Incara Pharmaceuticals Corporation and an affiliate of Elan Corporation plc have terminated their agreement regarding the development and option to license Incara's catalytic antioxidant compounds for use in combination with radiation treatment of cancer. In May 2002, Elan made an equity investment in Incara to enable the development of these catalytic antioxidant compounds. In return Incara granted Elan the option to license these compounds at a later date. Elan and Incara have agreed to terminate these agreements. As a result Incara is free to seek collaborations for its catalytic antioxidant program with other pharmaceutical industry companies.

Radiation therapy is the most common treatment used for cancer. Approximately 50% of cancer patients, or 500,000 individuals, receive radiation therapy annually in the United States during the course of their cancer therapy.Radiation therapy produces damage to cancer cells but also damages healthy cells, limiting the amount of radiation that can be administered and the overall success of treatment.

Incara's catalytic antioxidant compounds may reduce therapy-limiting side effects and improve outcome of cancer radiation therapy.In animal models, Incara's antioxidants have provided protection to normal cells and do not protect cancer cells from radiation. Target applications include protecting the lining of the mouth and the salivary glands during treatment of the head and neck, the lining of the bladder in cervical cancer therapy, protecting the colon in prostate cancer therapy and protecting the lungs in breast and lung cancer therapy.

Incara's catalytic antioxidant molecules inactivate reactive oxygen-derived molecules, such as superoxide, hydrogen peroxide and peroxynitrite, in a manner similar to that of naturally occurring enzymes that normally protect the body from these harmful oxygen breakdown products. These reactive molecules are believed to play an important role in the delayed tissue injuries that limit the use of radiation therapy for cancer treatment.