First-line treatment with sunitinib for type 1 and type 2 locally advanced or metastatic papillary renal cell carcinoma: a phase II study (SUPAP) by the French Genitourinary Group (GETUG)

Background: Papillary renal cell carcinoma (PRCC), type 1 and type 2, represents 10%-15% of renal cell carcinomas (RCC). There is no standard first-line treatment of metastatic PRCC (mPRCC). Anti-angiogenics have shown activity in retrospective studies but no prospective studies in pure papillary histology have been reported, but one with foretinib. Patients and methods: A prospective phase II study evaluated sunitinib in first-line treatment of mPRCC. The primary end point was overall response rate (ORR). Secondary end points were progression-free survival (PFS) and overall survival (OS). Results: Fifteen and 46 patients, respectively, with type 1 and type 2 mPRCC were enrolled. Using the MSKCC scoring system: 12 (20%), 33 (55%) and 9 (15%) patients were, respectively, in the favourable, intermediate or poor risk group and 7 undetermined. Median follow-up is 51.4 months. In type 1, 2 patients 13% [95% confidence interval (CI) 0.1-30.5] had a partial response (PR), 10 had stable disease (SD) with 5 (33%) >= 12 weeks. In type 2, 5 patients 11% (95% CI 1.9-20.3) had a PR, 25 had SD with 10(22%) >= 12 weeks. Median PFS was 6.6 months (95% CI 2.8-14.8) in type 1 and 5.5 months (95% CI 3.8-7.1) in type 2. Median OS was 17.8 (95% CI 5.7-26.1) and 12.4 (95% CI 8.2-14.3) months, respectively, in type 1 and 2. Safety was as expected with sunitinib for metastatic RCC. Conclusion: Sunitinib showed activity in treatment of type 1 and 2 mPRCC but lower than in clear-cell mRCC. Both PFS and OS are longer in type I PRCC. Sunitinib represents an acceptable option in first-line treatment of mPRCC.