A federal judge has invalidated the central patent underlying a noninvasive method of detecting Down syndrome in fetuses without the risk of inducing a miscarriage.
The ruling is a blow to Sequenom, a California company that introduced the first such noninvasive test in 2011 and has been trying to lock out competitors in a fast-growing market by claiming they infringe on the patent.
Sequenom’s stock fell 23 percent on Thursday, to $1.92.
The judge, Susan Illston of the United States District Court in Northern California, issued a ruling on Wednesday that the patent was invalid because it covered a natural phenomenon — the presence of DNA from the fetus in the mother’s blood.
The ruling was a sign that the Supreme Court’s decision in June declaring that human genes may not be patented because they are products of nature could make it more difficult to patent diagnostic techniques.
Judge Illston cited the gene patent case, which involved Myriad Genetics, in her ruling, along with a 2012 Supreme Court decision invalidating patents on a test used to determine the proper dosages of certain drugs.
“It’s hard to imagine patents on diagnostics surviving if that approach is taken,” Christopher M. Holman, a law professor at the University of Missouri-Kansas City, said of Wednesday’s ruling.
Paul V. Maier, chief financial officer of Sequenom, said the company would appeal. “We believe the court’s decision is wrong and misapplies or ignores the controlling law,” he said, adding that the patent involved a novel use of a natural phenomenon, not the phenomenon itself.
Until recently, women seeking to find out whether their fetuses had Down syndrome or other chromosomal abnormalities had to undergo either amniocentesis or chorionic villus sampling. Both are invasive techniques that obtain cell samples from the womb or placenta and carry a slight risk of inducing a miscarriage.
The new tests offered by Sequenom and several competitors take advantage of the fact that some DNA from the fetus can be found in a pregnant woman’s blood and can be analyzed with new genetic techniques.
Such tests do not completely replace the invasive ones, but they have caught on quickly and led to a sharp reduction in the use of the other tests. The noninvasive tests are now offered by Sequenom as well as Ariosa Diagnostics, Natera and Verinata.
In the current case, Ariosa filed a lawsuit in 2011 seeking a court ruling that its test, called Harmony, did not infringe on the patent controlled by Sequenom. Sequenom countersued and tried to win a preliminary injunction blocking Ariosa from marketing its test. The court denied the injunction but the appeals court vacated that decision and sent the case back to the district court.
Verinata and Natera have also been seeking rulings from the same judge that their tests do not infringe on Sequenom’s patent.
In her ruling, Judge Illston said that the presence of the DNA in the pregnant woman’s blood was a novel discovery but could not be patented because it was a natural phenomenon. And claims in the patent over how to detect that DNA were not eligible for a patent because they involved conventional genetic techniques.
Story Written by Andrew Pollack