulation in the single-dose group was more effective in the first two days after transplantation. After the third post-transplant day, CD3+T lymphocyte modulation was more efficient in the fractionated dose group. Both regimens resulted in low rejection rates and equivalent survival. The single and reduced dose regimen protects from the occurrence of bacterial infections. CD3+T lymphocyte modulation occurred with different kinetics, although it did not result in distinct outcomes.

Real-World Experience With CMV inSIGHT T Cell Immunity Testing in High-Risk Kidney and Pancreas Transplant Recipients.

Cytomegalovirus (CMV)-specific cell-mediated immunity is important for control of CMV after transplant. Assays exist to measure this, but their place in therapy is unclear, particularly in CMV high-risk recipients, without pretransplant exposure. The objective of this study was to evaluate predictive potential of a positive assay to determine freedom from DNAemia and describe subsequent 3-month CMV outcomes. Adult CMV high-risk kidney and/or pancreas transplant recipients were included if a CMV inSIGHT T Cell Immunity Panel (TCIP, Eurofins Viracor) was ordered and resulted between 1 August, 2019 and 30 July, 2022. Seventy-six patients were included in our study; 49 tested during prophylaxis and 27 during treatment. Most TCIP assays obtained in the prophylaxis cohort were negative (n = 46, 93.9%). Rate of post-TCIP CMV infection was 10.2%. In those tested during treatment, 33.3% were positive and rate of post-TCIP CMV recurrence was 22.2%. The positive predictive value of the assay to successfully predict immunity was 66.7% during both prophylaxis and treatment. There were 4 cases of TCIP predictive failure with progressive CMV replication. At time of replication, 2 patients had concomitant clinical confounders thought to influence immune control of viral replication. All patients had intensification of immunosuppression prior to recurrent replication, but after TCIP was collected. The data obtained from the TCIP are not static, immune control of CMV in latency can change and must be evaluated in clinical context. Timing of TCIP after transplant is significant, and patient-specific factors remain important to assess the likelihood of CMV in each unique patient-specific scenario. A CMV stewardship program can aid in application and interpretation of results.

Tixagevimab-cilgavimab as an Early Treatment for COVID-19 in Kidney Transplant Recipients.

Tixagevimab-cilgavimab as an Early Treatment for COVID-19 in Kidney Transplant Recipients.

Cytomegalovirus High-risk Kidney Transplant Recipients Show No Difference in Long-term Outcomes Following Preemptive Versus Prophylactic Management.

Following kidney transplantation (KT), cytomegalovirus (CMV) infection remains an important challenge. Both prophylactic and preemptive antiviral protocols are used for CMV high-risk kidney recipients (donor seropositive/recipient seronegative; D+/R-). We performed a nationwide comparison of the 2 strategies in de novo D+/R- KT recipients accessing long-term outcomes. A nationwide retrospective study was conducted from 2007 to 2018, with follow-up until February 1, 2022. All adult D+/R- and R+ KT recipients were included. During the first 4 y, D+/R- recipients were managed preemptively, changing to 6 mo of valganciclovir prophylaxis from 2011. To adjust for the 2 time eras, de novo intermediate-risk (R+) recipients, who received preemptive CMV therapy throughout the study period, served as longitudinal controls for possible confounders. A total of 2198 KT recipients (D+/R-, n = 428; R+, n = 1770) were included with a median follow-up of 9.4 (range, 3.1-15.1) y. As expected, a greater proportion experienced a CMV infection in the preemptive era compared with the prophylactic era and with a shorter time from KT to CMV infection ( P < 0.001). However, there were no differences in long-term outcomes such as patient death (47/146 [32%] versus 57/282 [20%]; P = 0.3), graft loss (64/146 [44%] versus 71/282 [25%]; P = 0.5), or death censored graft loss (26/146 [18%] versus 26/282 [9%]; P = 0.9) in the preemptive versus prophylactic era. Long-term outcomes in R+ recipients showed no signs of sequential era-related bias. There were no significant differences in relevant long-term outcomes between preemptive and prophylactic CMV-preventive strategies in D+/R- kidney transplant recipients.

A Systematic Review and Meta-analysis of Optimized CMV Preemptive Therapy and Antiviral Prophylaxis for CMV Disease Prevention in CMV High-Risk (D+R-) Kidney Transplant Recipients.

We conducted a systematic review and meta-analysis of PET with weekly CMV polymerase chain reaction monitoring for ≥3 mo and UP with 6 mo of valganciclovir. PubMed and Embase databases were reviewed from January 1, 2010, to April 1, 2022. Risk of bias was assessed with 3 instruments (Cochrane RoB, Cochrane RoBINS-I, and an instrument for assessing risk in observational studies). The primary outcome was CMV disease incidence by 1-y posttransplant. Secondary outcomes by 1-y were graft loss, acute allograft rejection, and mortality. Results were synthesized using generalized linear mixed model meta-analysis. PET studies were stratified into low-threshold (LT) and high-threshold (HT) PET based on the viral load threshold for initiation of antiviral therapy. Twenty-five studies met inclusion criteria (6 PET, 19 UP). CMV disease incidence was significantly higher in HT (0.30 [95% confidence interval (CI), 0.22-0.39]) versus LT PET (0.06 [95% CI, 0.03-0.12]). LT PET was associated with a significantly lower CMV disease incidence (0.06 [95% CI, 0.03-0.12]) versus UP (0.21 [95% CI, 0.17-0.27]). Incidence of graft loss, acute allograft rejection, or mortality was not significantly different between LT PET and UP (P > 0.05 for all comparisons). Receipt of lymphocyte-depleting antibodies was not associated with a significant difference in CMV disease incidence (odds ratio = 1.34 [95% CI, 0.80-2.25]). LT PET is associated with a significantly lower incidence of CMV disease compared to UP with similar rates of other clinical outcomes. These findings provide rationale and preliminary data for a randomized superiority trial of optimized LT-PET versus UP in donor seropositive recipient seronegative kidney transplant recipients.

Letermovir vs Valganciclovir for Prophylaxis of Cytomegalovirus in High-Risk Kidney Transplant Recipients

Valganciclovir for 200 days is standard care for cytomegalovirus (CMV) prophylaxis in high-risk CMV-seronegative kidney transplant recipients who receive an organ from a CMV-seropositive donor, but its use is limited by myelosuppression. To compare the efficacy and safety of letermovir with valganciclovir for prevention of CMV disease in CMV-seronegative kidney transplant recipients who receive an organ from a CMV-seropositive donor. Randomized, double-masked, double-dummy, noninferiority, phase 3 trial in adult CMV-seronegative kidney transplant recipients who received an organ from a CMV-seropositive donor at 94 participating sites between May 2018 and April 2021 (final follow-up in April 2022). Participants were randomized in a 1:1 ratio (stratified by receipt of lymphocyte-depleting induction immunosuppression) to receive letermovir, 480 mg, orally daily (with acyclovir) or valganciclovir, 900 mg, orally daily (adjusted for kidney function) for up to 200 days after transplant, with matching placebos. The primary outcome was CMV disease, confirmed by an independent masked adjudication committee, through posttransplant week 52 (prespecified noninferiority margin, 10%). CMV disease through week 28 and time to onset of CMV disease through week 52 were secondary outcomes. Exploratory outcomes included quantifiable CMV DNAemia and resistance. The rate of leukopenia or neutropenia through week 28 was a prespecified safety outcome. Among 601 participants randomized, 589 received at least 1 dose of the study drug (mean age, 49.6 years; 422 [71.6%] men). Letermovir (n = 289) was noninferior to valganciclovir (n = 297) for prevention of CMV disease through week 52 (10.4% vs 11.8% of participants with committee-confirmed CMV disease; stratum-adjusted difference -1.4% [95% CI, -6.5% to 3.8%]). No participants who received letermovir vs 5 participants (1.7%) who received valganciclovir developed CMV disease through week 28. Time to onset of CMV disease was comparable between the groups (hazard ratio, 0.90 [95% CI, 0.56-1.47]). Quantifiable CMV DNAemia was detected in 2.1% of participants in the letermovir group vs 8.8% in the valganciclovir group by week 28. Of participants evaluated for suspected CMV disease or CMV DNAemia, none (0/52) who received letermovir and 12.1% (8/66) who received valganciclovir had resistance-associated substitutions. The rate of leukopenia or neutropenia through week 28 was lower with letermovir vs valganciclovir (26% vs 64%; difference, -37.9% [95% CI, -45.1% to -30.3%]; P < .001). Fewer participants in the letermovir group than the valganciclovir group discontinued prophylaxis due to adverse events (4.1% vs 13.5%) or drug-related adverse events (2.7% vs 8.8%). Among adult CMV-seronegative kidney transplant recipients who received an organ from a CMV-seropositive donor, letermovir was noninferior to valganciclovir for prophylaxis of CMV disease over 52 weeks, with lower rates of leukopenia or neutropenia, supporting its use for this indication. ClinicalTrials.gov Identifier: NCT03443869; EudraCT: 2017-001055-30.

The Best Method for CMV Prevention in High-risk Kidney Transplant Recipients? Either, per National Norwegian Transplant Database: Commentary on Blom et al, Cytomegalovirus High-risk Kidney Transplant Recipients Show No Difference in Long-term Outcomes Following Preemptive Versus Prophylactic Management.

The Best Method for CMV Prevention in High-risk Kidney Transplant Recipients? Either, per National Norwegian Transplant Database: Commentary on Blom et al, Cytomegalovirus High-risk Kidney Transplant Recipients Show No Difference in Long-term Outcomes Following Preemptive Versus Prophylactic Management.

Comparison of intracellular cytokine staining versus an ELISA-based assay to assess CMV-specific cell-mediated immunity in high-risk kidney transplant recipients.

The best method for monitoring cytomegalovirus (CMV)-specific cell-mediated immunity (CMV-CMI) among high-risk kidney transplant (KT) recipients remains uncertain. We assessed CMV-CMI by intracellular cytokine staining (ICS) by flow cytometry and a commercial interferon (IFN)-γ release assay (QuantiFERON®-CMV [QTF-CMV]) at posttransplant months 3, 4, and 5 in 53 CMV-seropositive KT recipients that had received induction therapy with antithymocyte globulin (ATG) and a 3-month course of valganciclovir prophylaxis. The discriminative capacity (areas under receiver operating characteristics curve [auROCs]) and diagnostic accuracy to predict immune protection against CMV infection from the discontinuation of prophylaxis to month 12 were compared between both methods. There was significant although moderate correlations between CMV-specific IFN-γ-producing CD8+ T-cell counts enumerated by ICS and IFN-γ levels by QTF-CMV at months 3 (rho: 0.493; p = 0.005) and 4 (rho: 0.440; p = 0.077). The auROCs for CMV-specific CD4+ and CD8+ T-cells by ICS were nonsignificantly higher than that of QTF-CMV (0.696 and 0.733 vs. 0.678; p = 0.900 and 0.692, respectively). The optimal cut-off of ≥0.395 CMV-specific CD8+ T-cells yielded a sensitivity of 86.4%, specificity of 54.6%, positive predictive value of 79.2% and negative predictive value of 66.7% to predict protection. The corresponding estimates for QTF-CMV (IFN-γ levels ≥0.2 IU/mL) were 78.9%, 37.5%, 75.0%, and 42.9%, respectively. The enumeration of CMV-specific IFN-γ-producing CD8+ T-cells at the time of cessation of prophylaxis performed slightly better than the QTF-CMV assay to predict immune protection in seropositive KT recipients previously treated with ATG.

210. Neutropenia and Associated Infectious Complications Among Kidney Transplant Recipients Receiving Valganciclovir Prophylaxis in the United States: An Administrative Claims Database Study

Abstract Background Valganciclovir (VGCV) prophylaxis is commonly utilized to prevent cytomegalovirus (CMV) infection among high (D+/R-) and intermediate (R+) risk kidney transplant recipients (KTRs). Due to the myelosuppressive effects of VGCV, KTRs may be at an increased risk of opportunistic infections (OIs) resulting in interruptions to VGCV therapy. Therefore, we aimed to quantify the clinical burden of neutropenia among adult KTRs receiving VGCV prophylaxis. Methods A retrospective cohort design was utilized to identify adult KTRs who received VGCV prophylaxis using the IBM MarketScan Commercial and Medicare Supplemental claims databases. First-time KTRs between 1/1/2012 - 12/31/2018 with 1 year of continuous pharmacy and medical coverage before (baseline period) and after (follow-up period) were included. KTRs with a History of other solid organ transplantation were excluded. Fills of ≥ 1 prescription of VGCV (either 450 mg or 900 mg/day) within 30 days of the kidney transplant (KT). Neutropenia events were identified as either ≥ 1 inpatient, or ≥ 2 outpatient ICD-9/ICD-10 diagnoses codes within 14 days. Results Of the 4,965 adults KTRs with baseline and follow-up enrollment, 3,258 (66%) used VGCV prophylaxis. 311/3256 (9.5%) developed neutropenia within 1-year post KT. Baseline characteristics were similar between those with and without neutropenia (table 1). The majority received the following pre-transplant immunosuppression: tacrolimus (78.9%), mycophenolate mofetil (62.8%) and steroids (prednisone, 79.3%, methylprednisolone 10.6%). KTRs with neutropenia had a nearly two-fold increase in the development of CMV infection compared to those without neutropenia. In addition, KTRs with neutropenia had significantly higher rate of bacterial or fungal infections compared to those without neutropenia (Table 2). Interruptions in VGCV prophylaxis (gap &amp;gt;15 days) were more common in KTRs with neutropenia (P&amp;lt; 0.001). Conclusion Our findings showed that neutropenia was associated viral, bacterial, and fungal OIs among adults KT receiving VGCV prophylaxis. The findings highlight the needs for interventions to reduce neutropenia and its associated OIs. These results suggest that clinical management steps to reduce rates of neutropenia among KT recipients may warrant further study. Disclosures Vladimir Turzhitsky, PhD, Merck &amp; Co., Inc.,: Employee|Merck &amp; Co., Inc.,: Stocks/Bonds Amit D. Raval, PhD, Merck and Co., Inc.: Employee of Merck|Merck and Co., Inc.: Stocks/Bonds Pamela Moise, PharmD, Merck &amp; Co., Inc: Employee &amp; Shareholder Sanjay Merchant, PhD, Merck &amp; Co., Inc.: Stocks/Bonds.

Treatment with sotrovimab for SARS-CoV-2 infection in a cohort of high-risk kidney transplant recipients.

ABSTRACTBackgroundSotrovimab is a neutralizing monoclonal antibody (mAb) that seems to remain active against recent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants. The evidence on its use in kidney transplant (KT) recipients, however, is limited.MethodsWe performed a multicenter, retrospective cohort study of 82 KT patients with SARS-CoV-2 infection {coronavirus disease 2019 [COVID-19]} treated with sotrovimab.ResultsMedian age was 63 years. Diabetes was present in 43.9% of patients, and obesity in 32.9% of patients; 48.8% of patients had an estimated glomerular filtration rate under 30 mL/minute/1.73 m2. Additional anti–COVID-19 therapies were administered to 56 patients, especially intravenous steroids (65.9%). Sotrovimab was administered early (<5 days from the onset of the symptoms) in 46 patients (56%). Early-treated patients showed less likely progression to severe COVID-19 than those treated later, represented as a lower need for ventilator support (2.2% vs 36.1%; P < .001) or intensive care admission (2.2% vs 25%; P = .002) and COVID-19–related mortality (2.2% vs 16.7%; P = .020). In the multivariable analysis, controlling for baseline risk factors to severe COVID-19 in KT recipients, early use of sotrovimab remained as a protective factor for a composite outcome, including need for ventilator support, intensive care, and COVID-19–related mortality. No anaphylactic reactions, acute rejection episodes, impaired kidney function events, or non-kidney side effects related to sotrovimab were observed.ConclusionsSotrovimab had an excellent safety profile, even in high-comorbidity patients and advanced chronic kidney disease stages. Earlier administration could prevent progression to severe disease, while clinical outcomes were poor in patients treated later. Larger controlled studies enrolling KT recipients are warranted to elucidate the true efficacy of monoclonal antibody therapies.

1378. Impact of Cytomegalovirus Prophylaxis on Clinical Outcomes in Kidney Transplantation: A United States Renal Data System-Medicare Linked Database Study

BackgroundGuidelines recommends cytomegalovirus (CMV) prophylaxis by CMV serostatus/risk status, as the currently available antiviral agents may lead to myelosuppressive events in kidney transplant recipients (KTRs). Limited data exist for the United States (US) on the such clinical outcomes with CMV prophylaxis KTRs especially stratified by CMV risk strata. We examined the associations between clinical outcomes and CMV prophylaxis among adult KTRs stratified by CMV risk strata. MethodsWe employed a retrospective cohort design using the US Renal Data System registry-linked Medicare data (2011-2017). The cohort included 22,918 adult KTRs with continuous Medicare Part A & B coverage for ≥ 6-month pre and ≥ 12-month post KT and Part D coverage for ≥ 12-month post- KT. CMV prophylaxis was defined as ≥ 1 prescription fill or medical claim for valacyclovir or valganciclovir at prophylaxis doses within 28 days post-KT. ResultsCMV prophylaxis was utilized by 75% of the cohort. In no CMV prophylaxis group, 52.2% and 34.2% of high and intermediate risk KTRs received valganciclovir (as either pre-emptive or deferred therapy), respectively. Among high risk KTRs, CMV prophylaxis group had significantly lower proportions of KTRs with CMV infection, opportunistic infections (OIs) including bacterial, and fungal infections, and new onset of diabetes mellitus (NODAT) compared to no prophylaxis group. There were no differences in the rates of acute rejection or death; however, a trend towards lower rate of graft-failure at 12-month post-KT. Nearly 40% of high-risk KTRs had myelosuppressive events (leukopenia: 18%; neutropenia:15% thrombocytopenia :19%); however, their differences were non-significant except for thrombocytopenia by CMV prophylaxis status (Table 1). CMV infection and myelosuppressive event rates were higher in high-risk than intermediate/low risk KTRs irrespective of CMV prophylaxis status. ConclusionCMV prophylaxis was associated with lower rates of CMV infection, OIs, NODAT and graft failure compared to no prophylaxis, however, the burden of CMV infection, OIs and myelosuppression was greater in high-risk KTRs indicating further research is needed on factors associated with greater disease burden in high-risk KTRs. Table 1Disclosures Amit D. Raval, PhD, Merck and Co., Inc. (Employee) Yuexin Tang, PhD, JnJ (Other Financial or Material Support, Spouse’s employment)Merck & Co., Inc. (Employee, Shareholder)

1387. Impact of Cytomegalovirus Prophylaxis on Healthcare Resource Use and Costs among Kidney Transplant Recipients: A United States Renal Data System-Medicare Linked Database Study

BackgroundCytomegalovirus (CMV) management requires a balance between reducing the risk of CMV infection and avoiding anti-viral toxicities. Limited information is available on the impact of CMV prophylaxis on the healthcare resource use (HCRU) and costs among adult kidney transplant recipients (KTRs) in the United States. Therefore, we examined HCRU and cost associated with CMV prophylaxis stratified by the CMV risk categories among KTRs at 1-year post-KT. MethodsWe identified a cohort of 22,918 adults first-time KTRs during 2011–2017 using the US Renal Data System registry-linked Medicare data. Additional inclusion criteria were to have continuous coverage in Medicare Part A & B for ≥ 6-month pre- and ≥ 12-month post KT and Medicare Part D for ≥12-month post-KT. CMV prophylaxis was confirmed as ≥ 1 prescription fill for valacyclovir/(val)ganciclovir prophylaxis doses within 28 days post-KT. ResultsCMV prophylaxis was utilized in 86%, 82%, and 32% of high, intermediate, and low-risk KTRs with an average cost of prophylaxis per KTRs of &16,241, &9481, and &8,648, respectively. In no prophylaxis groups, valganciclovir was utilized in 52%, 34%, and 36% of KTRs (as either pre-emptive or deferred therapy) with an average cost of &6,719, &2,722, and &431 among high, intermediate, and low-risk KTRs, respectively. Among high-risk KTRs, CMV prophylaxis group had a significantly higher prescription drug cost (&26,060 vs. &13,433) but a lower average direct healthcare medical cost (&84,914 vs. &101,268), mainly due to lower all-cause hospitalization cost (&56,758 vs. &69,852) (Table 1). CMV prophylaxis group had lower rates of all-cause rehospitalization, and CMV-and opportunistic infection (OIs)-related hospitalization compared to no prophylaxis (Table 2). In high-risk KTRs, nearly 32% had myelosuppressive events-related hospitalization, and 15% filled granulocyte colony-stimulating factors with an average cost of &4,695 per treated KTR.ConclusionCMV prophylaxis had a higher cost of medications but had a lower medical cost with including all-cause and CMV-related hospitalizations. Myelosuppressive events were frequent and resource-intensive especially in high and intermediate-risk KTRs. Disclosures Amit D. Raval, PhD, Merck and Co., Inc. (Employee) Yuexin Tang, PhD, JnJ (Other Financial or Material Support, Spouse’s employment)Merck & Co., Inc. (Employee, Shareholder)

Bimonthly viral monitoring for late-onset cytomegalovirus infection in kidney transplant recipients.

Kidney transplant recipients with high-risk cytomegalovirus (CMV) serostatus (seropositive donor to seronegative recipient) are at risk for late-onset CMV after cessation of antiviral prophylaxis. We report findings from a strategy of bimonthly (every 2weeks) CMV screening for late-onset CMV. This is a single-center retrospective cohort study of 70 high-risk CMV kidney transplant recipients transplanted between June 2016 and September 2018. Patients were monitored at 6-12months post-transplantation for late-onset CMV using bimonthly CMV nucleic acid testing (NAT). Adherence to screening and its correlation with CMV-related hospitalizations were assessed. Failure to prevent CMV-related hospitalization was classified into three categories (non-adherence to CMV testing, rapid CMV progression, and health system failure). Twenty-one (30%) patients developed CMV DNAemia, of whom 10 (14%) required hospitalization. Reasons for CMV-related hospitalization despite screening were (i) screening non-adherence (50%), (ii) rapid progression (40%), and (iii) health system failure (10%). Adherence to screening was associated with lower viral counts at diagnosis (r=-.44, p=.049) and a trend towards lower risk of CMV-related hospitalization (OR: 0.97 per 1% increase in adherence; 95% CI: 0.94-1.00; p=.06). Bimonthly monitoring for late-onset CMV allows for early CMV detection and may lower CMV-related hospitalization.

The burden of cytomegalovirus infection remains high in high-risk kidney transplant recipients despite six-month valganciclovir prophylaxis.

Cytomegalovirus continues to be a concern after transplantation despite prophylaxis regimens. Our aim was to analyse post-prophylaxis primary cytomegalovirus infections among kidney transplant recipients after 6-month valganciclovir prophylaxis and to determine the usefulness of surveillance after prophylaxis. Data from all cytomegalovirus D+/R- kidney transplant recipients from January 2004 to October 2018 at our center who received 6-month prophylaxis with valganciclovir were retrospectively analysed (N=481). Detailed analyses were performed for 136 patients who were monitored every 2-4weeks for DNAemia after the discontinuation of prophylaxis. Post-prophylaxis primary cytomegalovirus infection occurred in 182/481 (38%) patients median 264days after transplantation (IQR: 226-367) and median 84days after the end of prophylaxis (IQR: 46-187). In 49% patients, cytomegalovirus infection occurred over 3 months after the end of prophylaxis. Cytomegalovirus infection was not associated with lower patient or graft survival and no independent risk factors for infection were found. From patients monitored closely, 71/136 (52%) patients developed post-prophylaxis primary cytomegalovirus infection. Altogether, 52/136 (38%) patients were diagnosed with probable post-prophylaxis cytomegalovirus disease and 19/136 (14%) patients had asymptomatic CMV infection. Recurrent infection occurred in 38/71 (39%) patients. The incidence of post-prophylaxis primary cytomegalovirus infection among D+/R- kidney transplant recipients remains high despite 6-month prophylaxis. Surveillance after prophylaxis was challenging as a considerable portion of the infections occurred late and already symptomatic.

Early cytomegalovirus DNAemia and antiviral dose adjustment in high vs intermediate risk kidney transplant recipients.

Cytomegalovirus (CMV) infection continues to negatively affect outcomes for solid organ transplant recipients, despite the advent of strategies for preemptive surveillance and prophylaxis. The impact is especially great for CMV seronegative recipients of donor seropositive organs, who typically lack the ability to control CMV infection at the time of transplantation. We reviewed episodes of CMV DNAemia in a modern cohort of kidney transplant recipients over a 3-year period at a high-volume transplant center to investigate the frequency of DNAemia during antiviral prophylaxis. Despite receipt of antiviral prophylaxis per current guidelines, 75 cases of CMV DNAemia were observed in the first 100days after transplantation. For high risk patients, median time to DNAemia was 75days after transplantation, and the majority of patients had experienced dose-reduction of valganciclovir due to renal insufficiency. Review of CMV seropositive intermediate risk patients demonstrated DNAemia occurring earlier after transplantation compared with high risk patients with a median time of 64days (P=.029). The impact of valganciclovir dose adjustment was less notable in the intermediate risk group. Guidelines recommend beginning routine surveillance for CMV after the completion of antiviral prophylaxis. Our findings suggest that closer monitoring may be beneficial, especially for high risk patients at risk for DNAemia. Patients requiring dose adjustment of valganciclovir due to renal insufficiency may be at increased risk for CMV DNAemia. Improved methods for CMV prophylaxis and evaluation of immunologic risk for CMV DNAemia and disease are needed to improve patient outcomes after kidney transplantation.

Effect of mTOR inhibitors during CMV disease in kidney transplant recipients: Results of a pilot retrospective study.

mTOR inhibitors exert a preventive effect on cytomegalovirus (CMV) disease in CMV seropositive (R+) kidney transplant recipients, but their impact during the curative treatment of CMV disease in high-risk kidney transplant recipients has not been investigated. We aimed to evaluate the efficacy and tolerance of mTOR inhibitors compared with mycophenolic acid in 63 consecutive kidney transplant recipients (80% of D+R-) suffering from CMV disease with a persistent or a recurrent CMV DNAemia. In this monocentric retrospective study, 16 had their treatment converted to mTOR inhibitors and 47 did not. The Kaplan-Meier curves did not show any significant differences in CMV DNAemia eradication (77% vs. 88% respectively; hazard ratio (HR), 1.648 [95% confidence interval (CI), 0.913-2.973]; log-rank test, P = .132), DNAemia recurrence (36% vs. 47%; HR, 1.517 [95% CI, 0.574-4.007]; log-rank test, P = .448) and CMV clinical recurrence (17% vs. 27%; HR, 1.375 [95% CI, 0.340-5.552]; log-rank test, P = .677) between patients who received mTOR inhibitors and those who did not. These results were confirmed in uni- and multivariate time-dependent Cox regressions. In summary, conversion from mycophenolic acid to mTOR inhibitors seems inadequate for improving CMV clearance or in better preventing CMV recurrences during severe or persistent CMV disease.