New SIRFLOX Study Data Presented at World Congress of Gastrointestinal Cancer
New data from the SIRFLOX study presented at the European Society for Medical Oncology (ESMO) 17th World Congress of Gastrointestinal Cancer (WCGIC) has shown that patients with unresectable metastatic colorectal cancer (mCRC) that has spread only to the liver experienced the greatest improvement in Progression-Free Survival (PFS) in the liver from the addition of SIR-Spheres Y-90 resin microspheres to a current first-line chemotherapy regimen.
• The 7.9 month improvement in PFS in the liver (from 12.6 to 20.5 months) with the addition of SIR-Spheres Y-90 resin microspheres to first-line chemotherapy applied to all patients in the study, whether they had metastases only in the liver or in other sites as well
• New analyses focused on the impact of two important factors on this treatment benefit:
- Among the 318 patients with metastases that had spread only to the liver at the time they entered the study, median PFS in the liver was 21.1 months for those treated with Y-90 resin microspheres plus chemotherapy compare to 12.4 months for those treated with chemotherapy alone
- The 8.7 month improvement was statistically significant (p-value = 0.003, with a hazard ratio of 0.64) and represents a notable 36 percent reduction in the risk of tumour progression in the liver
New findings were also disclosed regarding the impact of bevacizumab in the chemotherapy regimen used in the SIRFLOX study.
In both groups – the 292 patients who had an intention to treat using bevacizumab in addition to first-line mFOLFOX6 chemotherapy, and the 238 who did not – the addition of Y-90 resin microspheres resulted in a statistically significant 8.3 month delay and 31% reduction in the risk of disease progression in the liver (hazard ratio 0.69).
The clinical benefit of adding Y-90 resin microspheres to first-line chemotherapy appears to be independent of the use of bevacizumab.
The clinical benefit observed was accompanied by an acceptable level of adverse events resulting from the addition of Y-90 resin microspheres to first-line chemotherapy in mCRC.
This matters because:
- Oncologists are familiar with the effects of radiation on healthy liver tissue and have traditionally been very cautious of irradiating large liver volumes
- SIRFLOX has now shown that high doses of radiation can be delivered to the liver tumours safely, even with the concurrent administration of a potent chemotherapy regimen