Myriad Loses Appeals Court Bid to Block Breast Cancer Tests

Myriad Genetics Inc. can’t block competitors’ DNA tests to determine risk for breast and ovarian cancer after a U.S. appeals court said three patents on the tests never should have been issued.

The patents cover products of nature and ideas that aren’t eligible for legal protection, the U.S. Court of Appeals for the Federal Circuit said in an opinion posted today on the court’s docket. The court upheld a trial judge’s decision to allow the competing tests, including those made by Ambry Genetics Corp., to remain on the market.

The tests check genes known as BRCA to determine if there is a hereditary risk of developing the diseases. Myriad had been the only company offering the tests until the U.S. Supreme Court last year limited the ability to obtain patents on human genetic sequences. Some patent claims in this case were similar to those invalidated by the high court, a three-judge panel ruled.

“They are structurally identical to the ends of DNA strands found in nature,” Circuit Judge Timothy Dyk wrote for the panel. “A DNA structure with a function...