Sirtex has announced the presentation of the SIRFLOX/FOXFIRE Global right-side survival data in metastatic colorectal cancer at the 19th European Society for Medical Oncology (ESMO) World Congress on Gastrointestinal Cancer (WCGIC) in Barcelona, Spain.
Guy van Hazel, clinical professor of Medicine, University of Western Australia and coprincipal investigator on the SIRFLOX study presented the data. The combined SIRFLOX and FOXFIRE Global studies (n=530 and n=209, respectively) showed that for patients with a right-sided primary tumour, median overall survival was significantly improved with the addition of SIRSpheres Y-90 resin microspheres to standard chemotherapy versus chemotherapy alone (22 vs. 17.1 months, respectively; p=0.007;), but not for patients with a left-sided primary tumour.
Importantly, van Hazel also presented the baseline characteristics of the combined patient dataset between the two arms of the study for both left-sided and right-sided patients. There was no statistically significant difference in the baseline characteristics of patients who received SIR-Spheres microspheres plus chemotherapy vs. chemotherapy alone. Patients with a right-sided primary tumour were older (mean: 64.4 vs. 61.6 years) and a higher proportion were female (42.5% vs. 32%), compared to those with a left-sided primary tumour.
Andrew McLean, chief executive officer of Sirtex said “There is now solid scientific evidence to support the observation that for patients whose primary cancer is located on the right-side of the bowel, their prognosis is demonstrably worse, with fewer treatment options and a lower overall life expectancy. The statistically significant 4.9 month overall survival benefit observed in patients who received SIR-Spheres microspheres is clinically meaningful and subject to further confirmatory analyses, coupled with additional supporting evidence of this overall survival benefit from the FOXFIRE study. Collectively, this may support consideration of right-sided liver-only or liver-dominant metastatic colorectal cancer patients for SIRSpheres microspheres treatment.”
“This striking and essentially unexpected finding may bring new hope to metastatic colorectal cancer patients with liver-only or liver-dominant tumours that have spread from the right side of the bowel or colon. These cancers are genetically and structurally different from tumours that start on the left side of the colon. Patients with right-sided primary tumours have a worse prognosis for survival and fewer treatment options. They do not respond well to such biological therapies as cetuximab or panitumumab,” said van Hazel.