First-line single-agent everolimus provides some clinical benefit to patients with papillary metastatic renal cell carcinoma (mRCC), according to a final analysis of a study in press at the European Journal of Cancer.1

Treatment options are limited for patients with advanced papillary RCC, which accounts for only 10% to 15% of RCC cases. Researchers evaluated the efficacy and safety of everolimus monotherapy in newly diagnosed patients with this uncommon RCC subtype.

For the open-label, phase 2 RAPTOR trial (RAD001 in Advanced Papillary Tumor Program in Europe; Identifier: NCT00688753), investigators enrolled 92 previously untreated patients with type 1 or type 2 papillary mRCC. All participants received everolimus orally until disease progression or unacceptable toxicity.

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Results showed that 34% (80% CI, 25-45) of the first 44 patients did not have disease progression or die within 6 months of initiating treatment, indicating the study’s primary end point was not met.

Median progression-free survival was 4.1 months (95% CI, 3.6-5.5) among the 88 patients included in the intention-to-treat population; median overall survival was 21.4 months (95% CI, 15.4-28.4).

Researchers also observed that 65% of patients achieved stable disease.

Median progression-free survival was 7.9 months (95% CI, 2.1-11.0) and 5.1 months (3.3-5.5) among patients with type 1 and type 2 histology; median overall survival was 28.0 (95% CI, 7.6-not estimable) and 24.2 months (95% CI, 15.8-32.8), respectively, suggesting that median progression-free survival and overall survival were longer for patients with type 1 than for type 2 papillary RCC.

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The most common grade 2 or worse adverse events were asthenia, anemia, and fatigue, which was consistent with previous reports. Seven patients had treatment-related pneumonitis.

The authors note that additional studies are warranted to determine the optimal treatment strategy for patients with papillary mRCC.                                       


  1. Escudier B, Molinie V, Bracarda S, et al. Open-label phase 2 trial of first-line everolimus monotherapy in patients with papillary metastatic renal cell carcinoma: RAPTOR final analysis. Eur J Cancer. In press.