Table of Contents

Chapter 7: The Role of Chemotherapy

b. The Drugs: What We Use and Why

As we touched on earlier, the benefits of chemotherapy in prostate cancer were only first realized recently: mitoxantrone (Novantrone) was approved by the FDA in 1996 and docetaxel (Taxotere) was approved in 2004. Before these two drugs came along, no treatments had proven beneficial in men who had prostate cancer that was no longer responsive to hormone therapy. The availability of these drugs changed the way that researchers looked at chemotherapy and how it might be able to affect the lives of men with advanced prostate cancer.

In 1999, two clinical trials were started to see if docetaxel could provide a benefit to men with advanced prostate cancer and prolong their lives. By this time, two other clinical trials had shown that mitoxantrone could provide palliative benefit, or pain relief, to men with advanced prostate cancer. Once the results of the earlier trials became known, mitoxantrone was established as the "standard of care," or the accepted practice by doctors across the country when treating men with symptomatic prostate cancer.

The two docetaxel trials were designed somewhat differently from one another, but the goal of both trials was the same: to see if docetaxel can work at least as well as mitoxantrone, if not better. When the results were published in 2004, the trials showed that docetaxel prolonged the lives of the men who took it as well as relieved symptoms better than mitoxantrone.

The men who took docetaxel in these two trials lived for an average of two to three months longer. But many men saw prolonged benefits, and because most men at this stage of disease tend to have a shortened life expectancy, even those who didn’t were glad to have gotten even that short amount of extra time with their families and friends. Importantly, researchers looked at the results of these two trials as an important signal that if one chemotherapy drug could prolong the lives of men with metastatic hormone-refractory prostate cancer, other drugs might be able to match it or even surpass it.

At this time, there are dozens of clinical trials studying various combinations of chemotherapy drugs, some using new mixes of older drugs and some using newer drugs. Some trials are looking to find a chemotherapy regimen that’s more tolerable or more effective than docetaxel in men with metastatic disease, others are looking to find a chemotherapy regimen that can delay the onset of metastases, and still others are seeking to improve upon the results with docetaxel by adding to it other novel agents and testing the combination. Unlike what was thought just 10 years ago, there’s now little question in the minds of researchers whether we will find something that works even better than what we’ve already seen—it’s now just a question of when.