Isofol initiates last dose cohort in ongoing phase Ib study with arfolitixorin

The information in the press release is intended for investors.

Isofol is developing arfolitixorin, a proprietary clinical-stage drug candidate designed to enhance the efficacy of established cancer treatments. Based on extensive clinical research, arfolitixorin is now being tested in a phase Ib/II clinical study with an optimized dose regimen, initially conducted at the German hospital Charité – Universitätsmedizin Berlin. The drug candidate has the potential to fill a known treatment gap in cancer care.

The study is conducted in two parts, with the first part, phase Ib, evaluating increasing doses of the drug substance in patients with metastatic colorectal cancer. The third dose level, at 300 mg/m², was recently completed and successfully evaluated without dose-limiting toxicities. Based on recommendations from the study’s safety review committee, Isofol has decided that the newly initiated dose level, evaluating 500 mg/m², will be the final one in the dose-escalation phase. This decision is based on the favorable results generated in the three previous dose cohorts. Isofol continues to plan for the initiation of the phase II part of the arfolitixorin study in the second half of 2026.

“The fact that we can now initiate the final dose cohort and thereby move closer to the Phase II part of the study is an important milestone in the development of arfolitixorin. The results from the three dose levels completed so far in patients with metastatic colorectal cancer continue to support the dosing regimen underlying the study, and the safety profile has consistently been favorable,” says Petter Segelman Lindqvist, CEO of Isofol.

Colorectal cancer is the third most common form of cancer globally, and the second most common cause of cancer-related death, according to the World Health Organization (WHO). The need for new treatments in the field is therefore high.

For more information, please contact
Isofol Medical AB (publ)
Petter Segelman Lindqvist, Chief Executive Officer 
E-mail: petter.s.lindqvist@isofolmedical.com
Phone: +46 (0) 739 60 12 56

The information was submitted for publication, through the agency of the contact person set out above, at 11:30 CEST on July 8, 2026.

About Isofol
Isofol Medical AB (publ) is a clinical stage biotechnology company focused on improving outcomes for patients with severe forms of cancer. The Company’s drug candidate arfolitixorin, a next generation folate treatment, is designed to enhance the efficacy of established standard treatments for several types of solid tumors. Arfolitixorin is currently being evaluated in phase Ib/II in colorectal cancer, the world’s third most common cancer, where there is a significant unmet medical need. Isofol is listed on Nasdaq Stockholm.
www.isofolmedical.com