Low-Dose Abiraterone in Metastatic Prostate Cancer: Is It Practice Changing? Facts and Facets

Selective treatment de-escalation in advanced prostate cancer: have we come full circle?

Compelling evidence has solidified the notion of early treatment intensification in managing patients with metastatic hormone-sensitive prostate cancer (mHSPC). Landmark trials have provided Level 1 evidence for the survival benefits achieved by combining multiple agents. The efficacy of combined therapy relies not only on how treatment is intensified but also on how it is de-escalated. This underscores the importance of tailored treatment approaches, potentially involving a reduction in therapy for specific patients, to strike a balance between the benefits of hormonal treatment and its associated adverse effects. While de-escalation of therapy in mHSPC remains challenging due to limited evidence, it is recommended for elderly or frail patients, those with poor performance status, or experiencing significant toxicity. However, for patients with excellent prostate-specific antigen responses or favourable biomarkers, decisions should be personalised, weighing the potential benefits of continued treatment against the risk of long-term side effects, using risk stratification tools where appropriate.

Sotorasib's Accelerated Approval: Wrong Dose and Indication

This Viewpoint reviews the accelerated approval process and lack of postapproval studies to verify its benefit as it applied to sotorasib, a treatment for non–small cell lung cancer with the KRASg12c mutation, and recommends measures to ensure confirmatory follow-up studies.

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.

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.

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.

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.

Priorities for cancer research in low- and middle-income countries: a global perspective

Cancer research currently is heavily skewed toward high-income countries (HICs), with little research conducted in, and relevant to, the problems of low- and middle-income countries (LMICs). This regional discordance in cancer knowledge generation and application needs to be rebalanced. Several gaps in the research enterprise of LMICs need to be addressed to promote regionally relevant research, and radical rethinking is needed to address the burning issues in cancer care in these regions. We identified five top priorities in cancer research in LMICs based on current and projected needs: reducing the burden of patients with advanced disease; improving access and affordability, and outcomes of cancer treatment; value-based care and health economics; quality improvement and implementation research; and leveraging technology to improve cancer control. LMICs have an excellent opportunity to address important questions in cancer research that could impact cancer control globally. Success will require collaboration and commitment from governments, policy makers, funding agencies, health care organizations and leaders, researchers and the public.

Alternative trastuzumab dosing strategies in HER2-positive early breast cancer are associated with patient out-of-pocket savings

Patients with breast cancer frequently experience financial hardship, often due to the high costs of anti-cancer drugs. We sought to develop alternative trastuzumab dosing strategies, compare their pharmacokinetic effectiveness to standard dosing, and assess the expected financial implications of transitioning to them. We extracted clinical data from the records of 135 retrospectively identified patients with HER2-positive early breast cancer at a single, urban comprehensive cancer center who were treated with trastuzumab between 2017 and 2019. We performed pharmacokinetic simulations on a range of trastuzumab dose levels and frequencies, assessing efficacy by trough trastuzumab concentration (Ctrough) and population and individual likelihoods of Ctrough exceeding trastuzumab minimum effective concentration (MEC). We performed deterministic financial modeling to estimate the treatment-associated financial savings from alternative dosing strategies. Trastuzumab maintenance doses of 4 mg/kg every 3 weeks (Q3W) and 6 mg/kg every 4 weeks (Q4W) had nearly identical probabilities of Ctrough being above MEC as standard of care 6 mg/kg every 3 weeks. In the primary financial analysis, both trastuzumab 4 mg/kg Q3W and 6 mg/kg Q4W were associated with significant drug- and administration-related out-of-pocket cost savings over the duration of therapy, ranging from $765 (neoadjuvant, Q4W) to $2791 (adjuvant, Q4W). In particular, Q4W trastuzumab increased savings related to lost wages and travel cost avoidance. Low-dose and reduced frequency trastuzumab in appropriately selected patients may significantly reduce total drug utilization and meaningfully reduce patient financial toxicity. Prospective clinical trials evaluating low-dose or reduced-frequency administration of therapeutic monoclonal antibodies are warranted and needed.

Comparison of out-of-pocket costs and adherence between the two arms of the prospective, randomized abiraterone food effect trial

PURPOSE

Abiraterone acetate, prescribed for metastatic prostate cancer, has enhanced absorption with food. This effect was exploited in a randomized trial which showed noninferiority of PSA decline for 250 mg abiraterone with a low-fat meal (LOW) compared to 1,000 mg abiraterone fasting (STD). Drug was obtained via patient insurance. Patient out-of-pocket costs and adherence were surveyed.

METHODS

Trial participants were randomized to STD or LOW, and surveys of adherence and out-of-pocket costs were administered at baseline and just before coming off study (follow-up).

RESULTS

Out-of-pocket costs were available from 20 of 36 STD and 21 of 36 LOW patients. Median out-of-pocket costs for a month of drug were $0 (LOW) and $5 (STD); mean costs were $43.61 (LOW) and $393.83 (STD). The two groups did not differ significantly (p = 0.421). Maximum out-of-pocket cost was $1,000 (LOW) and $4,000 (STD). Monthly out-of-pocket costs > $500 were found in 1 LOW and 5 STD patients. For adherence, only 11 STD and 19 LOW patients had questionnaires completed at both baseline and follow-up. STD adherence was 98.18% at baseline and 91.69% at follow-up, differing significantly (p = 0.0078). LOW adherence was 96.52% at baseline and 97.86% at follow-up, not differing significantly (p = 0.3511). Adherence did not correlate with demographics. At follow-up, increasing adherence correlated significantly with decreasing dose (p = 0.013; rho =  - 0.458).

CONCLUSIONS

Out-of-pocket costs did not differ significantly in this limited analysis. Adherence was significantly different in STD as the trial progressed, which was not found in LOW.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01543776; registered March 5, 2012.

Is Low-Dose Abiraterone for Prostate Cancer An Attractive Strategy for Limited Resource Settings?

Abiraterone acetate in combination with prednisone is approved for locally advanced as well as metastatic (hormone-sensitive and castrate-resistant) prostate cancer, with overall or disease-free survival gains in suitable patients. Long-term use poses a significant financial strain on the self-paying patients as well as the national health insurance schemes. Abiraterone is known to be a drug with a high “food effect” with increased bioavailability following high fat diet. Some retrospective series and phase 1 and 2 clinical studies have explored the use of low-dose abiraterone (at 25% of standard dose) with high fat meal with similar bioavailability and biochemical response to the standard drug dose. We review and report the available literature for this approach and discuss the financial and scientific implications of the same.

Prognostic impact of dose reduction in androgen receptor pathway inhibitors for castration-resistant prostate cancer

Background

Androgen receptor pathway inhibitors (ARPIs) such as abiraterone and enzalutamide have been shown to prolong survival in patients with advanced prostate cancer. However, there is limited evidence on the anticancer effect of a reduced dose of ARPIs. This study compared the prognosis in patients with chemotherapy-naïve castration-resistant prostate cancer (CRPC) between ARPI treatment with standard dose and treatment with reduced dose.

Methods

Japanese patients who were treated with ARPI as first-line treatment for CRPC between 2014 and 2018 were included. The associations between dose reduction and clinicopathological factors, progression-free survival, and overall survival were investigated.

Results

Of the 162 patients included, 33 (20.4%) patients had their dose reduced during ARPI treatment. In the multivariate analysis, higher PSA, abiraterone treatment, and dose reduction were significant prognostic factors for progression-free survival (PFS); however, dose reduction was not associated with overall survival. In the enzalutamide-treated group, the median PFS was 12.1 months (95% CI, 8.5–21.4 months) in the standard-dose group and 7.2 months (95% CI, 5.0–11.5 months) in the reduced-dose group (P = 0.038).

Conclusion

This study suggests inferior oncological outcome when treated with reduced-dose ARPI for CRPC. Full-dose administration of ARPI for CRPC may be appropriate if feasible.

Analysis of Clinical Trials on Therapies for Prostate Cancer in Mainland China and Globally from 2010 to 2020

The overall aging of the world population has contributed to the continuous upward trend in the incidence of prostate cancer (PC). Trials on PC therapy have been extensively performed, but no study has analyzed the overall trends and characteristics of these trials, especially for those carried out in China. This study aimed to provide insights on the future direction of drug development in PC, thus supplying essential supportive data for stakeholders, including researchers, patients, investors, clinicians, and pharmaceutical industry. The details of the clinical trials of drug therapies for PC during January 1, 2010, to January 1, 2020, were collected from Pharmaprojects. A total of 463 clinical trials on different therapies with 132 different drugs were completed. The long-acting endocrine therapy with few side effects, radiotherapy combined with immune checkpoint inhibitors, gene-targeted chemotherapeutics, and novel immunotherapeutic products changed the concept of PC treatment. In mainland China, 31 trials with 19 drugs have been completed in the 10 assessment years. China has initiated a few trials investigating a limited number of drug targets, centered in a markedly uneven geographical distribution of leading clinical trial units; hence, the development of PC drugs has a long way to go. Given the large patient pool, China deserves widespread attention for PC drug research and development. These findings might have a significant impact on scientific research and industrial investment.

Epidemiology and genomics of prostate cancer in Asian men

Prostate cancer is a global health problem, but incidence varies considerably across different continents. Asia is traditionally considered a low-incidence area, but the incidence and mortality of prostate cancer have rapidly increased across the continent. Substantial differences in epidemiological features have been observed among different Asian regions, and incidence, as well as mortality-to-incidence ratio, is associated with the human development index. Prostate cancer mortality decreased in Japan and Israel from 2007 to 2016, but mortality has increased in Thailand, Kyrgyzstan and Uzbekistan over the same period. Genomic analyses have shown a low prevalence of ERG oncoprotein in the East Asian population, alongside a low rate of PTEN loss, high CHD1 enrichments and high FOXA1 alterations. Contributions from single-nucleotide polymorphisms to prostate cancer risk vary with ethnicity, but germline mutation rates of DNA damage repair genes in metastatic prostate cancer are comparable in Chinese and white patients from the USA and UK. Pharmacogenomic features of testosterone metabolism might contribute to disparities seen in the response to androgen deprivation between East Asian men and white American and European men. Overall, considerable diversity in epidemiology and genomics of prostate cancer across Asia defines disease characteristics in these populations, but studies in this area are under-represented in the literature. Taking into account this intracontinental and intercontinental heterogeneity, translational studies are required in order to develop ethnicity-specific treatment strategies.

COVIDOSE: A Phase II Clinical Trial of Low-Dose Tocilizumab in the Treatment of Noncritical COVID-19 Pneumonia

Interleukin-6 (IL-6)-mediated hyperinflammation may contribute to the mortality of coronavirus disease 2019 (COVID-19). The IL-6 receptor-blocking monoclonal antibody tocilizumab has been repurposed for COVID-19, but prospective trials and dose-finding studies in COVID-19 have not yet fully reported. We conducted a single-arm phase II trial of low-dose tocilizumab in nonintubated hospitalized adult patients with COVID-19, radiographic pulmonary infiltrate, fever, and C-reactive protein (CRP) ≥ 40 mg/L. We hypothesized that doses significantly lower than the emerging standards of 400 mg or 8 mg/kg would resolve clinical and laboratory indicators of hyperinflammation. A dose range from 40 to 200 mg was evaluated, with allowance for one repeat dose at 24 to 48 hours. The primary objective was to assess the relationship of dose to fever resolution and CRP response. Thirty-two patients received low-dose tocilizumab, with the majority experiencing fever resolution (75%) and CRP decline consistent with IL-6 pathway abrogation (86%) in the 24-48 hours following drug administration. There was no evidence of a relationship between dose and fever resolution or CRP decline over the dose range of 40-200 mg. Within the 28-day follow-up, 5 (16%) patients died. For patients who recovered, median time to clinical recovery was 3 days (interquartile range, 2-5). Clinically presumed and/or cultured bacterial superinfections were reported in 5 (16%) patients. Low-dose tocilizumab was associated with rapid improvement in clinical and laboratory measures of hyperinflammation in hospitalized patients with COVID-19. Results of this trial provide rationale for a randomized, controlled trial of low-dose tocilizumab in COVID-19.

The Right Dose: From Phase I to Clinical Practice

To realize the full potential of promising new anticancer drugs, it is of paramount importance to administer them at the right dose. The aim of this educational article is to provide several opportunities to optimize anticancer drug dosing, focusing on oral targeted therapies. First, therapeutic drug monitoring can optimize exposure in individual patients, if the optimal concentration is known. This approach is of particular interest in regard to oral kinase inhibitors with high interindividual pharmacokinetic variability. If exposure is related to response, then therapeutic drug monitoring is potentially feasible, although the clinical utility of this approach has not yet been established. Other approaches to reduce variability include administration of more frequent, smaller doses and administration under optimal prandial conditions. However, for many drugs, the labeled dose has not been demonstrated to be the optimal dose; for such agents, the vast majority of patients may be receiving excessive doses, which results in excessive toxicity. Furthermore, administration of lower off-label doses may reduce both medical and financial toxicity. These strategies should be applied from registration studies to clinical practice, with the goal of better optimizing anticancer treatment.