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Prostate CancerSeptember 2021Summary reviewed September 2026

New Pill Shrank Tumors in 3 in 10 Men With Advanced Prostate Cancer

Men with advanced prostate cancer who had specific gene changes and had already tried multiple treatments took a daily pill. Three in 10 saw their tumors shrink. The treatment worked best in men with BRCA1 or BRCA2 gene changes, which run in some families.

What the trial was testing

The TALAPRO-1 enrolled 128 patients with prostate cancer. The study was sponsored by Pfizer and tracked outcomes across the full group of patients who matched the trial's eligibility profile.

It was initial testing (phase 2). Trials at this stage are designed to produce evidence regulators and physicians can act on — not just observations to follow up later.

What the results showed

Three in 10 men with gene-altered prostate cancer saw their tumors shrink with this daily pill.

The Lancet. Oncology · 2021 · NCT03148795

These findings — that saw their tumors shrink after other treatments had stopped working — were published in the The Lancet. Oncology and represent the headline result of the study.

Researchers tracked outcomes across 128 patients enrolled in the trial. The result was consistent enough across the group that the team felt confident reporting it.

What this means for patients

For patients with prostate cancer, this result changes the calculus on what to ask their care team about. Whether it changes day-to-day care depends on factors like disease subtype, prior treatments, and where the patient is in their care journey.

What you can do now

If you have advanced prostate cancer that stopped responding to hormone therapy and chemotherapy, ask your doctor about genetic testing. If you have certain gene changes (especially BRCA1 or BRCA2), this pill might be an option. This was a mid-stage study and the treatment is not yet widely available. Talk to your doctor about open trials or related approved options.

Eligibility for the treatments mentioned above depends on specific test results and clinical history. Bring this summary, the trial name, and your most recent labs or pathology report to your next visit.