Selective internal radiation therapy (SIRT) using Y-90 resin microspheres combined with FOLFOX (fluorouracil, leucovorin, and oxaliplatin) chemotherapy in patients with metastatic colorectal cancer (mCRC) significantly improved control of liver tumors, although it did not improve progression-free survival (PFS), a phase 3 trial has found.1
“SIRFLOX demonstrated that liver-directed treatment of mCRC using Y-90 resin microspheres may have a role to play in the earlier management of this disease, combined with available chemotherapeutic and biological options,” Guy Van Hazel, MBBS, of the University of Western Australia, Perth, told Cancer Therapy Advisor.
A total of 530 chemotherapy-naïve patients with liver metastases were randomly assigned to receive either modified FOLFOX (263 patients) or FOLFOX with SIRT plus or minus bevacizumab (267 patients) between October 2006 and April 2013. PFS at any site was the primary endpoint, and objective response rate (OR) in the liver and overall survival (OS) were secondary endpoints.
Median PFS at any site was 10.2 months in the FOLFOX group and 10.7 months in the SIRT group. Median PFS in the liver was 12.6 months in FOLFOX and 20.5 months in SIRT. OR was 78.7% in the SIRT group, compared to 68.8% in FOLFOX.
“SIRT is the first treatment that allows us to deliver sufficiently high doses of radiation directly to liver tumors while sparing healthy liver tissue. As the majority of patients with mCRC will die as a result of the progression of their liver tumors, treatments such as SIRT with Y-90 resin microspheres…should be considered potentially beneficial for these patients,” he said.
Overall survival analysis from SIRFLOX will be combined with results from 2 ongoing studies, FOXFIRE and FOXFIRE Global, with results anticipated in 2017. More than 1100 patients were included in the 3 studies.