(UroToday.com) The 2025 American Society of Clinical Oncology (ASCO) Genitourinary (GU) Annual Symposium held in San Francisco, CA was host to a prostate cancer poster session. Dr. Pedro Barata presented the results of a population-based study evaluating docetaxel re-challenge versus cabazitaxel switch in metastatic castrate-resistant prostate cancer (mCRPC) patients previously treated with docetaxel.
In 2004, docetaxel, a semi-synthetic taxane, received regulatory approval for the treatment of mCRPC patients, based on the results of the TAX-327 trial that demonstrated improved overall survival outcomes with docetaxel plus prednisone therapy.1 In 2010, cabazitaxel, a closely related analog of docetaxel, was approved in 2010 for mCRPC patients previously exposed to docetaxel, following the results of the TROPIC trial.2
For patients previously treated with docetaxel, the relative benefits of a docetaxel re-challenge versus a cabazitaxel switch remain unknown. The study objective was to compare the efficacy of a docetaxel re-challenge versus cabazitaxel switch for mCRPC patients who previously received docetaxel in the castrate-resistant setting.
This was a retrospective cohort analysis using the nationwide VA healthcare system database and included patients who received initial docetaxel for mCRPC, subsequently discontinued docetaxel for a reason other than disease progression, and who later received a docetaxel re-challenge or cabazitaxel switch.
Time-to-event analyses were performed, with the date of docetaxel re-challenge or cabazitaxel switch marking the start of follow-up (i.e., T0). Inverse probability of treatment weighting (IPTW) was used to control for potential confounders (age, race/ethnicity, comorbidities, frailty, PSA, Gleason score, prostatectomy, radiation, neuropathy, baseline labs, stage, cycles of initial docetaxel, time from metastatic diagnosis to second taxane, time between taxanes, prostate cancer drugs received).
The study flow chart is summarized below:
This study included a total of 262 patients who received a docetaxel re-challenge and 407 who underwent a cabazitaxel switch. The median patient age was 72 years (IQR: 67–77). The majority of patients were Caucasian (60%), with 29% Black and 5% Hispanic.
As illustrated in the weighted Kaplan-Meier curve below, patients who received a docetaxel re-challenge had superior overall survival outcomes (median: 12.3 versus 9.6 months; HR: 1.24, 95% CI: 1.01–1.83, p=0.04).
PSA responses (i.e., PSA30, PSA50, PSA90) all favored patients receiving a docetaxel re-challenge, as summarized in the table below.
Dr. Barata concluded that a docetaxel re-challenge was associated with superior survival outcomes and deeper PSA responses, compared to a cabazitaxel switch, in docetaxel pre-treated mCRPC patients who discontinued docetaxel for a reason other than disease progression. He argued that the findings of this large-scale study provide guidance for making well-informed, cost-effective decisions regarding the sequential use of taxanes for the treatment of mCRPC patients.
Presented by: Pedro C. Barata, MD, MSc, Associate Professor at University Hospitals Seidman Cancer Center, Cleveland, OH
Written by: Rashid K. Sayyid, MD, MSc – Robotic Urologic Oncology Fellow at The University of Southern California, @rksayyid on Twitter during the 2025 Genitourinary (GU) American Society of Clinical Oncology (ASCO) Annual Meeting, San Francisco, CA, Thurs, Feb 13 – Sat, Feb 15, 2025.
References:
- Tannock IF, de Wit R, Berry WR, et al. Docetaxel plus prednisone or mitoxantrone plus prednisone for advanced prostate cancer. N Engl J Med 2004;351:1502-1512.
- de Bono JS, Oudard S, Ozguroglu M, et al. Prednisone plus cabazitaxel or mitoxantrone for metastatic castration-resistant prostate cancer progressing after docetaxel treatment: A randomised open-label trial. Lancet 2010;376(9747):1147-1154.