Radioligand in Metastatic Prostate Cancer: Trial Update on Overall Survival

By: Victoria Kuhr, MS
Posted: Tuesday, January 23, 2024

According to results from the TheraP phase II trial, lutetium-177–labeled PSMA-617 (LuPSMA) may prove to be an alternative treatment to cabazitaxel for men with prostate-specific membrane antigen (PSMA)-positive metastatic castration-resistant prostate cancer progressing after treatment with docetaxel. However, Michael S. Hofman, MBBS, of Peter MacCallum Cancer Centre, Melbourne Australia, and colleagues found no evidence of an overall survival benefit with the radioligand compared with cabazitaxel. These findings were published in The Lancet Oncology.

This study took place at 11 centers in Australia between February 2018 and September 2019. It included men with metastatic castration-resistant prostate cancer whose disease progressed after docetaxel treatment. Participants were randomly assigned to treatment with LuPSMA (every 6 weeks for a maximum of 6 cycles) or cabazitaxel (20 mg/m² every 3 weeks, maximum of 10 cycles). The study analyzed restricted mean survival time to account for nonproportional hazards, with a 36-month restriction time, which corresponded to the median follow-up.

A total of 200 participants were included in the study. Of them, 99 received LuPSMA and 101 received cabazitaxel. After completing the study treatment, 20 participants (20%) assigned to cabazitaxel and 32 (32%) assigned to LuPSMA were treated with the alternative regimen. After a median follow-up of 35.7 months, 77 participants given LuPSMA had died (78%), and 70 patients given cabazitaxel had died (69%). The overall survival rate was similar among those assigned to LuPSMA vs those assigned to cabazitaxel (restricted mean survival time, 19.1 months vs 19.6 months). Of the 61 men available for follow-up, the restricted mean survival time was 11.0 months.

Disclosure: For full disclosures of the study authors, visit thelancet.com.

The Lancet Oncology

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