Abiraterone acetate for chemotherapy-naive metastatic castration-resistant prostate cancer: a single-centre prospective study of efficacy, safety, and prognostic factors

Real-world outcomes for first line next-generation hormonal agents in metastatic prostate cancer: a systematic review

Aim: This review aims to summarize published evidence on the real-world (RW) outcomes of abiraterone or enzalutamide in first-line metastatic castration-resistant prostate cancer. Materials & methods: Studies reporting on RW effectiveness, safety, economic and/or health-related quality of life outcomes were identified by systematic literature review (2011-2021, incl. Embase®, MEDLINE®) and presented in a qualitative synthesis. Risk of bias was assessed using ROBINS-I or the Molinier checklist. Results: 88 studies (n = 83,427 patients) were included. Median progression-free (40 studies) and overall survival (38 studies) ranged from 3.7 to 20.9 months and 9.8 to 45 months, respectively. Survival, safety and economic outcomes were similar across individual treatments, while limited health-related quality of life evidence suggested improvements with abiraterone. Risk of bias was moderate to high. Conclusion: RW outcomes in first-line metastatic castration-resistant prostate cancer remain poor despite treatment, highlighting an unmet need for new regimens. This review was supported by AstraZeneca and Merck Sharp & Dohme.

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.

Clinical implication of prognostic and predictive biomarkers for castration-resistant prostate cancer: a systematic review

Background

Diagnosis of metastatic castrate resistant prostate cancer (mCRPC) with current biomarkers is difficult and often results in unnecessary invasive procedures as well as over-diagnosis and over-treatment. There are a number of prognostic biomarkers for CRPC, but there are no validated predictive biomarkers to guide in clinical decision-making. Specific biomarkers are needed that enable to understand the natural history and complex biology of this heterogeneous malignancy, identify early response to treatment outcomes and to identify the population of men most likely to benefit from the treatment. In this systematic review, we discuss the existing literature for the role of biomarkers in CRPC and how they aid in the prognosis, treatment selection and survival outcomes.

Methods

We performed a literature search on PubMed and EMBASE databases from January 2015 through February 2020 in accordance to Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines. Articles were assessed to identify relevant observational studies and randomized controlled trials regarding biomarkers which aid in identifying progression to mCRPC as well as predictive biomarkers which help in treatment selection.

Results

We identified 3640 number of hits of which 58 articles were found to be relevant. Here we addressed biomarkers in the context of prognosis, prediction and patient selection of therapy. These biomarkers were found to be effective as prognostic or predictive factors under variety of conditions. The higher levels for all these biomarkers were associated with shorter median OS and sometimes PFS. Lower amounts of biomarkers in serum or urine were associated with prolonged survival outcomes, longer time to CRPC development or CRPC progression and longer median follow-up irrespective of any therapy.

Conclusion

We observed that the biomarkers included in our study predicted clinically relevant survival outcomes and treatment exposure. Though the current biomarkers are prognostic when measured prior to initiating treatment, not all are validated as predictive markers in post treatment setting. A greater understanding of biomarkers in CRPC is need of the hour for development of more personalized approach to maximize benefit and minimize harm in men with CRPC.

Second-line Hormonal Therapy for the Management of Metastatic Castration-resistant Prostate Cancer: a Real-World Data Study Using a Claims Database

We evaluated the efficacy of second-line hormonal therapy for treatment of metastatic castration-resistant prostate cancer (mCRPC) in a real-world retrospective study. We conducted a population-based real-world cohort study of 258 mCRPC patients between 2014 and 2018 using the Chang Gung Research Database (CGRD) of Taiwan. The second-line hormonal therapy included abiraterone acetate and enzalutamide. The clinical efficacy outcomes were overall survival (OS) and prostate-specific antigen (PSA) doubling time. The median PSA level was also assessed. In total, 223 mCRPC patients who underwent second-line hormonal therapy met all of the inclusion and exclusion criteria for this study. Among them, 65 (29.1%) patients were in the PSA response group and 158 (70.9%) were in the non-response group. The median age was 72.9 years. The median OS was 12.3 months (range: 9.9–19.9 months) and 9.6 months (range: 5.3–15.9 months) in the response and non-response groups, respectively, and the respective PSA doubling times were 9.0 months (range: 4.4–11.6 months) and 3.9 months (range: 2.2–9.1 months), with a median follow-up period of 10.5 months. A significantly longer median OS was seen in the PSA response group. This real-world database study demonstrated that clinical outcomes of second-line hormonal therapy were better in patients with a PSA response. Further studies are warranted to achieve a better understanding of second-line hormonal therapy for mCRPC in Asian populations.

Neuroendocrine differentiation markers guide treatment sequence selection in metastatic castration-resistant prostate cancer

BACKGROUND

To evaluate the value of the serum neuroendocrine differentiation (NED) markers in helping to select the best treatment sequence of abiraterone acetate (AA) and docetaxel-prednisone (DP) in mCRPC.

METHODS

Eighty-eight mCRPC patients were identified (42 in the DP-to-AA group and 46 in the AA-to-DP group). The serum levels of NED markers were measured before the first-line treatment in 88 patients and also before and after DP therapy in 38 patients. We determined their impact on OS, radiographic progression-free survival (rPFS), and PSA-PFS.

RESULTS

In men with an elevation of at least one NED marker (n = 46) before the first-line treatment, those who received AA and then DP had significantly better worse OS (21.7 months [95% CI 21.0-22.4] vs 19.9 months (95% CI 15.3-24.5); P = 0.023. In a multivariate Cox regression analysis, treatment sequencing selection (selecting DP-AA rather than AA-DP) independently predicted OS (HR 0.4, 95% CI 0.2-0.9, P = 0.035) in patients with an elevation of at least one NED marker. However, in the subgroup without NED marker elevation, there was no significant difference in clinical outcomes between AA-DP and DP-AA groups (all P > 0.05). In the group with continued NED marker evaluation during DP treatment, patients with higher baseline NED markers and obtaining PSA response to DP were more inclined to experience NED markers decline.

CONCLUSIONS

Elevated pretreatment serum NED markers might indicate mCRPC patients would get better clinical outcomes from DP-AA than AA-DP. In contrast, those without NED marker elevation had similar outcomes regardless of which agent was chosen first. mCRPC patients with elevated NED markers and chemotherapy response were more inclined to obtain NED markers decline during DP therapy, which could account for this phenomenon.