Pazopanib is used for first-line metastatic RCC treatment, but the data for poor-risk patients are scarce. The FLIPPER study was designed to determine the safety and efficacy of first-line pazopanib in poor-risk patients with metastatic RCC.
FLIPPER was a single-arm, open-label, phase IV trial involving 60 patients with poor-risk metastatic mRCC. All patients were treated with pazopanib in the first-line. The 6-month progression-free survival was was 35.3%. Median progression-free survival was 4.5 months, and median overall survival was 9.3 months. Response rate was 32.4%, but there were no complete responses. Eleven patients had a partial response lasting a median of 9.7 months.
Severe or life-threatening adverse events were recorded by 14 patients (32.6%), the most frequent being fatigue, water on the lungs (pleural effusion), and hypertension.
Although the numbers of patients in this study were small, these findings demonstrate that pazopanib is active and well tolerated in poor-risk patients with clear cell metastatic RCC, supporting its use as a first-line treatment in this patient population. However, with the approval of immunotherapy combinations in the first-line for poor risk patients, there might be a niche for pazopanib for those patient who are unable to tolerate immunotherapy.