Trial could unlock new prostate cancer sales for Pfizer/Astellas’ Xtandi

Pfizer and Astellas’ Xtandi has shown it is effective in men with prostate cancer that has spread but has not yet become hormone resistant, stepping up pressure on rival therapy Zytiga from Johnson & Johnson. The results of the ARCHES trial show that giving androgen receptor antagonist Xtandi (enzalutamide) on top of androgen deprivation therapy (ADT) met the main objective of the study by significantly reducing the risk of radiographic progression or death in men with metastatic, hormone-sensitive prostate cancer (mHSPC). The results were presented at the recent ASCO Genitourinary (GU) symposium.
The new data is something of catch-up for Xtandi in this indication, as Zytiga (abiraterone) has already shown its worth in this patient group in the STAMPEDE and LATITUDE trials, and on the strength of the top-line data suggest that Pfizer and Astellas’ drug is an effective alternative. The two companies say they plan to submit the data to regulators in the coming months. Xtandi is currently approved in the US and Japan for the treatment of castration-resistant prostate cancer (CRPC) and in the EU for the treatment of metastatic and high-risk non-metastatic CRPC, but the new indication could add another 38,000 potential patients each year to the drug’s target population, according to Pfizer.