(CN) - In a decision that could have a profound effect on the future of patent law for medical treatments, the Federal Circuit ruled a test for determining the proper dosage of drugs to treat autoimmune disease is patentable under federal law.

A three-judge panel sent the patent dispute between Prometheus Laboratories and the Mayo Clinic's medical laboratory division back to a federal judge in Southern California, saying the judge incorrectly dismissed Prometheus' infringement claim against Mayo.

Mayo has long used Prometheus' patented test for determining the correct dosage of thiopurine drugs used to treat autoimmune diseases. In 2005 it announced that it would begin selling its own dosage test, prompting an infringement lawsuit from Prometheus.

Read more HERE.

Full legal ruling can be found HERE.