Drug Shows Promise Against Advanced Kidney Cancer
Nearly doubles progression-free survival to 7.4 months, but side effects reported, study shows
By Dennis Thompson
WEDNESDAY, Jan. 6, 2016 (HealthDay News) -- A targeted cancer drug appears to be effective against advanced kidney cancer, although its side effects may keep it from becoming widely used, researchers report.
The drug, cabozantinib, proved more effective across-the-board in kidney cancer patients than another targeted drug called everolimus, said lead researcher Dr. Bernard Escudier. He is chair of the genitourinary oncology committee at the Institut Gustave Roussy in Villejuif, France.
Overall, cabozantinib provided "almost a 50 percent improvement in progression-free survival" over everolimus, Escudier said.
Cabozantinib works by interrupting several different cellular processes that help cancer grow and spread, Escudier explained. Unfortunately, that widespread approach also creates worrisome toxic side effects, he added.
"Based on this multi-targeted action, we have quite a lot of side effects. Toxicity has been an issue with this drug, leading to a decrease in the dosing in many patients," he said. Diarrhea, fatigue and nausea are the most common side effects, the study found.
Escudier believes that cancer doctors likely will choose another drug, nivolumab, over cabozantinib as a follow-up option if initial chemotherapy treatment doesn't work. Nivolumab works by spurring the immune system to attack cancer cells.
"I think people are going to use nivolumab as a second-line in most patients and keep cabozantinib for nivolumab failure," he said. Nivolumab's side effects aren't as serious, he explained.
Escudier and his colleagues presented their findings Monday at the American Society of Clinical Oncology (ASCO) meeting in San Francisco. Findings presented at meetings are generally viewed as preliminary until they've been published in a peer-reviewed journal.
Cabozantinib (Cometriq) is currently FDA-approved for treatment of patients with a specific form of thyroid cancer, the researchers said. But, it's also being tested for many different cancer types, they added.
The current trial included more than 650 people with advanced renal cell carcinoma -- the most common form of kidney cancer. They were randomly assigned to receive cabozantinib or everolimus. All of the patients had been previously treated with drugs aimed at blocking the spread of nourishing blood vessels into cancerous tumors.