Adding Provenge to Xtandi or Zytiga Reduces Risk of Death by 45% in Metastatic Hormone Resistant Prostate Cancer

Data from more than 6,000 Medicare patients showed that adding the immunotherapy Provenge (sipuleucel-T) to a regimen containing the oral agents Zytiga (abiraterone acetate) or Xtandi (enzalutamide) significantly extended the lives of men with metastatic hormone-resistant prostate cancer (mCRPC). The findings were presented in a poster at the recent American Society of Clinical Oncology (ASCO) 2020 Genitourinary Cancers Symposium in San Francisco, California.

Provenge, marketed by Dendreon Pharmaceuticals, is an immunotherapy that uses a patient’s own immune cells to fight prostate cancer. In it, a fraction of white blood cells that have been exposed to a prostate cancer protein are primed to activate the remaining immune cells to fight cancer. Provenge is the only immunotherapy approved in the U.S. (2010) for prostate cancer that is made from a patient’s own immune cells. Since 2010, second-generation androgen receptor inhibitors, like Zytiga and Xtandi, have become the standard care treatment for men with mCRPC. This led researchers at Dendreon to assess the benefits of Provenge when used in combination with these agents. The researchers examined medical and pharmacy claims from 6,853 Medicare mCRPC patients who had not received any prior treatment, which means they had no treatment claims in the prior year.

Results indicated that the use of Provenge significantly extended patients’ lives from 20.7 months to 35.2 months. This 14.5-month increase in overall survival represented a 45% reduction in the risk of death. Notably, the benefits were seen at any point during treatment, with patients receiving Provenge as part of their first-line treatment seeing the same extension in overall survival as those receiving the therapy in later lines. At three years, nearly half (48%) of patients receiving Provenge in any line of treatment were alive, compared to 28% of those receiving only Zytiga or Xtandi without Provenge.

Recent findings from an observational registry study called PROCEED also showed that men with asymptomatic or minimally symptomatic mCRPC derive the same benefits from Provenge as those that had been demonstrated in IMPACT. Men with low prostate specific antigen (PSA) levels at baseline fared particularly well, living nearly four years after receiving Provenge.

This is in line with another study also presented at the ASCO GU Cancers Symposium, demonstrating that Provenge works better in men with early-stage prostate cancer — who likely have lower PSA levels — than in those with mCRPC.

“These real-world data contribute to a growing body of evidence that Provenge continues to deliver on its promise of helping men with advanced prostate cancer live longer,” said Bruce A. Brown, MD, chief medical officer at Dendreon.

Several blogs describing Provenge including my own experience with it have been posted on this website. See the following links from 2017, 2014, and 2011.

A portion of the above was an excerpt from the Feb. 20th Prostate Cancer News Today, by Iqra Mumal. I strongly encourage readers to subscribe to this e mail prostate cancer news service.

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