Judicial and legislative practice and related suggestions on off-label drug use in China.

BACKGROUND: Off-label drug use exists widely in medical practice and is also an area which easily triggers controversy between patients and medical institutions. Previous studies have identified the reasons why off-label drug use long exists. However, there is no multidimensional analysis on real judicial precedents about off-label drug use. This study aimed to investigate the dispute points on off-label drug use based on real cases in China, and proposed suggestions based on newly-leased Physicians Law. METHODS: Our study is a retrospective study with all the 35 judicial precedents on off-label drug use extracted from China Judgments Online from 2014 to 2019. This study mainly used the methods of statistical analysis, inferential analysis, exemplification, literature summarization and comparative analysis. RESULTS: According to the analysis of the 35 precedents of jurisdictions from 11 different aspects, it can be seen that the second-instance and retrial rates of this kind of cases are high, and the disputes between patients and medical institutions are fierce. In judicial practice of off-label drug use, medical institutions are determined whether to bear civil liability according to the constituent elements of medical tort liability: the rate of medical institutions' bearing liability for off-label drug use is not high, and medical institutions are not directly identified as infringing acts and they don't bear tort liability. The clear provisions about off-label drug use in Law of the People's Republic of China on Physicians which was implemented in March 2022 confirm this at the legislative level. CONCLUSIONS: By analyzing the current judicial practice of China's off-label drug use cases, and summarizing the dispute points between medical institution and patients, the constituent elements of tort liability, and the rules of evidence etc., suggestions are proposed to further regulate off-label drug use and promote safe and rational drug use.

Real-world data of off-label drug use in patients with actionable genomic alterations on next-generation sequencing.

Introduction We analyzed the outcomes of patients with advanced cancers in our institution treated with off-label drugs targeting actionable genomic alteration based on next-generation sequencing who did not qualify for clinical trials. Purposes Our study endpoint was objective tumor response or stable disease at 16 weeks or later after treatment initiation. Methods Sixteen patients were included, 8 treated with immune checkpoint inhibitors targeting PD-L1 expression or TP53 mutations and 8 with other drugs. Tumors were analyzed based on PD-L1 expression, TP53 mutation, MSI, TMB, MMR status, and other targetable alterations. Results Of the 16 patients in the intention-to-treat group, no patients had an objective response after 16 weeks. Eleven patients met the primary study endpoint with stable disease, 8 in the immune checkpoint inhibitors group and 3 in the non-immune checkpoint inhibitors group. Using the log-rank test, the p-value for the difference between groups was 0.008. Conclusions In this study with off-label drugs, immune checkpoint inhibitors targeting TP53 mutations or PD-L1 expression were superior to the other drugs. This suggests the possibility of off-label use of anti-cancer drugs based on next-generation sequencing to be beneficial for advanced cancer patients without other therapeutic options.

Off-label use of drugs in pediatrics: a scoping review.

To explore the current state of research on off-label drug use in children and identify the existing research gaps in this topic. Six literature databases were searched to identify studies focusing exclusively on off-label drug use in children (aged < 18 years) published in Chinese or English between 2016 and 2021. We also searched clinicaltrials.gov for pediatric clinical trials conducted in the same period and compared the numbers of studies on off-label use and clinical trials for the most commonly reported drugs and drug types. Our search revealed 568 studies on off-label drug use. Almost half of the studies (n = 240) were cross-sectional. A total of 212 specific drugs or drug types were addressed in 361 studies, the most frequent being antipsychotic agents (n = 12), dexmedetomidine (n = 10), and rituximab (n = 8). Antipsychotic agents were also the most common type of drug examined in clinical trials in children. We identified a total of 435 different types of off-label use, the top three being unapproved indication (n = 157), population (n = 96), or age (n = 36). Only about one-third of the studies reported collecting informed consent (n = 195) or having ethics committee approval (n = 166).    Conclusions: Off-label use of antipsychotics in children is widely reported in the literature. We suggest pediatric researchers to consider the number of studies on off-label use and existing clinical trials on different drugs when selecting target drugs for new studies and systematic reviews. What is Known: • There exist a large number of studies on off-label drug use in children. What is New: • This is the first scoping review of studies on off-label drug use in children. • Off-label use of antipsychotic agents is widely reported.

A multicenter case series documenting Medicare Part D plan denials of immunosuppressant drug coverage for organ transplant recipients.

Medicare Part D plans make coverage decisions according to FDA-labeled indications and off-label uses endorsed by two CMS-recognized compendia. Patients who rely on Medicare Part D for immunosuppressive drug coverage are at risk for denied coverage when these medications are prescribed off-label. The purpose of this multicenter collaboration was to assemble a case series documenting situations where immunosuppressive therapies prescribed for transplant patients were denied by Medicare Part D prescription drug plans. This case series documents 66 instances in 39 patients where immunosuppressive drug claims were denied coverage due to off-label use not endorsed by the compendia. Patients were recipients of lung (n = 28, 72%), heart (n = 7, 18%), or liver (n = 4, 10%) transplants. Denied claims were for mycophenolate mofetil (n = 22, 33%), azathioprine (n = 18, 27%), sirolimus (n = 15, 23%), mycophenolate sodium (n = 5, 8%), everolimus (n = 5, 8%), and belatacept (n = 1, 1%). Most denials were upheld across all the levels of attempted appeal, including those escalated to a Medicare Administrative Law Judge. This case series demonstrates a critical flaw in the construct of the Medicare Prescription Drug Benefit. The currently referenced compendia are not up to date and do not reflect best practices in organ transplantation.

Optimization of de novo belatacept-based immunosuppression administered to renal transplant recipients.

Kidney transplant recipients administered belatacept-based maintenance immunosuppression present with a more favorable metabolic profile, reduced incidence of de novo donor-specific antibodies (DSAs), and improved renal function and long-term patient/graft survival relative to individuals receiving calcineurin inhibitor (CNI)-based immunosuppression. However, the rates and severity of acute rejection (AR) are greater with the approved belatacept-based regimen than with CNI-based immunosuppression. Although these early co-stimulation blockade-resistant rejections are typically steroid sensitive, the higher rate of cellular AR has led many transplant centers to adopt immunosuppressive regimens that differ from the approved label. This article summarizes the available data on these alternative de novo belatacept-based maintenance regimens. Steroid-sparing, belatacept-based immunosuppression (following T cell-depleting induction therapy) has been shown to yield AR rates comparable to those seen with CNI-based regimens. Concomitant treatment with belatacept plus a mammalian target of rapamycin inhibitor (mTORi; sirolimus or everolimus) has yielded AR rates ranging from 0 to 4%. Because the optimal induction agent and number of induction doses; blood levels of mTORi; and dose, duration, and use of corticosteroids have yet to be determined, larger prospective clinical trials are needed to establish the optimal alternative belatacept-based regimen for minimizing early cellular AR occurrence.

Phosphodiesterase type 5 inhibitor use among pregnant and reproductive-age women in the United States.

PURPOSE: To assess the prevalence and potential indications of PDE5 inhibitor use among pregnant and reproductive-age women in the United States. METHODS: We identified women 15 to 50 years with a livebirth from January 2001 through March 2018 in Sentinel Database. We assessed the prevalence of PDE5 inhibitor use prior to and during pregnancy by trimester, identified potential on- and off-label indications using predefined diagnosis codes recorded within 90 days before the estimated last menstrual period through delivery. Separately, we used data from IQVIA's National Prescription Audit and Total Patient Tracker to estimate the dispensed prescriptions for PDE5 inhibitors and the number of patients with PDE5 inhibitor prescriptions. RESULTS: We identified approximately 3.3 million pregnancies during 2001 to 2018, 96 of which had PDE5 inhibitor use during pregnancy. Prevalence of PDE5 inhibitor use was 2.61, 0.62, and 0.62 per 100, 000 live-born pregnancies during the first, second, or third trimesters, respectively. Among women exposed to a PDE5 inhibitor from 90 days before conception to the end of pregnancy, 25.0%, 31.1%, and 15.5% had a diagnosis code for fetal growth restriction, preeclampsia, and pulmonary arterial hypertension. In IQVIA data, an estimated 223, 000 prescriptions from July 2015 through June 2018 and 58, 000 women received prescriptions for PDE5 inhibitors in 2017, of whom approximately 15, 000 (26%) were aged 15 to 50 years. CONCLUSION: We found a low prevalence of PDE5 inhibitor use in pregnant and reproductive-age women. Given the very low prevalence of use and the inconsistency of neonatal mortality data across STRIDER centers, the risk to public health is low at present.

Utilization of biotechnological drugs in rare diseases requiring the use of off-label drugs in children in Turkey

Background/aim: Pediatric patients, especially those with rare diseases, represent a population that has a high tendency towards off- label drug use (OLDU) and needs a more careful practice of pharmacotherapy than in adults. We aimed to investigate biotechnological drug use in children with rare diseases requiring OLDU. Materials and methods: This retrospective study examined all single-diagnosed OLDU applications (n = 5792) for 4992 children (<18- year) in Turkey. Applications of rare diseases were selected, and their descriptive characteristics were examined, including demographic features of patients, biotechnological drug utilization status, and disease categories. The off-label statuses of the drugs at the end of 2020 were also examined. Results: In total, 77.7% (n = 4501) of OLDU applications were made for rare diseases. Biotechnological drug use was higher in rare disease applications than in nonrare diseases (37.9% vs. 19.2%, respectively; p < 0.0001). Canakinumab was the top applied biotechnological drug (73.2%). Compared to that in small-molecule drugs, the mean age of patients was higher in biotechnological drug-containing applications (8.1 ± 5.3 vs. 9.7 ± 4.9, respectively; p < 0.0001). Biotechnological drug use was higher in nonneoplastic rare diseases (40.3%) than in neoplastic rare diseases (26.4%), (p < 0.0001). At the end of 2020, the approval status of the off-label indications covered in 2016 was significantly higher for rare (24.4%) vs. nonrare (5.2%, p < 0.0001) diseases and for biotechnological (32.3%) vs. small- molecule (13.9%, p < 0.0001) drugs. In total, 87.7% of the drugs would have to be still used in the off-label setting at the end of 2020. Conclusion: It was seen that more than three-quarters of the pediatric OLDU applications are for rare diseases, and the need for biotechnological OLDU in this group is almost 2-fold of small-molecule drug use. While further projected findings imply a higher approval tendency for rare diseases and biotechnological drugs, there seems to be more room for improvement for pediatric drug use.

Use of biomarkers to improve immunosuppressive drug development and outcomes in renal organ transplantation: A meeting report.

On September 27-28, 2018 the Food and Drug Administration (FDA) and the Critical Path Institute's Transplant Therapeutics Consortium convened a public workshop titled "Evidence-Based Treatment Decisions in Transplantation: The Right Dose & Regimen for the Right Patient/Individualized Treatment." The workshop facilitated cooperative engagement of transplant community stakeholders, including pharmaceutical industry, academic researchers, clinicians, patients, and regulators to discuss methods to advance the development of novel immunosuppressive drugs for use in solid organ transplantation. Day 1 focused on the utility of biomarkers in drug development, with considerations for seeking regulatory endorsement for use in clinical trials. Biomarkers add value to drug development by improving patient selection criteria, safety monitoring, endpoint selection, and more. Regulatory endorsement through the FDA Biomarker Qualification Program encourages the use of biomarkers in drug development by instilling confidence and consistency in biomarker interpretation across trials. Public-private partnerships or consortia allow stakeholders to share expertise, resources, and data in pursuit of biomarker qualification. Biomarkers relevant to pretransplant risk assessment, early posttransplant care, and assessment of immune response, immunosuppressive drug efficacy, and graft function as discussed on day 1 of the workshop are described.

Tocilizumab therapy in 5 solid and composite tissue transplant recipients with early ARDS due to SARS-CoV-2.

There are emerging data depicting the clinical presentation of coronavirus disease 19 (COVID-19) in solid organ transplant recipients but negligible data-driven guidance on clinical management. A biphasic course has been described in some infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), beginning with a flu-like illness followed by an intense inflammatory response characterized by elevated c-reactive protein (CRP), interleukin 6 (IL-6), and acute respiratory distress syndrome (ARDS) associated with high mortality. The exuberant and possibly dysregulated immune response has prompted interest in therapeutic agents that target the cytokines involved, particularly IL-6. Tocilizumab is an IL-6 receptor antagonist with a record of use for a variety of rheumatologic conditions and cytokine release syndrome due to chimeric antigen receptor T-cell therapy but experience in solid organ and composite tissue transplant recipients (SOT/CTTRs) with SARS-CoV-2-related ARDS has not been previously reported in detail. We present the clinical course of 5 SOT/CTTRs with SARS-CoV-2-related ARDS that received tocilizumab with favorable short-term outcomes in 4. Responses were characterized by reductions in CRP, discontinuation of vasopressors, improved oxygenation and respiratory mechanics, and variable duration of ventilator support. Four bacterial infections occurred within 2 weeks of tocilizumab administration. We discuss safety concerns and the need for randomized comparative trials to delineate tocilizumab's clinical utility in this population.

A case of SARS-CoV-2 pneumonia with successful antiviral therapy in a 77-year-old man with a heart transplant.

The SARS-CoV-2 infection can be seen as a single disease, but it also affects patients with relevant comorbidities who may have an increased risk of a severe course of infection. In this report, we present a 77-year-old patient with a heart transplant receiving relevant immunosuppressive therapy who tested positive for SARS-CoV-2 after several days of dyspnea, dry cough, and light general symptoms. Computed tomography confirmed interstitial pneumonia. The patient received antiviral therapy with hydroxychloroquine and showed no further deterioration of the clinical state. After 12 days of hospitalization, the patient was released; he was SARS-CoV-2 negative and completely asymptomatic.

Off-label use of prescription analgesics among hospitalized children in the United States.

PURPOSE: Analgesics are the most frequently administered medications among hospitalized children. However, current analgesic prescribing patterns have not been well defined among hospitalized children. In addition, it is unknown what proportion of prescription analgesics is approved for use in children and what proportion is used "off-label." METHODS: Nationally representative data from 52 tertiary care children's hospitals in the Pediatric Health Information System were queried to determine prescribing rates of analgesic medications. We analyzed hospitalizations for children <18 years occurring between 1 April 2010 and 30 June 2018. Food and Drug Administration (FDA) drug labels were reviewed for pediatric information, and prescriptions were classified as on- or off-label based on age, route, and formulation. RESULTS: Among 4.9 million hospitalizations, 1.8 million (37.6%, 95% confidence interval [CI] = 37.6-37.7) were associated with use of a prescription analgesic. Overall, 36.7% (95% CI = 36.7-36.7) of hospitalizations included off-label analgesic therapy, with 26.4% (95% CI = 26.4-26.5) associated with two or more off-label analgesics. Off-label analgesic use was higher among hospitalizations in the intensive care unit (61.5%) or with an operating room procedure (92.8%). Rates of off-label prescribing increased with age, peaking at 50.5% for adolescents. Prescription analgesics administered most frequently were morphine, fentanyl, and ketorolac, with off-label use occurring in 24.5%, 23.1%, and 11.3% of hospitalizations, respectively. CONCLUSIONS: Over a third of pediatric hospitalizations were associated with the administration of prescription analgesics that have not been labeled for use in children. Our findings highlight the critical need to ensure that safe and effective analgesics are developed for children and that pediatric labeling is expanded for existing analgesics to inform treatment decisions.

[Situation analysis of off-label drug use in China].

To introduce current literature reporting situations of the off-label drug use(OLDU) by analyzing relevant literatures published in China, this study comprehensively focused on literatures about OLDU in China in seven Chinese and English databases, then extracted and analyzed the data by different literature types. A total of 667 papers were analyzed. The number of literatures about OLDU data analyzed in hospitals was 325, and the number of clinical studies relating to OLDU was 329, in which case series and case reports were the majority(69.91%). In addition, there were 13 expert consensuses of OLDU and another 56 studies about drug use based on the real-world data characteristics and influencing factors. The number of OLDU data studies has increased year by year. Based on the existing studies, there were more western medicine reports than traditional Chinese medicines, and OLDU types were mainly for over-dosage use. The literatures from OLDU data in hospital were mostly limited to one or several tertiary hospitals in a certain area, and the OLDU types were not uniform. Clinical studies were mainly clinical control trials and case series/reports, but with contradictory reporting results. There were fewer OLDU consensus, and the recommended classification was not uniform. The characteristics and analysis of influencing factors of drug using data in real-world focused on traditional Chinese medicine injections, and the results were not the same. In the future, we shall pay more attention to and strengthen reporting and analysis of OLDU, define study objectives, and unify the content and reporting standards, so as to promote the integrated utilization of OLDU data and reflect real situations in our country.

Level of evidence used in recommendations by the National Comprehensive Cancer Network (NCCN) guidelines beyond Food and Drug Administration approvals.

BACKGROUND: A previous analysis of 113 National Comprehensive Cancer Network® (NCCN®) recommendations reported that NCCN frequently recommends beyond Food and Drug Administration (FDA)-approved indications (44 off-label recommendations) and claimed that the evidence for these recommendations was weak. METHODS: In order to determine the strength of the evidence, we carried out an in-depth re-analysis of the 44 off-label recommendations listed in the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®). RESULTS: Of the 44 off-label recommendations, 14 were later approved by the FDA and/or are supported by randomized controlled trial (RCT) data. In addition, 13 recommendations were either very minor extrapolations from the FDA label (n = 8) or were actually on-label (n = 5). Of the 17 remaining extrapolations, 8 were for mechanism-based agents applied in rare cancers or subsets with few available treatment options (median response rate = 43%), 7 were based on non-RCT data showing significant efficacy (>50% response rates), and 2 were later removed from the NCCN Guidelines because newer therapies with better activity and/or safety became available. CONCLUSION: Off-label drug use is a frequent component of care for patients with cancer in the United States. Our findings indicate that when the NCCN recommends beyond the FDA-approved indications, the strength of the evidence supporting such recommendations is robust, with a significant subset of these drugs later becoming FDA approved or supported by RCT. Recommendations without RCT data are often for mechanism-based drugs with high response rates in rare cancers or subsets without effective therapies.

The evidence-based choice for antipsychotics in children and adolescents should be guaranteed.

PURPOSE: Drug use in the pediatric population still often features off-label prescriptions, particularly for psychotropic drugs. We reviewed the registration status, scientific evidence, and recommendations from the guidelines for antipsychotics used for psychiatric disorders in children. METHODS: Antipsychotic drugs marketed in Italy, the United Kingdom (UK) and United States (US) were identified with the ATC Classification System. The licensing status and Summary of Product Characteristics (SPC) were taken from the national formularies. We analyzed reviews and guidelines on antipsychotics use in children and adolescents in the MEDLINE, EMBASE, and PsycINFO databases. RESULTS: Out of 67 drugs, 19 were marketed with a pediatric license in at least one country: three in all the selected countries, and only paliperidone with the same indications. Haloperidol was the only antipsychotic authorized for autism in Italy and the UK, and as well as risperidone and aripiprazole in the US. Aripiprazole and paliperidone were licensed in all three countries for schizophrenia. Aripiprazole was licensed for bipolar disorders in all three countries. Haloperidol was licensed for Tourette syndrome in Italy and the UK, and pimozide and aripiprazole in the US. We retrieved 21 pertinent reviews and 13 guidelines for the management of neuropsychiatric disorders in pediatrics. There was a complete overlap between the authorized therapeutic indications and the available scientific evidence for autism in the US, for conduct disorders and bipolar disorders in the UK, and for Tourette syndrome and tics in the UK and Italy. CONCLUSIONS: These results highlight the different regulatory processes that deny to many children and adolescents the most appropriate and rational antipsychotic therapy.

Current practice and awareness of pediatric off-label drug use in Shanghai, China -a questionnaire-based study.

BACKGROUND: Off-label drug use is widespread in pediatric drug treatment, and the implementation of guidelines on this topic remains challenging. The objective of this study was to evaluate current practice and awareness of healthcare professionals towards pediatric off-label drug use, as well as the barriers to guideline implementation among pediatric healthcare professionals in Shanghai, China. METHODS: A validated questionnaire was issued to representatives of pediatricians, pharmacists, nurses and administrators from hospitals with pediatric qualification in Shanghai. RESULTS: A total of 679 completed questionnaires from 69 hospitals were included in the analysis. Nearly half (47.9%) of the pediatricians acknowledged that they had prescribed off-label drugs. Most (88.4%) of the pharmacists acknowledged that they had dispensed off-label medicines. The main reason for off-label prescribing was the lack of pediatric dosage information. The most common category of off-label prescribing in children was dosage. Nearly half (42.0%) of the participating hospitals had developed internal protocols for off-label drug use. However, approximately half of the respondents reported that they did not adhere to the guidance and that it had barriers to implementation. Most respondents (84.5%) declared that they were familiar with the term "off-label drug use". However, the awareness rate of the Chinese Expert Consensus of Pediatric Off-Label Drug Use was low (45.7%). More than half (55.4%) of the respondents declared that they did not adhere to the process proposed in the consensus and that barriers existed for its utilization. CONCLUSIONS: Pediatric off-label drug use is widespread in Shanghai, China, and barriers exist to the implementation of the guideline. A legally recognized national guideline with a broad scope of application for off-label drug use is urgently needed; at the same time, more education and training on off-label drug use should be provided to targeted healthcare professionals.

Transplant recipients are vulnerable to coverage denial under Medicare Part D.

Transplant immunosuppressants are often used off-label because of insufficient randomized prospective trial data to achieve organ-specific US Food and Drug Administration (FDA) approval. Transplant recipients who rely on Medicare Part D for immunosuppressant drug coverage are vulnerable to coverage denial for off-label prescriptions, unless use is supported by Centers for Medicare & Medicaid Services (CMS)-approved compendia. An integrated dataset including national transplant registry data and 3 years of dispensed pharmacy records was used to identify the prevalence of immunosuppression use that is both off-label and not supported by CMS-approved compendia. Numbers of potentially vulnerable transplant recipients were identified. Off-label and off-compendia immunosuppression regimens are frequently prescribed (3-year mean: lung 66.5%, intestine 34.2%, pancreas 33.4%, heart 21.8%, liver 16.5%, kidney 0%). The annual retail cost of these at-risk medications exceeds $30 million. This population-based study of transplant immunosuppressants vulnerable to claim denials under Medicare Part D coverage demonstrates a substantial gap between clinical practice, current FDA approval processes, and policy mandates for pharmaceutical coverage. This coverage barrier reduces access to life-saving medications for patients without alternative resources and may increase the risk of graft loss and death from medication nonadherence.

Case report of high-dose hydroxocobalamin in the treatment of vasoplegic syndrome during liver transplantation.

A 66-year-old man with cryptogenic cirrhosis secondary to nonalcoholic steatohepatitis presented for orthotopic liver transplantation. Following organ reperfusion, the patient developed vasoplegic syndrome, with arterial blood pressures of approximately 60-70/30-40 mm Hg (mean arterial pressure [MAP] <45 mm Hg) for >90 minutes. He required high-dose norepinephrine and vasopressin infusions, as well as i.v. bolus doses of norepinephrine and vasopressin to reach a goal MAP> 60 mm Hg. There was minimal response to a 2 mg/kg i.v. bolus of methylene blue. Following the administration of 5 g of i.v.hydroxocobalamin, the patient had a profound improvement in arterial blood pressure, with subsequent discontinuation of the vasopressin infusion and rapid reduction of norepinephrine infusion from 20 to 2 µg/min. While there have been several reports of the efficacy of hydroxocobalamin for vasoplegia after cardiopulmonary bypass, there have been only limited cases of hydroxocobalamin used in liver transplantation, and none with high-dose administration. We present a case of vasoplegic syndrome during liver transplantation that was refractory to high-dose vasopressors and methylene blue but responsive to high-dose i.v. hydroxocobalamin.

Pirfenidone in restrictive allograft syndrome after lung transplantation: A case series.

Pirfenidone may attenuate the decline of pulmonary function in restrictive allograft syndrome (RAS) after lung transplantation. We retrospectively assessed all lung transplant recipients with RAS who were treated with pirfenidone for at least 3 months (n = 11) in our lung transplant center and report on their long-term outcomes following initiation of pirfenidone. Main outcome parameters included evolution of pulmonary function and overall survival. Pirfenidone appears to attenuate the decline in forced vital capacity and forced expiratory volume in 1 second. Notably, 3 patients were bridged to redo-transplantation with pirfenidone for 11 (5-12) months and are currently alive, while 3 other patients demonstrate long-term stabilization of pulmonary function after 26.6 (range 18.4-46.6) months of treatment. Median overall 3-year survival after RAS diagnosis was 54.5%. Subjective intolerance, mainly anorexia and nausea, necessitating pirfenidone dose de-escalation in 55% of patients, as well as calcineurin dose increase requirements with about 20% are important complications during pirfenidone treatment after lung transplantation. Our findings provide further evidence that pirfenidone appears to be safe and may attenuate the rate of decline in lung function in patients with RAS, but the actual clinical benefit cannot be assessed in the context of this study design and requires further investigation in a larger randomized trial.

Emergence of letermovir resistance in a lung transplant recipient with ganciclovir-resistant cytomegalovirus infection.

Following a year of valganciclovir prophylaxis, a lung transplant recipient developed cytomegalovirus (CMV) infection that became resistant to ganciclovir, as confirmed by detection of UL97 kinase mutation M460V and a previously uncharacterized UL54 DNA polymerase mutation L516P. The latter mutation is now shown to confer ganciclovir and cidofovir resistance. As predicted from the viral genotype, foscarnet therapy was effective, but resumption of valganciclovir as secondary prophylaxis resulted in a plasma viral load rebound to 3.6 log10 copies/mL several weeks later. Valganciclovir was then replaced by letermovir, resulting in gradual viral load reduction in the first 5 weeks to below the quantitation limit (2.7 log10 copies/mL) for 1 week, followed by 10 weeks of rising viral loads reaching 4.3 log10 copies/mL while on letermovir. At this point, CMV genotypic testing revealed UL56 mutation C325Y, which confers absolute resistance to letermovir. Retreatment with foscarnet was successful. This case adds to the considerable list of proven ganciclovir resistance mutations, and provides an early experience with letermovir resistance after off-label therapeutic use. This experience is consistent with in vitro observations of rapid emergence of letermovir-resistant CMV after drug exposure.