Isofol Medical AB has unveiled promising new data from a post-hoc analysis of their Phase III AGENT study, highlighting the potential of arfolitixorin in colorectal cancer treatment. The findings, presented at the 2025 American Society of Clinical Oncology Gastrointestinal (ASCO GI) Cancers Symposium in San Francisco, suggest that protocol adherence played a crucial role in treatment outcomes.
Regional Variations and Response Rates
The analysis revealed striking regional differences in treatment effectiveness. In North America, arfolitixorin demonstrated remarkable efficacy with an 85.7% objective response rate (ORR) compared to 45.5% for leucovorin (p<0.017) among 47 patients. When examining all regions excluding Japan, arfolitixorin maintained a statistically significant advantage, showing a 15.9 percentage point higher response rate (62.1% ORR vs. 46.2% ORR; p<0.026) in a cohort of 172 patients.
Protocol Compliance and Treatment Administration
The post-hoc per-protocol analysis, conducted by an external expert committee, focused on evaluating how compliance with the study protocol affected outcomes. Key factors included the timing between 5-FU bolus administration and arfolitixorin delivery, as well as the duration of 5-FU bolus injections.
Japanese Cohort Insights
A notable finding emerged from the Japanese patient population, where 55.2% of arfolitixorin-treated patients received reduced doses of the backbone chemotherapy 5-FU, compared to only 27.6% in the leucovorin arm. This regional disparity in dosing may explain the divergent results observed in Japan compared to other regions.
Expert Perspective
"Overall, the findings in this analysis are positive and show that even with the suboptimal dosing regimen used in the AGENT study, arfolitixorin could potentially have shown superiority vs. the standard treatment leucovorin if protocol adherence would have been higher," stated Petter Segelman Lindqvist, CEO of Isofol. "We now also have a likely explanation for why the results in Japan diverged from other regions and remain firm in our belief in the potential of arfolitixorin globally."
Moving Forward
The analysis, funded by Isofol and conducted by a committee including experts from Sahlgrenska University Hospital and APNC Sweden, provides valuable insights for the ongoing clinical program. A Phase Ib/II trial is currently underway, testing new dosage regimens designed to optimize arfolitixorin's efficacy in treating colorectal cancer, the third most common form of cancer worldwide.
