Cancer Treatment More Targeted, Deaths Decline
Pfeiffer, Naomi, Drug Topics
Researchers at the American Society of Clinical Oncology (ASCO) annual meeting stressed that treatment overall is far more targeted, with fewer side effects, than before - and cancer deaths are down for the first time in 70 years. Here are some highlights from the meeting, held recently in Chicago.
Focus on liver cancer
The centerpiece of the conference was the phase IU trial of sorafenib (Nexavar, Bayer/Onyx), which found that advanced liver cancer patients receiving the targeted drug live much longer than other patients with the lethal disease. Thus sorafenib, an oral kidney cancer medication (approved in 2005), became the first therapy to show a significant survival benefit in liver cancer.
"This is the first time we've had a systemic treatment for liver cancer/' explained lead author Joseph Llovet, M.D., director of liver cancer research at the Mount Sinai School of Medicine in New York. "Our findings demonstrate survival advantages that are both statistically significant and clinically meaningful."
Focus was both on survival and the time it took for tumors to grow among patients with previously untreated liver cancer. They were randomly assigned to receive either 400 mg of sorafenib twice daily (299 patients) or a placebo (303 patients) for six months. Median survival was 10.7 months versus 7.9 months - a 44% difference. Time to cancer progression was 5.5 versus 2.8 months. The study was terminated early due to these positive findings.
"As no [existing] treatment improves survival for the thousands of liver cancer patients worldwide, these results [promise] that Nexavar will be the new standard of care for first-line treatment of primary liver cancer," said Llovet.
A phase III trial calling attention to a related drug examined the survival potential of sunitinib (Sutent, Pfizer) versus interferon alfa as first-line treatment for advanced renal cell carcinoma. "Oral Sutent extended progression-free survival across all patient risk groups, including those with the poorest prognoses for survival," reported lead investigator Robert Motzer, M.D., an attending physician at Memorial Sloan-Kettering Cancer Center (MSKCC).
"Sutent treatment more than doubled progression-free survival compared with interferon-alfa," Motzer said. Like sorafenib, sunitinib is a multikinase inhibitor that works primarily by inhibiting angiogenesis. Notably, the first two targeted therapies in years recently approved by the Food & Drug Administration for renal cell carcinoma were sorafenib and sunitinib.
Treating ovarian cancer
The targeted therapy aflibercept (VEGF-Trap, Sanofi- Avenus/ Regeneran) - another blocker of angiogenesis - demonstrated in a global trial that it is active in patients with a common type of ovarian cancer that has recurred and is resistant to platinum-based chemotherapy drugs. The highly touted report dealt with the first phase II trial ever to look at aflibercept's effectiveness against epithelial ovarian cancer, which comprises nearly 90% of the 22,000 cases of the disease diagnosed annually in the United States.
"The [preliminary] results are very encouraging," said lead investigator William P. Tew, M.D., an assistant attending physician at MSKCC. "Most antiangiogenesis drugs are studied together with other chemotherapy agents. Ovarian cancer seems to be one of the few cancers in which these drugs apparently work better alone." Currently there is no approved treatment for advanced ovarian cancer, he noted.
To date, the trial has randomized 162 heavily pretreated patients to receive aflibercept at either 2 mg/kg or 4 mg/kg daily. Preliminary results: Some tumors shrank in 8% of patients; others stopped growing in 71%. The trial, which is still blinded, is ongoing with a goal of accruing 200 patients. …