A unit of Merck KGaA and Sweden’s Isofol Medical have joined forces to create a new treatment for cancer.

Merck Eprova, a Switzerland-based subsidiary of the German company, has signed an exclusive license agreement with Isofol which will use the former’s folate compound Modufolin ([6R]-5,10-methylenetetrahydrofolate), the active metabolite leucovorin, in clinical trials and commercial drug products.

Modufolin is a biomodulator originally designed to replace leucovorin as “the preferred folate to enhance the activity and reduce associated toxicity of 5-FU (5-fluorouracil)”, the firms noted. The combination of 5-FU and leucovorin is a commonly-used chemotherapy.

Isofol says it will conduct Phase I and II studies using a combination of Modufolin and antifolates which are starting soon and are expected to close by the end of 2010. No financial details of the link-up were disclosed.