PARIS — Patients with metastatic renal cell carcinoma treated with sorafenib and sunitinib experienced similar PFS and OS regardless of the sequence with which the drugs were administered, according to study results presented at the WIN Symposium.
In addition, researchers found no strong evidence of a correlation between PFS and OS in either treatment arm.
"Up to now, there is no clear consensus on the most appropriate sequencing of drugs following disease progression in metastatic renal cell carcinoma," the researchers wrote. "This study was performed to investigate the correlation between PFS and OS in a consecutive series of metastatic renal cell carcinoma patients treated with the sequence [of] sunitinib-sorafenib vs. sorafenib-sunitinib."
The analysis included 125 patients treated between November 2005 and January 2012 at the Istituto Nazionale Tumori in Milan, Italy.
Of them, 104 received sorafenib (Nexavar, Bayer) followed by sunitinib (Sutent, Pfizer). The other 21 patients received the drugs in the reverse sequence.
The majority of patients assigned to the sorafenib-sunitinib sequence had ECOG performance status of 0 (53.8%) or 1 (45.2%). Nearly 85% had clear-cell histology, and 94.2% had undergone previous nephrectomy. Based on Motzer criteria, 38.5% were classified as low risk, 53.9% were intermediate risk and 7.7% were poor risk.
The majority of patients assigned to the sunitinib-sorafenib sequence also had ECOG performance status of 0 (47.6%) or 1 (47.6%). Eighty-one percent had clear-cell histology, and 95.2% had undergone previous nephrectomy. Motzer criteria characterized 14.3% of patients as low risk, 61.9% as intermediate risk and 23.8% as poor risk.
Researchers used Kaplan-Meier curves to describe survival distributions and the log-rank test to detect a statistical significance between survival distributions. They used the Kendall's tau nonparametric index to evaluate the correlation between PFS and OS.
Median follow-up was 66.6 months (range, 6-84 months) in the sorafenib-sunitinib arm and 37.1 months (range, 4-60.1 months) in the sunitinib-sorafenib arm.
At the time of analysis, 98 patients (78%) had experienced disease progression and 88 patients (70%) had died.
Researchers reported a median PFS of 26.1 months in the sorafenib-sunitinib arm (95% CI; 21.8-34) vs. 20 months (95% CI, 10-33) in the sunitinib-sorafenib arm, a difference that was not statistically significant. Researchers reported no statistically significant difference in OS between the two arms (35.3 months for the sorafenib-sunitinib group vs. 27 months for the sunitinib-sorafenib group).
The results showed a low-positive correlation between PFS and OS for both the sorafenib-sunitinib sequence (t=0.13) and the sunitinib-sorafenib sequence (t=0.15).
For more information:
Biondani P. Abstract #P6.04. Presented at: WIN Symposium; July 10-12, 2013; Paris.
Disclosure: The researchers report no relevant financial disclosures.