Study Assessing Safety, Efficacy of Experimental Treatment in Metastatic Prostate Cancer Adds Additional Trial Sites

The study investigators will review the efficacy of [Lu-177]-PNT2002, a radioligand treatment, compared with Zytiga or Xtandi in patients with metastatic castration-resistant prostate cancer.

Several new treatment centers were recently added to a phase 3 clinical trial evaluating the safety and efficacy of an experimental treatment versus standard-of-care options in patients with metastatic castration-resistant prostate cancer that has progressed after hormone therapy.

The investigators of the trial, which is known as SPLASH, are analyzing how well the use of [Lu-177]-PNT2002, a radioligand treatment, delays disease progression in men with metastatic castration-resistant prostate cancer versus Zytiga (abiraterone) or Xtandi (enzalutamide). Of note, during radioligand treatment, small doses of radiation are delivered directly to the cancerous cells while sparing the healthy cells.

According to a filing on ClinicalTrials.gov, it is estimated that 415 patients will be enrolled onto the trial. The main goal of the SPLASH trial is to assess how well the study drug improves radiographic progression-free survival compared with standard of care. Radiographic progression-free survival is something that study investigators often look at, and it is defined as the time from the start of treatment to the date of disease progression confirmed by scan or death from any cause.

The investigators also plan to analyze other outcomes, including objective response rate (percentage of patients whose disease responds to treatment), duration of response (time a tumor continues to respond to treatment without the cancer growing or spreading) and overall survival (time from start of treatment to death from any cause).

Long-term follow-up will continue to monitor any side effects associated with the treatment options for up to five years.

Patients must fit several criteria to be enrolled onto the trial, including being ineligible for or averse to chemotherapy treatment options.

Although SPLASH is a randomized trial, meaning that patients are divided by chance into treatment groups, it is not blinded, so patients and their providers will know which drug they were assigned. Patients who were randomized to receive either Zytiga or Xtandi can crossover to receive the investigational drug if their disease gets worse.

“I believe that, when it comes to radioligand treatments and especially in the PSMA setting, the crossover design is crucial,” lead study author Dr. James Nagarajah, an assistant professor at Radboud University Medical Center in Nijmegen, Netherlands, said. “… It improves the motivation of patients to participate in this trial, since patients allocated to the control (group) are given the possibility to cross over to the Lu-177 PSMA I&T (group) if they show disease progression and (are) willing to receive Lu-177 PSMA I&T.”

It is estimated that all patients will be enrolled by March 2023, and that the trial will be completed by March 2028.

For patients interested in the SPLASH trial, they can check out the ClinicalTrials.gov filing here.

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