Generic immunosuppressants

Impact of varied immunosuppressive agents and posttransplant diabetes mellitus on prognosis among diverse transplant recipients (Experimental studies)

The success of solid organ transplantation (SOT) and the use of immunosuppressive agents offer hope to patients with end-stage diseases. However, the impact of posttransplant diabetes mellitus (PTDM) on SOT patients has become increasingly evident. In our study, we utilized the Scientific Registry of Transplant Recipients (SRTR) database to investigate the association between PTDM and patient survival in various types of organ transplantations, including liver, kidney, intestinal, heart, lung, and combined heart-lung transplantations (all P<0.001). Our findings revealed a negative effect of PTDM on the survival of these patients. Furthermore, we examined the effects of both generic and innovator immunosuppressive agents on the development of PTDM and the overall survival of different SOT populations. Interestingly, the results were inconsistent, indicating that the impact of these agents may vary depending on the specific type of transplantation and patient population. Overall, our study provides a comprehensive and systematic assessment of the effects of different immunosuppressive agents on prognosis, as well as the impact of PTDM on the survival of patients undergoing various types of SOT. These findings emphasize the need for further research and highlight the importance of optimizing immunosuppressive regimens and managing PTDM in SOT patients to improve their long-term outcomes.

Comparative safety of generic versus brand calcineurin inhibitors in solid organ transplant patients: a systematic review and meta-analysis

BACKGROUND

Although generic ciclosporin-A (CsA) and tacrolimus (TAC) have been used for the prophylaxis of organ rejection in transplant patients for decades, evidence in their safety profile compared to reference listed drugs (RLDs) in real-world transplant patients remains limited.

OBJECTIVES

To compare safety outcomes of generic CsA and TAC with the reference-listed drugs in solid organ transplant patients.

METHODS

We systematically searched MEDLINE, International Pharmaceutical Abstracts, PsycINFO, and Cumulative Index of Nursing and Allied Health Literature from inception until March 15, 2022, to select randomized and observational studies comparing safety profiles of generic versus brand CsA and TAC in de novo and/or stable solid organ transplant patients. Primary safety outcomes were changes in serum creatinine (Scr) and glomerular filtration rate (GFR). Secondary outcomes included incidences of infection, hypertension, diabetes, other serious adverse events (AEs), hospitalization, and death. Mean difference (MD) and relative risk (RR) with 95% confidence intervals (CIs) were calculated using random-effects meta-analyses.

RESULTS

Of 2612 publications identified, 32 studies met inclusion criteria. Seventeen studies had a moderate risk of bias. Scr was statistically significantly lower in patients using generic CsA compared to brand at 1 month (MD = -0.07; 95% CI: -0.11, -0.04), while there were no statistically significant differences at 4 months, 6 months, and 12 months. No differences were detected in Scr (MD = -0.04; 95% CI: -0.13, 0.04) and estimated GFR (MD = -2.06; 95% CI: -8.89, 4.77) between patients using generic and brand TAC at 6 months. No statistically significant differences between generic CsA and TAC with their RLDs were observed for secondary outcomes.

CONCLUSION

Findings support similarity in safety outcomes between generic and brand CsA and TAC in real-world solid organ transplant patients.

Biomaterial-based immunotherapeutic strategies for rheumatoid arthritis

Rheumatoid arthritis (RA) is an extremely painful autoimmune disease characterized by chronic joint inflammation leading to the erosion of adjacent cartilage and bone. Rheumatoid arthritis pathology is primarily driven by inappropriate infiltration and activation of immune cells within the synovium of the joint. There is no cure for RA. As such, manifestation of symptoms entails lifelong management via various therapies that aim to generally dampen the immune system or impede the function of immune mediators. However, these treatment strategies lead to adverse effects such as toxicity, general immunosuppression, and increased risk of infection. In pursuit of safer and more efficacious therapies, many emerging biomaterial-based strategies are being developed to improve payload delivery, specific targeting, and dose efficacy, and to mitigate adverse reactions and toxicity. In this review, we highlight biomaterial-based approaches that are currently under investigation to circumvent the limitations of conventional RA treatments.

A review on the effect of prolyl isomerization on immune response aberration and hypersensitivity reactions: A unifying hypothesis

Little is known about the causes and mechanisms of ectopic immune responses, including different types of hypersensitivity, superantigens, and cytokine storms. Two of the most questionable phenomena observed in immunology are why the intensity and extent of immune responses to different antigens are different, and why some self-antigens are attacked as foreign. The secondary structure of the peptides involved in the immune system, such as the epitope-paratope interfaces plays a pivotal role in the resulting immune responses. Prolyl cis/trans isomerization plays a fundamental role in the form of the secondary structure and the folding of proteins. This review covers some of the emerging evidence indicating the impact of prolyl isomerization on protein conformation, aberration of immune responses, and the development of hypersensitivity reactions.

Utility, promise, and limitations of liquid chromatography-mass spectrometry-based therapeutic drug monitoring in precision medicine

Therapeutic drug monitoring (TDM) is typically referred to as the measurement of the concentration of drugs in patient blood. Although in the past, TDM was restricted to drugs with a narrow therapeutic range in order to avoid drug toxicity, TDM has recently become a major tool for precision medicine being applied to many more drugs. Through compensating for interindividual differences in a drug's pharmacokinetics, improved dosing of individual patients based on TDM ensures maximum drug effectiveness while minimizing side effects. This is especially relevant for individuals that present a particularly high intervariability in pharmacokinetics, such as newborns, or for critically/severely ill patients. In this article, we will review the applications for and limitations of TDM, discuss for which patients TDM is most beneficial and why, examine which techniques are being used for TDM, and demonstrate how mass spectrometry is increasingly becoming a reliable and convenient alternative for the TDM of different classes of drugs. We will also highlight the advances, challenges, and limitations of the existing repertoire of TDM methods and discuss future opportunities for TDM-based precision medicine.

Important considerations for drugs, nutritional, and herbal supplements in pediatric solid organ transplant recipients

Pediatric transplant recipients are on multiple prescription and non-prescription drugs. Many patients also use dietary, nutritional, and herbal supplements. This manuscript researched formulations of immunosuppressive drugs currently available and presents information on generic immunosuppressive drugs, commonly used non-prescription medications, dietary supplements, and herbal supplements. Immunosuppressive drugs are available in various formulations. Not all formulations are interchangeable. A number of FDA-approved generic formulations are available commercially in the United States. Generally generic formulations produce similar blood concentration vs time profiles compared to brand name products in adults and are considered to be bioequivalent. NSAID should be avoided in transplant patients due to potential drug interactions and increased risk associated with NSAID use; and appropriate doses of acetaminophen should be used for treatment of pain. Over-the-counter medications, such as guaifenesin and dextromethorphan, antihistamine medications, including diphenhydramine, loratadine, cetirizine, and fexofenadine, can be safely used in pediatric solid organ transplant population. Many safe and effective over-the-counter options exist for stool softening and as laxative. Diarrhea can lead to an increase in calcineurin inhibitor levels. Food can alter the absorption of immunosuppressive drugs. Several herbal products can alter immune status of the patients or alter the blood concentration of immunosuppressive drugs or may produce renal or hepatic toxicities and should be avoided in pediatric transplant recipients. It is important to educate pediatric transplant recipients and their families about not only immunosuppressive drug therapy but also about non-prescription drugs, dietary, and herbal supplement use.

Oral generic tacrolimus initiation and substitution in the Medicaid population: a new user cohort study

OBJECTIVE

Although existing studies have compared clinical efficacy and pharmacokinetics of generic with brand tacrolimus, little is known about generic tacrolimus utilization patterns or factors predicting generic substitution. This study examines associations between patient-level factors and generic tacrolimus initiation or substitution among new users of oral generic or brand-name tacrolimus.

METHODS

This new user retrospective cohort study identified 374 beneficiaries who initiated generic or brand tacrolimus treatment, using 100% Medicaid administrative claims data from 11 states in 2011-2012. Outcomes were generic tacrolimus initiation and substitution within 12 months of treatment initiation. Multivariable logistic regression and Cox proportional hazards models were used to identify factors associated with generic tacrolimus initiation and substitution.

RESULTS

Two-thirds of oral tacrolimus new users initiated generic tacrolimus. Patients who were older age and black were significantly more likely to initiate generic tacrolimus (adjusted odds ratio [AOR] = 1.02, 95% confidence interval [CI] = 1.001-1.03; AOR = 2.54, 95% CI = 1.40-4.62; respectively). Patients with more concomitant prescriptions, more comorbidities, or higher initial daily dosage had significantly lower likelihoods of initiating generic tacrolimus (AOR = 0.93, 95% CI = 0.87-0.99; AOR = 0.87, 95% CI = 0.77-0.99; AOR = 0.96, 95% CI = 0.93-0.993). Among brand tacrolimus new users, 23.6% substituted with generics within 12 months, and an addition of prior hospitalization or unit of initial daily dosage increment was associated with 35% (subdistribution hazard ratio [SHR] = 1.35, 95% CI = 1.02-1.76) or 2% (SHR = 1.02, 95% CI = 1.00-1.04) increase in likelihood of generic substitution, respectively.

CONCLUSIONS

Understanding associations between patient-level factors with generic tacrolimus initiation and substitution could help practitioners and policymakers monitor treatment effect and facilitate generic tacrolimus utilization.

Real-life Bioequivalence of Tacrolimus in Patients With Living-Related Donor De Novo Renal Transplantation: An Observational Study

Tacrolimus is a narrow therapeutic index drug. As a result, regulatory agencies worldwide recommend stringent bioequivalence evaluation criteria for approval of generics. Despite this, the professional transplantation societies have raised concerns over the safety and efficacy of generic substitutions. We conducted this pragmatic real-life bioequivalence study to assess the effect of generic substitutions of tacrolimus. This was an observational study including recipients of renal transplantation who were considered for generic medication substitution. Transplanted organs were from living-related donors and were performed at least 1 month before the study. Time of administration of the drug, time of dosing with respect to meals, and time of blood sample collection were controlled; however, the lot number of the generic drugs was not controlled. The participants were allowed to use their usual supplies irrespective of the lot number. Concentration (C₀) was quantified by liquid chromatography with tandem mass spectrometry after the generic substitution from ABC brand to XYZ brand. The average C₀ ± SD with generic ABC was 11.09 ± 4.26 ng/mL and generic ABC was 9.7 ± 4.12 ng/mL. Though there was no statistically significant difference observed between the concentrations, when the individual patient data was examined, 2 patients were found to have a very high concentration of tacrolimus and at least 7 patients fell below the therapeutic range. These derangements called for retitration with the new generic tacrolimus (40%). The results of our study suggest that generic-to-generic substitutions should be carried out very carefully in a closely observed setting in patients with renal transplants. The strength of our study is that it matched the real clinical practice setting as much as possible unlike a bioequivalence study. Therefore, we recommend repeating C₀ at least 3 times over a period of 7 to 10 days with a generic substitution to prevent untoward consequences.

Cyclosporine Broadens the Therapeutic Potential of Lenalidomide in Myeloid Malignancies

The immunomodulatory drug lenalidomide is used for the treatment of certain hematologic malignancies, including myelodysplastic syndromes (MDS). Lenalidomide interacts with cereblon (CRBN), a component of the CRL4CRBN E3 ubiquitin ligase complex, leading to ubiquitination and subsequent degradation of substrates, such as transcription factor Ikaros (Ikaros family zinc finger 1, IKZF1). With a genome loss of function screen, we recently identified two novel pathways mediated by lenalidomide in MDS. In this review, we summarized the major findings of these two pathways and their clinical implications. Depletion of G protein-coupled receptor 68 (GPR68) or an endogenous calcineurin (CaN) inhibitor, regulator of calcineurin 1 (RCAN1), reversed the inhibitory effect of lenalidomide on MDSL cells, an MDS cell line. Intriguingly, both GPR68 and RCAN1 expression levels were upregulated in MDSL cells after treatment with lenalidomide that was dependent on diminishment of IKZF1, indicating that IKZF1 functioned as a transcription repressor for GPR68 and RCAN1. Mechanistic studies revealed that upregulation or activation of GPR68 induced a Ca2+/calpain pro-apoptotic pathway, while upregulation of RCAN1 inhibited the CaN pro-survival pathway in MDSL cells. Notably, the pharmacological CaN inhibitor, cyclosporine, enhanced the sensitivity to lenalidomide in MDS as well as acute myeloid leukemia (AML). Surprisingly, pretreatment with lenalidomide reversed the immunosuppressive effects of cyclosporine on T lymphocytes. Our studies suggest that lenalidomide mediates degradation of IKZF1, leading to derepression of GPR68 and RCAN1 that activates the Ca2+/calpain pro- apoptotic pathway and inhibits the CaN pro-survival pathway, respectively. Our studies implicate that cyclosporine extends the therapeutic potential of lenalidomide to myeloid malignancies without compromising immune function.

Limited sampling strategy to predict the area under the curve of tacrolimus in Mexican renal transplant pediatric patients receiving Prograf® or non-innovator formulations

TDM of tacrolimus is usually performed with trough levels (C_0h ). However, in pediatric patients, C_0h may not be an adequate marker. The AUC is considered a more suitable indicator of drug exposure. As several blood samples are needed for the estimation of AUC, and LSS for predicting tacrolimus AUC and optimizing the dose adjustment have been proposed. Moreover, in emerging countries such as Mexico, non-innovator formulations, which bioequivalence has not been demonstrated, are frequently used. Hence, the aim of this study was to develop and validate a LSS to predict the tacrolimus AUC_0-12h in Mexican pediatric kidney transplant recipients who received either Prograf^® or non-innovator tacrolimus formulations. A total of 56 pharmacokinetic profiles were randomized into two groups: model development (n = 28) and model validation (n = 28). The limited sampling equations were obtained after a stepwise multiple regression using AUC as the dependent variable and tacrolimus blood concentrations, quantified by CMIA, at different time points as the independent variables. The final equation included observed concentrations at 1 hour (C_1h ) and 4 hours (C_4h ) after dose administration. The predictive performance of the model was adequate in terms of both, bias and precision. Results strongly suggest that the clinical use of this LSS could provide an ethical, cost-, and time-effective method in the TDM of tacrolimus in pediatric patients with kidney transplant. The model proved to be adequate with either Prograf^® or non-innovator tacrolimus formulations of dubious bioequivalence.

Changes in the commercial brand of tacrolimus lead to subtherapeutic trough levels and acute rejection in renal transplant recipients

BACKGROUND

The vigilance of tacrolimus (TAC) trough levels is an essential part of renal transplant follow up. Reduced TAC trough levels and high variability are related to adverse outcomes. The aim of this study was to evaluate the impact of brand changes on tacrolimus (TAC) subtherapeutic (SubT) trough levels, acute rejection (AR), and kidney function.

METHODS

This is a prospective, observational cohort study of renal transplant recipients, between January 2016 and October 2018. Tacrolimus trough levels and brand used by the patient were both registered at every consult. Tacrolimus values ≤3.5 ng/mL were considered SubT.

RESULTS

445 patients were included. The median number of TAC brand changes was 2 (IQR, 1-4). Patients were grouped according to the number of brand changes: Group 1 = 0 (n = 107), Group 2 = 1-4 (n = 236), and Group 3 = ≥5 (n = 102). Patients with the greatest number of brand changes had a greater proportion and number of SubT TAC trough levels (Group 1 = 36.4%, average 0.53; Group 2 = 39.8%, average 0.65, Group 3 = 59.8%, average 1.17, P < .001) and AR (Group 1 = 0.9%, Group 2 = 11%, Group 3 = 14.7%, P < .001). On multivariate analysis, SubT levels and the number of brand changes were related to AR.

CONCLUSIONS

In Mexico, changes in TAC brand are associated with an elevated frequency of SubT levels. Brand changes and SubT levels are independently associated with acute rejection. The supply policies on TAC brands in Mexico require revision to avoid changing brands as much as possible.

Acute Rejection Is a Strong Negative Predictor of Graft Survival in Living-Donor Pediatric Renal Transplant: 10-Year Follow-Up in a Single Mexican Center

OBJECTIVES

Kidney transplant is the optimal treatment for children with end-stage renal disease. Multiple factors affect patient and graft survival. We assessed determinants of long-term patient/graft survival in our center by a retrospective review of pediatric living donor (< 18 years) kidney transplants from February 2003 to December 2016.

MATERIALS AND METHODS

Donor and recipient demo-graphic data and immunosuppression use were gathered for analyses. Transplant outcomes included patient/graft survival, acute rejection, and 1-year estimated glomerular filtration rate. Patient/graft survival results were analyzed by Kaplan-Meier, and Cox proportional hazards regression model was used for risk factors (univariate/multivariate). P ≤ .05 was statistically significant.

RESULTS

Ninety-nine patients were included. Age was 13.4 ± 3.08 years, 64.6% were male, and 88.9% were on dialysis with time of 17.1 ± 12.6 months. Mean donor age was 36.6 ± 7.7 years, and most were females (63.6%). Donor estimated glomerular filtration rate was 89.4 ± 16.9 mL/min/1.73 m2. HLA match was 3.2 ± 1.05. Panel reactive antibody showed 8.6 ± 20.5%. Of total patients, 47.5% used induction, 88.9% used cyclo-sporine, and 100% used mycophenolate mofetil. Five- and 10-year patient survival rates were 93.2% and 93.2%. One-year acute rejection was 14.1%, with rate of 24.2% throughout follow-up. One-year estimated glomerular filtration rate was 76.4 ± 25.6 mL/min/1.73 m2. Five- and 10-year graft survival rates were 62.6% and 43.3%. Multivariate analysis confirmed donor age and acute rejection episodes throughout follow-up as risk factors for graft survival (P < .05).

CONCLUSIONS

Acute rejection and donor age are important risk factors for 10-year graft survival in living-donor pediatric kidney transplant in our program.

Clinical aspects of tacrolimus use in paediatric renal transplant recipients

The calcineurin inhibitor tacrolimus, cornerstone of most immunosuppressive regimens, is a drug with a narrow therapeutic window: underexposure can lead to allograft rejection and overexposure can result in an increased incidence of infections, toxicity and malignancies. Tacrolimus is metabolised in the liver and intestine by the cytochrome P450 3A (CYP3A) isoforms CYP3A4 and CYP3A5. This review focusses on the clinical aspects of tacrolimus pharmacodynamics, such as efficacy and toxicity. Factors affecting tacrolimus pharmacokinetics, including pharmacogenetics and the rationale for routine CYP3A5*1/*3 genotyping in prospective paediatric renal transplant recipients, are also reviewed. Therapeutic drug monitoring, including pre-dose concentrations and pharmacokinetic profiles with the available "reference values", are discussed. Factors contributing to high intra-patient variability in tacrolimus exposure and its impact on clinical outcome are also reviewed. Lastly, suggestions for future research and clinical perspectives are discussed.

Causes of renal oligohydramnios: impact on prenatal counseling and postnatal outcome

The presence of renal oligohydramnios (ROH) in a fetus has been associated in the past with a poor prognosis for survival, although recent studies have shown that survival has improved considerably due to the advances in neonatology and pediatric nephrology. In an article recently published in Pediatric Nephrology, evaluation of a large series by Mehler and colleagues confirms the improved prognosis, showing a survival rate of 32 of 38 (84%). In addition, only 12 of 35 (34%) neonates required renal replacement therapy. In five of these 12 children the dialysis could be terminated after the neonatal period. This study has important implications on the decision-making process and counseling of families. While 37% of families of the study opted for termination of pregnancies, palliative care was chosen by 8% of the families, representing an important option when a decision cannot be made rapidly by affected families. A multidisciplinary approach is not only necessary in the active treatment of neonates with a history of ROH but also in antenatal counseling. In this regard future efforts should establish consensus on an ethical framework for the decision-making process in ROH.