CHICAGO – Here’s a novel idea: Ask patients which chemotherapy drug they prefer.
Given the choice between pazopanib (Votrient) and sunitinib (Sutent), patients with metastatic renal cell carcinoma who had undergone 10 weeks of chemotherapy with each drug said that they preferred pazopanib by a more than 3 to 1 margin, reported Dr. Bernard J. Escudier of the Institut Gustave Roussy in Villejuif, France.
Neil Osterweil/IMNG Medical Media
Dr. Bernard J. Escudier
In all, 70% of patients in the randomized, double-blind trial – sponsored by GlaxoSmithKline, maker of pazopanib – expressed a preference for pazopanib, compared with 22% for sunitinib (P less than .001). The remaining 8% of patients did not have a preference.
Physician preferences echoed those of their patients, with 60% saying they favored pazopanib, 21% liking sunitnib, and 19% reporting no preference.
"We didn’t ever expect such a big difference between the two drugs," Dr. Escudier said in a briefing at the meeting.
The investigators attributed the lopsided patient preference to less fatigue and better general quality of life associated with pazopanib. Patients also reported less mouth, throat, hand, and foot soreness with pazopanib; less nausea and vomiting; and less diarrhea.
"I think patient preference is relevant, but I don’t think this study actually captures patient preference in its entirety," commented Dr. Robin Wiltshire, global medical affairs lead for sunitinib for Pfizer Oncology.
He pointed out that the length of the study – 10 weeks on each drug, with a 2-week washout in between – is a relatively short amount of time and does not reflect how the drugs are used in the real world.
"Patients on these drugs nowadays are on treatment for a year, 2 years, or even more, and are surviving 2, 3, 4 years, so it’s a very long journey, and I think to base the preference on that very early time scale is quite naive. But more importantly, we deal with patients all the time in patient groups, and we know what motivates them the most is efficacy, and this study tells us nothing about efficacy," Dr. Wiltshire said in an interview.
Dr. Escudier and his colleagues randomly assigned patients to receive one of the two drugs as first-line therapy – either pazopanib 800 mg or sunitinib 50 mg – followed by crossover to the other drug after the washout period. The investigators, patients, pharmacists, and sponsor were blinded to the drugs the patients were receiving.
A total of 114 patients did not have disease progression after the first dosing period, completed at least one dose of each drug, and filled out the study questionnaire. These patients were included in the final analysis.
Preplanned sensitivity analyses significantly favored pazopanib, including a "worst-case" assumption imputing sunitinib for all unavailable patient-preference data.
There were also fewer dose reductions among patients on pazopanib (13% vs. 20%), and fewer interruptions (6% vs. 12%), Dr. Escudier said.
Although the study was not powered to look at efficacy, investigator-assessed Response Evaluation Criteria in Solid Tumors (RECIST) responses were seen in 22% of patients on pazopanib, compared with 24% of those on sunitinib, although this difference was not statistically significant.
The study was funded by GlaxoSmithKline, maker of pazopanib. Dr. Escudier disclosed serving as a consultant or advisor to the company. His coauthors also have served as advisors or consultants or have received honoraria from the company. Some coauthors are employees and own GSK stock. Dr. Wiltshire is an employee of Pfizer, maker of sunitinib.