Bernard J. Escudier, MD
More than two-thirds of patients with metastatic kidney cancer prefer pazopanib over another FDA-approved treatment, sunitinib, according to the results of a randomized, controlled, double-blind study released June 1 during the 48th Annual Meeting of the American Society of Clinical Oncology (ASCO). The finding will be helpful in maintaining quality of life for this population of patients, some of whom may remain on cancer therapies for years, said Bernard J. Escudier, MD, a physician at the Institut Gustave Roussy, Villejuif, France, and the study’s lead author.
Escudier said the investigation was an opportunity to learn more about side effects in a field that has enjoyed a recent explosion of new drugs, but that doesn’t offer clear evidence about which first-line treatment is the safest and most effective for metastatic patients. Pazopanib (Votrient, GlaxoSmithKline [GSK]) and sunitinib (Sutent, Pfizer) are kinase inhibitors.
“While we expected patients would prefer one drug over the other due to the known toxicity profiles, we didn’t expect this great a preference,” Escudier said of the results of the PISCES study, funded by GSK. “It’s an important reminder that the low-grade toxicities patients experience may not seem bad, but if you are experiencing the toxicity over a long time, it has an effect on your quality of life.”
In the year-long study that began in 2010, 168 patients were randomized to pazopanib for 10 weeks, took a two-week break from medication, and then received sunitinib for 10 weeks, or vice versa. In the primary analysis of 114 patients, pazopanib was preferred by 70% and sunitinib by 22%. Eight percent had no preference.
Patients most commonly cited better quality of life and less fatigue as their reasons for preferring pazopanib. In addition, patients on pazopanib noticed fewer changes in the way food tasted, Escudier said. While there were slightly more incidences of diarrhea and liver enzyme elevation with pazopanib, reports of hand and foot soreness, asthenia, and mucositis-dermatitis were less frequent, added study co-author Faisal Mehmud, MD, clinical development director, GSK Global Oncology.
Patients had fewer dose reductions on pazopanib than on sunitinib (13% vs 20%), and fewer interruptions in treatment (6% vs 12%).
Physicians were asked to participate in the study because of their awareness not just of symptomatic toxicities of the two drugs, but of asymptomatic toxicities, such as hypertension, Mehmud said. Of the physicians who participated, 60% preferred pazopanib, 21% preferred sunitinib, and 19% had no preference.
The PISCES study was innovative because it considered “how patients feel when they take a drug over many months,” a factor that traditional adverse event reporting does not reflect, Escudier said. He suggested that the study’s design can serve as a model for other investigators. According to Mehmud, the investigation relied on the administration of questionnaires including the validated Functional Assessment of Chronic Illness Therapy measurement of fatigue and a three-question quality-of-life query created for the PISCES study by GSK and the researcher who developed FACIT, David Cella, PhD, professor and chair of the Department of Medical Social Sciences at the Northwestern University Feinberg School of Medicine, in Chicago.
A related study, the COMPARZ trial, is comparing the efficacy of pazopanib and sunitinib in about 1,000 patients. The trial’s endpoint is progression-free survival, Escudier said, and results are expected soon.