Sotorasib associated with tacrolimus and everolimus: A significant drug interaction in lung transplant patients

The management of immunosuppressors in solid organ transplantation requires pharmacological therapeutic monitoring with regular adaptation of the dosage to the residual level. An obvious cause of these fluctuations is drug interactions, particularly for mTOR inhibitors and anti-calcineurin drugs, which are highly metabolized by cytochromes P450.A 72-year-old lung transplanted man, treated by tacrolimus and everolimus in the long term, had his residual immunosuppressor levels unbalanced by the introduction of sotorasib, which is used for metastatic pulmonary adenocarcinoma. This imbalance is explained by the fact that sotorasib is an inducer of CYP3A4 and an inhibitor of PGP, but the strength of the interaction has never been studied. This will have required a threefold increase in dosages and weekly monitoring before satisfactory residual levels were achieved.     

Recommendations on the use of everolimus in lung transplantation

The antiproliferative effect of everolimus provides a therapeutic option in the immunosuppression therapy of lung transplantation, by reducing both the risk of acute rejection and the process of progressive fibrosis that determines chronic graft rejection. However, few data on the use of everolimus in lung transplantation have been published to date, and the specific indications of the drug, along with the most adequate time for its introduction or dosing, have not been defined yet.The aim of this article is to propose recommendations for the use of everolimus in lung transplant recipients, including indications, dosing schedules and the use of concomitant immunosuppression. This consensus document has been developed by experts of all the Spanish lung transplant groups from the review of the existing literature and the clinical experience.     

Conversion to everolimus in liver transplant patients with renal dysfunction

Calcineurin inhibitor (CNI) immunosuppressive therapy post-liver transplantation (OLT) is important to reduce graft rejection episodes. However, these drugs show important side effects, particularly renal dysfunction (RDF). Changing from CNI to a nonnephrotoxic drug, as mammalian target of rapamycin (mTOR) inhibitor may solve the problem. Our objective was to evaluate renal function (RF) among liver transplant patients initially receiving CNI, among whom the patients with RDF were converted completely or partially to an mTOR inhibitor like everolimus (EVE). We performed a prospective study in liver transplant patients from 2000 to 2009. Creatinine levels and creatinine clearances (Cockroft-Gault) expressed as mean values ± standard deviations were measured pre- and postswitch for comparisons using Wilcoxon nonparametric tests. Six patients were converted fully or partially to EVE. Their mean age at the moment of introducing the new therapy was 52.2 ± 13.6 years (range = 28-60). Immunosuppression time prior to switching from CNI to EVE was 23.8 ± 26.6 months (range = 6-70). Postconversion follow-up was 25.8 ± 16.5 months (range = 8-42). All patients showed improvement in RF. The creatinine level improvement was significant (P = .03) namely, from a mean of 2.26 ± 0.49 to 1.21 ± 0.57 mg/dL. Glomerular filtration rate improved from a mean of 40 ± 15.13 to 72.60 ± 17.3 mL/min/m² (P = .03). Conversion from CNI to EVE improved creatinine concentrations and creatinine clearances with long-term effects free of graft rejection.     

Thrombotic thrombocytopenic purpura associated with everolimus use in a renal transplant patient

Thrombotic microangiopathy (TMA) in renal transplantation (RTX) generally develops during treatment with calcineurin inhibitors. We present a RTX case that developed TMA under everolimus treatment. A 40-year-old woman received a kidney allograft from her 77-year-old mother. She initially received tacrolimus, mycophenolate mofetil and steroids. She was discharged with a creatinine level of 2.2 mg/dl after treatment for a cellular rejection attack within the first two weeks after transplantation. Later on, tacrolimus was replaced with everolimus. One year later, she presented with fever and increased creatinine level (4 mg/dl), anemia and thrombocytopenia. Her peripheral blood smear revealed signs of microangiopathic hemolysis. Bone marrow examination revealed an increased number of megakaryocytes. We diagnosed the case as TMA and initiated plasma exchange, I.V. pulse steroid treatment and stopped everolimus. This approach improved laboratory and clinic abnormalities. The development of TMA after treatment with everolimus and the exclusion of other possible causes suggested TMA associated with proliferating signal inhibitors (PSIs) in our case.     

A retrospective 12-month study of conversion to everolimus in lung transplant recipients

Background

Everolimus has potent antifibrotic effects that may potentially affect the clinical course of bronchiolitis obliterans syndrome (BOS) or provide nephroprotective immunosuppressive regimens for lung transplantation.

Methods

We retrospectively assessed the 12-month outcomes of the conversion to everolimus among lung recipients in six Spanish centers.

Results

From March 2005 to December 2007, 65 lung recipients who were at a mean posttransplantation time of 10.2 ± 7.9 months were converted to everolimus, mainly because of BOS (64.6%) or renal insufficiency (RI; 12.3%). The initial dose of everolimus was 1.9 ± 0.6 mg/d and the mean blood trough levels were stable over time (6.4 ± 2.8 ng/mL at 12 months). Conversion to everolimus allowed us to eliminate the calcineurin inhibitor (CNI) in 21% of patients. Among the overall population, the forced expiratory volume at 1 second (FEV₁) and renal function remained stable. Mean FEV₁ did not change among the 35 (81%) patients surviving BOS at 12 months: preconversion FEV₁: 1.449.5 ± 641.9 mL vs 12-month FEV₁: 1420.0 ± 734.6 mL (P = .866). There was a significant improvement in renal function among the RI patients with mean glomerular filtration rates of 42.2 ± 15.2 mL/min/1.73 m² (P = .043) at 6 and 44.4 ± 18.8 mL/min/1.73 m² at 12 months, (P = .063) and a decrease in the use of CNIs from 1% of RI patients preconversion to 57% at 6 and 75% at 12 months. With a mean of 8.1- months follow-up (range: 1–31.3) overall survival was 84.6% at 1 year and 50% at 22.3 months. Progressive BOS was the main cause of death. Reasons for everolimus discontinuation were patient death (n = 10), lack of efficacy (n = 4), gastrointestinal adverse events (n = 2), and edema (n = 2).

Conclusions

BOS and RI were the main indications for conversion to everolimus among lung recipients. Conversion to everolimus improved renal function among patients converted because of RI. The present results were inconclusive regarding effects of everolimus on BOS.     

Tolerability and steady-state pharmacokinetics of everolimus in maintenance renal transplant patients.

BACKGROUND: Current immunosuppressant regimens need to be improved to prevent acute and chronic graft rejection. The novel macrocyclic immunosuppressant everolimus (Certican, RAD) is currently in clinical development to address this issue. METHODS: The primary objective of this multicentre, randomized, double-blind, placebo-controlled, dose-escalating phase 1 study was to evaluate the safety and tolerability of everolimus at four dose levels (0.75, 2.5, 5 and 10 mg/day) in maintenance renal transplant patients receiving cyclosporin and steroids. The secondary objective was to assess the pharmacokinetic profile of two different formulations (capsule and tablet) of everolimus. RESULTS: Fifty-four subjects were randomized for 4 weeks treatment with everolimus (n = 44) or placebo (n = 10). Dose levels of everolimus between 0.75 and 5 mg daily were well tolerated, permitting dose escalation to the highest everolimus dose of 10 mg daily. At this dose, everolimus was associated with a higher incidence and severity of adverse events, most notably thrombocytopenia. Pharmacodynamic assessment showed a relationship between drug exposure and thrombocytopenia. Notable reversible elevations of cholesterol were also observed at the 10 mg/day dose. Other changes in laboratory evaluations, including triglycerides, were minor, reversible and did not appear to be dose dependent. The bioavailability of the tablet formulation was 2.6-fold higher compared with the capsule, with evidence for dose proportionality over the dose range tested. Within-subject pharmacokinetic variability was low (coefficient of variation: 10-19%); however, between-subject variability ranged from 34 to 60% for AUC and C(max). CONCLUSIONS: These results indicate that up to 5 mg/day everolimus results in a dose-proportional exposure, and is adequately well tolerated in renal transplant recipients receiving cyclosporin and steroids.     

De novo use of everolimus with elimination or minimization of cyclosporine in renal transplant recipients

Background

The purpose of two similarly designed multicenter, prospective, parallel-group, open-label studies was to evaluate early cyclosporine (CsA) elimination versus minimization from an everolimus-CsA-steroid regimen in de novo renal transplant patients.

Methods

Within 24 hours after transplantation, 170 renal transplant patients received everolimus (trough levels 3-8 ng/mL), CsA, and steroids. Those eligible (n = 114) were randomized (1:1) at 3 months to have CsA elimination by month 4 to 6 (±1 week) with everolimus trough levels maintained at 6 to 12 ng/mL or CsA minimization, until 12 months. The randomized population excluded those who discontinued the study prior to randomization due to adverse events, acute rejection episodes of Banff grade IIb/III, or worsening renal function during the month prior to randomization.

Results

At 12 months, the estimated glomerular filtration rate (Nankivell) with CsA elimination was noninferior versus CsA minimization (P < .0001, α-level 0.05; 90% confidence interval 0.6-8.5) by 7 mL/min/1.73 m² (noninferiority margin). Composite efficacy failure was comparable with CsA elimination and CsA minimization (18.9% and 17.5%, respectively, P = 1.000) and no graft loss or death was reported after randomization. Cytomegalovirus infections were rare under everolimus treatment, and no pneumonitis episode was reported.

Conclusion

In our selected randomized study population, immediate initiation of everolimus allowed CsA elimination. Renal function was stable on everolimus-based, CsA-free maintenance regimen without compromising efficacy.     

Malignancy development in lung transplant patients

Introduction

The most common neoplasias among transplant patients are skin cancers and lymphoproliferative disorders.

Objective

To characterize lung transplanted recipients who developed malignancies.

Methods

A retrospective analysis of clinical records of our patients.

Results

Seven patients developed malignancies: skin cancer (n = 5; 71%), and adenocarcinomas of prostatic, gastric, and lung (n = 1 each). One patient developed two hematologic malignancies: T-cell lymphoma and multiple myeloma. Among five patients who died (71%), 3 were due to advanced neoplasia. The mean presentation time was 4.3 years. Skin cancers were resected. The patient with lung adenocarcinoma developed pleural involvement and died. The patient with T-cell lymphoma was treated, but succumbed afterward due to multiple myeloma. The patient with gastric adenocarcinoma died at 3 months after the diagnosis, and the patient with prostate cancer underwent surgery without disease recurrence.

Conclusion

Malignancies are a late complication of transplant recipients that require a prompt diagnosis and treatment to improve outcomes.     

Use of everolimus as a rescue immunosuppressive therapy in liver transplant patients with neoplasms

Everolimus is a new immunosuppressant with antitumoral properties and few side effects, but limited use in liver transplantation. The aim of the present study was to evaluate the effect on survival and safety of everolimus in post liver transplantation neoplasms in a single center. Ten liver transplant recipients with a posttransplant diagnosis of neoplasm received everolimus during a median of 12.7 (5.5-27.5) months; median survival was 21.3 (7.5-40.5) months. The probability of survival of everolimus group was significantly greater than the observed in a historical cohort of 14 liver recipients with comparable tumors who did not receive everolimus (100%, 90%, 72% vs. 50%, 29%, 14%) at 6, 12, and 24 months, respectively (HR=4.6, 95% confidence interval: 1.3-16.4; P=0.008). During everolimus therapy no patients showed rejection. Renal function improved in three patients. Furthermore, severe adverse effects and infections were infrequent. In summary, everolimus seems safe for liver transplant recipients with cancer and may improve short-term survival, but further studies are needed to determine long-term benefits and safety.     

高危患者肾移植长期存活的临床经验

目的 总结高危肾移植的临床经验,寻找提高长期存活率的方法.方法 将1991年4月至2008年12月我院治疗的921例高危.肾移植病例分为儿童组(34例)、再次移植(再植)组(169例)、高敏组(35例)、高龄组(297例)、糖尿病组(112例)和肝炎病毒感染或携带(肝炎)组(274例),并以807例普通肾移植受者作为对照组,对受者和移植.肾(人/肾)存活率、急性和慢性排斥反应(AR/CR)以及并发症的发生率进行回顾性分析.结果 再植组、高敏组以及肝炎组人/肾存活率均低于对照组(P＜0.05);高龄组仅患者生存率低于对照组(P＜0.05).同对照组相比,儿童组和高敏组等免疫性高危受者AR/CR发生率高(P＜0.05);高龄组、精尿病组以及肝炎组等非免疫性高危受者并发症的种类多,且发病率高.结论 减少AR发生,有利于提高免疫性高危患者的长期存活率;降低并发症发生率,有利于提高非免疫性高危患者的长期存活率.     

Long-term outcomes of sensitized lung transplant recipients after peri-operative desensitization

The Toronto Lung Transplant Program has been using a peri-operative desensitization regimen of plasma exchange, intravenous immune globulin, and antithymocyte globulin in order to accept donor-specific antibody (DSA)-positive lung transplants safely since 2008. There are no long-term data on the impact of this practice on allograft survival or the development of chronic lung allograft dysfunction (CLAD). We extended our prior study to include long-term follow-up of 340 patients who received lung transplants between January 1, 2008 and December 31, 2011. We compared allograft survival and CLAD-free survival among patients in three cohorts: DSA-positive, panel reactive antibody (PRA)-positive/DSA-negative, and unsensitized at the time of transplant. The median follow-up time in this extension study was 6.7 years. Among DSA-positive, PRA-positive/DSA-negative, and unsensitized patients, the median allograft survival was 8.4, 7.9, and 5.8 years, respectively (p = .5908), and the median CLAD-free survival was 6.8, 7.3, and 5.7 years, respectively (p = .5448). This follow-up study confirms that long-term allograft survival and CLAD-free survival of patients who undergo DSA-positive lung transplants with the use of our protocol do not differ from other lung transplant recipients. Use of protocols such as ours, therefore, may improve access to transplant for sensitized candidates.     

Long-term renoprotective effect of candesartan in renal transplant patients

Background

The renoprotective effects of angiotensin II type 1 receptor blockers (ARBs) have been demonstrated in a number of clinical studies, but there are few evaluations of long-term ARB treatment. We measured blood pressure, urine protein, and estimated glomerular filtration rate (eGFR) among patients under long-term (up to 9 years) treatment with candesartan cilexetil to evaluate its safety and effectiveness to protect renal graft function.

Methods

This study of 41 patients (31 male and 10 female) who presented with proteinuria and hypertension (blood pressure >140/90 mm Hg) after receiving a renal graft. Their serum creatinine level at baseline was 1.51 ± 0.53 mg/dL. Cyclosporine or tacrolimus were concomitantly prescribed for 18 (43.9%) and 22 (53.7%) subjects, respectively. The ARB treatment period was ≥12 months (up to 9 years, mean 4.8 years). Combination with other antihypertensive drugs (calcium antagonists) was necessary in 14/41 subjects (34.1%).

Results

Significant declines in blood pressure were observed during the treatment period; blood pressure reduction target (blood pressure <130/80 mm Hg) was met in 56.1% for systolic and 68.3% for diastolic pressure. No significant increase in serum creatinine level or eGFR was observed. Urinary protein was reduced to negative or marginal in 63.4% of the subjects, demonstrating a significant decrease.

Conclusions

Candesartan cilexetil was considered to be safe even for long-term treatment in renal transplant patients, and effective to protect renal graft function.     

Efficacy and safety of sirolimus and everolimus in heart transplant patients: a retrospective analysis

Background

Since its introduction as an immunosuppressant in the late 1990s, sirolimus (SRL) has been used to prevent rejections after heart transplantation (HTx) in the United States. An analogue, everolimus (ERL) has been mainly used in Europe. We performed a retrospective longitudinal single-center study to evaluate efficacy and side effects of SRL and ERL.

Patients and Methods

We analyzed 71 patients, 39 in the SRL and 32 in the ERL group. The following data were collected: Trough levels of SRL and ERL, biopsy-proven rejections, renal function, blood lipids, hematology, blood pressure, pulse rate, and side effects (via an anonymous questionnaire). Follow-up time was 6 months. No prisoners or organs from prisoners were used in the study.

Results

Introduction of SRL or ERL into therapy took place 44 or 42 months (average) after HTx. SRL and ERL were equally effective in preventing rejection (8/39 versus 6/32). Hemoglobin levels decreased slightly in the SRL group (nonsignificant). Leucocytes and thrombocyte levels decreased in both groups (P < .05 only in the ERL group). Creatinine levels remained unchanged. Cholesterol and triglyceride levels increased significantly in the SRL group. High-density lipoprotein levels increased significantly in the ERL group. Vital signs remained stable in both groups. Side effects (mainly edema, gastrointestinal symptoms and infections) were considerable and prompted discontinuation in 39% of all patients in both groups. Infections were more frequent in SRL (18/39 versus 12/32, nonsignificant). Calcineurin therapy could be reduced by 25% in SRL and 45% in ERL.

Conclusion

The impact of SRL and ERL on laboratory values and rejection rates, as well as on clinical parameters, is similar with a slight advantage to ERL regarding lipids and rate of infections (not significant). Both SRL and ERL allow an important reduction of calcineurin-therapy; however, both drugs have considerable side effects, which often require discontinuation of therapy.     

Long-term survival in lung transplant recipients after successful preoperative coronary revascularization

OBJECTIVE: Coronary artery disease is considered a contraindication to lung transplantation. We studied effect of pre-lung transplantation nonobstructive coronary artery disease and revascularized coronary artery disease on long-term lung transplant survival. METHODS: Clinical courses of 172 lung transplant recipients from December 1990 to May 2003 were reviewed. Significant coronary artery disease, defined as left main stenosis of greater than 50% or other epicardial vessel stenosis of greater than 70%, was present in 7 patients; 6 received percutaneous coronary intervention and 1 received coronary artery bypass grafting before transplantation. RESULTS: Groups were similar with regard to sex, race, or length of intensive care days. The group with normal coronary arteries was significantly younger than the groups with coronary artery disease. The revascularized group had a significant increase in dysrhythmias (P < .003) and 1-, 3-, and 5-year survivals of 85%, 85%, and 69%, respectively. Those with insignificant coronary artery disease (14 patients) demonstrated a 1-, 3-, and 5-year survival of 64%, 40%, and 32%, respectively. The normal coronary group (151 patients) had a 1-, 3-, and 5-year survival of 75%, 58%, and 40%, respectively. The revascularized group had a significant survival advantage compared with that of the insignificant coronary artery disease group (P < .04, log-rank test). CONCLUSION: Long-term survival of lung transplant recipients with revascularized coronary arteries is similar to that of subjects with normal coronary arteries, despite an increased incidence of dysrhythmias. Lung transplant recipients with insignificant coronary artery disease had a worse survival than the revascularized group. More studies are needed to ascertain the cause and determine the optimal management for lung transplant recipients with insignificant coronary artery disease.