Adding drug to androgen suppression boosts progression-free survival in prostate cancer

CANCER DIGEST – Nov. 6, 2022 – An investigational therapy increased progression-free survival in 40 percent of nine patients whose prostate cancer had become resistant to hormone-blocking therapy according to a study was published in the August 30, 2022 journal Molecular Therapy.

The small trial conducted at Cedars-Sinai Cancer Center in Los Angeles involved giving the 9 patients the monoclonal antibody immunotherapy drug, carotuximab.

In the trial led by Neil Bhowmick, PhD and Edwin Posada, MD, each of the 9 patients had become totally resistant to at least one androgen suppressor, these are drugs that suppress the hormones that fuel prostate cancer growth.

“Every single one of the patients in our trial was totally resistant to at least one androgen suppressor, and the normal course of action would be to simply try a different one or chemotherapy, which research has shown generally doesn’t stop tumor growth for more than about three months,” Bhowmick said in a press release. “Carotuximab prevented the cancer’s workaround and made the tumor sensitive to androgen-suppressing therapy.”

In these nine patients, the researchers instead began a regimen of carotuximab, which blocks the protein made by a gene called CD105. What happened next surprised the physicians, 40 percent of the patients experienced progression-free survival, based on x-ray imaging. Progression-free survival is the amount of time a patient’s tumor stops growing or begins to shrink.

When they looked at what was happening, the researchers found that the carotuximab re-sensitized the prostate cancer tumor to the androgen-blockers. Furthermore, the drug prevented cells surrounding the tumor from becoming resistant to the hormone-blockers.

In addition, the researchers have identified three biomarkers that could help identify which patients will respond to adding carotuximab to androgen-blocker therapy. The group is now planning a larger clinical trial to validate their findings.

Source: Cedars Sinai press release