Cabazitaxel vs Androgen Deprivation in Metastatic Prostate Cancer
The report was published on researchsquare.com as a preprint and has not yet been peer-reviewed.
Key Takeaway
Cabazitaxel is more effective than androgen receptor-axis-targeted therapy (ARAT) for third-line treatment of metastatic castration-resistant prostate cancer (mCRPC) in a real-world setting, even when using lower doses than in the clinical trial setting and treating patients with more advanced disease.
Why This Matters
Following progress on docetaxel followed by an ARAT regimen, the CARD trial demonstrated a 1.7-month progression-free survival and 2.6-month overall survival benefit with the taxane cabazitaxel instead of an additional ARAT regimen.
The new findings confirm similar benefits in a real-world setting.
Study Design
Investigators reviewed nationwide cabazitaxel postmarketing surveillance data in Japan.
Participants had received docetaxel followed by a year or less of an ARAT regimen (abiraterone or enzalutamide) for mCRPC.
The team compared outcomes of 247 men who subsequently received cabazitaxel with 288 who went on to receive an alternative ARAT.
Among those receiving cabazitaxel, 73.3% had TNM classifications of M1 or MX and 78.5% had a Gleason score of 8-10; the mean PSA level was 483 ng/mL.
In the ARAT group, 68.1% had a TNM classification of M1 or MX and 79.2% had a Gleason score of 8-10; the mean PSA level was 594 ng/mL.
Key Results
The median time to treatment failure was 109 (94-108) days with cabazitaxel versus 58 (57-66) days for a second ARAT (hazard ratio [HR], 0.34 favoring cabazitaxel).
Similar results were obtained after propensity-score matching (HR, 0.323 favoring cabazitaxel).
Median overall survival was shorter in the current study compared with the CARD trial: 326 days with cabazitaxel versus 413 days with cabazitaxel in the CARD trial; the authors suggest the reasons could be that patients had more advanced disease or lower exposure to cabazitaxel in clinical practice compared with those in the CARD trial.
Cabazitaxel was administered at a dose below 25 mg/m2 in 81.4% of men versus 21.4% in the CARD trial.
Patients in both the cabazitaxel and ARAT arms had higher Gleason scores and serum PSA levels than those in the CARD arm.
Limitations
The data are observational, nonblinded, nonrandomized, and noncontrolled, and limited to men in Japan.
The proportions of patients receiving abiraterone and enzalutamide as a second ARAT were balanced in the CARD trial, but most patients in the current study received enzalutamide followed by abiraterone.
The observation period was limited to 1 year.
Disclosures
The work was funded by cabazitaxel maker Sanofi.
Three investigators are Sanofi employees. Another investigator reported personal fees from the company.
This is a summary of a preprint research study, “Real-world effectiveness of third-line cabazitaxel in patients with metastatic castration-resistant prostate cancer: CARD-like analysis of data from a post-marketing surveillance in Japan,” led by Hideyasu Matsuyama of Yamaguchi University, Japan, provided to you by Medscape. The study has not been peer-reviewed. The full text can be found at researchsquare.com.
M. Alexander Otto is a physician assistant with a master’s degree in medical science and a journalism degree from Newhouse. He is an award-winning medical journalist who worked for several major news outlets before joining Medscape, and is also an MIT Knight Science Journalism fellow. Email: [email protected].
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