Dr. Taplin on Neoadjuvant Abiraterone and Leuprolide

Mary-Ellen Taplin, MD, associate professor of Medicine at Harvard Medical School and the Dana-Farber Cancer Institute, discusses a randomized phase II trial that administered abiraterone acetate (Zytiga) in combination with the hormonal therapy leuprolide acetate before prostatectomy for men with localized high-risk prostate cancer (LHRPC).

The trial randomized 58 men into two groups that both received 24 weeks of leuprolide acetate and either 12 or 24 weeks of abiraterone acetate, which is indicated to be given with prednisone. The primary endpoint of the trial was to assess the hormone levels in the excised tissue following prostatectomy. The secondary endpoint examined the amount of tumor tissue left, following surgery.

Traditionally, patients receiving leuprolide acetate experience a low level of pathological complete response (pCR), which Taplin defines as no remaining tumor tissue. However, the addition of abiraterone acetate for the full 24 weeks of treatment resulted in a pCR of 10% and a near pCR of 24%.

Taplin notes that the relevance of pCR as an endpoint in prostate cancer has not received evidence-based validation. In other tumors; however, patients who experience a pCR after receiving a neoadjuvant therapy have a higher cure rate at 5 and 10 years but a larger study with a longer follow up is needed to validate this in prostate cancer.