Patients with metastatic renal cell carcinoma who transitioned to a modified 2/1 schedule of sunitinib experience an improved safety profile compared with that observed during the initial 4/2 schedule, a new study published online ahead of print in the journal Annals of Oncology has shown.

Patients receiving first-line sunitinib to treat metastatic renal cell carcinoma typically receive 4 weeks of treatment followed by 2 weeks off, but that schedule is often associated with relevant toxicities and related dose reductions. Therefore, researchers sought to evaluate the safety profile of an alternative schedule, 2 weeks on and 1 week off.

For the study, researchers retrospectively analyzed data from 249 patients with metastatic renal cell carcinoma who received first-line treatment with sunitinib.

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Of those, 208 initiated sunitinib on the 4/2 schedule and then transitioned to the 2/1 schedule due to toxicity and 41 patients started with sunitinib on the 2/1 schedule.

Researchers compared the safety of those patients with 211 patients treated with the 4/2 schedule at another institution.

Results showed that among those who started on the 4/2 schedule and switched to the 2/1 schedule, the overall incidence of grade 3 or higher toxicities was significantly reduced from 45.7% to 8.2% (P<0.001). 

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Researchers found that the incidence of fatigue, hypertension, hand-foot syndrome, and thrombocytopenia were less common with the 2/1 schedule.

In regard to efficacy, median progression-free survival was 30.2 months in the group that switched schedules, 10.4 months in the 2/1 group, and 9.7 months in the 4/2 group.


  1. Bracarda S, Iacovelli R, Boni L, et al. Sunitinib administered on 2/1 schedule in patients with metastatic renal cell carcinoma: the RAINBOW analysis. Ann Oncol. 2015. [epub ahead of print]. doi: 10.1093/annonc/mdv315.