Potential and real drug interactions in patients treated with abiraterone or enzalutamide in clinical practice

Impact of Comorbidities and Drug Interactions in Patients With Metastatic Castration-Resistant Prostate Cancer Receiving Androgen Receptor Pathway Inhibitors

PURPOSE

Androgen receptor pathway inhibitors (ARPIs) are widely prescribed in metastatic castration-resistant prostate cancer (mCRPC). Real-world frequencies and potential impacts of comorbidities and concomitant medication (conmed) interactions with ARPIs are not well described.

METHODS

Patients receiving ARPIs for mCRPC were identified from the electronic Prostate Cancer Australian Database (ePAD). Demographics, clinicopathologic characteristics, and outcome data were extracted. Conmeds and comorbidities were collected from medical records. Potential interacting comorbidities were defined from trial and post-trial data. Clinically significant drug-drug interactions (DDIs) were identified using UpToDate Lexicomp and Stockley's databases. Patient characteristics, comorbidity interactions, DDIs, and outcomes were analyzed.

RESULTS

Two hundred thirty-five patients received first- or second-line ARPIs for mCRPC from 2012 to 2021, with a median follow-up of 27 months. One hundred sixteen received abiraterone acetate (AAP) and 135 received enzalutamide (ENZ). The median age was 74 years, and the median number of conmeds was 4. Clinically significant DDIs occurred in 55 (47%) AAP patients and 90 (67%) ENZ patients. Only 5% of DDIs were predicted to affect ARPI pharmacokinetics (PK) or pharmacodynamics, whereas 95% were predicted to impact conmed PK or increase toxicity risk. In patients receiving ENZ, DDIs were associated with lower PSA50 (50% v 74%, P = .04) and poorer overall survival (28 v 45 months, P = .04), although statistical significance was not maintained on multivariate analysis. No significant survival differences were seen with DDIs in patients receiving AAP. Potential interactions between comorbidities and ARPI were present in 72% on AAP and 14% on ENZ with no significant associated survival differences.

CONCLUSION

DDIs and drug-comorbidity interactions in real-world patients receiving ARPIs for mCRPC are common and may affect outcomes. Ongoing clinician education regarding DDIs is necessary to optimize patient outcomes.

Pharmacokinetic Interactions Between Abiraterone, Apalutamide, Darolutamide or Enzalutamide and Antithrombotic Drugs: Prediction of Clinical Events and Review of Pharmacological Information

PURPOSE

Abiraterone, apalutamide, darolutamide and enzalutamide are second-generation hormone therapies used for advanced prostate cancer; the majority of patients receiving these treatments are elderly, poly-medicated patients. Since their first market authorizations, their pharmacokinetic (PK) characteristics are increasingly well known. A potential risk of drug-drug interaction (DDI), especially with cardiovascular drugs, needs to be considered. In the case of antithrombotics, treatment imbalance can lead to severe consequences.

OBJECTIVES

To describe PK profiles of hormone therapies and antithrombotics and to predict DDIs and potentially related clinical events.

METHODS

PK profiles (CYP450 and P-gp substrate, inducer or inhibitor) are described by cross-referencing data sources (summary of product characteristics, European public assessment reports, PubMed database, Micromedex®, etc.); a description of the potential interactions with anti-cancer drugs for each DDI and related clinical events is provided. We discuss management recommendations, including those set out in international guidelines.

RESULTS

Antithrombotics are mainly metabolized by CYP 2C9, 2C19 or 3A4. For abiraterone (CYP 2C8, 2D6 inhibitor) and darolutamide (CYP 3A4 inducer), no interaction was identified with antithrombotics. For apalutamide (CYP 2C9, 2C19, 3A4 and P-gp inducer) and enzalutamide (CYP 2C9, 2C19, 3A4 inducer and P-gp inhibitor), several PK interactions were identified with antithrombotics, which could lead to various clinical events (haemorrhage or thromboembolism).

CONCLUSION

Numerous interactions are expected between enzalutamide or apalutamide and antithrombotics, for which management should be deployed on a case-by-case basis. PK and pharmaco-epidemiological studies could shed light on whether or not there are clinically significant events related to DDIs with antithrombotics.

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.

Drug-Drug Interactions in Hospitalized Urological Patients: A Retrospective Cohort Study

INTRODUCTION

Exposure to potential drug-drug interactions (pDDIs) can be a notable source of avoidable drug-related harm that requires adequate management to prevent medical errors. We aimed to evaluate pDDIs and associated factors in hospitalized urological patients on admission, during hospitalization, and on discharge.

METHODS

A retrospective cohort study was conducted at the Clinic of Urology of the University Clinical Centre Kragujevac, Serbia. To detect pDDIs, we used Lexicomp, which categorizes pDDIs as follows: X (avoid combination), D (consider therapy modification), C (monitor therapy), B (no action needed), and A (no known interaction). Multiple linear regression analysis was used to identify factors associated with the number of pDDIs.

RESULTS

More than half of the 220 included patients had at least one pDDI on admission and discharge (57.3% and 63.6%, respectively), whereas 95.0% had at least one pDDI during hospitalization. The total number and number of X, D, C, and B categories of pDDIs were the highest during hospitalization and the lowest on admission. Duration of hospitalization, arrhythmias, dementia, renal failure, cancer, surgery during hospitalization, number of prescribed drugs, and various pharmacological drug classes were risk factors for a higher number of pDDIs, while age, ischemic heart disease, hypertension, and development of infection during hospitalization were protective factors in at least one of the stages. The impact of renal colic depended on the stage and category of pDDI.

CONCLUSION

More than half of the urological patients were exposed to at least one pDDIs at all stages. Medical professionals should regularly screen for pDDIs, particularly in patients with risk factors.

Efficacy and safety outcomes of darolutamide in patients with non-metastatic castration-resistant prostate cancer with comorbidities and concomitant medications from the randomised phase 3 ARAMIS trial

PURPOSE

In patients with non-metastatic castration-resistant prostate cancer (nmCRPC) in the Androgen Receptor Antagonizing Agent for Metastasis-free Survival (ARAMIS) trial, darolutamide significantly improved median metastasis-free survival by nearly 2 years and reduced the risk of death by 31% versus placebo, with a favourable safety/tolerability profile. This post hoc analysis of ARAMIS evaluated efficacy and safety in patients by number of comorbidities and concomitant medications.

METHODS

Patients with nmCRPC were randomised 2:1 to darolutamide (n = 955) or placebo (n = 554) while continuing androgen-deprivation therapy. Overall survival (OS) and treatment-emergent adverse events (TEAEs) were evaluated in subgroups by median numbers of ongoing comorbidities and concomitant medications. HRs were determined from univariate analysis using Cox regression.

FINDINGS

Median numbers of comorbidities and concomitant medications were 6 and 10, respectively, with 41.6% of patients having >6 comorbidities and 48.8% taking >10 concomitant medications. For patients with ≤ 6 and >6 comorbidities, darolutamide increased OS versus placebo (hazard ratio [HR] 0.65 and 0.73, respectively), and this benefit was consistent for cardiovascular, metabolic, and other comorbidities (HR range: 0.39-0.88). For patients taking ≤ 10 and >10 concomitant medications, increased OS was also observed with darolutamide versus placebo (HR 0.76 and 0.66, respectively), and the benefit was consistent across medication classes (HR range: 0.45-0.80). Incidences of TEAEs and TEAEs leading to treatment discontinuation with darolutamide were similar to placebo across subgroups by numbers of comorbidities and concomitant medications.

CONCLUSIONS

The OS benefit and safety of darolutamide remained consistent with that observed in the overall ARAMIS population, even in patients with high numbers of comorbidities or concomitant medications.

CLINICALTRIALS

GOV REGISTRATION

NCT02200614.

TWEETABLE ABSTRACT

Darolutamide increased overall survival versus placebo, and incidences of most adverse events were similar between treatments in patients with ≤ 6 or >6 comorbidities and those taking ≤ 10 or >10 concomitant medications.

A new method to quantify the effect of co-medication on the efficacy of abiraterone in metastatic castration-resistant prostate cancer patients

Background and Objective: Patients with metastatic castration-resistant prostate cancer (mCRPC) treated with abiraterone acetate (AA) have co-morbidities treated with different drugs. The aim was to quantify the potential effect of co-medications on AA treatment duration (TD) and overall survival (OS). Methods: A new parameter, called "individual drug score" (IDS) was calculated by summing the "drug score"-s (DS) of all co-medications for each patient. The DS was determined by quantifying the effect of a given co-drug on enzymes involved in steroidogenesis and metabolism of AA. The correlation between log (IDS) and TD was tested by non-linear curve fit. Kaplan-Meier method and multivariate Cox regression was used for analysis of TD and OS. Results: The IDS and TD of AA+prednisolone showed a dose-response correlation (n = 166). Patients with high IDS had significantly longer TD and OS (p <0.001). In multivariate analysis IDS proved to be an independent marker of TD and OS. The same analysis was performed in a separate group of 81 patients receiving AA+dexamethasone treatment. The previously observed relationships were observed again between IDS and TD or OS. After combining the AA+prednisolone and AA+dexamethasone groups, analysis of the IDS composition showed that patients in the high IDS group not only used more drugs (p <0.001), but their drugs also had a higher mean DS (p = 0.001). Conclusion: The more co-drugs with high DS, the longer the duration of AA treatment and OS, emphasizing the need for careful co-medication planning in patients with mCRPC treated with AA. It is recommended that, where possible, co-medication should be modified to minimize the number of drugs with negative DS and increase the number of drugs with high DS. Our new model can presumably be adapted to other drugs and other cancer types (or other diseases).

A multidisciplinary consensus statement on the optimal pharmacological treatment for metastatic hormone-sensitive prostate cancer

Androgen deprivation therapy (ADT) is the mainstay treatment for metastatic hormone-sensitive prostate cancer (mHSPC). The addition of docetaxel or new hormone therapies (abiraterone, apalutamide, or enzalutamide) improves overall survival and is currently the standard of care. However, the decision on the specific regimen to accompany ADT should be discussed with the patient, considering factors such as possible associated toxicities, duration of treatment, comorbidities, patient preferences, as there is no sufficient evidence to recommend one regimen over the other in most cases. This paper summarizes the evidence on the management of mHSPC and provides consensus recommendations on the optimal treatment in combination with ADT in mHSPC patients, with special attention to the patient's clinical profile.