Zytiga metabolite looks promising as amped-up prostate cancer therapy

Cleveland Clinic's Nima Sharifi

J&J's ($JNJ) blockbuster cancer drug Zytiga (abiraterone) has helped redraw the map for treating prostate cancer since its approval four years ago. And now a researcher at the Cleveland Clinic says that a metabolite of the drug may work better than the therapy itself in treating the disease.

Cleveland Clinic researcher Nima Sharifi says that Zytiga is converted into varying levels of D4A in both patients as well as mice after they take the drug.

Zytiga works by targeting the enzyme CYP17A1, which is needed to produce androgen, which fuels prostate cancer. But Sharifi and his team of researchers determined that D4A also blocks two other enzymes involved in producing androgen while also blocking the androgen receptor, making it a better therapy than the original.

In his work, the investigator tracked serum levels of D4A in 12 patients. But the metabolite of the drug was available in varying levels.

"More studies are needed to uncover the exact mechanisms involved, but we predict that direct treatment with D4A could prolong survival in some patients with metastatic prostate cancer," said Dr. Sharifi, "Further studies will also help us develop a potential biomarker profile to predict which patients will respond to D4--abiraterone."

Prostate cancer remains a big target for drug researchers. There are some 240,000 new cases each year, making it the most common form of cancer. This new research was published online June 1 in Nature.

- here's the release
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