Quality of life differences between two therapies may appear relatively modest to physicians, but can be perceived very differently by patients who may have to take therapies for many months or years.

A randomised, double-blind study of patients with metastatic kidney cancer found that the quality of life differences that patients experienced between two FDA-approved therapies were enough to demonstrate a strong preference for one treatment, pazopanib, over the other, sunitinib.

“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,” said the study’s lead author, Bernard J. Escudier, MD, a physician at the Institut Gustave Roussy, Villejuif, France.

“This is an excellent method to report the way patients are feeling about the toxicity of drugs. It’s an important reminder that 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. How patients feel when they take a drug over many months isn’t reflected in traditional adverse event reporting.”

Increasingly, patient-reported outcomes like these are being added to traditional efficacy outcomes to better understand the clinical relevance of differences in toxicity between therapies. In metastatic renal cell carcinoma, patients may take therapies for many months or even years.

In the study, 168 patients were randomised to pazopanib for 10 weeks followed by a two-week break and then sunitinib for 10 weeks, or vice versa. In the primary analysis of 114 patients, pazopanib was preferred by 70%, sunitinib by 22%, and 8% had no preference. The differences were statistically significant.

The most common reasons that patients gave for preferring pazopanib were better quality of life and less fatigue. Patients on pazopanib had fewer dose reductions than those taking sunitinib (13% vs. 20%) as well as fewer treatment interruptions (6% vs. 12%).

In a signal that physicians may not fully appreciate patient-experienced quality of life differences, physician preference wasn’t as strong as patient preference: 60% preferred pazopanib, 21% preferred sunitinib and 21% had no preference.

The study was funded by GlaxoSmithKline, the maker of pazopanib, and involved several European, UK and US cancer centers. 

Source: ASCO