Posted 5/17/2012 6:20 AM (GMT -7)
The New York Times
May 17, 2012
Trial Supports Earlier Use of a Prostate Cancer Drug
By ANDREW POLLACK
A new drug used to treat advanced prostate cancer may also help men if used early in the course of the disease, before an operation, researchers reported Wednesday.
In a small clinical trial, six months of treatment with the drug, Johnson & Johnson’s Zytiga, added to standard therapy, eliminated or nearly eliminated tumors in about one-third of men whose disease had not yet spread beyond the prostate gland but was considered likely to do so.
The exact significance of this must still be determined through larger studies. But researchers said that with breast cancer and bladder cancer, patients whose tumors are eliminated before an operation, by what is called neoadjuvant chemotherapy, tend to live longer.
“This is the first time we’ve seen this degree of complete response in prostate cancer given neoadjuvant therapy,” Dr. Nicholas J. Vogelzang, who represents the American Society of Clinical Oncology, said during a telephone news conference on Wednesday.
The prostate study is one of more than 4,500 that will be presented at the oncology society’s annual meeting in Chicago in early June.
Abstracts for all but a small number of the most significant studies were released on Wednesday, setting off a scramble by Wall Street analysts and investors to sift through the data for information that could move stocks.
As for Zytiga, also known as abiraterone, it was approved in April 2011 for use by men whose cancer has spread beyond the prostate gland and who have already tried the chemotherapy drug docetaxel. Zytiga powerfully inhibits the production of testosterone, which fuels prostate tumor growth.
The trial reported Wednesday involved 58 men with localized high-risk disease. Unlike lower-risk localized prostate cancer, the high-risk cases are not often cured by surgery, said Dr. Mary-Ellen Taplin of the Dana-Farber Cancer Institute, the trial’s lead investigator.
The men took Zytiga for either 12 or 24 weeks. They were also given a steroid and the standard hormone therapy leuprolide acetate, also known by the brand name Lupron. Their prostate glands were then removed by surgery and examined.
Among the men who took Zytiga for 24 weeks, 10 percent had a pathological complete response, meaning no tumor was detected upon surgery, and another 24 percent had a near-complete response, meaning only a tiny amount of tumor was present. In the group that received 12 weeks of Zytiga, 4 percent had a complete response, and 11 percent had a near-complete response.
Lupron alone has not been shown to produce such a high rate of responses, said Dr. Taplin, who has received research funds, consulting fees and honorariums from Johnson & Johnson.
She said it was too soon for doctors to start prescribing Zytiga, which costs about $5,000 a month, so early in the course of the disease.
“This is a 58-patient trial and with a very, very expensive drug,” Dr. Taplin said. “So I don’t think anyone is going to be encouraging this type of treatment without more data.”
Wall Street is focusing less on this study than on a larger one in which Zytiga was used for metastatic prostate cancer, but before chemotherapy rather than afterward. If this trial succeeds, Zytiga should become a competitor to the Dendreon drug Provenge.
Johnson & Johnson has already said Zytiga succeeded, but it did not release the data. It will be held until the conference itself in June.