The open label, single-arm, multicenter study will evaluate Xtandi as a monotherapy for the treatment of advanced, androgen receptor (AR)-positive, triple-negative breast cancer (TNBC). Meanwhile, results from a phase I breast cancer study on Xtandi will be presented at an upcoming medical conference.
We note that Xtandi is already approved for the treatment of patients with metastatic castration-resistant prostate cancer who have previously received docetaxel. While Xtandi gained approval in the US last year, EU approval was announced earlier this week.
Xtandi is off to a strong start with first quarter 2013 sales coming in at $75.4 million, $18 million above the last quarter of 2012.
Medivation and Astellas are currently working on expanding Xtandi's label. In addition to the breast cancer study, Medivation is studying Xtandi in early stage prostate cancer patients, which could represent a very big market for the product. A phase III study (PREVAIL) in chemotherapy-naïve advanced prostate cancer patients is currently ongoing with data read-outs expected later this year.
Medivation is also evaluating Xtandi at the earliest stage of prostate cancer, when the disease is initially diagnosed. The company is conducting an open-label trial which will study Xtandi as a new adjuvant therapy prior to prostatectomy. Moreover, Medivation intends to start a phase III trial in patients with non-metastatic castration-resistant prostate cancer this year.