Two-drug combination boosts survival in patients with metastatic prostate cancer
Patients with newly diagnosed metastatic, hormone-sensitive prostate cancer gained a dramatic survival benefit with simultaneous initiation of two drugs, rather than delaying the second drug until the cancer began to worsen, according to results of a clinical trial recently published in The New England Journal of Medicine (2015; doi:10.1056/NEJMoa1503747).
Patients who underwent six cycles of treatment with docetaxel along with a hormone blocker survived for a median of 57.6 months, more than 1 year longer than the median 44-month survival for men who received only the hormone-blocker. The immediate combination also prolonged the period before the cancer began to worsen, to a median of 20.2 months vs 11.7 months with the single agent.
The multicenter, phase III trial, involving 790 patients, "is the first to identify a strategy that prolongs survival in men [with] newly diagnosed with metastatic, hormone-sensitive prostate cancer," said Christopher J. Sweeney, MBBS, of Dana-Farber's Lank Center for Genitourinary Oncology in Boston, Massachusetts. He said the results of the multicenter phase III trial should change the way doctors have routinely treated such patients since the 1940s.
Sweeney had reported initial results of the trial in June 2014 at the annual meeting of the American Society of Clinical Oncology (ASCO), and they were so favorable that the new regimen has been adopted by some physicians. Since then, confirmatory data from the STAMPEDE trial were presented at the 2015 ASCO meeting, and those results, along with the new publication in the New England Journal of Medicine, are the final pieces "required for treatment guidelines to be updated around the globe," Sweeney said.
The standard practice for decades has been to treat this group of patients with prostate cancer with hormone blockers; chemotherapy is withheld until the hormone blockers become ineffective, which they do, on average, in approximately 3 years.
The new trial was designed and conducted by the ECOG-ACRIN Cancer Research Group to test Sweeney's hypothesis that adding chemotherapy to hormone treatment from the start would impair the tumor cells' ability to repair damage, delaying the development of resistance.