Comparison of Treatments for Nonmetastatic Castration-Resistant Prostate Cancer: Matching-Adjusted Indirect Comparison and Network Meta-Analysis

Safety profile of darolutamide versus placebo: a systematic review and meta-analysis

BACKGROUND

Darolutamide is an androgen receptor pathway inhibitor (ARPI) used in patients with prostate cancer (PC). In pivotal trials, it has demonstrated a favorable toxicity profile. There are no head-to-head comparison studies between the different ARPIs, but the efficacy of these drugs seems to be similar making the toxicity profile a key element for treatment selection.

METHODS

We conducted a systematic review of all clinical trials assessing treatment with darolutamide for patients with PC using placebo as the control using the PubMed/Medline and Cochrane library databases. We also performed a meta-analysis to compare the safety of darolutamide versus placebo evaluating adverse events (AE) leading to treatment discontinuation and the rate of the AE reported as "AE of interest" in the ARAMIS trial. The comparison among darolutamide and the placebo group in terms of safety and tolerability was performed using odds ratio (OR) as meta-analytic outcome.

RESULTS

We identified three articles comprising 2902 patients for the systematic review and meta-analysis (1652 treated with darolutamide and 1250 with placebo). Darolutamide did not increase AE leading to treatment discontinuation compared to placebo (pooled OR: 1.176, 95% CI 0.918-1.507, p = 0.633). Regarding the "AE of interest" there was no difference between darolutamide and placebo in terms of asthenia, cardiac arrhythmia, cardiac disorder, coronary artery disorder, depression mood disorder, falls, fatigue, heart failure, hot flushes, hypertension, mental-impairment disorder, rash, seizure and weight loss. The only "AE of interest" with a statistically significant difference in favor of placebo was bone fractures (pooled OR: 1.523, 95% CI 1.081-2.146).

CONCLUSIONS

In our systematic review and meta-analysis, darolutamide showed a toxicity profile comparable to placebo with the exception of bone fractures. In the absence of head-to-head comparison studies between the different ARPIs, the results of our research suggest a preferred use of darolutamide in the approved settings.

Evaluation of Second-Line Treatment for Castration-Resistant Prostate Cancer following the Administration of Upfront Androgen Receptor Signaling Inhibitors

This study evaluated the effects of docetaxel and androgen receptor signaling inhibitors as second-line treatments in patients with castration-resistant prostate cancer after androgen receptor signaling inhibitors as first-line treatment. This study retrospectively evaluated the clinical outcomes of second-line treatment with docetaxel or androgen receptor signaling inhibitor in patients with castration-resistant prostate cancer who received first-line treatment with androgen receptor signaling inhibitors. Clinical backgrounds and outcomes were compared between docetaxel and androgen receptor signaling inhibitors as second-line treatment. Of 59 patients, 21 (35.6%) and 38 (64.4%) received docetaxel and androgen receptor signaling inhibitors as second-line treatment after first-line treatment with androgen receptor signaling inhibitors, respectively. In the second-line setting, the median progression-free survival was longer with androgen receptor signaling inhibitor than with docetaxel (17 versus 6 months, P=0.014). In the first-line setting, the median progression-free survival was longer with androgen receptor signaling inhibitors than with docetaxel (32 versus 25 months, P=0.014); however, no significant difference was found in the overall survival. Multivariate analysis revealed that there was no significant association between second-line treatment and survival, and first-line treatment with abiraterone was identified as a prognostic factor for progression-free survival. Subgroup analysis showed that the abiraterone-enzalutamide sequence was more effective than the other three sequences for progression-free survival and overall survival. This study suggests that second-line treatment with an androgen receptor signaling inhibitor for castration-resistant prostate cancer after androgen receptor signaling inhibitors as first-line treatment may be more beneficial, particularly with abiraterone as the upfront treatment.

Adverse events and costs among non-metastatic castration-resistant prostate cancer patients

BACKGROUND

Limited real-world evidence exists on the economic burden of adverse events (AEs) to the healthcare system among patients with non-metastatic castration-resistant prostate cancer (nmCRPC) treated with second-generation androgen receptor antagonists (ARAs). Current data is needed to understand real-world clinical event rates among ARAs and the cost of these events.

OBJECTIVES

Describe the incidence of non-central nervous system (CNS)-related AEs and CNS-related AEs among nmCRPC patients treated in the United States with second-generation ARAs (apalutamide and enzalutamide) and evaluate healthcare resource utilization (HCRU) and costs for these patients.

METHODS AND STUDY DESIGN

This was a retrospective observational cohort study using claims data from Optum Clinformatics Data Mart to identify adult males with prostate cancer, castration, no metastases, and >1 claim for apalutamide or enzalutamide. The study was conducted from January 2017 to March 2020, with a patient index identification period from January 2018 to December 2019. AEs were classified as CNS-related or non-CNS-related.

RESULTS

Of 605 patients (156 apalutamide and 449 enzalutamide), most were ≥65 years (94%) and had ≥1 non-CNS-related AE (55%). Many had ≥1 CNS-related AE (32%). Pain (12%) and arthralgia (11%) were the most frequently reported non-CNS-related AEs. Fatigue/asthenia (14%) and dizziness (7%) were the most frequently reported CNS-related AEs. Among patients with versus without non-CNS-related AEs, 34% versus 8% had emergency room (ER) events, and 25% versus 2% had inpatient events. Among patients with versus without CNS-related AEs, 41% versus 14% had ER events, and 38% versus 4% had inpatient events. Adjusted per-patient per-year cost (in 2020 USD) differences were significant between patients with and without non-CNS-related AEs ($30,765, p = 0.0018) and between patients with and without CNS-related AEs ($40,689, p = 0.0017).

CONCLUSION

There is significant HCRU and cost burden among nmCRPC patients treated with ARAs developing AEs, highlighting the need for treatments with improved tolerability. Additional studies are warranted to include recently approved agents.

Safety and tolerability of long-term treatment with darolutamide in patients with metastatic castration-resistant prostate cancer

BACKGROUND

In patients with metastatic castration-resistant prostate cancer, darolutamide was well tolerated for 25 months, but minimal long-term safety data are available.

METHODS

Treatment-emergent adverse events (TEAEs) for patients receiving darolutamide for a median of 38 months (n = 13) are described in this pooled analysis of individual patient data from phase 1/2 studies.

RESULTS

All patients reported TEAEs (mostly grade 1/2). The most common TEAEs were diarrhea, abdominal pain, and nausea. Serious TEAEs were reported in six patients (none related to darolutamide). All treatment-related TEAEs (n = 5) were grade 1.

CONCLUSIONS

Long-term darolutamide treatment was well tolerated; no new safety signals observed. In patients with mCRPC, long-term darolutamide treatment was well tolerated and no new safety signals were observed. These findings are consistent with previous reports, demonstrating a favorable safety and tolerability profile of darolutamide.

Real-world survival outcome comparing abiraterone acetate plus prednisone and enzalutamide for nonmetastatic castration-resistant prostate cancer

BACKGROUND

There is little evidence of abiraterone acetate (AA) plus prednisone for patients with non-metastatic castration-resistant prostate cancer (nmCRPC). In this study, we conducted a comparative analysis of real-world survival outcomes between AA plus prednisone and enzalutamide (Enz) in patients with nmCRPC, utilizing our consortium dataset.

MATERIALS AND METHODS

The clinical records of 133 nmCRPC patients treated with first-line Enz or AA plus prednisone were analyzed. The primary endpoints of the study were overall survival (OS) and cancer-specific survival (CSS). Cumulative incidence function (CIF) using Fine and Gray models was also utilized to assess non-cancer-caused death considering the competing risk of cancer-caused death.

RESULTS

During a median follow-up of 36 months, 34 patients (25.6%) had deceased, with a median OS of 99 months in the entire cohort. There were no significant differences in comorbidities between the Enz and AA groups. Time to PSA progression (TTPP: HR 0.81, 95% CI 0.51-1.30, P = 0.375) and CSS (HR 1.32, 95% CI 0.55-3.44, P = 0.5141) were comparable between the two groups. However, intriguingly, there was a trend towards shorter OS in patients treated with AA plus prednisone compared to Enz (HR 0.57, 95% CI 0.29-1.12, P = 0.0978, median of 99 and 69 months in Enz and AA groups, respectively). CIF analysis revealed that nmCRPC patients treated with AA plus prednisone were more likely to result in non-cancer-caused death than those treated with Enz (HR 5.22, 95% CI 1.88-14.50, P = 0.0014).

CONCLUSIONS

Our real-world survival analysis suggests that while AA plus prednisone may demonstrate comparable treatment efficacy to Enz in the context of nmCRPC, there may be an increased risk of non-cancer-caused death. Physicians should take into consideration this information when making treatment decisions for patients with nmCRPC.

Darolutamide for non-metastatic castration-resistant prostate cancer: Efficacy, safety, and clinical perspectives of use

Darolutamide, a second-generation androgen receptor inhibitor (SGARI), has been shown to increase metastasis-free survival and overall survival among men with non-metastatic castration-resistant prostate cancer (nmCRPC). Its unique chemical structure potentially provides efficacy and safety advantages over the SGARIs apalutamide and enzalutamide, which are also indicated for nmCRPC. Despite a lack of direct comparisons, the SGARIs appear to have similar efficacy, safety, and quality of life (QoL) results. Indirect evidence suggests that darolutamide is preferred for its good adverse event profile, an attribute valued by physicians, patients, and their caregivers for maintaining QoL. Darolutamide and others in its class are costly; access may be a challenge for many patients and may lead to modifications to guideline-recommended regimens.

Matching-adjusted indirect treatment comparison of the efficacy of enzalutamide versus apalutamide for the treatment of nonmetastatic castration-resistant prostate cancer

BACKGROUND

To date, the efficacy of the androgen receptor inhibitors enzalutamide and apalutamide for the treatment of nonmetastatic castration-resistant prostate cancer (nmCRPC) has not been compared directly in a clinical trial setting. Indirect comparisons can be used to assess relative efficacy and provide important information to guide treatment decisions. PROSPER and SPARTAN were double-blind, randomized, placebo-controlled, phase III trials in patients with nmCRPC with overall similar study designs and inclusion and exclusion criteria. Using an anchored matching-adjusted indirect comparison, based on the final data from the PROSPER and SPARTAN studies, we assessed the comparative efficacy of enzalutamide and apalutamide, both plus androgen deprivation therapy.

METHODS

Using placebo as the common comparator, individual patient data from PROSPER were matched to the aggregate patient data from SPARTAN and efficacy endpoints from PROSPER were re-weighted accordingly. Patient baseline characteristics and endpoints were clinically and statistically tested to identify potential effect modifiers, according to National Institute for Health and Care Excellence guidelines. Hazard ratios for overall survival (OS), metastasis-free survival (MFS), and time to chemotherapy (TTCx) were re-estimated for PROSPER using weighted Cox proportional hazards models and indirectly compared with those of SPARTAN using a Bayesian network meta-analysis.

RESULTS

Estimated hazard ratios [95% credible interval (CrI)] for enzalutamide versus apalutamide were 0.80 (95% CrI 0.58-1.10) for OS, 0.94 (95% CrI 0.69-1.29) for MFS2, and 0.90 (95% CrI 0.63-1.29) for TTCx. Similar results were seen for sensitivity analyses conducted for OS and MFS. Bayesian probability analyses showed a 91.7% favoring enzalutamide for OS, 65.1% for MFS, and 71.4% for TTCx.

CONCLUSIONS

The results of this matching-adjusted indirect comparison of final data from PROSPER and SPARTAN indicate comparable efficacy of enzalutamide and apalutamide with potentially a greater probability of longer MFS, OS, and TTCx in patients with nmCRPC treated with enzalutamide versus apalutamide.

Decisions and dilemmas in non-metastatic castration-resistant prostate cancer management

Non-metastatic castration-resistant prostate cancer (nmCRPC) indicates a condition characterized by the progression of the prostate-specific antigen without radiographic evidence of distant metastasis on conventional imaging during androgen deprivation therapy (ADT). Recently, 3 phase III trials have shown that the addition of next-generation androgen-receptor inhibitors (ARIs) apalutamide, darolutamide, and enzalutamide to ADT allows patients with high-risk nmCRPC to delay the appearance of metastasis and to obtain long-term clinical benefits. However, the lack of head-to head comparison makes it difficult to choose one among these agents. We reviewed the literature and explained the rationale of the possible therapeutic choices. In any case, the availability of novel ARIs means that patients with nmCRPC have now a new effective treatment option that provides them a renewed hope.

Effects of Four Types of Watermelon Frost Combination Medications for the Treatment of Oral Ulcers: A Network Meta-Analysis

Objective. The aim of this study is to identify the effectiveness of the four different watermelon frost combination medications in the treatment of oral ulcers through network meta-analysis and rank them based on their performances. Methods. Five randomized controlled studies of four distinct types of a combination medication for the treatment of oral ulcers were observed in numerous databases, and a network meta-analysis was conducted to evaluate the odds ratio (OR) and sequence of the diverse treatments using Stata software (version 13.0). The underlined studies were categorized into two groups: the control group (watermelon frost alone) and the observation group (one of four watermelon frost combinations). Results. The study comprised of 598 cases and the findings indicated that the pooled OR and 95% CI of oral ulcers that improved relative to watermelon frost alone were 3.26 (1.28 to 8.30) for watermelon frost and Kangfuxin fluid, 8.74 (2.94 to 26.02) for watermelon frost and erythromycin, 6.53 (1.81 to 23.50) for watermelon frost and metronidazole, and 2.62 (0.63 to 10.95) for watermelon frost and cydiodine buccal tablets. The study showed the significant efficacy of watermelon frost combination medications. In terms of clinical efficacy, the combination of watermelon frost and erythromycin was the most promising concomitant medication. It had an 86.3 surface under cumulative ranking (SUCRA). Conclusion. All the studied watermelon frost combinations were effective against oral ulcers validating the use of watermelon frost for oral ulcers. The combination of watermelon frost and erythromycin is the most promising candidate among the four combinations for the treatment of oral ulcers.

Cost-effectiveness of enzalutamide versus apalutamide versus androgen deprivation therapy alone for the treatment of metastatic castration-sensitive prostate cancer in Canada

AIMS

There are no direct comparisons of the relative cost-effectiveness of second-generation anti-androgens (enzalutamide and apalutamide) used in managing metastatic castration-sensitive prostate cancer (mCSPC) in Canada. This study compared the cost-effectiveness of enzalutamide versus apalutamide versus androgen deprivation therapy (ADT) alone (standard of care) in patients with mCSPC from the Canadian public payer perspective using a Markov model with a 15-year time horizon.

MATERIALS AND METHODS

Efficacy data for enzalutamide and ADT alone were informed by the ARCHES and ENZAMET clinical trials, while a Bayesian network meta-analysis enabled comparison with apalutamide and ADT alone.

RESULTS

Over the 15-year period, enzalutamide achieved the highest number of life-years (LY, 7.6) and quality-adjusted life-years (QALY, 5.62) compared with apalutamide (LY, 6.1; QALY, 4.59) and ADTs (LY, 4.9; QALY, 3.61). Enzalutamide incurred the most costs ($349,345) compared with apalutamide ($294,349) and ADT ($162,550). Sequential analysis showed that enzalutamide lies on the cost-effectiveness frontier with ADT alone (incremental cost-effectiveness ratio: $92,868/QALY), with apalutamide extendedly dominated through enzalutamide and ADT alone.

LIMITATIONS

Limitations include the heterogeneity of the studies included in the network meta-analysis and the validations for the treatment sequencing assumptions in the modeling.

CONCLUSIONS

Enzalutamide was the most effective treatment option for mCSPC in the Canadian market, with the greatest LYs and QALYs, and incurred the most costs.

The Hospitalization-Related Costs of Adverse Events for Novel Androgen Receptor Inhibitors in Non-Metastatic Castration-Resistant Prostate Cancer: An Indirect Comparison

INTRODUCTION

Three novel androgen receptor inhibitors are approved in the USA for the treatment of non-metastatic castration-resistant prostate cancer (nmCRPC): apalutamide, enzalutamide, and darolutamide. All three therapies have demonstrated prolonged metastasis-free survival in their respective phase III trials, with differing safety profiles. The objective of this study was to compare the mean per-patient costs of all-cause adverse events (AEs) requiring hospitalization between darolutamide versus apalutamide and enzalutamide for nmCRPC in the USA.

METHODS

All-cause grade ≥ 3 AEs with corresponding any-grade AEs reported among at least 10% of patients in any arm of the ARAMIS (darolutamide), SPARTAN (apalutamide), and PROSPER (enzalutamide) trials were selected for inclusion in the primary analyses. After matching-adjusted indirect comparison, AE costs were calculated by multiplying the AE rates from the trials by their respective unit costs of hospitalization taken from the US Healthcare Cost and Utilization Project (HCUP) database. Sensitivity analyses which further included any-grade AEs reported among at least 5% of patients were also performed.

RESULTS

After reweighting and adjusting for the trials' placebo arms, the mean per-patient AE costs were $1021 and $387 lower for darolutamide than for apalutamide and enzalutamide, respectively, over the trials' duration (SPARTAN and PROSPER, 43 months; ARAMIS, 48 months). For darolutamide vs. apalutamide, the largest drivers of the per-patient cost differences were fracture (adjusted difference $416), hypertension ($143), and rash ($219); for darolutamide vs. enzalutamide, they were fatigue not including asthenia ($290) and hypertension including increased blood pressure (i.e., any AE of hypertension or with elevated blood pressure not yet classified as hypertension) ($60). The results of the sensitivity analyses were consistent with the primary results.

CONCLUSIONS

Patients with nmCRPC treated with darolutamide in ARAMIS incurred lower AE-related costs (USD), as determined using HCUP costing data, compared with patients treated with either apalutamide (in SPARTAN) or enzalutamide (in PROSPER).

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

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