Prospective International Randomized Phase II Study of Low-Dose Abiraterone With Food Versus Standard Dose Abiraterone In Castration-Resistant Prostate Cancer

Safety and Efficacy of Reduced Dose of Enzalutamide in Patients with Castration-Resistant Prostate Cancer: A Systematic Review

Objective: To review the efficacy and safety of reduced dose compared to standard dose Enzalutamide treatment for patients with castration-resistant prostate cancer (CRPC). Methods: PubMed, Scopus, Web of Science, and Cochrane databases were searched for randomized controlled trials and cohort studies reporting the use of Enzalutamide in reduced and standard doses in patients with castration-resistant prostate cancer. Searches were limited to articles published in the English language. Outcome assessments included progression-free survival (PFS), overall survival (OS), adverse events, and serum prostate-specific antigen (PSA) response. Results: Ten studies met the inclusion criteria, including 2481 patients treated with Enzalutamide. Seven studies were retrospective cohorts, two were prospective trials, and one was a prospective cohort. No consistent relationship was identified between OS and PFS and the Enzalutamide dosage. Reduced doses of Enzalutamide decreased the incidence of adverse events, particularly among elderly patients. Conclusions: This systematic review suggests that reduced doses of Enzalutamide in CRPC may maintain therapeutic efficacy in selected patients while improving tolerability. However, inconsistent findings and methodological limitations highlight the need for prospective randomized trials to define optimal and individualized dosing strategies.

A randomized, open-label, multi-center, active-controlled phase II study comparing abiraterone acetate tablets (II), an improved formulation, versus originator abiraterone acetate in patients with metastatic castration-resistant prostate cancer

BACKGROUND

Abiraterone is a 17α-hydroxylase/C17-20 lyase inhibitor used for the treatment of metastatic castration-resistant prostate cancer (CRPC). This multi-center, randomized, open-label, active-controlled phase II study compared the pharmacodynamics (PD), pharmacokinetics (PK), and safety of abiraterone acetate tablets (II) (AAT[II]), a new formulation of abiraterone acetate, and ZYTIGA®, the originator abiraterone acetate (OAA), in patients with metastatic CRPC.

METHODS

Patients were randomized 1:1 to receive 300 mg AAT(II) daily plus 5 mg prednisone twice daily or 1000 mg OAA daily plus 5 mg prednisone twice daily for 84 days. The primary endpoint was the serum testosterone level (rounded-up) on Day 9 and/or Day 10. Absolute testosterone concentration, prostate-specific antigen (PSA) concentration, steady-state PK of abiraterone, and safety were also evaluated.

RESULTS

Sixty-nine patients were enrolled in the study, with 35 assigned to AAT(II) and 34 to OAA. The least squares (LS) mean (standard error) of serum testosterone concentration (rounded-up) on Day 9 and/or Day 10 were 1.075 (0.034) and 1.000 (0.034) in the AAT(II) and OAA groups, respectively. The geometric mean ratio (AAT[II] vs. OAA) was 1.053 (90% confidence interval [CI], 0.998 to 1.110) and the LS mean difference was 0.075 (95% CI, -0.021 to 0.171). The 90% CI fell within the 80.0% to 125.0% equivalence limits, suggesting equivalent PD effect of the two formulations. AAT(II) also exhibited high testosterone inhibition rate (> 90% at all visits) and PSA-50 rate (> 65% on Days 56 and 84), which were comparable to that of OAA. AAT(II) also demonstrated an improved safety profile with lower incidence of adverse events compared to OAA.

CONCLUSIONS

AAT(II) at 300 mg plus prednisone demonstrated equivalent PD as OAA at 1000 mg plus prednisone in reducing serum testosterone on Day 9 and/or Day 10, and the effect was maintained up to the end of the study. Compared to OAA, AAT(II) was given at a much lower dosage and was not affected by food consumption. AAT(II) was well tolerated, and no new safety issues were found.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT04862091.

Virtual High-Throughput Screening of Ligands for Disrupting PRMT5/pICLn Interaction in Prostate Cancer Cells

Prostate cancer (PC) is the most commonly diagnosed cancer in men worldwide. While androgen deprivation therapy (ADT) is initially effective, many patients develop resistance, progressing to castration-resistant prostate cancer (CRPC). Recent studies have identified the interaction between PRMT5 (protein arginine methyltransferase 5) and pICLn as a promising therapeutic target, as it promotes the transcription of double-strand break (DSB) repair genes that contribute to therapy resistance. To target this pathway, a screening campaign identified J021-0199 as a potential hit compound that disrupts the PRMT5/pICLn interaction. Biochemical assays demonstrated that J021-0199 binds to the N-terminal TIM barrel domain of PRMT5. In CRPC cell lines (LNCaP and 22Rv1), J021-0199 selectively inhibited cancer cell growth. qPCR analysis further revealed downregulation of DNA damage response (DDR) genes involved in homologous recombination, nonhomologous end joining, and G2 arrest. These results support J021-0199 as a promising lead compound for overcoming resistance in CRPC.

From Dose-Finding to Dose-Optimization in Early-Phase oncology clinical trials

Dose optimization in Phase I oncology trials balances therapeutic efficacy and patient safety. Traditional dose-escalation methods, such as the 3 + 3 design, primarily focus on safety, often resulting in prolonged exposure to subtherapeutic or excessively toxic doses. Additionally, these methods may fail to account for modern therapies' complex pharmacokinetics and pharmacodynamics, including targeted agents and immunotherapies. Contemporary approaches address these gaps by incorporating biomarkers, pharmacokinetic profiling, and patient-reported outcomes to guide personalized dosing strategies. Such methods improve the precision of dose selection and promote individualized cancer care. This review underscores the importance of distinguishing between dose-finding and dose optimization, advocating for designs that integrate patient perspectives and pharmacologic insights from early-phase trials. Additionally, we highlight the challenges of traditional methodologies and the importance of simplifying complex designs without compromising their scientific rigor. By embracing innovative approaches and patient-centered metrics, Phase I trials can evolve beyond safety assessments to expedite the delivery of effective and tailored cancer therapies.

Determining the optimal use of approved drugs in oncology

Optimising the use of approved drugs requires evidence from post-approval trials that investigate variations of their use. Determining optimal drug use goes beyond the dominant, academic effort to conduct trials to identify effective lower doses of new drugs. Other important therapeutic approaches that use either less, similar, or more drug than the standard dose need testing in clinical trials, to get the most out of these drugs. Trial objectives on survival outcomes vary greatly; some aim for superiority, others for equivalent exposure or non-inferiority. This Personal View aims to inform academic trialists in how to conceive and prioritise questions aimed at determining the optimal use of drugs, taking into account the perspectives of patients, clinicians, and trial funders, to maximise the chances of successful delivery and impact for patients globally.

Formulation-Based Cost Savings with Cabozantinib Capsules

This Viewpoint asserts that the formulation (tablet vs capsule) and the dosage of cabozantinib can be optimized to reduce toxicities and cost while maintaining efficacy.

Zoledronic acid in metastatic castrate-sensitive prostate cancer: A state-of-the-art review

Prostate cancer is the most common cancer in men in developed countries. Despite its slow growing pattern, metastatic disease to bone occurs and results in a significant number of deaths. Since more than eight decades, the classical androgen deprivation therapy (ADT) leads to clinical response in most patients with metastatic castration-sensitive prostate cancer (mCSPC). Moving backward docetaxel and androgen receptor pathway inhibitors (ARPI) from castrate-resistant setting to castrate sensitive setting improves overall survival (OS) compared to ADT alone. Recently, studies suggested that triplet therapy by adding ARPIs such as abiraterone acetate or darolutamide to ADT + docetaxel is more effective than ADT/docetaxel alone in patients with high-volume mCSPC. Although the scientific progress during the last decade, has led to improvements in outcome for patients with mCSPC, there are still several areas impacting daily practice, for which high-level evidence is lacking, especially for adding monthly zoledronic acid in this setting. We structured this review by conducting a comprehensive analysis of the existing literature. This manuscript reviews both the benefits and potential harms of zoledronic acid in the treatment of mCSPC and provides conclusions on the criteria for its use, and the possible use of alternative bone protecting agents (BPA).

Feasibility and efficacy of therapeutic drug monitoring of abiraterone in metastatic castration resistant prostate cancer patients

BACKGROUND

Previous studies demonstrated better outcomes for mCRPC (metastatic castration resistant prostate cancer) patients with higher abiraterone exposure (minimal plasma concentration (Cmin) > 8.4 ng/mL), but around 40% of patients experience exposure below this target. Pharmacokinetic (PK)-guided interventions following Therapeutic Drug Monitoring (TDM) could optimise exposure and outcomes. We aimed to evaluate the feasibility and effect on treatment outcomes of abiraterone TDM.

METHODS

Patients with low exposure levels (Low-group, Cmin < 8.4 ng/mL) got a PK-guided intervention. We compared exposure, adverse event (AE) incidence, time on treatment (ToT) and Prostate-Specific Antigen response rate (PSArr) between the Low-group and Adequate-group.

RESULTS

We included 167 mCRPC patients, with 56 in the Adequate-group and 111 in the Low-group. Interventions were successful 86% of the time. Exposure between groups became corresponding (Low-group: 7.95 to 20.5 ng/mL, Adequate-group: 20.8 ng/mL, p = 0.72) with comparable AE incidence (17% vs. 23%, p = 0.4). Median ToT and PSArr were similar (351 vs. 379 days, p = 0.35; 61.3% vs. 67.9%, p = 0.51).

CONCLUSIONS

PK-guided interventions improved above target exposure from 33.5% to 81.4% of patients without additional AEs. While historically, low exposure patients had significantly shorter survival, PK-guided interventions eliminated this disparity. As interventions are effective, low-cost and safe, TDM for abiraterone should be considered to enhance treatment outcomes.

Dose optimisation to improve access to effective cancer medicines

Access to many cancer medicines on WHO's Essential Medicines List (EML) is restricted because of price, especially in low-income and middle-income countries (LMICs). Other cancer medicines that have been shown to improve survival, such as immune checkpoint inhibitors for lung cancer, are not included on the EML because approved doses and schedules exceed affordable prices in LMICs. Multiple strategies are therefore needed to reduce medicine costs or circumvent these problems, such as optimising doses and schedules. Cancer medicines are approved by regulatory agencies, such as the US Food and Drug Administration and the European Medicines Agency, following rigorous clinical trials. However, these approvals can involve dosing regimens and treatment schedules that, although effective in showing statistically significant benefits in trials, can be higher in intensity, frequency, or duration than is necessary to achieve meaningful improved survival. In clinical practice, these regimens can lead to concerns about balancing optimal therapeutic outcomes with the risk of side-effects, patient quality of life, and long-term health effects. Various types of evidence can, and should, be used to explore and show near-equivalence of beneficial outcomes from reduced-intensity treatments, including randomised clinical trials, dose-finding phase 1 and 2 studies, and pharmacokinetic and pharmacodynamic studies. The positive effects of proving that lower doses or less intensive schedules retain therapeutic activity include reduced toxicity and large price reductions, leading to better cost-effectiveness and greater access to treatments that improve survival. Beyond regulatory approvals, identification of regimens that have similar outcomes with reduced doses and less intense schedules should be a priority for clinicians and policy makers in the selection process to identify effective medicines at national and global levels.

Androgen receptor dynamics in prostate cancer: from disease progression to treatment resistance

Prostate cancer is the most common cancer among men worldwide, especially in those over 65, and is a leading cause of cancer-related mortality. The disease typically advances from an androgen-dependent state to castration-resistant prostate cancer (CRPC), which poses significant treatment challenges. The androgen receptor (AR) on the X chromosome is a central driver in this process, activating genes that govern proliferation and survival. Mutations and amplifications of the AR are closely associated with disease progression and treatment resistance. While traditional therapies such as androgen deprivation therapy (ADT) and AR antagonists like enzalutamide have been effective, resistance persists due to reactivation of AR signaling through mechanisms like ligand-independent activation. Recent research highlights the role of epigenetic modifications in enhancing AR activity and drug resistance. The tumor microenvironment, particularly interactions with cancer-associated fibroblasts (CAFs) and tumor-associated macrophages (TAMs), further complicates treatment by promoting aggressive tumor behavior and immune evasion. Future directions include developing next-generation AR antagonists, identifying AR-related biomarkers for personalized therapy, and exploring combinations with immune checkpoint inhibitors. Additionally, basal cell-lumen-derived organoids provide innovative models that can enhance understanding and treatment strategies in prostate cancer.

A novel peptide encoded by circSRCAP confers resistance to enzalutamide by inhibiting the ubiquitin-dependent degradation of AR-V7 in castration-resistant prostate cancer

BACKGROUND

The sustained activation of androgen receptor splice variant-7 (AR-V7) is a key factor in the resistance of castration-resistant prostate cancer (CRPC) to second-generation anti-androgens such as enzalutamide (ENZ). The AR/AR-V7 protein is regulated by the E3 ubiquitin ligase STUB1 and a complex involving HSP70, but the precise mechanism remains unclear.

METHODS

High-throughput RNA sequencing was used to identify differentially expressed circular RNAs (circRNAs) in ENZ-resistant and control CRPC cells. The coding potential of circSRCAP was confirmed by polysome profiling and LC-MS. The function of circSRCAP was validated in vitro and in vivo using gain- and loss-of-function assays. Mechanistic insights were obtained through immunoprecipitation analyses.

RESULTS

A novel ENZ-resistant circRNA, circSRCAP, was identified and shown to be upregulated in ENZ-resistant C4-2B (ENZR-C4-2B) cells, correlating with increased AR-V7 protein levels. circSRCAP is generated via splicing by eIF4A3, forming a loop structure and is exported from the nucleus by the RNA helicase DDX39A. Mechanistically, circSRCAP encodes a 75-amino acid peptide (circSRCAP-75aa) that inhibits the ubiquitination of AR/AR-V7's co-chaperone protein HSP70 by disrupting the interaction with the E3 ligase STUB1. This process results in the upregulation of AR-V7 expression and promotes ENZ resistance in CRPC cells. Xenograft tumor models further confirmed the role of circSRCAP in CRPC progression and its potential as a therapeutic target for ENZ-resistant CRPC.

CONCLUSIONS

circSRCAP provides an epigenetic mechanism influencing AR-V7 stability and offers a promising therapeutic target for treating ENZ-resistant CRPC.

Real-world Efficacy and Safety of Low-Dose Abiraterone With Food and Standard-Dose Abiraterone in De Novo Metastatic Hormone-Sensitive Prostate Cancer: A Retrospective Analysis

BACKGROUND

The standard treatment for de novo metastatic hormone-sensitive prostate cancer (mHSPC) involves androgen deprivation therapy (ADT) combined with next-generation hormonal agents and/or docetaxel. While the standard dose (STD) of abiraterone is 1,000 mg administered while fasting, recent evidence suggests that a low dose (LOW) of 250 mg taken with a low-fat meal may achieve comparable pharmacokinetic outcomes.

OBJECTIVES

This study aimed to evaluate the failure-free survival (FFS) and safety of LOW and STD in de novo high-risk mHSPC patients.

MATERIALS AND METHODS

We conducted a retrospective analysis of males with de novo high-risk mHSPC treated with ADT plus abiraterone (250 mg with a low-fat meal or 1000 mg fasting) at the Vietnam National Cancer Hospital from January 2019 to May 2024. The primary endpoint was FFS, assessed using Kaplan-Meier and multivariate Cox regression analyses.

RESULTS

The study included 183 patients, with 91 in the LOW group and 92 in the STD group. The rates of patients who achieved undetectable PSA (PSA < 0.2 ng/ml) were 52.7% in the LOW group and 47.8% in the STD group. The median time to undetectable PSA was 6.9 months in the LOW group and 6.4 months in the STD group. The median overall FFS was 28.1 months (95% CI: 21.1 to 35.0) in the LOW group and 25.4 months (95% CI: 15.5 to 35.3) in the STD group (P = .286). Multivariate analysis indicated that visceral metastases and detectable PSA (PSA ≥ 0.2 ng/ml) were significant negative predictors of FFS in both groups. The incidence of grade 3 and grade 4 adverse events was similar between the LOW group and the STD group.

CONCLUSIONS

The LOW group and STD group showed effectiveness and safety in de novo high-risk mHSPC. The use of low-dose abiraterone in de novo mHSPC can significantly reduce treatment costs.

Amino polycarboxylic acids-modified abiraterone derivatives as potential injectable anti-prostate cancer agents

Abiraterone (Abi), an effective cytochrome oxidase P450 C17 (CYP17) inhibitor, inhibits androgen synthesis in testes, adrenal glands, and prostate tumors. However, their low bioavailability and dissolution rate due to their poor solubility and toxic side effects have hindered their clinical applications. In this study, water-soluble and injectable Abi derivatives were developed by introducing amino polycarboxylic acids into Abi, and their antiproliferation effects in vitro, mechanism of action, antitumor activities in vivo, pharmacokinetics, and toxicity were investigated. Compared to Abi, the water-soluble derivative Abi-DTPA exhibited excellent antitumor activity in vitro and in vivo. It decreased cell migration, invasion, and mitochondrial membrane potential. A mechanistic study revealed that it still targeted the CYP17 enzyme and increased the expression levels of apoptosis-related proteins, including cleaved caspase 9, cleaved PARP, and cleaved caspase 3. Abi-DTPA was the main form in the plasma and exhibited lower toxicity after intravenous administration. These findings suggest that Abi-DTPA can be used as a novel injectable anti-prostate cancer agent.

Real-world treatment trends for patients with advanced prostate cancer and renal cell carcinoma and their cost-a survey in Japan

BACKGROUND

Advanced (Stage IV) prostate and renal cancer have poor prognosis, and several therapies have been developed, but many are very costly. This study investigated drug regimens used in patients with untreated Stage IV prostate cancer and renal cell carcinoma and calculated the monthly cost of each.

METHODS

We surveyed first-line drugs administered to patients with untreated Stage IV prostate cancer and renal cancer at Japan Clinical Oncology Group affiliated centers from April 2022 to March 2023. Drug costs were calculated according to drug prices in September 2023. Individual drug costs were calculated or converted to 28-day costs.

RESULTS

A total of 700 patients with untreated Stage IV prostate cancer were surveyed. Androgen deprivation therapy + androgen receptor signaling inhibitor was the most common regimen (56%). The cost of androgen deprivation therapy + androgen receptor signaling inhibitor was 10.6-30.8-fold compared with conventional treatments. A total of 137 patients with Stage IV renal cancer were surveyed. Among them, 91% of patients received immune-oncology drug-based regimen. All patients received treatments with a monthly cost of ≥500 000 Japanese yen, and 80.4% of patients received treatments with a monthly cost of ≥1 million Japanese yen, of combination treatments. The cost of immune-oncology drug-based regimen was 1.2-3.1-fold that of TKI alone.

CONCLUSION

To the best of our knowledge, this is the first report of a survey of first-line drug therapy in untreated Stage IV prostate cancer and renal cell carcinoma stratified by age and treatment costs. Our results show that most Japanese patients received state-of-the-art, effective treatments with high financial burden.

Low-dose abiraterone plus Olaparib as a late-line treatment for mCRPC patients without BRCA1/2 mutations: a multicenter retrospective pilot study

Although overall survival data are still premature, the PROpel study found radiological progression-free survival (PFS) benefits of abiraterone and olaparib in patients with metastatic castration-resistant prostate cancer (mCRPC). However, for patients who have not been genetically tested or lack BRCA1/2 mutations (BRCAm), this combination therapy has been questioned as a first-line conventional treatment for mCRPC, mainly due to significant health economics and side effects. In our retrospective study, we found that treatment with low-dose abiraterone plus olaparib as a late-line treatment for mCRPC could lead to prostate-specific antigen (PSA) and symptom PFS in selective cases even without BRCAm. The median PSA-PFS was 8 months (IQR: 6.5-11.5), with a median follow-up duration of 39.0 months (IQR: 27.5-64.5). Gene tests were conducted in all patients, identifying non-BRCA mutations through ctDNA testing (24%), tumor tissue testing (12%), or both (64%). Adverse events occurred in 72% of patients, with 16% experiencing Grade ≥ 3 events. Common adverse events included anemia (64%), decreased appetite (48%), and fatigue (25%). Our findings support low-dose abiraterone plus olaparib as a potential option for mCRPC patients without BRCAm, offering manageable safety and efficacy profiles.

Optimising oncology drug expenditure in Ireland

A combination of improvements in patient survival, increasing treatment duration, and the development of more expensive agents has led to a doubling of per-capita spending on cancer medicines in Ireland (2008-2018). Despite this, access to new drugs is poor in comparison to other EU countries. We examine methods to optimise oncology drug spending to facilitate access to newer anticancer agents. Key targets for spending optimisation (biosimilar use, clinical trials and expanded access programs, waste reduction, avoidance of futile treatment, and altered drug scheduling) were identified through an exploratory analysis. A structured literature search was performed, with a focus on articles relevant to the Irish Healthcare system, supplemented by reports from statutory bodies. At the present time, EMA-approved agents are available once approved by the NCPE. Optimising drug costs occurs through guideline-based practice and biosimilar integration, the latter provides €80 million in cost savings annually. Access to novel therapies can occur via over 50 clinical trials and 28 currently available expanded access programmes. Additional strategies include reversion to weight-based immunotherapy dosing, potentially saving €400,000 per year in our centre alone, vial sharing, and optimisation of treatment schedules. A variety of techniques are being employed by oncologists to optimise costs and increase access to innovation for patients. Use of biosimilars, drug wastage, and prescribing at end of life should be audited as key performance indicators, which may lead to reflective practice on treatment planning. Such measures could further optimise oncology drug expenditure nationally facilitating approval of new agents.

Intra-individual Dose Escalation of Abiraterone According to Its Plasma Exposure in Patients with Progressive Metastatic Castration-Resistant Prostate Cancer: Results of the OPTIMABI Trial

BACKGROUND AND OBJECTIVE

Trough abiraterone concentration (ABI Cmin) of 8.4 ng/mL has been identified as an appropriate efficacy threshold in patients treated for metastatic castration-resistant prostate cancer (mCRPC). The aim of the phase II OPTIMABI study was to evaluate the efficacy of pharmacokinetics (PK)-guided dose escalation of abiraterone acetate (AA) in underexposed patients with mCRPC with early tumour progression.

METHODS

This multicentre, non-randomised study consisted of two sequential steps. In step 1, all patients started treatment with 1000 mg of AA once daily. Abiraterone Cmin was measured 22-26 h after the last dose intake each month during the first 12 weeks of treatment. In step 2, underexposed patients (Cmin < 8.4 ng/mL) with tumour progression within the first 6 months of treatment were enrolled and received AA 1000 mg twice daily. The primary endpoint was the rate of non-progression at 12 weeks after the dose doubling. During step 1, adherence to ABI treatment was assessed using the Girerd self-reported questionnaire. A post-hoc analysis of pharmacokinetic (PK) data was conducted using Bayesian estimation of Cmin from samples collected outside the sampling guidelines (22-26 h).

RESULTS

In the intention-to-treat analysis (ITT), 81 patients were included in step 1. In all, 21 (26%) patients were underexposed in step 1, and 8 of them (38%) experienced tumour progression within the first 6 months. A total of 71 patients (88%) completed the Girerd self-reported questionnaire. Of the patients, 62% had a score of 0, and 38% had a score of 1 or 2 (minimal compliance failure), without a significant difference in mean ABI Cmin in the two groups. Four patients were enrolled in step 2, and all reached the exposure target (Cmin > 8.4 ng/mL) after doubling the dose, but none met the primary endpoint. In the post-hoc analysis of PK data, 32 patients (39%) were underexposed, and ABI Cmin was independently associated with worse progression-free survival [hazard ratio (HR) 2.50, 95% confidence interval (CI) 1.07-5.81; p = 0.03], in contrast to the ITT analysis.

CONCLUSION

The ITT and per-protocol analyses showed no statistical association between ABI underexposure and an increased risk of early tumour progression in patients with mCRPC, while the Bayesian estimator showed an association. However, other strategies than dose escalation at the time of progression need to be evaluated. Treatment adherence appeared to be uniformly good in the present study. Finally, the use of a Bayesian approach to recover samples collected outside the predefined blood collection time window could benefit the conduct of clinical trials based on drug monitoring. OPTIMABI trial is registered as National Clinical Trial number NCT03458247, with the EudraCT number 2017-000560-15).

Optimizing the doses of cancer drugs after usual dose finding

Since the middle of the 20th century, oncology's dose-finding paradigm has been oriented toward identifying a drug's maximum tolerated dose, which is then carried forward into phase 2 and 3 trials and clinical practice. For most modern precision medicines, however, maximum tolerated dose is far greater than the minimum dose needed to achieve maximal benefit, leading to unnecessary side effects. Regulatory change may decrease maximum tolerated dose's predominance by enforcing dose optimization of new drugs. Dozens of already approved cancer drugs require re-evaluation, however, introducing a new methodologic and ethical challenge in cancer clinical trials. In this article, we assess the history and current landscape of cancer drug dose finding. We provide a set of strategic priorities for postapproval dose optimization trials of the future. We discuss ethical considerations for postapproval dose optimization trial design and review three major design strategies for these unique trials that would both adhere to ethical standards and benefit patients and funders. We close with a discussion of financial and reporting considerations in the realm of dose optimization. Taken together, we provide a comprehensive, bird's eye view of the postapproval dose optimization trial landscape and offer our thoughts on the next steps required of methodologies and regulatory and funding regimes.

Comparative analysis of real-world data of frequent treatment sequences in metastatic prostate cancer

Background

The incidence of prostate cancer is increasing worldwide. A significant proportion of patients develop metastatic disease and are initially prescribed androgen deprivation therapy (ADT). However, subsequent sequences of treatments in real-world settings that may improve overall survival remain an area of active investigation.

Materials and methods

Data were collected from 384 patients presenting with de novo metastatic prostate cancer from 2011 to 2015 at a tertiary cancer center. Patients were categorized into surviving (n = 232) and deceased (n = 152) groups at the end of 3 years. Modified sequence pattern mining techniques (Generalized Sequential Pattern Mining and Sequential Pattern Discovery using Equivalence Classes) were applied to determine the exact order of the most frequent sets of treatments in each group.

Results

Degarelix, as the initial form of ADT, was uniquely in the surviving group. The sequence of ADT followed by abiraterone and docetaxel was uniquely associated with a higher 3-year overall survival. Orchiectomy followed by fosfestrol was found to have a unique niche among surviving patients with a long duration of response to the initial ADT. Patients who received chemotherapy followed by radiotherapy and those who received radiotherapy followed by chemotherapy were found more frequently in the deceased group.

Conclusions

We identified unique treatment sequences among surviving and deceased patients at the end of 3 years. Degarelix should be the preferred form of ADT. Patients who received ADT followed by abiraterone and chemotherapy showed better results. Patients requiring palliative radiation and chemotherapy in any sequence were significantly more frequent in the deceased group, identifying the need to offer such patients the most efficacious agents and to target them in clinical trial design.

Cost-Effectiveness Analysis of Systemic Therapy for Intensification of Treatment in Metastatic Hormone-Sensitive Prostate Cancer in India

BACKGROUND AND OBJECTIVE

Androgen-deprivation therapy is the mainstay of treatment for patients with newly diagnosed metastatic hormone-sensitive prostate cancer (mHSPC). However, the intensification of treatment with either docetaxel or novel anti-androgens (abiraterone-acetate plus prednisone [AAP], enzalutamide, and apalutamide) is being recommended based on the improved clinical outcomes and quality of life among patients. This study aimed to determine the most cost-effective drug for treatment intensification for patients with mHSPC in India.

METHODS

A Markov model was developed with four health states: progression-free survival, progressive disease, best supportive care, and death. Lifetime costs and consequences were estimated for four treatment sequences: AAP-first, enzalutamide-first, apalutamide-first, and docetaxel-first. Incremental cost per quality-adjusted life-year (QALY) gained with a given treatment option was compared against the next best alternative and assessed for cost effectiveness using a willingness to pay threshold of 1 × per capita gross domestic product in India.

RESULTS

We estimated that the total lifetime cost per patient was ₹1,367,454 (US$17,487), ₹2,168,885 (US$27,735), ₹7,678,501 (US$98,190), and ₹1,358,746 (US$17,375) in the AAP-first, enzalutamide-first, apalutamide-first, and docetaxel-first treatment sequence, respectively. The mean quality-adjusted life-years lived per patient were 4.78, 5.03, 3.22, and 2.61, respectively. The AAP-first sequence incurs an incremental cost of ₹4014 (US$51) per quality-adjusted life-year gained as compared with the docetaxel-first sequence, with a 87% probability of being cost effective at the willingness-to-pay threshold of 1 × per-capita gross domestic product of India. The use of AAP-first also incurs an incremental net monetary benefit of ₹396,491 (US$5070) as compared with the docetaxel-first treatment sequence. Nearly a 48% reduction in the price of enzalutamide is required to make it a cost-effective treatment sequence as compared with AAP-first in India.

CONCLUSIONS

We concur with the inclusion of standard-dose AAP in India's publicly financed health insurance scheme for the intensification of treatment in mHSPC as it is the only cost-effective sequence among the various novel anti-androgens when compared with the docetaxel-first treatment sequence. Furthermore, a systematic reduction in the price of enzalutamide would further help to improve clinical outcomes among patients with mHSPC.

The Lancet Commission on prostate cancer: planning for the surge in cases

Prostate cancer is the most common cancer in men in 112 countries, and accounts for 15% of cancers. In this Commission, we report projections of prostate cancer cases in 2040 on the basis of data for demographic changes worldwide and rising life expectancy. Our findings suggest that the number of new cases annually will rise from 1·4 million in 2020 to 2·9 million by 2040. This surge in cases cannot be prevented by lifestyle changes or public health interventions alone, and governments need to prepare strategies to deal with it. We have projected trends in the incidence of prostate cancer and related mortality (assuming no changes in treatment) in the next 10–15 years, and make recommendations on how to deal with these issues.

For the Commission, we established four working groups, each of which examined a different aspect of prostate cancer: epidemiology and future projected trends in cases, the diagnostic pathway, treatment, and management of advanced disease, the main problem for most men diagnosed with prostate cancer worldwide. Throughout we have separated problems in high-income countries (HICs) from those in low-income and middle-income countries (LMICs), although we acknowledge that this distinction can be an oversimplification (some rich patients in LMICs can access high-quality care, whereas many patients in HICs, especially the USA, cannot because of inadequate insurance coverage). The burden of disease globally is already substantial, but options to improve care are already available at moderate cost. We found that late diagnosis is widespread worldwide, but especially in LMICs, where it is the norm. Early diagnosis improves prognosis and outcomes, and reduces societal and individual costs, and we recommend changes to the diagnostic pathway that can be immediately implemented. For men diagnosed with advanced disease, optimal use of available technologies, adjusted to the resource levels available, could produce improved outcomes. We also found that demographic changes (ie, changing age structures and increasing life expectancy) in LMICs will drive big increases in prostate cancer, and cases are also projected to rise in high-income countries. This projected rise in cases has driven the main thrust of our recommendations throughout. Dealing with this rise in cases will require urgent and radical interventions, particularly in LMICs, including an emphasis on education (both of health professionals and the general population) linked to outreach programmes to increase awareness. If implemented, these interventions would shift the case mix from advanced to earlier-stage disease, which in turn would necessitate different treatment approaches: earlier diagnosis would prompt a shift from palliative to curative therapies based around surgery and radiotherapy. Although age-adjusted mortality from prostate cancer is falling in HICs, it is rising in LMICs. And, despite large, well known differences in disease incidence and mortality by ethnicity (eg, incidence in men of African heritage is roughly double that in men of European heritage), most prostate cancer research has disproportionally focused on men of European heritage. Without urgent action, these trends will cause global deaths from prostate cancer to rise rapidly.

Pharmacy Assistance Programs for Oral Anticancer Drugs: A Narrative Review

Oral anticancer medications (OAMs) are high priced with a significant cost-sharing burden to patients, which can lead to catastrophic financial, psychosocial, and clinical repercussions. Cost-conscious prescribing and inclusion of low-cost alternatives can help mitigate this burden, but cost transparency at the point of prescribing remains a major barrier to doing so. Pharmacy assistance programs, including co-payment cards and patient assistance programs administered by manufacturers and foundation-based grants, remain an essential resource for patients facing prohibitive co-payments for OAMs. However, access to these programs is fraught with complexities, including lack of trained financial navigators, limited transparency on eligibility criteria, onerous documentation burdens, and limits in available funding. Despite these drawbacks and the potential for such programs to incentivize manufacturers to keep list prices high, assistance programs have been demonstrated to improve financial well-being for patients with cancer. The increasing development of integrated specialty pharmacies with dedicated, trained pharmacy staff can help improve and standardize access to such programs, but these services are disproportionately available to patients seen at tertiary care centers. Multistakeholder interventions are needed to mitigate the burden of cost sharing for OAMs, including increased clinician knowledge of financial resources and novel assistance mechanisms, investment of institutions in trained financial navigation services and centralized platforms to identify assistance programs, and policies to cap out-of-pocket spending and improve transparency of rates charged by pharmacy benefit managers to a health plan.

Opportunity Strikes for Reducing Cancer Drug Waste: Bortezomib as an Example of Vial Mis-Sizing in Oncology

Mis-sized packaging leads to millions of dollars in drug waste annually. Now is the time to act.

Prostate cancer management in Southeast Asian countries: a survey of clinical practice patterns

Background

Prostate cancer (PC) has a serious public health impact, and its incidence is rising due to the aging population. There is limited evidence and consensus to guide the management of PC in Southeast Asia (SEA). We present real-world data on clinical practice patterns in SEA for advanced PC care.

Method

A paper-based survey was used to identify clinical practice patterns and obtain consensus among the panelists. The survey included the demographics of the panelists, the use of clinical guidelines, and clinical practice patterns in the management of advanced PC in SEA.

Results

Most panelists (81%) voted prostate-specific antigen (PSA) as the most effective test for early PC diagnosis and risk stratification. Nearly 44% of panelists agreed that prostate-specific membrane antigen positron emission tomography-computed tomography imaging for PC diagnostic and staging information aids local and systemic therapy decisions. The majority of the panel preferred abiraterone acetate (67%) or docetaxel (44%) as first-line therapy for symptomatic mCRPC patients. Abiraterone acetate (50%) is preferred over docetaxel as a first-line treatment in metastatic castration-sensitive prostate cancer patients with high-volume disease. However, the panel did not support the use of abiraterone acetate in non-metastatic castration-resistant prostate cancer (nmCRPC) patients. Apalutamide (75%) is the preferred treatment option for patients with nmCRPC. The cost and availability of modern treatments and technologies are important factors influencing therapeutic decisions. All panelists supported the use of generic versions of approved therapies.

Conclusion

The survey results reflect real-world management of advanced PC in a SEA country. These findings could be used to guide local clinical practices and highlight the financial challenges of modern healthcare.

Global inequalities in availability of systemic therapies for cancer care and strategies to address them

Many Low and middle-income countries face challenges in delivering chemotherapy services due to limitations in infrastructure, inadequate healthcare facilities, and a shortage of trained medical professionals. High-income countries often have well-developed healthcare systems and advanced technology.

Unraveling Complexities in the Absorption and Disposition Kinetics of Abiraterone via Iterative PBPK Model Development and Refinement

BACKGROUND AND OBJECTIVE

Abiraterone is a first-in-class inhibitor of cytochrome P450 17A1 (CYP17A1), and its pharmacokinetic (PK) profile is susceptible to intrinsic and extrinsic variabilities. Potential associations between abiraterone concentrations and pharmacodynamic consequences in prostate cancer may demand further dosage optimization to balance therapeutic outcomes. Consequently, we aim to develop a physiologically based pharmacokinetic (PBPK) model for abiraterone via a middle-out approach to prospectively interrogate the untested, albeit clinically relevant, scenarios.

METHODS

To characterize in vivo hydrolysis of prodrug abiraterone acetate (AA) and supersaturation of abiraterone, in vitro aqueous solubility data, biorelevant measurements, and supersaturation and precipitation parameters were utilized for mechanistic absorption simulation. CYP3A4-mediated N-oxidation and sulfotransferase 2A1-catalyzed sulfation of abiraterone were subsequently quantified in human liver subcellular systems. Iterative PBPK model refinement involved evaluation of potential organic anion transporting polypeptide (OATP)-mediated abiraterone uptake in transfected cells in the absence and presence of albumin.

RESULTS

The developed PBPK model recapitulated the duodenal concentration-time profile of both AA and abiraterone after simulated AA administration. Our findings established abiraterone as a substrate of hepatic OATP1B3 to recapitulate its unbound metabolic intrinsic clearance. Further consideration of a transporter-induced protein-binding shift established accurate translational scaling factors and extrapolated the sinusoidal uptake process. Subsequent simulations effectively predicted the PK of abiraterone upon single and multiple dosing.

CONCLUSION

Our systematic development of the abiraterone PBPK model has demonstrated its application for the prospective interrogation of the individual or combined influences of potential interindividual variabilities influencing the systemic exposure of abiraterone.

Financial toxicity of oral therapies in advanced prostate cancer

The treatment landscape of advanced prostate cancer (CaP) has evolved significantly over the past 20 years. As the number of oral anticancer treatment options continues to increase, so do the costs of these drugs. Furthermore, payment responsibility for these treatments is increasingly shifted from insurers to patients. In this narrative review, we sought to summarize existing assessments of financial toxicity (FT) associated with oral advanced CaP treatments, describe efforts targeted at limiting FT from these agents, and identify areas in need of further investigation. FT is understudied in advanced CaP. Oral treatment options are associated with significantly higher direct costs to patients compared to standard androgen deprivation therapy or chemotherapy. Financial assistance programs, Medicare low-income subsidies, and recent health policy changes help offset these costs for some patients. Physicians are reluctant to discuss treatment costs with patients and further work is needed to better understand best practices for inclusion of FT discussions in shared decision-making. Oral therapies for advanced CaP are associated with significantly higher patient out-of-pocket costs which may contribute to FT. Currently, little is known regarding the extent and severity of these costs on patients' lives. While recent policy changes have helped reduce these costs for some patients, more work is needed to better characterize FT in this population to inform interventions that improve access to care and lessen the harms associated with the cost of novel treatments.

Clinical outcomes in patients with metastatic castrate-resistant prostate cancer treated with abiraterone with or without ongoing androgen deprivation therapy: A retrospective case-control study

INTRODUCTION

Abiraterone and concurrent androgen deprivation therapy (ADT) are used in the treatment of patients with metastatic castration-resistant prostate cancer. Recently, it has been suggested that the use of abiraterone alone (without ADT) may have comparable efficacy to abiraterone with ongoing ADT. Here, we sought to assess the impact of ADT cessation in patients beginning abiraterone for castration-resistant prostate cancer.

METHODS

We identified 39 patients at our institution who received abiraterone alone (with discontinuation of ADT) between 2011 and 2022. We then procured a comparable group of 39 patients (matched by age, Gleason score, and prostate-specific antigen [PSA] level) who received abiraterone with ongoing ADT during the same period. We assessed and compared clinical outcomes in the two groups (abiraterone-alone vs. abiraterone-ADT) with respect to PSA response rates, PSA progression-free survival, and overall survival. Results were adjusted using Cox proportional-hazards multivariable models.

RESULTS

The median PSA before treatment initiation was 12.7 (range: 0.2-199) ng/mL in the abiraterone-alone group and 15.5 (range: 0.6-212) ng/mL in the abiraterone-ADT group. Use of abiraterone alone adequately suppressed testosterone levels in 35/37 (94.6%) patients. Patients receiving abiraterone alone had a median PSA reduction of 80.2% versus 79.5% in patients receiving abiraterone plus ADT. The median PSA progression-free survival in patients receiving abiraterone alone was 27.4 versus 25.8 months in patients receiving abiraterone plus ADT (hazard ratio [HR] 1.10; 95% confidence interval [CI] 0.65-1.71; p = 0.82). In addition, abiraterone alone was associated with an overall survival of 3.6 versus 3.1 years in patients receiving abiraterone plus ADT (HR 0.90; 95% CI 0.50-1.62; p = 0.72). There were no differences in PFS or OS between groups after performing Cox multivariable regression analyses.

CONCLUSION

Use of abiraterone alone was associated with comparable clinical outcomes to patients who received abiraterone together with ADT. Further prospective studies are warranted to evaluate the impact of abiraterone alone on treatment outcomes and cost savings.

Outcomes and toxicity of oral Fosfestrol in metastatic castration-resistant prostate cancer-a real-world experience

Introduction

Although there are multiple drugs approved for the treatment of metastatic castration-resistant prostate cancer (CRPC), the cost can be a limiting factor in using them in a resource-limited setting. Therefore, less expensive alternatives are the need of the hour. We have been using Fosfestrol which is a cheap and orally administered oestrogen analogue in metastatic CRPC. We carried out a retrospective study to analyse its efficacy and toxicity.

Results

A total of 65 patients received Fosfestrol during 2015-2020. The median age was 65 years (range 50-83 years). Thirty-four patients (53%) had other medical comorbidities. Skeletal-only metastasis was the commonest pattern of metastasis (n = 41, 64%) followed by skeletal with nodal metastasis (n = 15, 23%). The majority of the patients had undergone upfront surgical castration (n = 60, 93%). All the patients had adenocarcinoma and 38 patients (58%) had a high Gleason's score. Forty-one patients (63%) had a prostate-specific antigen (PSA) response (decrease of ≥50% in the PSA concentration from the pre-treatment baseline PSA value) and 54 patients (83%) had a symptomatic response. At the end of a median follow-up of 16 months, the median progression-free survival (PFS) was 8.3 months (CI 4.7-11.8) and the median overall survival (OS) was 27.5 months (CI 25.4-29.5). PSA response and prior treatment with abiraterone acetate were found to have a significant association with survival outcomes. Patients with PSA response had better median PFS and OS; while patients who have received prior abiraterone acetate therapy had worse survival outcomes. Twenty-nine patients (45%) received some form of subsequent treatment after stopping Fosfestrol. The most common oxicity observed was thrombosis (n = 9, 13%) followed by gynecomastia (n = 4, 6%).

Conclusion

We conclude that oral Fosfestrol is a cheap and effective agent in the armamentarium against metastatic CRPC and warrants further studies in a clinical trial setting.

Dose optimization during drug development: whether and when to optimize

The goal of dose optimization during drug development is to identify a dose that preserves clinical benefit with optimal tolerability. Traditionally, the maximum tolerated dose in a small phase I dose escalation study is used in the phase II trial assessing clinical activity of the agent. Although it is possible that this dose level could be altered in the phase II trial if an unexpected level of toxicity is seen, no formal dose optimization has routinely been incorporated into later stages of drug development. Recently it has been suggested that formal dose optimization (involving randomly assigning patients between 2 or more dose levels) be routinely performed early in drug development, even before it is known that the experimental therapy has any clinical activity at any dose level. We consider the relative merits of performing dose optimization earlier vs later in the drug development process and demonstrate that a considerable number of patients may be exposed to ineffective therapies unless dose optimization is delayed until after clinical activity or benefit of the new agent has been established. We conclude that patient and public health interests may be better served by conducting dose optimization after (or during) phase III evaluation, with some exceptions when dose optimization should be performed after activity shown in phase II evaluation.

Pharmacokinetics of cancer therapeutics and energy balance: the role of diet intake, energy expenditure, and body composition

Energy balance accounts for an individual's energy intake, expenditure, and storage. Each aspect of energy balance has implications for the pharmacokinetics of cancer treatments and may impact an individual's drug exposure and subsequently its tolerance and efficacy. However, the integrated effects of diet, physical activity, and body composition on drug absorption, metabolism, distribution, and excretion are not yet fully understood. This review examines the existing literature on energy balance, specifically the role of dietary intake and nutritional status, physical activity and energy expenditure, and body composition on the pharmacokinetics of cancer therapeutics. As energy balance and pharmacokinetic factors can be influenced by age-related states of metabolism and comorbidities, this review also explores the age-related impact of body composition and physiologic changes on pharmacokinetics among pediatric and older adult populations with cancer.

REFINE-Lung implements a novel multi-arm randomised trial design to address possible immunotherapy overtreatment

Increasing evidence suggests that some immunotherapy dosing regimens for patients with advanced cancer could result in overtreatment. Given the high costs of these agents, and important implications for quality of life and toxicity, new approaches are needed to identify and reduce unnecessary treatment. Conventional two-arm non-inferiority designs are inefficient in this context because they require large numbers of patients to explore a single alternative to the standard of care. Here, we discuss the potential problem of overtreatment with anti-PD-1 directed agents in general and introduce REFINE-Lung (NCT05085028), a UK multicentre phase 3 study of reduced frequency pembrolizumab in advanced non-small-cell lung cancer. REFINE-Lung uses a novel multi-arm multi-stage response over continuous interventions (MAMS-ROCI) design to determine the optimal dose frequency of pembrolizumab. Along with a similarly designed basket study of patients with renal cancer and melanoma, REFINE-Lung and the MAMS-ROCI design could contribute to practice-changing advances in patient care and form a template for future immunotherapy optimisation studies across cancer types and indications. This new trial design is applicable to many new or existing agents for which optimisation of dose, frequency, or duration of therapy is desirable.

Low-Dose Immunotherapy: Is It Just an Illusion?

The development and use of immunotherapy in the last decade have led to a drastic improvement in results in the onco-haematological field. This has implied, on the one hand, the need for clinicians to manage a new type of adverse event and, on the other hand, a significant increase in costs. However, emerging scientific evidence suggests that, as with other drugs in the recent past, the registry dosage can be drastically reduced for immunotherapies without penalizing their effectiveness. This would also lead to an important reduction in costs, expanding the audience of cancer patients who could access immunotherapy-based treatments. In this “Commentary”, we analyze the available evidence of pharmacokinetics and pharmacodynamics and the most recent literature in favor of low-dose immunotherapy.

Novel hormonal therapies in the management of advanced prostate cancer: extrapolating Asian findings to Southeast Asia

There is a paucity of information on the use of novel hormonal agents in Southeast Asian patients. We reviewed the clinical roles of novel hormonal therapy (NHT), namely abiraterone acetate (AA), enzalutamide, apalutamide and darolutamide, in the management of advanced prostate cancer, and data on its use in Asian patients, in order to extrapolate these findings to the Southeast Asian patient population. There are some differences in the molecular features between the NHTs, which influenced their respective permeabilities through the blood-brain barrier. The Asian sub-analyses of the landmark studies of each NHT were limited. The primary endpoints of the Asian sub-analyses generally reflect the efficacy outcomes of the respective landmark study. Hypertension, fatigue, musculoskeletal disorders, rash, and hot flushes were among the common toxicities observed in Asian patients. Real-world data on AA in the Asian setting is favourable, but data is limited for enzalutamide, apalutamide and darolutamide. Based on the sub-analyses and real-world data, the efficacy and safety of NHTs in the Asian patients showed a similar trend to the respective landmark studies. The lack of clinical trials in the Southeast Asian region hampers the ability to make a robust conclusion on any specific efficacy or safety differences that may be present; clinicians must assume that the broader Asian sub-analyses and real-world data reflects Southeast Asian patients' outcomes.

Impact of trough abiraterone level on adverse events in patients with prostate cancer treated with abiraterone acetate

PURPOSE

We assessed the impact of plasma trough concentrations of abiraterone (ABI) and its metabolite Δ4-abiraterone (D4A) and related polymorphisms on adverse events (AEs) in patients with metastatic prostate cancer who received abiraterone acetate (AA).

METHODS

This prospective study enrolled patients with advanced prostate cancer treated with AA between 2016 and 2021. Plasma trough concentrations of ABI and D4A were measured using high-performance liquid chromatography. The impact of HSD3B1 rs1047303, SRD5A2 rs523349, and cytochrome P450 family 3A member 4 rs2242480 polymorphisms on plasma concentrations of ABI and D4A and the incidence of AEs were also assessed.

RESULTS

In 68 patients treated with AA, the median ABI and D4A concentrations were 18.1 and 0.94 ng/mL, respectively. The high plasma trough concentration of ABI (≥ 20.6 ng/mL) was significantly associated with the presence of any AE and its independent risk factor based on multivariable analysis (odds ratio, 7.20; 95% confidence interval (CI): 2.20-23.49). Additionally, a high plasma trough concentration of ABI was an independent risk factor of time to withdraw AA (hazard ratio, 4.89; 95% CI: 1.66-14.38). The risk alleles of three polymorphisms were not statistically associated with the ABI and D4A concentrations and the incidence of AEs.

CONCLUSIONS

The plasma trough concentration of ABI is associated with the presence of AEs and treatment failure after AA administration. ABI concentration monitoring may be useful in patients with prostate cancer who received AA.

Treatment of Patients with Metastatic Hormone-Sensitive Prostate Cancer: A Systematic Review of Economic Evaluations

The management of patients with metastatic hormone-sensitive prostate cancer (mHSPC) has been significantly modified by the availability of innovative but expensive treatments, increasing the economic burden of prostate cancer. Here, we aimed to systematically identify and review published economic evaluations (EEs) related to the treatment of mHSPC and assess their quality. A systematic search was performed of the PubMed and Cochrane databases. Three reviewers independently selected EEs by defined inclusion and exclusion criteria. They extracted all data from each EE (general information, study population, data about the EE, interventions and comparators, and outcomes). They also assessed the quality of the selected EEs according to Drummond's checklist. Fourteen EEs published between 2016 and 2021 were eligible for the systematic review. The EEs found ADT + docetaxel to be the most cost-effective of all available treatments as a first-line strategy for mHSPC (abiraterone acetate plus prednisone, enzalutamide, and apalutamide). Five EEs showed that a simple price reduction of abiraterone acetate of 50% to 75% could change the results to render this treatment also cost-effective relative to that with docetaxel. Twelve EEs were of high quality, with a Drummond score ≥ 7. Analysis of the 14 EEs identified by our systematic review, amongst which 78.6% met high quality standards, showed that ADT + docetaxel tends to be the most cost-effective alternative for mHSPC. These results were assessed by sensitivity analysis. The data provided by this systematic review help to provide a better understanding of these treatments and the better use of healthcare resources.

Low-Dose Enzalutamide in Metastatic Prostate Cancer-Longevity Over Conventional Survival Analysis

BACKGROUND

Enzalutamide is an important drug in the treatment of prostate cancer. Standard dosing often requires dose reduction because of side effects. There is no information on survival outcomes with lower doses. We investigated the impact of starting enzalutamide at ≤ 50% dose on metastatic prostate cancer outcomes including patients' longevity.

PATIENTS AND METHODS

Records of metastatic prostate cancer patients treated with enzalutamide at one center were retrospectively reviewed. Low-dose enzalutamide (≤80 mg/day) was compared with standard-dose (160 mg/day). The primary objective was to compute the restricted mean survival time (RMST - time scale) and restricted mean attained age (RMAA - age scale) using the Irwin method. Secondary objectives included overall survival (OS), progression-free survival (PFS), and PSA progression per PCWG3 criteria (PSA PFS). We used the logrank test and the ∆ difference between RMSTs for comparison.

RESULTS

Of 111 patients treated, 32 received a low-dose and 79 the standard-dose. Low-dose patients had less prior abiraterone or chemotherapy (28.1% vs. 65.8%, P < .001); more testosterone assessment (65.6% vs. 40.5%, P = .016); poorer ECOG performance status (48.3% score ≥2 vs. 26.6%; P = .040), more comorbidities (75.9% vs. 46.3%; P = .010)) including increased cardiovascular disease (51.7% vs. 21.4%, P = .004). Baseline PSA value and doubling time at start of enzalutamide and distribution of metastases were similar between the groups. OS and PFS did not differ between low-dose and standard-dose. Patients on low-dose had a better longevity with significantly longer RMAA, 89.1 years, versus standard-dose RMAA of 83.8 years (∆ = 5.3 years, P = .003, logrank P = .025). In a subgroup analysis by age at start of enzalutamide, <75 versus ≥75 years old, longevity was also better with low-dose in younger patients (∆ = 2.9 years, P = .034, and older, ∆ = 3.3 years, P = .011).

CONCLUSION

The longevity advantage and reduced adverse events seen in patients with prostate cancer treated with low-dose enzalutamide warrants further investigation.

Efficacy and safety of therapies for advanced prostate cancer in Asia: Evidence from a systematic literature review

Objectives

Several therapies are available for the treatment of advanced/metastatic prostate cancer (PC). However, the systematic assessment of evidence pertaining to the use of these therapies in Asian patients is lacking.

Methods

A systematic literature review (SLR) was conducted using PubMed/Medline search in May 2021 to identify the randomized/nonrandomized controlled trials (RCTs/non-RCTs) and real-world observational studies (prospective/retrospective). Only studies published as full manuscripts in English were included if reporting the efficacy, effectiveness, and/or safety of treatments in Asian patients with advanced/metastatic PC.

Results

Of the 1,898 retrieved publications, 24 studies were included. These studies had patients with nonmetastatic castration-resistant PC (n = 2), metastatic castration-sensitive PC (n = 4), and metastatic castration-resistant PC (n = 18). Study designs included RCTs (n = 7), non-RCTs (n = 2), and real-world studies (n = 15). Treatments used in included studies were abiraterone acetate plus prednisone (AAP; n = 6), enzalutamide, lutetium-177 prostate-specific membrane antigen (177Lu-PSMA; n = 4 each), docetaxel (n = 3), apalutamide, radium-223 (n = 2 each), darolutamide, cabazitaxel, and pembrolizumab (n = 1 each). The evidence from RCTs (i.e., ARAMIS, SPARTAN, ARCHES, TITAN, LATITUDE, PREVAIL) demonstrated the clinical benefits of apalutamide, darolutamide, enzalutamide, and AAP in terms of overall, disease-free, and metastasis-free survival in Asian patients. These treatments were reported to be well tolerated, with no new safety signals identified in Asian population. The efficacy and safety profiles in Asian patients were consistent with the overall trial population. Data from real-world studies supported the effectiveness and tolerability of AAP, enzalutamide, radium-223, docetaxel, cabazitaxel, 177Lu-PSMA, and pembrolizumab in patients with advanced/metastatic PC.

Conclusions

This SLR of the Asian data on therapies for advanced PC from the pivotal and real-world studies confirms similar efficacy and safety outcomes, consistent with the results from the pivotal clinical trials. These findings will help clinicians make better treatment decisions in clinical practice for patients with advanced/metastatic PC.

Functional impact of androgen-targeted therapy on patients with castration-resistant prostate cancer

Context

Second-generation androgen receptor inhibitors (ARIs) extend metastasis-free survival, prolong overall survival, and delay symptoms when added to androgen deprivation therapy for the treatment of castration-sensitive or castration-resistant prostate cancer (CRPC). However, ARIs may adversely impact physical and cognitive function, thereby decreasing quality of life and prognosis.

Objective

To evaluate the evidence regarding the potential effects of ARIs on physical and cognitive function and to contextualize how drug-related adverse effects may influence treatment decisions in CRPC.

Evidence acquisition

We performed a literature search using MEDLINE from January 1998 to June 2020 using terms relating to prostate cancer, androgen deprivation, and physical and cognitive function. We selected 61 publications for analysis.

Evidence synthesis

Treatment-induced deterioration in physical and cognitive function may impair the independence and well-being of patients with CRPC. Patient-reported outcomes from clinical trials of ARIs provide quantitative evidence of their impact on these domains, which appears to vary between ARIs, reflecting the different adverse event profiles of these agents. Thus, the risk of physical or cognitive dysfunction may be managed or mitigated by appropriate selection of treatment options. Studies in patients with CRPC have assessed the cognitive effects of ARIs with validated instruments, whereas quantitative analysis of the impact on physical function has been limited.

Conclusion

Several validated instruments utilized for the assessment of physical and cognitive function in clinical studies have been adapted for clinical practice; however, consensus on the standardization of these assessments is required. Future clinical studies employing validated tools may generate data on the impact of ARIs and guide treatment decisions for patients with CRPC.

Patient summary

We review the hormonal therapies used to treat men with prostate cancer and the effects they have on physical and cognitive function. We discuss how to measure these effects and how this may assist when choosing treatment.

A phase I study of capivasertib in combination with abiraterone acetate in patients with metastatic castration-resistant prostate cancer

BACKGROUND

Although androgen receptor-targeted agents prolong the lives of patients with metastatic prostate cancer, patients develop therapy resistance and most ultimately succumb to the disease. The PI3K/AKT/PTEN pathway has been associated with the development of resistance, raising the possibility that pathway inhibitors may produce a clinical benefit. This open-label phase Ib study examined the safety, tolerability, pharmacokinetics (PK) and preliminary clinical activity of adding capivasertib - a potent, selective inhibitor of AKT1/2/3 - to approved abiraterone acetate therapy.

METHODS

Twenty-seven patients with metastatic castration-resistant prostate cancer who had undergone at least 1 prior line of systemic therapy received abiraterone acetate 1000 mg (orally administered once daily), plus oral prednisone 5 mg (twice daily) with capivasertib 400 mg (orally, twice daily, with an intermittent schedule of 4 days on, 3 days off).

RESULTS

No dose-limiting toxicity was observed. The most frequent adverse events (all grade) were diarrhea (30%), anemia (26%), asthenia (22%), and nausea (22%). The most frequent grade 3 or higher adverse events were acute kidney injury (19%), hyperglycemia (7%), rash (7%), abdominal pain (7%), and asthenia (7%). Capivasertib and abiraterone PK were consistent with previously reported results from monotherapy dosing. Nine participants (33%) showed a 20% or greater decrease in prostate-specific antigen during study treatment.

CONCLUSION

The combination of capivasertib and abiraterone acetate had an acceptable tolerability profile consistent with the known profile of each agent. These data support further evaluation of capivasertib and abiraterone acetate in patients with advanced prostate cancer.

Modern developments in germline pharmacogenomics for oncology prescribing

The integration of genomic data into personalized treatment planning has revolutionized oncology care. Despite this, patients with cancer remain vulnerable to high rates of adverse drug events and medication inefficacy, affecting prognosis and quality of life. Pharmacogenomics is a field seeking to identify germline genetic variants that contribute to an individual's unique drug response. Although there is widespread integration of genomic information in oncology, somatic platforms, rather than germline biomarkers, have dominated the attention of cancer providers. Patients with cancer potentially stand to benefit from improved integration of both somatic and germline genomic information, especially because the latter may complement treatment planning by informing toxicity risk for drugs with treatment-limiting tolerabilities and narrow therapeutic indices. Although certain germline pharmacogenes, such as TPMT, UGT1A1, and DPYD, have been recognized for decades, recent attention has illuminated modern potential dosing implications for a whole new set of anticancer agents, including targeted therapies and antibody-drug conjugates, as well as the discovery of additional genetic variants and newly relevant pharmacogenes. Some of this information has risen to the level of directing clinical action, with US Food and Drug Administration label guidance and recommendations by international societies and governing bodies. This review is focused on key new pharmacogenomic evidence and oncology-specific dosing recommendations. Personalized oncology care through integrated pharmacogenomics represents a unique multidisciplinary collaboration between oncologists, laboratory science, bioinformatics, pharmacists, clinical pharmacologists, and genetic counselors, among others. The authors posit that expanded consideration of germline genetic information can further transform the safe and effective practice of oncology in 2022 and beyond.

Health Disparities in Prostate Cancer and Approaches to Advance Equitable Care

The American Cancer Society estimates approximately 268,490 new cases of prostate cancer and approximately 34,500 deaths caused by prostate cancer in the United States for 2022. Globally, a total of 1,414,259 new cases of prostate cancer and 375,304 related deaths were reported in 2020. Well-documented health disparities and inequities exist along the continuum of care for prostate cancer management-from screening to diagnostic and staging work-up, surveillance, and treatment-ultimately impacting clinical outcomes. This session-based article discusses innovative patient-centered approaches to advance equitable prostate cancer care. It begins with a review of domestic health disparities in diagnostic imaging and radiotherapy for prostate cancer, and it summarizes barriers and solutions to achieving health equity, such as equity metrics and practice quality improvement projects. Next, a global perspective is provided that describes approaches to address financial and geographic barriers to prostate cancer care, including specific examples of strategies that emphasize the use of the cheapest method of care delivery while maintaining outcomes for drug delivery and radiotherapy.

Cost-utility analysis of adding abiraterone acetate plus prednisone/prednisolone to long-term hormone therapy in newly diagnosed advanced prostate cancer in England: Lifetime decision model based on STAMPEDE trial data

Adding abiraterone acetate (AA) plus prednisolone (P) to standard of care (SOC) improves survival in newly diagnosed advanced prostate cancer (PC) patients starting hormone therapy. Our objective was to determine the value for money to the English National Health Service (NHS) of adding AAP to SOC. We used a decision analytic model to evaluate cost-effectiveness of providing AAP in the English NHS. Between 2011-2014, the STAMPEDE trial recruited 1917 men with high-risk localised, locally advanced, recurrent or metastatic PC starting first-line androgen-deprivation therapy (ADT), and they were randomised to receive SOC plus AAP, or SOC alone. Lifetime costs and quality-adjusted life-years (QALYs) were estimated using STAMPEDE trial data supplemented with literature data where necessary, adjusting for baseline patient and disease characteristics. British National Formulary (BNF) prices (£98/day) were applied for AAP. Costs and outcomes were discounted at 3.5%/year. AAP was not cost-effective. The incremental cost-effectiveness ratio (ICER) was £149,748/QALY gained in the non-metastatic (M0) subgroup, with 2.4% probability of being cost-effective at NICE's £30,000/QALY threshold; and the metastatic (M1) subgroup had an ICER of £47,503/QALY gained, with 12.0% probability of being cost-effective. Scenario analysis suggested AAP could be cost-effective in M1 patients if priced below £62/day, or below £28/day in the M0 subgroup. AAP could dominate SOC in the M0 subgroup with price below £11/day. AAP is effective for non-metastatic and metastatic disease but is not cost-effective when using the BNF price. AAP currently only has UK approval for use in a subset of M1 patients. The actual price currently paid by the English NHS for abiraterone acetate is unknown. Broadening AAP's indication and having a daily cost below the thresholds described above is recommended, given AAP improves survival in both subgroups and its cost-saving potential in M0 subgroup.