A combination of two targeted drugs produced better PSA results than one drug alone in men with a form of advanced prostate cancer that has spread beyond the prostate, according to findings published in Nature Medicine.
The trial looked at men with metastatic hormone-sensitive prostate cancer (mHSPC) — a stage of the disease where cancer has travelled to other parts of the body but still responds to treatments that lower testosterone. Researchers tested whether adding the PARP inhibitor talazoparib to the androgen receptor inhibitor enzalutamide produced better outcomes than enzalutamide on its own.
It did.
In a randomised phase 2 trial — meaning patients were assigned to treatment groups by chance, and the study was designed to test safety and early effectiveness — those who received both drugs showed an improved PSA response. PSA (prostate-specific antigen) is a protein measured in the blood that doctors use to track how prostate cancer is behaving. A stronger PSA response generally suggests the cancer is reacting more to treatment.
PARP inhibitors work by blocking a protein that helps cancer cells repair their DNA. Androgen receptor inhibitors cut off the hormonal signals that drive prostate cancer growth. Used together, the two drugs target the disease through different mechanisms at the same time.
The findings were posted by the journal Nature Medicine and reference researchers including those affiliated with VHIO, the Vall d’Hebron Institute of Oncology in Barcelona. The trial was phase 2, and the researchers note that further study would be needed to establish this combination as standard care in the hormone-sensitive setting specifically — though the same drug pairing has already received regulatory approval in a related form of the disease.
Prostate cancer is the most common cancer in men in the UK, according to the NHS. Men with concerns about prostate symptoms — including difficulty urinating, needing to go more frequently, or blood in the urine — should speak to their GP rather than wait.
Anyone with questions about a prostate cancer diagnosis or treatment options can call the Prostate Cancer UK helpline on 0800 074 8383, or contact NHS 111 for general health concerns.
Source: @NatureMedicine