(Corrects second paragraph to show that Xtandi second-quarter sales were for Pfizer in the United States, not global overall sales)
By Divya Grover
Sept 14 (Reuters) - Pfizer Inc and Japan's Astellas Pharma Inc said on Thursday their prostate cancer drug met the main goal of a trial testing it for a more common form of the disease.
The drug, Xtandi, is already approved to treat metastatic castration-resistant prostate cancer (CRPC) - where the cancer has spread to other parts of the body - and raked in U.S. sales of $141 million in the second quarter for Pfizer.
An approval to treat non-metastatic CRPC would significantly boost sales of Xtandi, which Pfizer got access to when it bought Medivation for $14 billion last year. Astellas owns the rights to sell Xtandi outside the United States.
Pfizer said on Thursday that Xtandi, in combination with an anti-hormone therapy, was statistically significant in improving survival rate in men with non-metastatic CRPC without their cancer spreading, when compared with the standalone anti-hormone therapy.
Patients with CRPC experience cancer progression despite androgen deprivation therapy, a treatment that blocks the production of the hormone.
Pfizer is pinning its growth on the success and approvals of 15 drugs over the next five years, a list that includes Xtandi and breast cancer drug Ibrance.
Earlier this month, the U.S. Food and Drug Administration approved Pfizer's Mylotarg for certain patients with acute myeloid leukemia, re-clearing a drug that had been pulled off the market in 2010.
Prostate cancer a big market for drugmakers. More than 161,000 men are estimated to be diagnosed with prostate cancer in 2017 in the United States, according to the American Cancer Society.
Pfizer's shares rose 1.4 percent to $35.55 in light premarket trading. (Reporting by Divya Grover and Tamara Mathias in Bengaluru; Editing by Savio D'Souza and Saumyadeb Chakrabarty)