Influential Factors Impacting Treatment Decision-making and Decision Regret in Patients with Localized or Locally Advanced Prostate Cancer: A Systematic Literature Review.

CONTEXT: Treatment decision-making (TDM) for patients with localized (LPC) or locally advanced (LAPC) prostate cancer is complex, and post-treatment decision regret (DR) is common. The factors driving TDM or predicting DR remain understudied. OBJECTIVE: Two systematic literature reviews were conducted to explore the factors associated with TDM and DR. EVIDENCE ACQUISITION: Three online databases, select congress proceedings, and gray literature were searched (September 2022). Publications on TDM and DR in LPC/LAPC were prioritized based on the following: 2012 onward, ≥100 patients, journal article, and quantitative data. The Preferred Reporting Items Reviews and Meta-analyses guidelines were followed. Influential factors were those with p < 0.05; for TDM, factors described as "a decision driver", "associated", "influential", or "significant" were also included. The key factors were determined by number of studies, consistency of evidence, and study quality. EVIDENCE SYNTHESIS: Seventy-five publications (68 studies) reported TDM. Patient participation in TDM was reported in 34 publications; overall, patients preferred an active/shared role. Of 39 influential TDM factors, age, ethnicity, external factors (physician recommendation most common), and treatment characteristics/toxicity were key. Forty-nine publications reported DR. The proportion of patients experiencing DR varied by treatment type: 7-43% (active surveillance), 12-57% (radical prostatectomy), 1-49% (radiotherapy), 28-49% (androgen-deprivation therapy), and 21-47% (combination therapy). Of 42 significant DR factors, treatment toxicity (sexual/urinary/bowel dysfunction), patient role in TDM, and treatment type were key. CONCLUSIONS: The key factors impacting TDM were physician recommendation, age, ethnicity, and treatment characteristics. Treatment toxicity and TDM approach were the key factors influencing DR. To help patients navigate factors influencing TDM and to limit DR, a shared, consensual TDM approach between patients, caregivers, and physicians is needed. PATIENT SUMMARY: We looked at factors influencing treatment decision-making (TDM) and decision regret (DR) in patients with localized or locally advanced prostate cancer. The key factors influencing TDM were doctor's recommendation, patient age/ethnicity, and treatment side effects. A shared, consensual TDM approach between patients and doctors was found to limit DR.

Population-based study of disease trajectory after radical treatment for high-risk prostate cancer.

OBJECTIVES: To investigate long-term disease trajectories among men with high-risk localized or locally advanced prostate cancer (HRLPC) treated with radical radiotherapy (RT) or radical prostatectomy (RP). MATERIAL AND METHODS: Men diagnosed with HRLPC in 2006-2020, who received primary RT or RP, were identified from the Prostate Cancer data Base Sweden (PCBaSe) 5.0. Follow-up ended on 30 June 2021. Treatment trajectories and risk of death from prostate cancer (PCa) or other causes were assessed by competing risk analyses using cumulative incidence for each event. RESULTS: In total, 8317 men received RT and 4923 men underwent RP. The median (interquartile range) follow-up was 6.2 (3.6-9.5) years. After RT, the 10-year risk of PCa-related death was 0.13 (95% confidence interval [CI] 0.12-0.14) and the risk of death from all causes was 0.32 (95% CI 0.31-0.34). After RP, the 10-year risk of PCa-related death was 0.09 (95% CI 0.08-0.10) and the risk of death from all causes was 0.19 (95% CI 0.18-0.21). The 10-year risks of androgen deprivation therapy (ADT) as secondary treatment were 0.42 (95% CI 0.41-0.44) and 0.21 (95% CI 0.20-0.23) after RT and RP, respectively. Among men who received ADT as secondary treatment, the risk of PCa-related death at 10 years after initiation of ADT was 0.33 (95% CI 030-0.36) after RT and 0.27 (95% CI 0.24-0.30) after RP. CONCLUSION: Approximately one in 10 men with HRLPC who received primary RT or RP had died from PCa 10 years after diagnosis. Approximately one in three men who received secondary ADT, an indication of PCa progression, died from PCa 10 years after the start of ADT. Early identification and aggressive treatment of men with high risk of progression after radical treatment are warranted.

Prostate-specific Membrane Antigen Positron Emission Tomography-detected Disease Extent and Overall Survival of Patients with High-risk Nonmetastatic Castration-resistant Prostate Cancer: An International Multicenter Retrospective Study.

Previously, we demonstrated that prostate-specific membrane antigen positron emission tomography (PSMA-PET) revealed distant metastases in 109/200 patients (39% distant nodes, 24% bone, and 6% visceral organ) with nonmetastatic castration-resistant prostate cancer (nmCRPC) and high-risk features (International Society of Urological Pathology score ≥4 and/or prostate-specific antigen doubling time ≤10 mo) without metastases by conventional imaging. However, the impact of disease extent determined by PSMA-PET on patient outcomes is unknown. We followed these 200 patients for a median of 43 mo after PSMA-PET and retrospectively assessed the association between patient characteristics, PSMA-PET findings, treatment management, and outcomes using a Kaplan-Meier model and Cox multivariable regressions. Among assessed disease characteristics, polymetastatic disease (five or more distant lesions on PET) was independently associated with shorter overall survival (OS; median 61 mo vs not reached; hazard ratio [95% confidence interval], 1.81 [1.00-3.27]; p = 0.050) and time to new metastases (median 38 vs 60 mo; 1.80 [1.10-2.96]; p = 0.019), and initial pN1 status with shorter OS (55 mo vs not reached; 1.94 [1.12-3.37]; p = 0.019). Following PSMA-PET, locoregional salvage therapies were used most commonly in no/local disease (58%), and androgen receptor signaling inhibitors were used in distant metastatic disease (51%). PSMA-PET provides additional risk stratification for patients with nmCRPC. Polymetastatic disease (five or more distant lesions) is associated with worse outcomes. PATIENT SUMMARY: A novel sensitive imaging technology, called prostate-specific membrane antigen positron emission tomography (PSMA-PET), allows doctors to detect the spread of prostate cancer, known as distant metastases, earlier and more accurately than in the past. In our study, PSMA-PET detected none to many metastases in patients who were considered free of distant metastasis by conventional imaging. These findings predicted outcomes and were used to select appropriate treatment.

Apalutamide efficacy, safety and wellbeing in older patients with advanced prostate cancer from Phase 3 randomised clinical studies TITAN and SPARTAN.

BACKGROUND: Apalutamide plus androgen-deprivation therapy (ADT) improved outcomes in metastatic castration-sensitive prostate cancer (mCSPC) and non-metastatic castration-resistant PC (nmCRPC) in the Phase 3 randomised TITAN and SPARTAN studies, respectively, and maintained health-related quality of life (HRQoL). Apalutamide treatment effect by patient age requires assessment. METHODS: Post-hoc analysis assessed patients receiving 240 mg/day apalutamide (525 TITAN and 806 SPARTAN) or placebo (527 TITAN and 401 SPARTAN) with ongoing ADT, stratified by age groups. Prostate-specific antigen declines, radiographic progression-free survival, metastasis-free survival, overall survival (OS), HRQoL and safety were assessed using descriptive statistics, Kaplan-Meier method, Cox proportional-hazards model and mixed-effects model for repeated measures. RESULTS: Hazard ratios (95% confidence intervals) generally favoured apalutamide plus ADT versus ADT alone across all endpoints regardless of age; e.g., OS values were 0.57 (0.40-0.80), 0.70 (0.54-0.91) and 0.74 (0.40-1.39) (TITAN) and 0.39 (0.19-0.78), 0.89 (0.69-1.16) and 0.81 (0.58-1.15) (SPARTAN) in patients aged <65, 65-79 and ≥80 years. Regardless of age, apalutamide also maintained HRQoL and was tolerated well with a potential trend in rates of adverse events increasing with age. Limitations include post-hoc nature and variability in sample size of age groups. CONCLUSIONS: Apalutamide plus ADT was an effective and well-tolerated option maintaining HRQoL in patients with mCSPC and nmCRPC regardless of age. CLINICAL TRIAL REGISTRATION: TITAN (NCT02489318); SPARTAN (NCT01946204).

Prostate-specific antigen (PSA) decline with apalutamide therapy is associated with longer survival and improved outcomes in individuals with metastatic prostate cancer: a plain language summary of the TITAN study.

WHAT IS THIS SUMMARY ABOUT?: This summary describes the results from an additional (or post hoc) analysis of the TITAN study. The TITAN study looked at whether the prostate cancer treatment apalutamide could be used to treat individuals with metastatic castration-sensitive prostate cancer (or mCSPC). A total of 1052 participants with mCSPC were included in the TITAN study. Treatment with apalutamide was compared with treatment with placebo. All participants received androgen deprivation therapy (or ADT), which is a type of hormone therapy that has been part of the main treatment for mCSPC for many years. The results showed that apalutamide plus ADT increased the length of time that participants remained alive compared with placebo plus ADT. Apalutamide plus ADT also controlled the growth of the cancer for a longer length of time compared with placebo plus ADT. Additionally, participants who received apalutamide plus ADT experienced a greater reduction in the blood levels of prostate-specific antigen (or PSA), called a deep PSA decline, compared with those who received placebo plus ADT. An additional (or post hoc) analysis was carried out to understand whether a decrease in blood PSA levels, in response to treatment, was associated with improved outcomes, including longer survival time. WHAT WERE THE RESULTS OF THE ADDITIONAL ANALYSIS?: In participants who received apalutamide plus ADT, a deep PSA decline in response to treatment was associated with longer survival time and improved outcomes. WHAT DO THESE RESULTS MEAN FOR INDIVIDUALS WITH MCSPC?: These results demonstrate that individuals with mCSPC can benefit from treatment with apalutamide plus ADT. The association seen between deep PSA decline and the longer survival time and improved outcomes highlights how PSA measurements can be used to help monitor cancer disease evolution in response to treatment. Monitoring PSA levels will assist doctors and other healthcare professionals to understand how effectively a treatment is working for a patient and to tailor their treatment approach to improve PSA decline.

Post Hoc Analysis of Rapid and Deep Prostate-specific Antigen Decline and Patient-reported Health-related Quality of Life in SPARTAN and TITAN Patients with Advanced Prostate Cancer.

BACKGROUND: Adding apalutamide to androgen-deprivation therapy (ADT) resulted in a rapid (at 3- and 6-mo treatment) and deep prostate-specific antigen (PSA) decline (to ≤0.2 ng/ml or ≥90% from baseline), improved overall survival, reduced risk of disease progression, and prolonged health-related quality of life (HRQoL) in nonmetastatic castration-resistant prostate cancer (nmCRPC) in SPARTAN and metastatic castration-sensitive PC (mCSPC) in TITAN. OBJECTIVE: To evaluate the association of a rapid, deep PSA decline at 3 and 6 mo achieved with the addition of apalutamide to ADT with patient-reported outcomes (PROs) in SPARTAN and TITAN. DESIGN, SETTING, AND PARTICIPANTS: A post hoc analysis of SPARTAN and TITAN PRO data was performed. INTERVENTION: Apalutamide versus placebo plus concurrent ADT. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: PROs were assessed using Functional Assessment of Cancer Therapy-Prostate (FACT-P; SPARTAN and TITAN), Brief Pain Inventory-Short Form (BPI-SF; TITAN), and Brief Fatigue Inventory (BFI; TITAN) at baseline, prespecified cycles during treatment, and after progression for ≤1 yr. The association between a deep PSA decline at landmark 3 or 6 mo of apalutamide and the time to worsening of PROs was assessed using the Kaplan-Meier methodology and Cox proportional-hazard modeling. RESULTS AND LIMITATIONS: Among 806 SPARTAN and 525 TITAN apalutamide-treated patients, the median treatment duration was 32.9 and 39.3 mo, respectively. Patients achieving a deep PSA decline at 3 mo had longer time to worsening in FACT-P total, FACT-P physical well-being, BPI-SF worst pain intensity, or BFI worst fatigue intensity. The 6-mo PSA decline results were similar. Limitations of patient characteristics in clinical studies should be considered. CONCLUSIONS: Attaining a deep and rapid PSA decline at 3 mo with apalutamide plus ADT was associated with longer preservation of overall HRQoL and physical well-being in nmCRPC and mCSPC. PATIENT SUMMARY: Quality of life is maintained in individuals with advanced prostate cancer who achieve a deep prostate-specific antigen decline at 3 mo of apalutamide plus drugs that lower male sex hormones.

A US real-world study of treatment patterns and outcomes in localized or locally advanced prostate cancer patients.

PURPOSE: Men with localized or locally advanced prostate cancer (LPC/LAPC) are at risk of progression after radiotherapy (RT) or radical prostatectomy (RP). Using real-world data, we evaluated patient characteristics, treatment patterns, and outcomes in LPC/LAPC. METHODS: Optum claims and electronic health records (EHR) data from January 2010 to December 2021 were queried for men with LPC/LAPC who received primary RT, RP, or androgen deprivation therapy alone within 180 days after diagnosis. Survival outcomes were analyzed using descriptive statistics and Kaplan-Meier curves. Real-world overall survival (rwOS) was compared in patients with and without evidence of disease (i.e., disease recurrence, metastasis, diagnosis of castration-resistant PC) at defined time points. RESULTS: 61,772 and 62,361 men in claims and EHR cohorts met the inclusion criteria. Median follow-up was 719 and 901 days, respectively. Most men received primary RT (51.0% claims, 35.0% EHR) or RP (39.4% claims, 53.8% EHR). Survival was greatest among men treated with RP, followed by RT. Adjusted for age and comorbidity, rwOS was shorter among men with evidence of disease within 1, 3, 4, and 5 years after primary treatment than those without at the same time points. CONCLUSION: Real-world claims and EHR data show that survival among men with LPC/LAPC differs by primary treatment and time point of disease recurrence thereafter. Poor outcomes in men with LPC/LAPC who progress early indicate an unmet medical need for more effective primary treatment. If validated for surrogacy, no evidence of disease at specific time points could represent an intermediate efficacy endpoint in future trials.

Apalutamide plus androgen deprivation therapy in clinical subgroups of patients with metastatic castration-sensitive prostate cancer: A subgroup analysis of the randomised clinical TITAN study.

BACKGROUND: Whether disease burden in patients with metastatic castration-sensitive prostate cancer (mCSPC) predicts treatment outcomes is unknown. We assessed apalutamide treatment effect in TITAN patients with mCSPC by disease volume, metastasis number and timing of metastasis presentation. METHODS: These protocol-defined and post hoc analyses of the phase III randomised TITAN study evaluated clinical outcomes in patients receiving 240 mg/day apalutamide (n = 525) or placebo (n = 527) plus androgen-deprivation therapy (ADT). Subgroups were defined by volume (high: visceral and ≥1 bone metastases or ≥4 bone lesions with ≥1 beyond vertebral column/pelvis), development of metastases per conventional imaging (synchronous: at initial diagnosis; metachronous: after localised disease) and oligometastases (≤5 bone-only metastases) or polymetastases (>5 in bone ± other locations or ≤5 in bone plus other locations). Overall survival (OS), radiographic or second progression-free survival, and time to prostate-specific antigen progression or castration resistance were assessed using Cox proportional hazards models. RESULTS: Of 1052 patients, 63%, 81%, 54%, 27%, 5.7%, and 8.0% had high-volume, synchronous, synchronous/high-volume, synchronous/low-volume, metachronous/high-volume, and metachronous/low-volume disease, respectively. The OS benefit favoured apalutamide plus ADT versus ADT alone in synchronous/high-volume (hazard ratio = 0.68 [95% confidence interval: 0.53-0.87]; p = 0.002), synchronous/low-volume (0.65 [0.40-1.05]; p = 0.08), metachronous/high-volume (0.69 [0.33-1.44]; p = 0.32) and metachronous/low-volume (0.22 [0.09-0.55]; p = 0.001) subgroups. Apalutamide improved other clinical outcomes regardless of subgroup, with similar safety profiles. Most favourable outcomes were observed in oligometastatic disease. CONCLUSION: TITAN patients derived a robust benefit with apalutamide plus ADT regardless of disease volume and timing of metastasis presentation without differences in safety, supporting early apalutamide intensification in mCSPC. CLINICAL TRIAL REGISTRATION: NCT02489318.

Clinical characteristics associated with falls in patients with non-metastatic castration-resistant prostate cancer treated with apalutamide.

BACKGROUND: The phase III SPARTAN study demonstrated that apalutamide significantly improves metastasis-free survival and overall survival vs. placebo in patients with non-metastatic castration-resistant prostate cancer (nmCRPC). However, patients receiving apalutamide experienced falls more frequently vs. those receiving placebo (15.6% vs. 9.0%). METHODS: 806 patients with nmCRPC randomized to apalutamide in SPARTAN and treated with apalutamide in addition to ongoing androgen deprivation therapy (ADT) were included in this post-hoc analysis investigating clinical variables associated with a subsequent fall. Time to a fall was assessed with Cox proportional-hazards models adjusted for baseline characteristics and time-varying factors. Statistical inference was based on final multivariable models. RESULTS: Falls were reported for 125/803 (15.6%) patients treated with apalutamide and ADT. Most falls were grade 1 or 2 and did not require hospitalization. Median time from randomization to first fall was 9.2 months (range 0.1-25.3 months). In the final multivariable model of both baseline and after-baseline covariates, baseline patient characteristics (older age, poor Eastern Cooperative Oncology Group performance status, history of neuropathy, and α-blocker use before study treatment) remained significantly associated with fall; after-baseline clinical characteristics significantly associated with time to fall were development of neuropathy, arthralgia, and weight loss before fall. CONCLUSIONS: This analysis identified risk factors for fall among nmCRPC patients treated with apalutamide. Clinical management can minimize these identified risks while enhancing patient outcomes. Preventive interventions should be considered when the identified baseline conditions and post-treatment neuropathy, arthralgia, or weight decrease are present, to reduce risk of fall. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01946204.

Deep Prostate-specific Antigen Response following Addition of Apalutamide to Ongoing Androgen Deprivation Therapy and Long-term Clinical Benefit in SPARTAN.

BACKGROUND: Apalutamide plus androgen deprivation therapy (ADT) significantly improved metastasis-free survival (MFS), overall survival (OS), and time to prostate-specific antigen (PSA) progression in the placebo-controlled SPARTAN study of high-risk nonmetastatic castration-resistant prostate cancer (nmCRPC). OBJECTIVE: To assess the relationships between PSA kinetics, outcomes, and molecular subtypes in SPARTAN. DESIGN, SETTING, AND PARTICIPANTS: The authors conducted a post hoc analysis of nmCRPC patients randomized to receive apalutamide (n = 806) or placebo (n = 401) plus ADT and a subset stratified by molecular classifiers. INTERVENTION: Apalutamide 240 mg/d. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The association between PSA kinetics and MFS, OS, time to PSA progression, and molecular subtypes was evaluated using the landmark analysis and Kaplan-Meier methods. RESULTS AND LIMITATIONS: By 3 mo, PSA decreased in most apalutamide-treated patients and increased in most placebo-treated patients. After apalutamide, the median time to PSA nadir, confirmed ≥50% PSA reduction, ≥90% PSA reduction, and PSA ≤0.2 ng/ml were 7.4, 1.0, 1.9, and 2.8 mo, respectively. By 6 mo, 90%, 57%, and 32% of apalutamide patients had ≥50% PSA reduction, ≥90% PSA reduction, and PSA ≤0.2 ng/ml, respectively, while only 1.5% of placebo patients experienced ≥50% PSA reduction. PSA reductions were observed within 3 mo and up to 12 mo of apalutamide treatment, and were similar across molecular subtypes. Deep PSA responses (≥90% PSA reduction or PSA ≤0.2 ng/ml) at landmark 6-mo apalutamide treatment were significantly associated with improved time to PSA progression (hazard ratio {HR} [95% confidence interval {CI}] 0.25 [0.18-0.33] or 0.13 [0.08-0.21]), MFS (0.41 [0.29-0.57] or 0.3 [0.19-0.47]), and OS (0.45 [0.35-0.59] or 0.26 [0.18-0.38]; p < 0.001 for all). CONCLUSIONS: Apalutamide plus ADT produced rapid, deep, and durable PSA responses by 6-mo treatment regardless of assessed molecular prognostic markers. An early PSA response with apalutamide was associated with clinical benefits, supporting prognostic value of PSA monitoring. PATIENT SUMMARY: In this report, we describe how prostate-specific antigen (PSA) levels relate to outcomes in patients with nonmetastatic castration-resistant prostate cancer treated with apalutamide plus androgen deprivation therapy (ADT). We found that treatment with apalutamide plus ADT resulted in rapid, deep, and durable PSA responses in the majority of patients, including those with high-risk molecular subtypes, which were associated with improved survival.

Apalutamide plus abiraterone acetate and prednisone versus placebo plus abiraterone and prednisone in metastatic, castration-resistant prostate cancer (ACIS): a randomised, placebo-controlled, double-blind, multinational, phase 3 study.

BACKGROUND: The majority of patients with metastatic castration-resistant prostate cancer (mCRPC) will have disease progression of a uniformly fatal disease. mCRPC is driven by both activated androgen receptors and elevated intratumoural androgens; however, the current standard of care is therapy that targets a single androgen signalling mechanism. We aimed to investigate the combination treatment using apalutamide plus abiraterone acetate, each of which suppresses the androgen signalling axis in a different way, versus standard care in mCRPC. METHODS: ACIS was a randomised, placebo-controlled, double-blind, phase 3 study done at 167 hospitals in 17 countries in the USA, Canada, Mexico, Europe, the Asia-Pacific region, Africa, and South America. We included chemotherapy-naive men (aged ≥18 years) with mCRPC who had not been previously treated with androgen biosynthesis signalling inhibitors and were receiving ongoing androgen deprivation therapy, with an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1, and a Brief Pain Inventory-Short Form question 3 (ie, worst pain in the past 24 h) score of 3 or lower. Patients were randomly assigned (1:1) via a centralised interactive web response system with a permuted block randomisation scheme (block size 4) to oral apalutamide 240 mg once daily plus oral abiraterone acetate 1000 mg once daily and oral prednisone 5 mg twice daily (apalutamide plus abiraterone-prednisone group) or placebo plus abiraterone acetate and prednisone (abiraterone-prednisone group), in 28-day treatment cycles. Randomisation was stratified by presence or absence of visceral metastases, ECOG performance status, and geographical region. Patients, the investigators, study team, and the sponsor were masked to group assignments. An independent data-monitoring committee continually monitored data to ensure ongoing patient safety, and reviewed efficacy data. The primary endpoint was radiographic progression-free survival assessed in the intention-to-treat population. Safety was reported for all patients who received at least one dose of study drug. This study is completed and no longer recruiting and is registered with ClinicalTrials.gov, number NCT02257736. FINDINGS: 982 men were enrolled and randomly assigned from Dec 10, 2014 to Aug 30, 2016 (492 to apalutamide plus abiraterone-prednisone; 490 to abiraterone-prednisone). At the primary analysis (median follow-up 25·7 months [IQR 23·0-28·9]), median radiographic progression-free survival was 22·6 months (95% CI 19·4-27·4) in the apalutamide plus abiraterone-prednisone group versus 16·6 months (13·9-19·3) in the abiraterone-prednisone group (hazard ratio [HR] 0·69, 95% CI 0·58-0·83; p<0·0001). At the updated analysis (final analysis for overall survival; median follow-up 54·8 months [IQR 51·5-58·4]), median radiographic progression-free survival was 24·0 months (95% CI 19·7-27·5) versus 16·6 months (13·9-19·3; HR 0·70, 95% CI 0·60-0·83; p<0·0001). The most common grade 3-4 treatment-emergent adverse event was hypertension (82 [17%] of 490 patients receiving apalutamide plus abiraterone-prednisone and 49 [10%] of 489 receiving abiraterone-prednisone). Serious treatment-emergent adverse events occurred in 195 (40%) patients receiving apalutamide plus abiraterone-prednisone and 181 (37%) patients receiving abiraterone-prednisone. Drug-related treatment-emergent adverse events with fatal outcomes occurred in three (1%) patients in the apalutamide plus abiraterone-prednisone group (2 pulmonary embolism, 1 cardiac failure) and five (1%) patients in the abiraterone-prednisone group (1 cardiac failure and 1 cardiac arrest, 1 mesenteric arterial occlusion, 1 seizure, and 1 sudden death). INTERPRETATION: Despite the use of an active and established therapy as the comparator, apalutamide plus abiraterone-prednisone improved radiographic progression-free survival. Additional studies to identify subgroups of patients who might benefit the most from combination therapy are needed to further refine the treatment of mCRPC. FUNDING: Janssen Research & Development.

Apalutamide in Patients With Metastatic Castration-Sensitive Prostate Cancer: Final Survival Analysis of the Randomized, Double-Blind, Phase III TITAN Study.

PURPOSE: The first interim analysis of the phase III, randomized, placebo-controlled TITAN study showed that apalutamide significantly improved overall survival (OS) and radiographic progression-free survival in patients with metastatic castration-sensitive prostate cancer (mCSPC) receiving ongoing androgen deprivation therapy (ADT). Herein, we report final efficacy and safety results after unblinding and placebo-to-apalutamide crossover. METHODS: Patients with mCSPC (N = 1,052) were randomly assigned 1:1 to receive apalutamide (240 mg QD) or placebo plus ADT. After unblinding in January 2019, placebo-treated patients were allowed to receive apalutamide. Efficacy end points were updated using the Kaplan-Meier method and Cox proportional-hazards model without formal statistical retesting and adjustment for multiplicity. Change from baseline in Functional Assessment of Cancer Therapy-Prostate total score was assessed. RESULTS: With a median follow-up of 44.0 months, 405 OS events had occurred and 208 placebo-treated patients (39.5%) had crossed over to apalutamide. The median treatment duration was 39.3 (apalutamide), 20.2 (placebo), and 15.4 months (crossover). Compared with placebo, apalutamide plus ADT significantly reduced the risk of death by 35% (median OS not reached v 52.2 months; hazard ratio, 0.65; 95% CI, 0.53 to 0.79; P < .0001) and by 48% after adjustment for crossover (hazard ratio, 0.52; 95% CI, 0.42 to 0.64; P < .0001). Apalutamide plus ADT delayed second progression-free survival and castration resistance (P < .0001 for both). Health-related quality of life, per total Functional Assessment of Cancer Therapy-Prostate, in both groups was maintained through the study. Safety was consistent with previous reports. CONCLUSION: The final analysis of TITAN confirmed that, despite crossover, apalutamide plus ADT improved OS, delayed castration resistance, maintained health-related quality of life, and had a consistent safety profile in a broad population of patients with mCSPC.

Mathematical modeling of bone marrow - peripheral blood dynamics in the disease state based on current emerging paradigms, part II.

The cancer stem cell hypothesis has gained currency in recent times but concerns remain about its scientific foundations because of significant gaps that exist between research findings and comprehensive knowledge about cancer stem cells (CSCs). In this light, a mathematical model that considers hematopoietic dynamics in the diseased state of the bone marrow and peripheral blood is proposed and used to address findings about CSCs. The ensuing model, resulting from a modification and refinement of a recent model, develops out of the position that mathematical models of CSC development, that are few at this time, are needed to provide insightful underpinnings for biomedical findings about CSCs as the CSC idea gains traction. Accordingly, the mathematical challenges brought on by the model that mirror general challenges in dealing with nonlinear phenomena are discussed and placed in context. The proposed model describes the logical occurrence of discrete time delays, that by themselves present mathematical challenges, in the evolving cell populations under consideration. Under the challenging circumstances, the steady state properties of the model system of delay differential equations are obtained, analyzed, and the resulting mathematical predictions arising therefrom are interpreted and placed within the framework of findings regarding CSCs. Simulations of the model are carried out by considering various parameter scenarios that reflect different experimental situations involving disease evolution in human hosts. Model analyses and simulations suggest that the emergence of the cancer stem cell population alongside other malignant cells engenders higher dimensions of complexity in the evolution of malignancy in the bone marrow and peripheral blood at the expense of healthy hematopoietic development. The model predicts the evolution of an aberrant environment in which the malignant population particularly in the bone marrow shows tendencies of reaching an uncontrollable equilibrium state. Essentially, the model shows that a structural relationship exists between CSCs and non-stem malignant cells that confers on CSCs the role of temporally enhancing and stimulating the expansion of non-stem malignant cells while also benefitting from increases in their own population and these CSCs may be the main protagonists that drive the ultimate evolution of the uncontrollable equilibrium state of such malignant cells and these may have implications for treatment.

Mathematical modeling of bone marrow--peripheral blood dynamics in the disease state based on current emerging paradigms, part I.

Stemming from current emerging paradigms related to the cancer stem cell hypothesis, an existing mathematical model is expanded and used to study cell interaction dynamics in the bone marrow and peripheral blood. The proposed mathematical model is described by a system of nonlinear differential equations with delay, to quantify the dynamics in abnormal hematopoiesis. The steady states of the model are analytically and numerically obtained. Some conditions for the local asymptotic stability of such states are investigated. Model analyses suggest that malignancy may be irreversible once it evolves from a nonmalignant state into a malignant one and no intervention takes place. This leads to the proposition that a great deal of emphasis be placed on cancer prevention. Nevertheless, should malignancy arise, treatment programs for its containment or curtailment may have to include a maximum and extensive level of effort to protect normal cells from eventual destruction. Further model analyses and simulations predict that in the untreated disease state, there is an evolution towards a situation in which malignant cells dominate the entire bone marrow - peripheral blood system. Arguments are then advanced regarding requirements for quantitatively understanding cancer stem cell behavior. Among the suggested requirements are, mathematical frameworks for describing the dynamics of cancer initiation and progression, the response to treatment, the evolution of resistance, and malignancy prevention dynamics within the bone marrow - peripheral blood architecture.

Use of prednisone with abiraterone acetate in metastatic castration-resistant prostate cancer.

Abiraterone acetate, a prodrug of the CYP17A1 inhibitor abiraterone that blocks androgen biosynthesis, is approved for treatment of patients with metastatic castration-resistant prostate cancer (mCRPC) in combination with prednisone or prednisolone 5 mg twice daily. This review evaluates the basis for the effects of prednisone on mineralocorticoid-related adverse events that arise because of CYP17A1 inhibition with abiraterone. Coadministration with the recommended dose of glucocorticoid compensates for abiraterone-induced reductions in serum cortisol and blocks the compensatory increase in adrenocorticotropic hormone seen with abiraterone. Consequently, 5 mg prednisone twice daily serves as a glucocorticoid replacement therapy when coadministered with abiraterone acetate, analogous to use of glucocorticoid replacement therapy for certain endocrine disorders. We searched PubMed to identify safety concerns regarding glucocorticoid use, placing a focus on longitudinal studies in autoimmune and inflammatory diseases and cancer. In general, glucocorticoid-related adverse events, including bone loss, immunosuppression, hyperglycemia, mood and cognitive alterations, and myopathy, appear dose related and tend to occur at doses and/or treatment durations greater than the low dose of glucocorticoid approved in combination with abiraterone acetate for the treatment of mCRPC. Although glucocorticoids are often used to manage tumor-related symptoms or to prevent treatment-related toxicity, available evidence suggests that prednisone and dexamethasone might also offer modest therapeutic benefit in mCRPC. Given recent improvements in survival achieved for mCRPC with novel agents in combination with prednisone, the risks of these recommended glucocorticoid doses must be balanced with the benefits shown for these regimens.

Transient therapy-related surge in serum tumor biomarkers: characterizing behavior and postulating its biologic role.

A phenomenon of serum tumor biomarker surge or flare that ensues shortly after initiating cancer therapy and that may precede the actual therapeutic response-related decline is poorly understood and remains under-appreciated. However, it may have a significant clinical implication as it could be misinterpreted in clinical practice as therapeutic failure and lead to a premature discontinuation of potentially effective therapy. Therefore, in the present study, attempts have been made to understand the behavior of this phenomenon with respect to a reported median incidence, duration, and its relationship to clinical response. The results of these analyses suggest a significantly lower incidence of this phenomenon with carcinoembryonic antigen (CEA) as determined in colorectal cancer and prostate specific antigen (PSA) in prostate cancer as compared to the other biomarkers studied (p=0.006). Furthermore, regardless of the type of biomarker or the extent of its incidence, a therapy-related initial surge appears to correlate with eventual response to therapy. Although, the biologic significance of this phenomenon is currently elusive, two distinct hypothesis-generating cases with CEA and alpha-fetoprotein (AFP) are presented that, if supported by further research, would provide insights into the role of a biomarker surge in overall tumor growth control by cancer therapy.

Erythropoiesis-stimulating agents versus RBC transfusion in MDS: comparison of long-term outcomes.

Impaired erythropoiesis and refractory anemia are clinical hallmarks of the myelodysplastic syndromes (MDS). As the disease evolves, a steady decline in hemoglobin in these disorders invariably results in dependence on packed red blood cell (PRBC) transfusion. Such chronic transfusion dependence has been associated with iron overload causing cardio-hepatic toxicity and alloimmunization, and can result in reduced survival in these patients. The use of hematopoietic growth factors, particularly erythropoiesis-stimulating agents (ESAs), has been reported to reduce the need for PRBC transfusion, raise hemoglobin and improve quality of life, at least in patients responding to such a therapy. Importantly, the clinical benefits of ESA are well balanced, with an apparently favorable safety profile in MDS, thus providing an eminent therapeutic option to delay or avoid transfusion dependence in these patients. The present report provides a detailed comparative profile of long-term PRBC transfusions and the balance of clinical benefits versus risks associated with ESA therapy for MDS.