Pharmacokinetic Drug–Drug Interaction of Apalutamide, Part 2: Investigating Interaction Potential Using a Physiologically Based Pharmacokinetic Model

Real-world study: Impact of multidisciplinary management of apalutamide-associated adverse events in prostate cancer

OBJECTIVE

To analyse the adverse events (AEs) associated with apalutamide and the impact of a multidisciplinary team (MDT) protocol on its management at a tertiary care hospital in a real-world setting.

METHODS

This was an observational, prospective, cohort study based on real-world evidence at the Hospital Clínic de Barcelona. Includes patients diagnosed with metastatic hormone-sensitive prostate cancer (mHSPC) or high-risk nonmetastatic castration-resistant prostate cancer (nmCRPC) and who started treatment with apalutamide between May 2019 and March 2023 in a real-world clinical setting.

RESULTS

Of the 121 patients treated with apalutamide, 52.1% experienced an AE, 19.8% experienced temporarily interruption or a reduction in the dose of apalutamide, and 13.2% discontinued treatment due to AEs. Without MDT protocol (49 patients), 24.5% of patients had to temporarily interrupt or reduce the dose of apalutamide due to AEs, with a median time from the start of treatment of 10.1 months, and 24.5% discontinued apalutamide due to AEs, with a median time from the start of treatment of 3.1 months. Meanwhile, whit MDT protocol (72 patients), 16.7% of patients had to temporarily interrupt or reduce the dose of apalutamide due to AEs, with a median time from the start of treatment of 1.6 months, and 5.6% discontinued apalutamide due to AEs, with a median time from the start of treatment of 4 months. The risk reduction associated with treatment discontinuation was statistically significant (p-value = 0.003).

CONCLUSIONS

This study highlights the importance of MDT management of AEs associated with apalutamide to reduce treatment discontinuation.

Review of drug-drug interactions in patients with prostate cancer

OBJECTIVE

The objective of this review is to provide an overview of common drug-drug interactions (DDIs) associated with prostate cancer treatments and outline recommendations for managing polypharmacy.

DATA SOURCES

A literature search of PubMed, Embase, and CINAHL was carried out to identify pharmacokinetic and pharmacodynamic changes caused by DDIs that are relevant for prostate cancer patients, DDIs between prostate cancer therapies and co-administered medications (both prescription and over-the-counter), and measures to prevent DDIs. Medication package inserts were used to identify the impact of DDI on the prostate cancer therapy and suggested interventions.

DATA SUMMARY

No DDIs are expected for the LHRH agonists leuprolide acetate, histrelin, goserelin, or leuprolide mesylate. However, DDIs have been reported for GnRH antagonists, anti-androgens, PARP inhibitors, and taxanes. Although there are no confirmed DDIs for sipuleucel-T to date, it is not generally recommended to use sipuleucel-T concurrently with immunosuppressive medications. Interventions to prevent DDIs include the use of software that can detect clinically significant DDIs, up-to-date medication reconciliation, the inclusion of dedicated clinical pharmacists in cancer treatment teams, and patient/caregiver education.

CONCLUSIONS

Prostate cancer patients have a high risk of potential DDIs due to numerous new anti-cancer therapies, the increased use of treatment combinations, and the likelihood of comorbid conditions also requiring drug therapy. Drug-drug interaction screening software, up-to-date medication reconciliation, inclusion of oncology pharmacists on healthcare teams, and patient/caregiver education will aid the development of treatment plans that focus on achieving an optimal risk-benefit profile whilst reducing the risk of DDIs.

Clinical implications of the Drug-Drug Interaction in Cancer Patients treated with innovative oncological treatments

In the last two-decades, innovative drugs have revolutionized cancer treatments, demonstrating a significant improvement in overall survival. These drugs may present several pharmacokinetics interactions with non-oncological drugs, and vice versa, and, non-oncological drugs can modify oncological treatment outcome both with pharmacokinetic interaction and with an "off-target impact" on the tumor microenvironment or on the peripheral immune response. It's supposed that the presence of a drug-drug interaction (DDI) is associated with an increased risk of reduced anti-tumor effects or severe toxicities. However, clinical evidence that correlate the DDI presence with outcome are few, and results are difficult to compare because of difference in data collection and heterogeneous population. This review reports all the clinical evidence about DDI to provide an easy-to-use guide for DDI management and dose adjustment in solid tumors treated with inhibitors of the cyclin-dependent kinases CDK4-6, Antibody-drug conjugates, Poly ADPribose polymerase inhibitors, androgen-receptor targeted agents, or immunecheckpoints inhibitors.

New-generation androgen receptor signaling inhibitors (ARSIs) in metastatic hormone-sensitive prostate cancer (mHSPC): pharmacokinetics, drug-drug interactions (DDIs), and clinical impact

INTRODUCTION

The therapeutic scenario of metastatic hormone-sensitive prostate cancer (mHSPC) has dramatically changed in recent years, with the approval of new-generation Androgen Receptor Signaling Inhibitors (ARSIs), in combination with the androgen deprivation therapy (ADT), which was the previous standard of care. Despite showing a similar clinical efficacy, ARSIs, all of which are administered orally, are different in terms of pharmacokinetic and drug-drug interactions (DDIs).

AREAS COVERED

This review covers the main pharmacokinetic characteristics of ARSIs that have been approved for the first-line therapy of mHSPC patients, underlying the differences among these molecules and focusing on the known or possible interactions with other drugs. Full-text articles and abstracts were searched in PubMed.

EXPERT OPINION

Since prostate cancer occurs mainly in older age, comorbidities and the consequent polypharmacy increase the DDI risk in mHSPC patients who are candidates for ARSI. Waiting for new therapeutic options, in the absence of direct comparisons, pharmacokinetic knowledge is essential to guide clinicians in prescribing ARSI in this setting.

Bioequivalence of 240 mg Apalutamide Tablets and Preparation in Aqueous Food Vehicles for Alternative Administration

A 240-mg single tablet has been developed with the focus of reducing the pill burden of the apalutamide daily dose of 240 mg (4 × 60-mg tablets). An open-label, randomized, single-dose phase 1 study with a 2-sequence and 2-period crossover design in healthy men determined the bioequivalence of a 240-mg single tablet versus the currently available 4 × 60-mg tablets (Part 1, N = 74) and assessed effect of a high-fat meal (Part 2, N = 21) on apalutamide maximum plasma concentration (Cmax) and the area under the plasma concentration-time curve (AUC0-72 h). The 90% confidence interval of geometric mean ratios for Cmax and AUC0-72 h fell between 80% and 125% for both Part 1 and Part 2. No new safety concerns with the 240-mg single tablet were observed. To support the use of different food vehicles as well as nasogastric (NG) tubes for alternative administration, we conducted in vitro compatibility studies to evaluate the purity, dose, and stability of 240-mg tablets dispersed in applesauce/yogurt/orange juice/green tea as well as in NG tubes (polyurethane/silicone/polyvinyl chloride). The studies confirmed the alternative administrations do not affect the purity, dose-accuracy, or stability of apalutamide. The apalutamide 240-mg tablet is bioequivalent to 4 × 60-mg tablets and compatible with the tested food vehicles and NG tubes.

Can Mechanistic Static Models for Drug-Drug Interactions Support Regulatory Filing for Study Waivers and Label Recommendations?

BACKGROUND AND OBJECTIVE

Mechanistic static and dynamic physiologically based pharmacokinetic models are used in clinical drug development to assess the risk of drug-drug interactions (DDIs). Currently, the use of mechanistic static models is restricted to screening DDI risk for an investigational drug, while dynamic physiologically based pharmacokinetic models are used for quantitative predictions of DDIs to support regulatory filing. As physiologically based pharmacokinetic model development by sponsors as well as a review of models by regulators require considerable resources, we explored the possibility of using mechanistic static models to support regulatory filing, using representative cases of successful physiologically based pharmacokinetic submissions to the US Food and Drug Administration under different classes of applications.

METHODS

Drug-drug interaction predictions with mechanistic static models were done for representative cases in the different classes of applications using the same data and modelling workflow as described in the Food and Drug Administration clinical pharmacology reviews. We investigated the hypothesis that the use of unbound average steady-state concentrations of modulators as driver concentrations in the mechanistic static models should lead to the same conclusions as those from physiologically based pharmacokinetic modelling for non-dynamic measures of DDI risk assessment such as the area under the plasma concentration-time curve ratio, provided the same input data are employed for the interacting drugs.

RESULTS

Drug-drug interaction predictions of area under the plasma concentration-time curve ratios using mechanistic static models were mostly comparable to those reported in the Food and Drug Administration reviews using physiologically based pharmacokinetic models for all representative cases in the different classes of applications.

CONCLUSIONS

The results reported in this study should encourage the use of models that best fit an intended purpose, limiting the use of physiologically based pharmacokinetic models to those applications that leverage its unique strengths, such as what-if scenario testing to understand the effect of dose staggering, evaluating the role of uptake and efflux transporters, extrapolating DDI effects from studied to unstudied populations, or assessing the impact of DDIs on the exposure of a victim drug with concurrent mechanisms. With this first step, we hope to trigger a scientific discussion on the value of a routine comparison of the two methods for regulatory submissions to potentially create a best practice that could help identify examples where the use of dynamic changes in modulator concentrations could make a difference to DDI risk assessment.

Real-world analysis of apalutamide-associated skin adverse events in Japanese patients with advanced prostate cancer: a multi-institutional study in the Chu-shikoku Japan Urological Consortium

BACKGROUND

Apalutamide-associated skin adverse events are more common in the Japanese than in the global population. However, limited clinical data have hampered further understanding. This real-world study investigated the clinical characteristics of skin adverse events in patients with advanced prostate cancer.

METHODS

We retrospectively reviewed 119 patient records from 16 institutions in Japan. Skin adverse events were graded according to the Common Terminology Criteria for Adverse Events (v5.0). The incidence and characteristics of skin adverse events (along with the clinical risk factors for their incidence, worsening, and recurrence) were evaluated.

RESULTS

Fifty-five patients (46.2%) experienced skin adverse events. The median times to the incidence and remission of skin adverse events were 62 and 30 days, respectively. Grade 3 skin adverse events were observed in 15 patients (12.6%). The median time from the first incidence to apalutamide interruption was significantly longer in patients with progression to grade 3 skin adverse events than in those without such a progression (8 vs. 0 days, p = 0.005). Skin adverse events were observed in 45.2% of patients who resumed apalutamide treatment (median treatment interruption time: 31.5 days). Sixteen patients (13.4%) permanently discontinued apalutamide due to skin adverse events. No significant clinical risk factors for the incidence, worsening and recurrence of apalutamide-associated skin adverse events were observed.

CONCLUSIONS

Nearly half of the Japanese patients in this study experienced skin adverse events following apalutamide administration. The time to apalutamide discontinuation after the incidence of skin adverse events was positively correlated with the worsening of these events.

Impact of Pineapple Juice on Expression of CYP3A4, NAT2, SULT1A1 and OATP1B1 mRNA in HepG2 Cells

<b>Background and Objective:</b> Pineapple (<i>Ananas comosus</i>) is a popular fruit worldwide with natural antioxidant properties. This study examined how pineapple modified the expression of drug-metabolizing enzymes (CYP1A2, CYP2C9, CYP3A4, UGT1A6, NAT2 and SULT1A1) and a drug transporter (OATP1B1) in human hepatocarcinoma (HepG2) cells. <b>Materials and Methods:</b> HepG2 cells (2.5×10<sup>5</sup> cells/well in a 24-well plate) were incubated with pineapple juice extract (125-1,000 μg mL<sup>1</sup>) for 48 hrs in phenol red-free medium. Resazurin reduction, ROS, AST and ALT assays were performed. The mRNA expression of target genes was determined by RT/qPCR. <b>Results:</b> Pineapple juice slightly reduced HepG2 cell viability to 80% of the control, while ROS, AST and ALT levels were not changed. Pineapple juice did not alter the expression of CYP1A2, CYP2C9 and UGT1A6 mRNA. All tested concentrations of pineapple juice suppressed CYP3A4, NAT2 and OATP1B1 expression, while SULT1A1 expression was induced. <b>Conclusion:</b> Though pineapple juice slightly decreased the viability of HepG2 cells, cell morphology and cell function remained normal. Pineapple juice disturbed the expression of phase I (CYP3A4) and phase II (NAT2 and SULT1A1) metabolizing genes and the drug transporter OATP1B1. Therefore, the consumption of excessive amounts of pineapple juice poses a risk for drug interactions.

EXOGENOUS Sex Hormones and Sex Hormone Receptor Modulators in COVID-19: Rationale and Clinical Pharmacology Considerations

Male patients with coronavirus disease 2019 (COVID-19) fare much worse than female patients in COVID-19 severity and mortality according to data from several studies. Because of this sex disparity, researchers hypothesize that the use of exogenous sex hormone therapy and sex hormone receptor modulators might provide therapeutic potential for patients with COVID-19. Repurposing approved drugs or drug candidates at late-stage clinical development could expedite COVID-19 therapy development because their clinical formulation, routes of administration, dosing regimen, clinical pharmacology, and potential adverse events have already been established or characterized in humans. A number of exogenous sex hormones and sex hormone receptor modulators are currently or will be under clinical investigation for COVID-19 therapy. In this review, we discuss the rationale for exogenous sex hormones and sex hormone receptor modulators in COVID-19 treatment, summarize ongoing and planned clinical trials, and discuss some of the clinical pharmacology considerations on clinical study design. To inform clinical study design and facilitate the clinical development of exogenous sex hormones and sex hormone receptor modulators for COVID-19 therapy, clinical investigators should pay attention to clinical pharmacology factors, such as dosing regimen, special populations (i.e., geriatrics, pregnancy, lactation, and renal/hepatic impairment), and drug interactions.

Current Practices, Gap Analysis, and Proposed Workflows for PBPK Modeling of Cytochrome P450 Induction: An Industry Perspective

The International Consortium for Innovation and Quality (IQ) Physiologically Based Pharmacokinetic (PBPK) Modeling Induction Working Group (IWG) conducted a survey across participating companies around general strategies for PBPK modeling of induction, including experience with its utility to address various questions, regulatory interactions, and regulatory acceptance. The results highlight areas where PBPK modeling is used with high confidence and identifies opportunities where confidence is lower and further evaluation is needed. To enhance the survey results, the PBPK-IWG also collected case studies and analyzed recent literature examples where PBPK models were applied to predict CYP3A induction-mediated drug-drug interactions. PBPK modeling of induction has evolved and progressed significantly, proving to have great potential to accelerate drug discovery and development. With the aim of enabling optimal use for new molecular entities that are either substrates and/or inducers of CYP3A, the PBPK-IWG proposes initial workflows for PBPK application, discusses future trends, and identifies gaps that need to be addressed.

Plumbagin and Plumbago indica Differentially Modulated Cytochrome P450 and Transporter Profiles in BeWo and HepG2 Cells

<b>Background and Objective:</b> The medicinal herb <i>Plumbago indica</i> (PI) and its major constituent plumbagin have reported pharmacological properties but there is a lack of information about their herb-drug interactions. The effects of methanolic (PI-MeOH) and ethanolic (PI-EtOH) crude extracts of PI and plumbagin on the expression of cytochrome P450s (<i>CYP1A2</i>, <i>CYP2E1</i> and <i>CYP3A4</i>) and transporters (<i>ABCC1</i>, <i>ABCG2</i> and <i>SLC22A11</i>) were investigated in BeWo and HepG2 cells. <b>Materials and Methods:</b> BeWo or HepG2 cells were treated with 0.5-5 μM plumbagin or 25-500 μg mL<sup>1</sup> of PI-MeOH or PI-EtOH for 24 hrs. Total RNA was extracted and mRNA expression of CYPs and transporters were determined using RT-qPCR. <b>Results:</b> PI and plumbagin affected mRNA expression differently in the two tested cell types. In BeWo cells, all concentrations of PI-MeOH induced <i>CYP2E1</i>, 100 and 500 μg Ml<sup>1</sup> PI-MeOH and PI-EtOH up-regulated <i>CYP1A2</i>, <i>CYP3A4 </i>and <i>ABCG2 </i>and 500 μg mL<sup>1</sup> PI-EtOH induced <i>ABCG2</i> expression. Plumbagin suppressed <i>CYP1A2</i> and induced <i>SLC22A11 </i>expression at the highest concentration, 5 μM. In HepG2 cells, 5 μM plumbagin and 500 μg Ml<sup>1</sup> PI-EtOH suppressed <i>CYP3A4 </i>expression and 500 μg mL<sup>1</sup> PI-MeOH and PI-EtOH up-regulated <i>CYP1A2</i> and <i>CYP2E1 </i>expression. <i>ABCC1</i> expression was induced by all treatments while <i>ABCG2</i> and <i>SLC22A11 </i>were induced only by 500 μg mL<sup>1</sup> PI-MeOH and PI-EtOH. <b>Conclusion:</b> The use of PI or plumbagin supplements in large quantities or for long periods should be carefully considered due to the risk of herbal drug interactions via modulated expression of CYPs and transporters.

Physiologically-Based Pharmacokinetic Modelling of Entrectinib Parent and Active Metabolite to Support Regulatory Decision-Making

BACKGROUND AND OBJECTIVE

Entrectinib is a selective inhibitor of ROS1/TRK/ALK kinases, recently approved for oncology indications. Entrectinib is predominantly cleared by cytochrome P450 (CYP) 3A4, and modulation of CYP3A enzyme activity profoundly alters the pharmacokinetics of both entrectinib and its active metabolite M5. We describe development of a combined physiologically based pharmacokinetic (PBPK) model for entrectinib and M5 to support dosing recommendations when entrectinib is co-administered with CYP3A4 inhibitors or inducers.

METHODS

A PBPK model was established in Simcyp^® Simulator. The initial model based on in vitro-in vivo extrapolation was refined using sensitivity analysis and non-linear mixed effects modeling to optimize parameter estimates and to improve model fit to data from a clinical drug-drug interaction study with the strong CYP3A4 inhibitor, itraconazole. The model was subsequently qualified against clinical data, and the final qualified model used to simulate the effects of moderate to strong CYP3A4 inhibitors and inducers on entrectinib and M5 pharmacokinetics.

RESULTS

The final model showed good predictive performance for entrectinib and M5, meeting commonly used predictive performance acceptance criteria in each case. The model predicted that co-administration of various moderate CYP3A4 inhibitors (verapamil, erythromycin, clarithromycin, fluconazole, and diltiazem) would result in an average increase in entrectinib exposure between 2.2- and 3.1-fold, with corresponding average increases for M5 of approximately 2-fold. Co-administration of moderate CYP3A4 inducers (efavirenz, carbamazepine, phenytoin) was predicted to result in an average decrease in entrectinib exposure between 45 and 79%, with corresponding average decreases for M5 of approximately 50%.

CONCLUSIONS

The model simulations were used to derive dosing recommendations for co-administering entrectinib with CYP3A4 inhibitors or inducers. PBPK modeling has been used in lieu of clinical studies to enable regulatory decision-making.

Application of PBPK Modeling and Simulation for Regulatory Decision Making and Its Impact on US Prescribing Information: An Update on the 2018-2019 Submissions to the US FDA's Office of Clinical Pharmacology

Since 2016, results from physiologically based pharmacokinetic (PBPK) analyses have been routinely found in the clinical pharmacology section of regulatory applications submitted to the US Food and Drug Administration (FDA). In 2018, the Food and Drug Administration's Office of Clinical Pharmacology published a commentary summarizing the application of PBPK modeling in the submissions it received between 2008 and 2017 and its impact on prescribing information. In this commentary, we provide an update on the application of PBPK modeling in submissions received between 2018 and 2019 and highlight a few notable examples.

Pharmacokinetics and Use-Testing of Apalutamide Prepared in Aqueous Food Vehicles for Alternative Administration

Patients may have difficulty swallowing a whole daily dose of 240 mg (4 × 60-mg tablets) of apalutamide. One of the unique properties of apalutamide tablets is easy disintegration and dispersion when mixed into aqueous vehicles, avoiding the need to crush/split the tablets. To evaluate whether this method of apalutamide tablet administration would be conducive in a patient setting, different variations in preparation were evaluated, and one preparation was tested in humans. In vitro compatibility studies evaluated purity, dose, or stability of different variations of apalutamide in applesauce/yogurt/orange juice/green tea. An open-label, randomized, crossover phase 1 study in healthy men determined the bioavailability of an apalutamide-applesauce mixture versus whole tablets based on maximum plasma analyte concentration (C_max ), area under the plasma analyte concentration-time curve: AUC_0-72h and AUC_0-168h . Different amounts of applesauce/yogurt/orange juice/green tea as well as durations (up to 6 hours) did not affect the total apalutamide content available. The phase 1 study (n = 12) showed increased total exposure of 5% and peak exposure of 27.6% when comparing the apalutamide-applesauce mixture with whole-tablet administration. Variations in preparation times and total content for applesauce/yogurt/orange juice/green tea did not affect the purity, dose, or stability of apalutamide. An apalutamide-applesauce mixture is a suitable alternative administration method to whole tablets.

Impact of Pineapple on Mitochondrial Permeability Transition and Drug Metabolizing Genes in Caco-2 Cells

<b>Background and Objective:</b> Pineapple (<i>Ananas comosus</i> L.) has antioxidant and other pharmacological properties. This study examined how pineapple modified mitochondrial permeability transition and expression of drug-metabolizing enzymes, i.e., CYP1A2, CYP2C9, CYP3A4, UGT1A6, NAT2 and the drug transporter OATP1B1 in human colorectal adenocarcinoma (Caco-2) cells. <b>Materials and Methods:</b> Caco-2 cells (2.5×10<sup>5</sup> cells well<sup>1</sup> in 24-well plates) were incubated with pineapple (125 to 1,000 μg mL<sup>1</sup>) for 48 hrs in a phenol red-free medium. Mitochondrial permeability transition, resazurin cell viability and AST and ALT levels were investigated. The mRNA expression of target genes was determined by RT/qPCR. <b>Results:</b> Pineapple significantly reduced depolarized mitochondria, slightly decreased cell viability and did not change AST and ALT levels. Pineapple did not modify the mRNA expressions of CYP1A2, CYP2C9 and CYP3A4 but markedly induced UGT1A6 expression. The highest tested concentration of pineapple (1,000 μg mL<sup>1</sup>) significantly suppressed NAT2 and OATP1B1 expression. <b>Conclusion:</b> Although pineapple slightly decreased cell viability to ~80% of control, the morphology and functions of the cells were unaffected. Pineapple showed a beneficial effect to reduce depolarized mitochondria, which consequently decreased reactive oxygen species production. Pineapple did not modify the expression of CYPs, whilst it altered the expression of phase 2 metabolizing genes UGT1A6 and NAT2 and the transporter OATP1B1. Therefore, the consumption of large amounts of pineapple is of concern for the risk of drug interaction via alteration of UGT1A6, NAT2 and OATP1B1 expression.