Drug-drug interaction potential among patients with nonmetastatic castration-resistant prostate cancer (nmCRPC) treated with novel androgen receptor inhibitors.

BACKGROUND: Nonmetastatic castration-resistant prostate cancer (nmCRPC) patients are often older and use concurrent medications that increase the potential for drug-drug interactions (pDDIs). This study assessed pDDI prevalence in real-world nmCRPC patients treated with apalutamide, darolutamide, or enzalutamide. RESEARCH DESIGN AND METHODS: Castrated prostate cancer patients without metastases prior to androgen receptor inhibitor initiation were identified retrospectively via Optum Clinformatics Data Mart claims data (8/2019-3/2021). The top 100 concomitant medications were assessed for pDDIs. RESULTS: Among 1,515 patients (mean age: 77 ± 8 years; mean Charlson Comorbidity Index: 3 ± 3), 340 initiated apalutamide, 112 darolutamide, and 1,063 enzalutamide. Common concomitant medication classes were cardiovascular (80%) and central nervous system (52%). Two-thirds of the patients received ≥5 concomitant medications; 30 (30/100 medications) pDDIs were identified for apalutamide and enzalutamide each and 2 (2/100 medications) for darolutamide. Most pDDIs had risk ratings of C or D, but four for apalutamide were rated X. Approximately 58% of the patients on apalutamide, 5% on darolutamide, and 54% on enzalutamide had ≥1 identified pDDI. CONCLUSIONS: Results showed a higher frequency of pDDIs in patients receiving apalutamide and enzalutamide vs darolutamide. The impact of these could not be determined retrospectively. DDI risk should be carefully evaluated when discussing optimal therapy for patients with nmCRPC.

A meta-analysis on overall survival and safety outcomes in patients with nonmetastatic castration-resistant prostate cancer treated with novel hormonal agents.

Several novel androgen receptor (AR)-inhibitors have been introduced for nonmetastatic castration-resistant prostate cancer (nmCRPC) treatment, with the improvement of survival outcomes which need to be balanced against the risk of adverse events. We performed a systematic review and meta-analysis of randomized controlled trials (RCTs) investigating enzalutamide, apalutamide and darolutamide in nmCRPC patients, to assess overall survival (OS), incidence and risk of adverse drug events, adverse-events-related death and adverse-events-related treatment discontinuation. We selected three RCTs (SPARTAN, PROSPER and ARAMIS). New hormonal agents administration resulted in better OS, despite the increased risk of several any grade and grade 3-4 adverse events. In the decision-making process, careful evaluation of expected adverse events, patients' comorbidities and maintenance of quality of life are mandatory.

Risk of cardiovascular toxicities and hypertension in nonmetastatic castration-resistant prostate cancer patients treated with novel hormonal agents: a systematic review and meta-analysis.

Background: With hormonal agents quickly expanding as novel therapeutic options in nonmetastatic castration-resistant prostate cancer (nmCRPC), the toxicity profile of enzalutamide, apalutamide, and darolutamide should be kept in mind.Methods: We performed an updated meta-analysis with the aim to analyze the risk of treatment-related cardiovascular (CV) events, any grade, and grade 3-4 (G3-4) hypertension in nmCRPC patients treated with enzalutamide, apalutamide, and darolutamide plus androgen deprivation therapy (ADT) versus ADT plus placebo in randomized controlled trials (RCTs). Results were compared by calculating Relative Risk (RR) with 95% confidence intervals (CIs); RRs were combined with Mantel-Haenszel method.Results: Three RCTs involving 4110 patients were available for the meta-analysis. According to our results, the addition of novel hormonal agents was associated with a significantly increased risk of CV events (RR = 1.71; 95% CI 1.29-2.27) and G3-4 hypertension (RR = 1.53; 95% CI 1.19-1.97). In addition, a trend toward a higher risk of any grade hypertension was reported in the experimental arm.Conclusions: The use of enzalutamide, apalutamide, and darolutamide in nmCRPC patients implies a careful benefit-risk assessment. Real-world, large-cohort studies are warranted to confirm the findings of our meta-analysis.

3,5,6-trichloro-2-pyridinol intensifies the effect of chlorpyrifos on the paracrine function of Sertoli cells by preventing binding of testosterone and the androgen receptor.

3,5,6-Trichloro-2-pyridinol (TCP) is an important biomarker and one of the final metabolites of chlorpyrifos (CPF). TCP inhibits secretion of sex hormones. Similar to CPF, TCP can bind to sex steroid hormone receptors and decrease the secretion of sex hormones. However, little attention has been paid to the ability of TCP and CPF to interfere with androgen receptor (AR) in Sertoli cells. This study aimed to explain how TCP promotes the inhibitory effect of CPF on the paracrine function of Sertoli cells. Western blotting indicated that after 20 weeks of exposure, expression of AR in testes was significantly reduced by CPF. An in vitro assay measured the cytotoxicity of CPF, TCP and diethylphosphate (DEP) on viability of Sertoli cells by Cell Counting Kit-8. CPF cytotoxicity was greater than that of TCP, and TCP cytotoxicity was greater than that of DEP at concentrations of 1000 µmol/L. Western blotting indicated that TCP and CPF both decreased expression of AR and cAMP-response element binding protein phosphorylation, while DEP had no effect in Sertoli cells, which are important in regulating paracrine function of Sertoli cells. The fluorescence measurements and docking studies revealed that testosterone, CPF and TCP showed four types of intermolecular interactions with AR, highlighting alkyl bonds with some of the same amino acids. Compared with testosterone, CPF and TCP also showed significant synergistic interaction with AR. CPF interacted with more amino acids and interaction energy than TCP did. This research elucidates TCP in the antiandrogenic effect of CPF on the paracrine function and suggests that TCP or chemicals with a trichloropyridine structure must be considered during reproductive toxicity assessment of potential environmental pollutants.

Cabazitaxel multiple rechallenges in metastatic castration-resistant prostate cancer.

INTRODUCTION: Cabazitaxel multiple rechallenges may be a treatment option in heavily pretreated patients with metastatic castration-resistant prostate cancer (mCRPC) who had a good initial response to cabazitaxel and who are still fit to receive it. Our objective was to assess the efficacy and toxicity of multiple rechallenges. PATIENTS AND METHODS: We retrospectively identified 22 mCRPC patients previously treated with docetaxel and/or androgen receptor-targeted agents who received multiple cabazitaxel rechallenges in 9 French centers. Cabazitaxel was initiated at a dose of 25 mg/m2 q3week. A reduced dose (20 mg/m2 q3w) or an alternative schedule (mainly 16 mg/m2 q2w) was increasingly used for subsequent rechallenges. Progression-free survival, prostate-specific antigen (PSA) response, best clinical response, and grade ≥3 toxicities were collected. Overall survival was calculated from various time points. RESULTS: Twenty-two patients with an initial response to cabazitaxel were rechallenged at least twice. The median number of cabazitaxel cycles was 7 at first cabazitaxel treatment, 6 at first rechallenge, and 5 at subsequent rechallenges. Median progression-free survival at first rechallenge was 9.6 months and 5.6 months at second rechallenge. Median overall survival was 50.9 months from the first cabazitaxel dose, 114.9 months from first life-extending therapy initiation in mCRPC, and 105 months from mCRPC diagnosis. There was no cumulative grade ≥3 neuropathy or nail disorder and one case of febrile neutropenia. CONCLUSION: Cabazitaxel multiple rechallenges may be a treatment option without cumulative toxicity in heavily pretreated patients having a good response to first cabazitaxel use and still fit to receive it. NOVELTY & IMPACT STATEMENTS: Patients with metastatic castration-resistant prostate cancer can be treated with Cabazitaxel after docetaxel and androgen receptor-targeted agent. This chemotherapy can be used multiple times with efficacy and manageable toxicity.

A drug safety evaluation of enzalutamide to treat advanced prostate cancer.

INTRODUCTION: Prostate cancer (PC) is the most common cancer in North American men. Advanced PC is incurable. The androgen receptor antagonist enzalutamide is used to manage advanced PC, often over a period of months or years; it is therefore important to evaluate the safety profile of enzalutamide. AREAS COVERED: This literature review presents safety data from pivotal trials and real-world data studies of enzalutamide in patients with advanced PC, including metastatic hormone-sensitive prostate cancer (mHSPC), nonmetastatic castration-resistant prostate cancer (nmCRPC), and metastatic castration-resistant prostate cancer (mCRPC). A large body of evidence supports the maintenance or improvement in the health-related quality of life (HRQoL) afforded by enzalutamide treatment in patients with mHSPC, nmCRPC, or chemotherapy-naïve mCRPC, as well as improvement in the HRQoL in patients with later-stage symptomatic mCRPC. Efficacy data from clinical trials are also briefly discussed. EXPERT OPINION: We aim to provide clinicians with a better understanding of how to properly interpret enzalutamide clinical trial safety data. This knowledge may help clinicians guide their patients with PC to achieve optimal clinical benefit from enzalutamide therapy, and to properly manage their patients to mitigate any potential risk.

Triple-arm androgen blockade for advanced prostate cancer: a review.

Prostate cancer is estimated to be the second most common malignancy in men in the USA in 2020 and represents the second highest mortality from cancer behind lung and bronchial neoplasms. Management of advanced prostate cancer is evolving. Medical androgen deprivation therapy is currently a cornerstone of therapy for prostate cancer; however molecular mechanisms of resistance have emerged leading to castration-resistant prostate cancer that is proliferation of prostate cancer in the setting of low testosterone (< 50 ng/dl). The benefit of double androgen blockade like ADT plus abiraterone acetate or androgen receptor blockers is proven in many clinical trials; however multiple mechanisms of resistance still exist. In theory, another layer of androgen blockade will prevent, or at least slow, prostate cancer proliferation. This direction of thought has recently been explored with multiple clinical trials. In this review article, we summarize the current knowledge regarding androgen resistance, newer androgen inhibition therapies, and the implications of a triple-arm anti-androgen blockade in advanced prostate cancer.

Deep and ongoing response of castrate-resistant prostate cancer on very low-dose enzalutamide in an elderly chemotherapy-naïve patient: a case report.

BACKGROUND: Enzalutamide is an orally administered drug that blocks signaling in the androgen receptor with clinical activity in both chemotherapy-naive and post-chemotherapy patients with castrate-resistant prostate cancer (CRPC). Enzalutamide is generally well-tolerated, but dose reductions are nonetheless needed in case of side effects. CASE: An 82-year-old patient with chemotherapy-naive metastatic castration-resistant prostate cancer was treated with a very low dose of 40 mg enzalutamide once daily. The trough levels of enzalutamide and the active metabolite N-desmethylenzalutamide were 4.5 mg/L and 3.0 mg/L, respectively. This exposure provided a long-term response without any significant side effects. CONCLUSION: Low doses of enzalutamide may be efficacious, while also reducing the risk of side effects. Furthermore, employing a lower dose would reduce healthcare costs and increase access to enzalutamide. Studies exploring the efficacy of lower enzalutamide doses are warranted.

Indirect Comparison of Darolutamide versus Apalutamide and Enzalutamide for Nonmetastatic Castration-Resistant Prostate Cancer.

PURPOSE: No published head-to-head randomized trials have compared the safety and efficacy of darolutamide vs apalutamide or enzalutamide in nonmetastatic castration-resistant prostate cancer. This study compares prespecified adverse events and metastasis-free survival associated with darolutamide vs apalutamide, and darolutamide vs enzalutamide, via matching-adjusted indirect comparisons. MATERIALS AND METHODS: Individual patient data from the phase III ARAMIS trial (NPLACEBO=553; NDAROLUTAMIDE=943) were selected and reweighted to match the inclusion criteria and baseline characteristics published for the phase III SPARTAN (NPLACEBO=401; NAPALUTAMIDE=806) and PROSPER (NPLACEBO=468; NENZALUTAMIDE=933) trials. Only baseline factors consistently reported across trials were included as matching covariates. Both indirect comparisons matched on age, prostate specific antigen level and doubling time, Eastern Cooperative Oncology Group performance status, Gleason score, and bone-sparing agent use. Darolutamide vs apalutamide also matched on prior surgery and darolutamide vs enzalutamide also matched on region. Risk differences and odds ratios were calculated for adverse events and hazard ratios for metastasis-free survival. RESULTS: No differences in metastasis-free survival hazard ratios were found after matching in either comparison. However, fall, fracture and rash rates were statistically significantly lower in favor of darolutamide vs apalutamide. Fall, dizziness, mental impairment, fatigue and severe fatigue rates were statistically significantly lower in favor of darolutamide vs enzalutamide. CONCLUSIONS: While metastasis-free survival did not differ across drugs in these cross-trial indirect comparisons, darolutamide showed a favorable safety and tolerability profile in prespecified adverse events vs apalutamide and enzalutamide. Consideration of these adverse events is important in clinical decision-making and treatment selection in nonmetastatic castration-resistant prostate cancer.

Darolutamide in hormone-sensitive and castration-resistant prostate cancer.

Introduction: Important changes in the treatment of prostate cancer have taken place in recent years. Non-metastatic castration-resistant prostate cancer (nmCRPC) has been clinically delineated. In this setting, three drugs have been approved in high-risk disease: apalutamide, enzalutamide and darolutamide.Areas covered:This manuscript aims to profile darolutamide, its clinical development, pharmacologic properties, efficacy and safety. We presented the results of published clinical studies, but we also investigated ongoing ones.Expert opinion: An indirect comparison with the other two aforementioned drugs emerged. While the clinical efficacy is comparable, the toxicity profile is different for darolutamide, resulting in greater tolerance. We must wait for the results of the trials that study darolutamide in hormone-sensitive disease, both in the metastatic phase and in the localized phase. Clinical experience will also be important to determine ever more personalized treatments for patients.

Metabolism and Mass Balance of the Novel Nonsteroidal Androgen Receptor Inhibitor Darolutamide in Humans.

The biotransformation and excretion of darolutamide were investigated in a phase I study. Six healthy male volunteers received a single dose of 300 mg 14C-darolutamide as an oral solution in the fasted state. Plasma, urine, and feces samples were analyzed for mass balance evaluation by liquid scintillation counting (LSC). Metabolite profiling and identification were determined using liquid chromatography mass-spectrometry with off-line radioactivity detection using LSC. Complete mass balance was achieved, with mean radioactivity recovery of 95.9% within 168 hours (63.4% in urine, 32.4% in feces). The administered 1:1 ratio of (S,R)- and (S,S)-darolutamide changed to approximately 1:5, respectively, in plasma. Darolutamide and the oxidation product, keto-darolutamide, were the only components quantifiable by LSC in plasma, accounting for 87.4% of total radioactivity, with a 2.1-fold higher plasma exposure for keto-darolutamide. Aside from darolutamide, the most prominent metabolites in urine were O-glucoronide (M-7a/b) and N-glucuronide (M-15a/b), as well as pyrazole sulfates (M-29, M-24) and glucuronides (M-21, M-22) resulting from oxidative cleavage of the parent. The darolutamide diastereomers were mainly detected in feces. In vitro assays showed that darolutamide metabolism involves a complex interplay between oxidation and reduction, as well as glucuronidation. Interconversion of the diastereomers involves oxidation to keto-darolutamide, primarily mediated by CYP3A4, followed by reduction predominantly catalyzed by cytosolic reductase(s), with aldo-keto reductase 1C3 playing the major role. The latter reaction showed stereoselectivity with preferential formation of (S,S)-darolutamide. SIGNIFICANCE STATEMENT: The metabolism and excretion of darolutamide in humans revealed that oxidation (CYP3A4) and glucuronidation (UGT1A9, UGT1A1) were the main metabolic routes of elimination. Direct excretion also contributed to overall clearance. The two pharmacologically equipotent diastereomers of darolutamide interconvert primarily via oxidation to the active metabolite keto-darolutamide, followed by reduction predominantly by cytosolic reductase(s). The latter reaction showed stereoselectivity with preferential formation of (S,S)-darolutamide. Data indicate a low drug-drug interaction potential of darolutamide with inducers or inhibitors of metabolizing enzymes.

Sequencing radium 223 and other life-prolonging agents in castration-resistant prostate cancer patients.

Background: Radium 223 (RA223) is currently administered as part of a therapeutic sequence with the other life-prolonging agents (LPAs) for metastatic castration-resistant prostate cancer (mCRPC). Patients & methods: We retrospectively reviewed the clinical records of patients who had received at least three LPAs including RA223. Results: Median overall survival (OS) from the start of first-line treatment was 39.8 months, with the patients who completed all six planned courses of RA223 having a longer OS than those who did not (53.2 vs 29.5 months; p < 0.0001). Conclusions: Our study confirms the activity of RA223 regardless of the treatment line in which it is administered and suggests that patient selection plays a central role in maximizing this activity.

Safety evaluation of enzalutamide dose-escalation strategy in patients with castration-resistant prostate cancer.

PURPOSE: Enzalutamide (ENZ) is an androgen receptor inhibitor used for the treatment of castration-resistant prostate cancer (CRPC). The aim of this study was to evaluate the safety of the ENZ by dose-escalation strategy in patients with CRPC. METHODS: We retrospectively reviewed patients with CRPC who received standard ENZ (started at 160 mg) or dose-escalation ENZ (started at 80 mg followed by dose escalation) from May 2014 to June 2019 in our hospital. Safety and time to treatment failure (TTF) were evaluated. Multivariate logistic regression analysis was used to evaluate adverse events and drug discontinuation. Multivariate Cox regression analysis was used to evaluate TTF. RESULTS: Among 107 patients, 17 patients received standard ENZ and 90 patients received dose-escalation ENZ therapy. Adverse events (any grade) were observed in 88.2% of patients in the standard group and 63.3% in the dose-escalation group (P = 0.020). Grade ≥3 adverse events were observed in 23.5% and 6.7% of the patients in the standard and dose-escalation groups, respectively, (P = 0.021). Discontinuation due to adverse events was 35.3% and 12.2% in the standard and dose-escalation groups, respectively (P = 0.070). Median TTF was 10.4 months (95% confidential interval [CI]: 2.6-31.3 months) and 18.0 months (95% CI: 11.5-22.8 months) in the standard and dose-escalation groups, respectively (Hazard ratio: 0.60, 95% CI: 0.29-1.30, P = 0.194). CONCLUSIONS: With the ENZ dose-escalation strategy, adverse events related to ENZ of any grade and grade ≥3 were significantly decreased, and discontinuation due to adverse events also decreased. Therefore, the dose-escalation strategy could be useful in optimizing the dose of ENZ.

The development of apalutamide for the treatment of prostate cancer.

INTRODUCTION: Prostate cancer progresses, despite androgen-deprivation therapy, the backbone of its treatment. This progression is mainly related to the androgen receptor (AR)-related mechanisms of resistance, and, several AR-targeted therapies have demonstrated benefit in metastatic and nonmetastatic disease. Apalutamide is a third-generation AR-targeted therapy which competitively blocks the AR and prevents AR dimerization, nuclear internalization, thereby avoiding cancer progression. Early studies have demonstrated that apalutamide was safe and demonstrated clinical benefit. Phase II and phase III studies had confirmed preliminary results of clinical benefit with apalutamide in patients with nonmetastatic castration-resistant prostate cancer (nmCRPC) and in metastatic hormone-sensitive prostate cancer (mHSPC). AREAS COVERED: Herein, the authors discuss the development of apalutamide, from its discovery and early studies to phase III trials. They also examine new perspectives and biomarkers that may help oncologists to make decisions in patients taking apalutamide. Studies evaluating apalutamide in other settings and in combination with other therapies are also debated. EXPERT OPINION: Apalutamide has become a relevant therapy for patients with nmCRPC and mHSPC for its benefit in delaying metastasis in addition to its improvement of overall survival, without compromising the quality of life. Apalutamide should be considered as a standard-of-care for patients with nmCRPC and patients with mHSPC.

To treat or not to treat: is it acceptable to avoid active therapies in advanced prostate cancer today?

Introduction: Recently, there has been a paradigm shift in the treatment of advanced prostate cancer (PCa) because the approval of a number of new agents has significantly improved overall survival. However, as PCa is a heterogeneous disease that may be more or less aggressive and patients may be more or less responsive to treatment, it is often debated whether or not it is acceptable to avoid active therapies.Areas covered: This review discusses different settings of advanced PCa.Expert opinion: In metastatic castration-resistant PCa, it is unethical not to use active treatments but the use of both androgen receptor targeting agents (ARTA) in sequence should be avoided in most patients and the use of the available agents for fourth-line treatment or beyond should only be considered for highly selected patients. In metastatic hormone-sensitive PCa, patients with de novo disease should receive one additional agent in combination with androgen deprivation therapy (ADT), whereas patients in relapse should be managed with ADT alone. In non-metastatic castration-resistant prostate cancer (PCa), all patients with a PSA doubling time of ≤6 months should receive one ARTA, whereas the others might wait until there is an acceleration in the kinetics of their PSA levels.

Current and emerging therapies for localized high-risk prostate cancer.

Introduction: Despite progress in the field of high-risk localized prostate cancer (HRPCa) treatments, high-risk patients treated with curative intent are at increased risk of biochemical recurrence, metastatic progression and cancer-related death. The optimal treatment strategy remains a topic of debate. This review provides an overview of the current and investigational therapeutic options for HRPCa.Areas covered: A PubMed search was performed for papers on the current perspectives on the multimodality treatment of HRPCa. We focus on both primary local treatment as well as systemic treatment options. Finally, relevant ongoing trials focusing on systemic treatments (including [neo]adjuvant treatments) enrolling at least 50 patients were retrieved, to highlight ongoing research and treatment optimization.Expert opinion: Disease progression in HRPCa patients is driven by local tumor extension and subclinical metastases. Therefore, the main treatment concept is a multimodal approach targeting the primary tumor with extended surgery or RT with long-term ADT and simultaneously targeting micro-metastatic deposits. However, there is still room for optimization. Upcoming clinical trials comparing surgery versus RT as local treatment, trials with (neo)adjuvant chemotherapy or androgen receptor signaling inhibitors will likely change the treatment landscape. However, a multimodal treatment strategy will stay as the cornerstone in the treatment of HRPCa.

Development of Force Field Parameters for p-Carborane to Investigate the Structural Influence of Carborane Derivatives on Drug Targets by Complex Formation.

Androgen receptor (AR) has a key role in the development and progression of prostate cancer, and AR antagonists are used for its remedy. Recently, carborane derivatives, which are carbon-containing boron clusters have attracted attention as new AR ligands. Here we determined the force field parameters of 10-vertex and 12-vertex p-carborane to facilitate in silico drug design of boron clusters. Then, molecular dynamics (MD) simulations of complexes of AR-carborane derivatives were performed to evaluate the parameters and investigate the influences of carborane derivatives on the three-dimensional structure of AR. Energy profiles were obtained using quantum chemical calculations, and the force-field parameters were determined by curve fitting of the energy profiles. The results of MD simulations indicated that binding of the antagonist-BA341 changed some hydrogen-bond formations involved in the structure and location of helix 12. Those results were consistent with previously reported data. The determined parameters are also useful for refining the structure of the carborane-receptor complex obtained by docking simulations and development of new ligands with carborane cages not only for AR but also for various receptors.

Clascoterone: First Approval.

Clascoterone (Winlevi®) is an androgen receptor inhibitor being developed as a topical cream and solution by Cassiopea (a spin-out company of Cosmo Pharmaceuticals) for the treatment of androgen-dependent skin disorders, including androgenetic alopecia and acne vulgaris. Although the exact mechanism of action of clascoterone for the topical treatment of acne vulgaris is unknown, the drug is believed to compete with the androgen dihydrotestosterone for binding to androgen receptors in the sebaceous gland and hair follicles to attenuate signalling necessary for acne pathogenesis. In August 2020, clascoterone cream 1% received its first approval in the USA for the topical treatment of acne vulgaris in patients 12 years of age or older. Clinical studies of a different formulation of clascoterone (a solution containing a higher concentration of the drug) for the treatment of androgenetic alopecia are underway in Germany and the USA. This article summarizes the milestones in the development of clascoterone leading to this first approval for the topical treatment of acne vulgaris.

Apalutamide: A Review in Metastatic Castration-Sensitive Prostate Cancer.

Apalutamide (Erleada®) is an oral selective androgen receptor (AR) inhibitor that binds directly to the ligand-binding domain of the AR. It is approved in the EU and the USA for the treatment of adult men with metastatic castration-sensitive prostate cancer (mCSPC). In a multinational, phase III study (TITAN) in this patient population, the addition of apalutamide (240 mg once daily) to androgen deprivation therapy (ADT) significantly improved median radiographic progression-free survival (rPFS), median overall survival (OS) and the median time to cytotoxic chemotherapy, while maintaining health-related quality of life (HR-QOL) and not substantially differing from placebo plus ADT in safety. Although mature OS data are awaited with interest, the addition of apalutamide to ADT extends the treatment options available for standard of care in adult men with mCSPC.