A Phase I Study Evaluating the Effect of Everolimus on the Pharmacokinetics of Midazolam in Healthy Subjects

An Open-Label Study to Evaluate the Effect of Eluxadoline on the Single-Dose Pharmacokinetics of Midazolam in Healthy Participants

Eluxadoline is a mixed μ-opioid, κ-opioid receptor agonist, and δ-opioid receptor antagonist, approved in the United States for adults with diarrhea-predominant irritable bowel syndrome. This phase 1, single-center, open-label, single-sequence study was conducted on 30 healthy participants to establish whether steady-state eluxadoline increases systemic exposure of the cytochrome P450 (CYP) 3A4 substrate midazolam. Participants received oral midazolam 4 mg on day 1 with a 7-day washout period. On days 8-16, oral eluxadoline 100 mg was administered twice daily. On day 15, midazolam 4 mg was coadministered with the eluxadoline 100-mg morning dose. Primary outcome measures were pharmacokinetic parameters of midazolam and 1-hydroxy-midazolam. The midazolam and 1-hydroxy-midazolam geometric mean ratios and 90%CIs for maximum plasma drug concentration were 99.0% (91.6-107.0) and 113.8% (104.9-123.5), respectively, and area under the plasma concentration-time curves were 90.5% (83.9-97.6) and 105.1% (99.8-110.7), respectively, demonstrating the 2 treatments were bioequivalent, and there was no clinically significant drug interaction. All treatment-emergent adverse events were treatment related, mild in intensity, with no serious adverse events. These results suggest that eluxadoline has no clinically significant effect on CYP3A4 activity and is, therefore, unlikely to affect the pharmacokinetics of other CYP3A4 substrates.

Phase I study of ribociclib and everolimus in children with newly diagnosed DIPG and high-grade glioma: A CONNECT pediatric neuro-oncology consortium report

Background

Genomic aberrations in the cell cycle and PI3K/Akt/mTOR pathways have been reported in diffuse intrinsic pontine glioma (DIPG) and high-grade glioma (HGG). Dual inhibition of CDK4/6 and mTOR has biologic rationale and minimal overlapping toxicities. This study determined the recommended phase 2 dose (RP2D) of ribociclib and everolimus following radiotherapy in children with DIPG and HGG.

Methods

Patients were enrolled according to a Rolling-6 design and received ribociclib and everolimus once daily for 21 and 28 days, respectively. All patients with HGG and biopsied DIPG were screened for retinoblastoma protein presence by immunohistochemistry. Pharmacokinetics were analyzed.

Results

Nineteen patients enrolled (median age: 8 years [range: 2-18]). Three patients enrolled at each dose level 1 and 2 without dose-limiting toxicities (DLT). Thirteen patients were enrolled at dose level 3, with one patient experiencing a DLT (grade 3 infection). One patient came off therapy before cycle 9 due to cardiac toxicity. The most common grade 3/4 toxicities were neutropenia (33%), leucopenia (17%), and lymphopenia (11%). Steady-state everolimus exposures in combination were 1.9 ± 0.9-fold higher than single-agent administration. Median overall survival for 15 patients with DIPG was 13.9 months; median event-free survival for four patients with HGG was 10.5 months. Two longer survivors had tumor molecular profiling identifying CDKN2A/B deletion and CDK4 overexpression.

Conclusion

The combination of ribociclib and everolimus following radiotherapy in children with newly diagnosed DIPG and HGG was well tolerated, with a RP2D of ribociclib 170 mg/m² and everolimus 1.5 mg/m². Results will inform a molecularly guided phase II study underway to evaluate efficacy.

Not your usual drug-drug interactions: Monoclonal antibody-based therapeutics may interact with antiseizure medications

Therapeutic monoclonal antibodies (mAbs) have emerged as the fastest growing drug class. As such, mAbs are increasingly being co-prescribed with other drugs, including antiseizure medications (ASMs). Although mAbs do not share direct targets or mechanisms of disposition with small-molecule drugs (SMDs), combining therapeutics of both types can increase the risk of adverse effects and treatment failure. The primary goal of this literature review was identifying mAb-ASM combinations requiring the attention of professionals who are treating patients with epilepsy. Systematic PubMed and Embase searches (1980-2021) were performed for terms relating to mAbs, ASMs, drug interactions, and their combinations. Additional information was obtained from documents from the US Food and Drug Administration (FDA) and the European Medicines Agency (EMA). Evidence was critically appraised - key issues calling for clinicians' consideration and important knowledge gaps were identified, and practice recommendations were developed by a group of pharmacists and epileptologists. The majority of interactions were attributed to the indirect effects of cytokine-modulating antibodies on drug metabolism. Conversely, strong inhibitors or inducers of drug-metabolizing enzymes or drug transporters could potentially interact with the cytotoxic payload of antibody-drug conjugates, and ASMs could alter mAb biodistribution. In addition, mAbs could potentiate adverse ASM effects. Unfortunately, few studies involved ASMs, requiring the formulation of class-based recommendations. Based on the current literature, most mAb-ASM interactions do not warrant special precautions. However, specific combinations should preferably be avoided, whereas others require monitoring and potentially adjustment of the ASM doses. Reduced drug efficacy or adverse effects could manifest days to weeks after mAb treatment onset or discontinuation, complicating the implication of drug interactions in potentially deleterious outcomes. Prescribers who treat patients with epilepsy should be familiar with mAb pharmacology to better anticipate potential mAb-ASM interactions and avoid toxicity, loss of seizure control, or impaired efficacy of mAb treatment.

Effects of Repeated Oral Administration of Esaxerenone on the Pharmacokinetics of Midazolam in Healthy Japanese Males

BACKGROUND AND OBJECTIVE

Esaxerenone showed the potential to inhibit and induce activity against cytochrome P450 (CYP) 3A in in vitro studies. We investigated whether repeated administration of 5 mg/day esaxerenone for 14 days influences the pharmacokinetics of midazolam, a sensitive CYP3A substrate, in healthy Japanese males.

METHODS

This single-centre, open-label, single-sequence study had two administration periods: period 1: single oral dose of 2 mg midazolam (day 0); period 2: repeated oral doses of 5 mg/day esaxerenone for 14 days, with a single oral dose of 2 mg midazolam on day 14. Full pharmacokinetic profiles of midazolam and 1-hydroxymidazolam on days 0 and 14 and safety data were obtained. Primary pharmacokinetic endpoints for midazolam were area under the plasma concentration-time curve (AUC) from zero to time of the last measurable concentration (AUC_last), AUC from zero to infinity (AUC_inf), and peak plasma concentration (C_max).

RESULTS

The study included 28 male subjects. One subject was withdrawn because of a mild adverse event (increased hepatic enzyme levels) that resolved without intervention. Repeated administration of esaxerenone increased midazolam AUC_last, AUC_inf, and C_max by about 1.2-fold (1.201, 1.201, and 1.224, respectively) compared with administration of midazolam alone. However, repeated administration of esaxerenone did not affect the elimination half-life of midazolam (2.86 versus 2.63 h with and without esaxerenone). There were no safety concerns associated with concomitant administration of esaxerenone and midazolam.

CONCLUSIONS

Esaxerenone 5 mg/day had no clinically significant effect on midazolam pharmacokinetics and was not associated with any safety issues. Esaxerenone can be concomitantly administered with drugs of CYP3A substrates without dose adjustments.

CLINICAL TRIAL REGISTRATION

JapiCTI-152832.

A Phase I and Surgical Study of Ribociclib and Everolimus in Children with Recurrent or Refractory Malignant Brain Tumors: A Pediatric Brain Tumor Consortium Study

PURPOSE

Genomic aberrations in cell cycle and PI3K pathways are commonly observed in pediatric brain tumors. This study determined the MTD/recommended phase II dose (RP2D) of ribociclib and everolimus and characterized single-agent ribociclib concentrations in plasma and tumor in children undergoing resection.

PATIENTS AND METHODS

Patients were enrolled in the phase I study according to a rolling 6 design and received ribociclib and everolimus daily for 21 and 28 days, respectively. Surgical patients received ribociclib at the pediatric RP2D (350 mg/m2) for 7-10 days preoperatively followed by enrollment on the phase I study. Pharmacokinetics were analyzed for both cohorts.

RESULTS

Sixteen patients were enrolled on the phase I study (median age, 10.3 years; range, 3.9-20.4) and 6 patients in the surgical cohort (median age, 11.4 years; range: 7.2-17.1). Thirteen patients were enrolled at dose level 1 without dose-limiting toxicities (DLT). Two of the 3 patients at dose level 2 experienced DLTs (grade 3 hypertension and grade 4 alanine aminotransferase). The most common grade 3/4 toxicities were lymphopenia, neutropenia, and leukopenia. The RP2D of ribociclib and everolimus was 120 and 1.2 mg/m2 for 21 and 28 days, respectively. Steady-state everolimus exposures with ribociclib were 2.5-fold higher than everolimus administered alone. Ribociclib plasma, tumor concentrations, and cerebrospinal fluid (CSF) samples were collected. The mean tumor-to-plasma ratio of ribociclib was 19.8 (range, 2.22-53.4).

CONCLUSIONS

Ribociclib and everolimus were well-tolerated and demonstrated pharmacokinetic properties similar to those in adults. Potential therapeutic ribociclib concentrations could be achieved in CSF and tumor tissue, although interpatient variability was observed.

Model-based assessment of pharmacokinetic changes of sunitinib, tacrolimus, and everolimus in a patient with metastatic renal cell carcinoma after renal transplantation

The safety of the coadministration of sunitinib with tacrolimus and everolimus with regard to therapeutic drug monitoring has not been demonstrated. Here, we report a patient who showed high sunitinib concentrations, in addition to pharmacokinetic changes in tacrolimus and everolimus after sunitinib therapy. A living-donor renal transplant patient treated with tacrolimus and everolimus was diagnosed with pulmonary and pleural metastases of renal cell carcinoma. The patient received sunitinib therapy (37.5 mg/day, 2 weeks on and 1 week off). This patient exhibited a high total sunitinib concentration (sunitinib, 105.8 ng/mL; N-desethyl sunitinib, 27.9 ng/mL) on day 10 postinitiation and experienced grade 3 diarrhea. The observed sunitinib concentrations were a little higher than those reported in the 421C>A polymorphism of the ATP-binding cassette subfamily G member 2 gene carrier. The observed concentrations of both tacrolimus and everolimus gradually decreased compared with the Bayesian-predicted values after the onset of sunitinib therapy, and the doses of tacrolimus and everolimus were increased. Careful therapeutic drug monitoring of sunitinib, tacrolimus, and everolimus concentrations is necessary during combination therapy, especially after episodes of diarrhea.

Potential drug-drug interactions associated with drugs currently proposed for COVID-19 treatment in patients receiving other treatments

Patients with COVID-19 are sometimes already being treated for one or more other chronic conditions, especially if they are elderly. Introducing a treatment against COVID-19, either on an outpatient basis or during hospitalization for more severe cases, raises the question of potential drug-drug interactions. Here, we analyzed the potential or proven risk of the co-administration of drugs used for the most common chronic diseases and those currently offered as treatment or undergoing therapeutic trials for COVID-19. Practical recommendations are offered, where possible.

Pharmacologic Treatment of Transplant Recipients Infected With SARS-CoV-2: Considerations Regarding Therapeutic Drug Monitoring and Drug-Drug Interactions

COVID-19 is a novel infectious disease caused by the severe acute respiratory distress (SARS)-coronavirus-2 (SARS-CoV-2). Several therapeutic options are currently emerging but none with universal consensus or proven efficacy. Solid organ transplant recipients are perceived to be at increased risk of severe COVID-19 because of their immunosuppressed conditions due to chronic use of immunosuppressive drugs (ISDs). It is therefore likely that solid organ transplant recipients will be treated with these experimental antivirals.

Preincubation With Everolimus and Sirolimus Reduces Organic Anion-Transporting Polypeptide (OATP)1B1- and 1B3-Mediated Transport Independently of mTOR Kinase Inhibition: Implication in Assessing OATP1B1- and OATP1B3-Mediated Drug-Drug Interactions

Organic anion transporting polypeptides (OATP)1B1 and OATP1B3 mediate hepatic uptake of many drugs including lipid-lowering statins. Current studies determined the OATP1B1/1B3-mediated drug-drug interaction (DDI) potential of mammalian target of rapamycin (mTOR) inhibitors, everolimus and sirolimus, using R-value and physiologically based pharmacokinetic models. Preincubation with everolimus and sirolimus significantly decreased OATP1B1/1B3-mediated transport even after washing and decreased inhibition constant values up to 8.3- and 2.9-fold for OATP1B1 and both 2.7-fold for OATP1B3, respectively. R-values of everolimus, but not sirolimus, were greater than the FDA-recommended cutoff value of 1.1. Physiologically based pharmacokinetic models predict that everolimus and sirolimus have low OATP1B1/1B3-mediated DDI potential against pravastatin. OATP1B1/1B3-mediated transport was not affected by preincubation with INK-128 (10 μM, 1 h), which does however abolish mTOR kinase activity. The preincubation effects of everolimus and sirolimus on OATP1B1/1B3-mediated transport were similar in cells before preincubation with vehicle control or INK-128, suggesting that inhibition of mTOR activity is not a prerequisite for the preincubation effects observed for everolimus and sirolimus. Nine potential phosphorylation sites of OATP1B1 were identified by phosphoproteomics; none of these are the predicted mTOR phosphorylation sites. We report the everolimus/sirolimus-preincubation-induced inhibitory effects on OATP1B1/1B3 and relatively low OATP1B1/1B3-mediated DDI potential of everolimus and sirolimus.

Glycyrrhizin accelerates the metabolism of triptolide through induction of CYP3A in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Triptolide (TP), a major active component of Tripterygium wilfordii, possesses various pharmacological activities with narrow therapeutic window and severe toxicities. Glycyrrhizin (GL), the principal bioactive ingredient of licorice root extract, has been reported to be concomitantly administered with TP in treatment of rheumatoid arthritis with the aim of potentiated efficacy and reduced toxicity. The aim of the study is to investigate the effect of GL on the pharmacokinetic profiles of TP and related mechanisms.

MATERIALS AND METHODS

Male and female Wistar rats were randomly divided into two groups: Control group and GL group (pretreated with GL at 100 mg/kg/day for seven consecutive days). After oral administration of TP at a single dose of 450 μg/kg, plasma concentrations of TP were determined using HPLC-MS/MS and pharmacokinetic parameters were calculated by non-compartmental analysis using Phoenix WinNonlin 6.3 software. Since CYP3A is the primary isoform of cytochrome P450s responsible for the metabolism of TP, we further determined to what extent ketoconazole (KCZ), a potent CYP3A inhibitor, could influence the effect of GL on the pharmacokinetics of TP by comparing the pharmacokinetic profiles of TP in GL group (pretreated with GL) and GL+KCZ group (pretreated with both GL and KCZ), as well as verified whether pretreatment of GL could induce the activity of hepatic CYP3A by comparing the AUC parameters after intravenous administration of midazolam (MDZ), a typical probe drug for CYP3A, in rats pretreated with vehicle or GL.

RESULTS

Our study revealed marked differences in pharmacokinetic profiling patterns of TP between male and female rats in the Control group; the plasma level of TP in males was far lower than that in females. After pretreatment with GL, the pharmacokinetic profiles of TP were significantly altered in both male and female rats; a remarkable decrease was found in the value of AUC∞, MRT∞ and t1/2 in the GL group, compared with the Control group. But such a decrease was reversed by KCZ; compared with the GL group, the values of AUC∞, MRT∞ and t1/2 were significantly increased in the GL+KCZ group. Pretreatment with GL notably increased the AUC∞ of 1׳-hydroxymidazolam (OH-MDZ) and the ratio of AUC∞ of OH-MDZ to MDZ, demonstrating induction of the activity of CYP3A by GL.

CONCLUSION

Pretreatment with GL significantly accelerates the metabolic elimination of TP from the body mainly through induction of hepatic CYP3A activity. These results may help explain why toxicity of TP may be attenuated with concomitant use of GL.

Relationship between everolimus exposure and safety and efficacy: meta-analysis of clinical trials in oncology

BACKGROUND

In patients with solid tumours, daily everolimus dosing demonstrated dose proportionality and linear pharmacokinetics. A meta-analysis was conducted to characterise the relationship between everolimus Cmin and efficacy and safety and the effect of CYP3A4 and P-glycoprotein (PgP) substrate/inhibitor/inducer coadministration on everolimus trough concentration (Cmin).

METHODS

Individual patient data from five phase 2/3 studies, in which steady state, predose pharmacokinetic samples were taken from patients with solid tumours administered everolimus 10mg/day, were pooled.

FINDINGS

Efficacy and safety were evaluable for 945 and 938 patients, respectively. A 2-fold increase in everolimus Cmin increased the likelihood of tumour size reduction (odds ratio 1.40, 95% confidence interval (CI) 1.23-1.60), was associated with a trend for reduced risk of progression-free survival events (risk ratio [RR] 0.90, 95% CI 0.69-1.18) and increased the risk of grade ⩾3 pulmonary (RR 1.93, 95% CI 1.12-3.34), stomatitis (RR 1.49, 95% CI 1.05-2.10) and metabolic (RR 1.30, 95% CI 1.02-1.65) events. Coadministering everolimus with strong CYP3A4 and PgP inhibitors increased everolimus Cmin by 10% and 20%, respectively; coadministration with CYP3A4 inducers reduced Cmin by 7%.

INTERPRETATION

A 2-fold increase in everolimus Cmin was associated with improved tumour size reduction and increased risk of high-grade pulmonary, metabolic and stomatitis events.

FUNDING

Novartis Pharmaceuticals Corporation.