A US court has invalidated a key Sequenom patent for non-invasive prenatal testing (NIPT).

Sequenom was originally the market leader in NIPT technology, developing the MaterniT21 and SafeT21 tests. The MaterniT21 test was the first non-invasive test for Down’s syndrome to reach the market in 2011 (see previous news), although Sequenom had already lost much of their commercial lead in the market after results of a key clinical trial were retracted. 
 
Ariosa, which owns the Harmony non-invasive prenatal test, has been in legal dispute with Sequenom for more than two years. Now a district court for in California has rejected Sequenom’s request for a summary judgement against Ariosa for patent infringement of US patent no. 6,258,540 (sometimes referred to in reports simply as 540) and ruled that the patent was ineligible as, although it claims a method of testing, it is based on a naturally occurring phenomenon.
 
The patent refers to a method of testing ‘a paternally inherited nucleic acid of fetal origin’ from a serum or plasma sample from a pregnant woman, with variations and different applications (for example, the detection of not merely aneuploidies in the fetus, but also maternal conditions such as pre-eclampsia).
 
Judge Susan Illston reportedly referred to two previous Supreme Court judgements, one invalidating patent claims for a method of monitoring patient blood to determine drug dosage (Mayo v. Promethus) and for BRCA gene sequences (Association for Molecular Pathology v. Myriad Inc). She also said that, whilst the patent was based on a novel discovery (fetal DNA in maternal blood) of a natural phenomenon, the detection methods cited used conventional genetic techniques.
 
Ariosa have claimed the judgement as a ‘complete victory’; Sequenom, which has seen a sharp fall in share price since the decision, has said that it ‘vigorously disagrees’ with the outcome and plans to appeal via the Federal Circuit Court of Appeals.
 
Market rivals Illumina (owners of the Verinata Verifi test) and Natera (owners of the Panorama test), who have also been seeking judgements against Sequenom, joined Ariosa in announcing the availability of their individual tests in the state via the California Prenatal Screening Program. It remains to be seen whether or not Sequenom will be granted leave to appeal, and if so whether or not other judges will form the same view.