No significant impact of patient age and prior treatment profile with docetaxel on the efficacy of cabazitaxel in patient with castration-resistant prostate cancer

Current Evidence on Cabazitaxel for Prostate Cancer Therapy: A Narrative Review

The incidence of prostate cancer (PC) has recently increased in Japan. Androgen deprivation therapy (ADT) has been a key treatment in patients with castration-sensitive PC (CSPC); however, resistance typically emerges through multiple mechanisms, leading to metastatic castration-resistant PC (mCRPC). Taxane-based therapy (i.e., docetaxel, cabazitaxel) has been standard care in patients with mCRPC. New evidence supporting the addition of androgen receptor signaling inhibitors (ARSIs, e.g., enzalutamide, abiraterone) to docetaxel and ADT for patients with metastatic CSPC (mCSPC) raises questions about the role of taxane-based therapies and their optimal sequencing, as well as how to identify patients who may benefit from taxane-based therapy. Here we review the evidence on taxane-based therapy, including cabazitaxel, in the treatment of PC, with a focus on clinical and real-world evidence from Japan. Cabazitaxel has proven effective for patients with mCRPC who have a history of ARSI and docetaxel use, and it is preferable to a second alternative ARSI, as indicated in the CARD study. The safety profile of cabazitaxel (particularly, the incidence of neutropenia) can be managed through prophylactic use of granulocyte colony-stimulating factor, as well as a lower dosage and possibly variation of the dosage interval. However, a certain dose intensity is required because neutropenia has been identified as a potential prognostic indicator for treatment effectiveness. In the ARSI era for mCSPC, evidence on mCRPC treatment sequencing is limited. A better understanding of PC biology and the collection of real-world data is essential for effective treatment and improved safety-benefit outcomes.

The prognostic value of Eastern Cooperative Oncology Group performance status on overall survival among patients with metastatic prostate cancer: a systematic review and meta-analysis

Background

There is heterogeneity in the literature regarding the strength of association between Eastern Cooperative Oncology Group performance status (ECOG PS) and mortality. We conducted a systematic review and meta-analysis of studies reporting the prognostic value of ECOG PS on overall survival (OS) in metastatic prostate cancer (mPC).

Methods

PubMed was searched from inception to March 21, 2022. A meta-analysis pooling the effect of ECOG PS categories (≥2 vs. <2, 2 vs. <2, and ≥1 vs. <1) on OS was performed separately for studies including patients with metastatic castration-resistant prostate cancer (mCRPC) and metastatic castration-sensitive prostate cancer (mCSPC) using a random-effects model. Analyses were stratified by prior chemotherapy and study type.

Results

Overall, 75 studies, comprising 32,298 patients, were included. Most studies (72/75) included patients with mCRPC. Higher ECOG PS was associated with a significant increase in mortality risk, with the highest estimate observed among patients with mCRPC with an ECOG PS of ≥2 versus <2 (hazard ratio [HR]: 2.10, 95% confidence interval [CI]: 1.87-2.37). When stratifying by study type, there was a higher risk estimate of mortality among patients with mCRPC with an ECOG PS of ≥1 versus <1 in real-world data studies (HR: 1.98, 95% CI: 1.72-2.26) compared with clinical trials (HR: 1.32, 95% CI: 1.13-1.54; p < 0.001). There were no significant differences in the HR of OS stratified by previous chemotherapy.

Conclusion

ECOG PS was a significant predictor of OS regardless of category, previous chemotherapy, and mPC population. Additional studies are needed to better characterize the effect of ECOG PS on OS in mCSPC.

The efficacy of sequential therapy with docetaxel and cabazitaxel for castration-resistant prostate cancer: A retrospective multi-institutional study in Japan

OBJECTIVE

This study investigated the efficacy of docetaxel (DOC) and cabazitaxel (CBZ) and examined the factors associated with the prognosis of patients with castration-resistant prostate cancer (CRPC) receiving DOC-CBZ sequential treatment in Japanese real-world data.

METHODS

We retrospectively evaluated data for 146 patients who received DOC followed by CBZ. The correlations of prostate specific antigen (PSA) decrease rate and time to progression between DOC and CBZ treatment were examined. Combined progression-free survival (PFS) of DOC-CBZ and overall survival (OS) from the initiation of DOC and the diagnosis of CRPC were evaluated and compared between patients with high and low PSA levels at the start of DOC and CBZ treatment.

RESULTS

No correlations of PSA decrease rate and time to progression were observed between DOC and CBZ. The patients for whom DOC was started in higher PSA levels had significantly shorter combined PFS (p = 0.003) and OS from the initiation of DOC (p = 0.002). In patients who started DOC at high PSA levels, those who switched to CBZ at low PSA levels had longer OS than those who switched at high PSA levels (p = 0.048). The OS from CRPC of patients who started DOC at low PSA levels was significantly longer than those that started at high PSA levels (p = 0.030).

CONCLUSIONS

For patients for whom DOC was not effective, sequential CBZ might have change to be effective. The PSA levels at the start of DOC and CBZ might be a potential prognostic biomarker.

Sequencing impact and prognostic factors in metastatic castration-resistant prostate cancer patients treated with cabazitaxel: A systematic review and meta-analysis

BACKGROUND

Cabazitaxel is an effective treatment of post-docetaxel metastatic castration-resistant prostate cancer (mCRPC). We aimed to assess the sequencing impact and identify prognostic factors of oncologic outcomes in mCRPC patients treated with cabazitaxel.

METHODS

PUBMED, Web of Science, and Scopus databases were searched for articles published before January 2022 according to the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analyses) statement. Studies were deemed eligible if they investigated pretreatment clinical or hematological prognostic factors of overall survival (OS) in mCRPC patients with progression after docetaxel treated with available treatments including cabazitaxel.

RESULTS

Overall, 22 studies were eligible for the meta-analysis. In mCRPC patients treated with docetaxel, subsequent treatment with cabazitaxel was associated with better OS compared to that without cabazitaxel (pooled hazard ratio [HR]: 0.70, 95% confidence interval [CI]: 0.56-0.89). Among the patients treated with cabazitaxel, several pretreatment clinical features and hematologic biomarkers were associated with worse OS as follows: poor performance status (PS) (pooled HR: 1.92, 95% CI: 1.33-2.77), presence of visceral metastasis (pooled HR: 2.13, 95% CI: 1.62-2.81), symptomatic disease (pooled HR: 1.47, 95% CI: 1.25-1.73), high PSA (pooled HR: 1.76, 95% CI: 1.27-2.44), high alkaline phosphatase (ALP) (pooled HR: 1.45, 95% CI: 1.28-1.65), high lactate dehydrogenase (LDH) (pooled HR: 1.54, 95% CI: 1.00-2.38), high c-reactive protein (CRP) (pooled HR: 4.40, 95% CI: 1.52-12.72), low albumin (pooled HR:1.09, 95% CI: 1.05-1.12) and low hemoglobin (pooled HR:1.55, 95% CI: 1.20-1.99).

CONCLUSIONS

Sequential therapy with cabazitaxel significantly improves OS in post-docetaxel mCRPC patients. In mCRPC patients treated with cabazitaxel, patients with poor PS, visceral metastasis, and symptomatic disease were associated with worse OS. Further, pretreatment high PSA, ALP, LDH or CRP as well as low hemoglobin or albumin, were blood-based prognostic factors for OS. These findings might help guide the clinical decision-making for the use of cabazitaxel and prognostication of its OS benefit.

Long-Term Prostate-Specific Antigen Response on a Low-Dose Cabazitaxel Regimen for Metastatic Castration-Resistant Prostate Cancer: A Case Report

BACKGROUND Cabazitaxel is a second-generation taxane approved for patients with metastatic castration-resistant prostate cancer (CRPC). Although cabazitaxel improves overall survival when used following docetaxel chemotherapy, duration of the clinical response is relatively short, and few patients achieve a long-term response. CASE REPORT A 71-year-old man with prostate adenocarcinoma with an initial prostate-specific antigen (PSA) level of 4956 ng/ml, Gleason score 4+5 and cTxN0M1b was referred to our department for treatment. Several therapeutic approaches, including androgen deprivation therapy, with a combination of bicalutamide and a luteinizing hormone-releasing hormone analogue, and 4 sequential hormonal therapies including flutamide, estramustine, enzalutamide, and abiraterone, all failed to prevent disease progression. Subsequently, after 5 cycles of docetaxel chemotherapy were also ineffective, cabazitaxel chemotherapy at a dose of 20 mg/m² together with prednisone and pegfilgrastim was initiated. The patient developed grade 4 thrombocytopenia during the first 4 cycles, and the dosage of cabazitaxel had to be tapered to 12.5 mg/m² by the fifth cycle. In subsequent cycles, the treatment was continued without grade 4 thrombocytopenia or any other toxicities ³grade 3. The patient achieved a long-term clinical response over 4 years and his PSA level continued to decrease, from 29.8 ng/ml at treatment initiation to a nadir of 2.0 ng/ml after the 60th cycle. CONCLUSIONS The present case is a rare example of a sustained response to low-dose cabazitaxel, and suggests its potential as a treatment option for metastatic CRPC patients. In our patient, this approach achieved a good clinical response with manageable toxicity over the long term.

Sarcopenia and Visceral Metastasis at Cabazitaxel Initiation Predict Prognosis in Patients With Castration-resistant Prostate Cancer Receiving Cabazitaxel Chemotherapy

BACKGROUND/AIM

Cabazitaxel is recommended as first-line treatment after docetaxel for metastatic castration-resistant prostate cancer. However, the efficacy, adverse events and prognostic factors associated with cabazitaxel are unclear.

PATIENTS AND METHODS

This single-centre retrospective study including 30 patients with CRPC treated with cabazitaxel between 2014 and 2020 investigated efficacy, outcomes and prognostic factors.

RESULTS

Fourteen patients had visceral metastases. The median cabazitaxel dose was 20 mg/m² The prostate-specific antigen response rate, time to prostate-specific antigen response, and overall survival were 13.3%, 3.48 months, and 7.92 months, respectively. The rates of grade 3 or more neutropenia and febrile neutropenia were 20% and 6.7%, respectively. By multivariate analysis, sarcopenia and visceral metastasis at the time of cabazitaxel initiation were independent and significant factors conferring a poor prognosis.

CONCLUSION

The early introduction of cabazitaxel, prior to the development of sarcopenia and visceral metastasis, might contribute to improved prognosis in CRPC.

Sequential Docetaxel in ≥7 Cycles Followed by Cabazitaxel Improves Oncological Outcomes in Patients with Metastatic Castration-Resistant Prostate Cancer

Background. Docetaxel (DOC) was the first regimen that increased the survival and became the standard-of-care in patients with metastatic castration-resistant prostate cancer (mCRPC). However, it is unclear whether switching to second-line chemotherapy or optimal sequencing of cabazitaxel (CBZ) ensures better clinical outcomes. We aimed to evaluate the efficacy of sequential therapy with DOC and CBZ and the effect of the number of prior DOC cycles on oncological outcomes in patients with mCRPC. Methods. We retrospectively included 46 mCRPC patients who received DOC followed by CBZ at quaternary hospitals in Japan between February 2015 and March 2019. Participants received intravenous DOC (40–75 mg/m2) every 3–4 weeks; CBZ (15–25 mg/m2) was administered every 3–4 weeks. Androgen-deprivation therapy and prednisolone 5 mg (twice daily) were administered throughout both regimens. The primary endpoints were overall (OS) and progression-free survival (PFS). The secondary endpoints were the rates of ≥30% and ≥50% reduction in prostate-specific antigen (PSA) levels at chemotherapy initiation. Results. Participants were divided into two groups according to DOC cycles (Groups A and B: ≤6 and ≥7 DOC cycles, respectively). The rates of ≥30% and ≥50% reduction in PSA levels were higher in Group B than in Group A, but there were no significant differences in both groups. Median OS in Groups A and B was 12.7 and 71.0 months, respectively $\left(P<0.001\right)$ ; median PFS in Groups A and B was 3 and 12 months, respectively $\left(P<0.001\right)$ . Conclusions. Administration of ≥7 cycles of DOC followed by CBZ may improve oncological outcomes in patients with mCRPC.

Efficacy and safety of cabazitaxel therapy in elderly (≥75 years) patients with castration-resistant prostate cancer: A multiinstitutional study

Background

There is little data on the outcome of cabazitaxel (CBZ) treatment of elderly patients with castration-resistant prostate cancer (CRPC). This study assessed the efficacy and safety of CBZ chemotherapy in patients with CRPC aged 75 years or older in a multiinstitutional study.

Methods

We retrospectively reviewed the 74 patients with CRPC treated with CBZ enrolled in 10 institutions. Clinicopathological backgrounds, prognosis including prostate-specific antigen decline, time to treatment failure, progression-free survival, overall survival, and safety profiles were compared between younger (<75 years) and elder (≥75 years) patients.

Results

In total, 74 patients were enrolled; 50 patients were younger than 75 years and 24 were ≥75 years. Clinicopathological characteristics were comparable between younger and elder patients, with the exception of serum albumin values at the time of CBZ treatment. The median prostate-specific antigen decline in younger and elder men was −8.8% and −32.3% from baseline, respectively. The median time to treatment failure, progression-free survival, and overall survival for younger and elder men were 0.24 and 0.33 years, 0.23 and 0.43 years, and 0.69 and 1.17 years, respectively. In addition, safety profiles were comparable between younger and elder patients.

Conclusions

This multiinstitutional study suggests that patients with CRPC aged 75 years or older eligible for CBZ treatment can be treated safely and with noninferior efficacy compared with those younger than 75 years.

Cabazitaxel in patients aged ≥80 years with castration-resistant prostate cancer: Results of a post-marketing surveillance study in Japan

OBJECTIVES

Data on the safety and efficacy of cabazitaxel in patients aged ≥80 years with castration-resistant prostate cancer (CRPC) are limited. We report the safety (adverse drug reactions [ADRs]) and efficacy (overall survival [OS], time to treatment failure [TTF], and prostate-specific antigen [PSA] response rates) in patients aged <80 or ≥80 years treated with cabazitaxel for CRPC in clinical practice.

MATERIALS AND METHODS

We performed post-hoc subgroup analyses of a Japanese post-marketing surveillance study involving 662 patients with CRPC treated with cabazitaxel between September 2014 and June 2016.

RESULTS

In patients aged <80 (n = 610) and ≥80 years (n = 49), median PSA at baseline was 168.7 and 109.0 ng/mL, and 86.7% and 83.7% of patients were previously treated with enzalutamide and/or abiraterone. ADRs (all grade) occurred in 77.2% and 79.6% of patients aged <80 and ≥80 years, with grade three/worse ADRs in 61.8% and 63.3% of patients. Hematologic toxicities were the most common grade three/worse ADRs, including neutropenia, febrile neutropenia, and anemia in both subgroups. No specific ADRs were observed in patients aged ≥80 years. The PSA response and median OS and TTF were 28.3%, 292 days, and 116 days in patients aged ≥80 years, and 29.7%, 319 days, and 125 days in patients aged <80 years.

CONCLUSION

Cabazitaxel could be a treatment option for CRPC in patients aged ≥80 years based on its safety and efficacy profiles. This is the first report to investigate the safety and efficacy of cabazitaxel in patients aged ≥80 years with CRPC.

Safety and efficacy of cabazitaxel in 660 patients with metastatic castration-resistant prostate cancer in real-world settings: results of a Japanese post-marketing surveillance study

Objective

To evaluate the real-world safety and efficacy of cabazitaxel in Japanese patients with metastatic castration-resistant prostate cancer (mCRPC) previously treated with a docetaxel-containing regimen.

Methods

This prospective multicenter observational study registered all patients with mCRPC treated with cabazitaxel following its launch in Japan in September 2014. Patient enrollment continued until at least 500 patients were enrolled. Adverse drug reactions (ADRs) were evaluated according to CTCAE ver. 4.0. Efficacy endpoints were assessed for up to 1 year, and included prostate specific antigen (PSA) response rates (defined as a decrease of ≥30% or ≥50% from baseline), overall survival (OS), and time to treatment failure (TTF).

Results

A total of 660 mCRPC patients were enrolled across 316 centers by June 2016. Frequent ADRs (any grade) were neutropenia (49.1%), febrile neutropenia (18.0%) and anemia (15.0%). Most ADRs occurred in cycle 1. Neutropenia and febrile neutropenia were significantly less frequent in patients who received prophylactic granulocyte colony-stimulating factor. The PSA response rates for decrease of ≥30% or ≥50% from baseline were 28.1% and 17.5%, respectively, in patients with baseline PSA of ≥5 ng/ml. Median OS and TTF were 319 days (95% confidence interval: 293.0–361.0) and 116 days (95% confidence interval: 108.0–135.0), respectively.

Conclusions

This study of cabazitaxel in 660 Japanese patients treated in real-world settings, the largest study of cabazitaxel to date, demonstrated a safety profile that was generally consistent with those of pivotal clinical studies. Cabazitaxel was also effective in terms of the PSA response, OS, and TTF.

Safety and efficacy of cabazitaxel in Japanese patients with castration-resistant prostate cancer

Background

Several studies have reported the efficacy of cabazitaxel in cancer therapy; however, investigations of its safety are few. The aim of this study was to retrospectively analyze the efficacy and safety of cabazitaxel based on treatment outcome data.

Methods

A questionnaire form on the use of cabazitaxel was mailed to hospitals associated with the Shinshu University. Responses were received from 11 institutions regarding 55 cases.

Results

Patients received a median of 4 courses of cabazitaxel treatment. Decreases in prostrate-specific antigen (PSA) were observed in 61.5% of cases with declines of 30%, 50%, and 90% in 36.5%, 23.0%, and 7.6% of cases, respectively. PSA progression-free survival was 5.0 months, and overall survival after the start of cabazitaxel was 13.0 months. Forty-five patients received postcabazitaxel treatment; 17 showed decreased PSA. Safety assessment indicated that white blood cell and neutrophil counts were significantly higher in the second than in the first course of treatment and Grade 3 to 4 leukopenia and neutropenia significantly decreased. Twenty-four subjects were aged ≥75 years; 79% of them had their doses reduced at the first administration. The mean dose was 20 mg/m². However, there was no significant difference in the PSA progression-free survival between the ≥75-year-old and <75-year-old groups. Patients in the ≥75-year-old group, particularly those whose doses were not reduced, experienced several Grade 3 to 4 adverse effects. Ten patients discontinued treatment owing to adverse effects and systemic worsening.

Conclusions

To use cabazitaxel effectively, starting administration as early as possible before disease progression is important, and even if Grade 3 to 4 leukopenia and neutropenia are observed during the first course, it is important to carefully maintain the dose. Even when treating elderly patients, reducing the dose does not reduce therapeutic efficacy. However, because this cohort experienced several ≥ Grade 3 adverse effects, a great deal of caution is required.