US court refuses Sequenom appeal for prenatal test patent

The US federal court of appeals has declined to rehear arguments on the patentability of a prenatal blood test, saying that it remains bound by the Supreme Court to determine the claims as non-patentable.

The US Court of Appeals for the Federal Circuit ruled last June that Sequenom's prenatal MaterniT21 test was not patentable (see BioNews 807), upholding a lower court decision on the matter.

It said that the method of detecting fetal DNA in maternal blood to test for abnormalities was not patentable under the Supreme Court's test set out in the case of Mayo in 2012, which excluded natural phenomena and 'abstract ideas', like mathematical formulae and drug metabolites in the blood, from patent protection.

In Mayo, the US Supreme Court set out the relevant test of patentability as being, first, to decide if the subject of the patent is a mere discovery of natural phenomena (non-patentable) or an abstract idea arising out of a discovery (patentable). The second step is to consider whether there has been an 'inventive concept' which has transformed the abstract idea into a patentable invention.

Applying this test with some dissatisfaction, the Court of Appeals said in June that Sequenom's patent related to a discovery of inherited cell-free fetal DNA (cffDNA) in maternal blood, which was a 'natural phenomenon'. Furthermore, the methods used in the test were 'well-understood, conventional and routine', and not sufficiently 'inventive'.

Refusing to reconsider this decision, the Court of Appeals most recently reiterated that it was bound by Mayo to decide this way, but appeared to agree with concerns that the current law may discourage innovation in the field of diagnostic testing, where methods are often premised on identifying new natural phenomena.

Circuit Judge Alan Lourie, said: 'It is said that the whole category of diagnostic claims is at risk. It is also said that a crisis of patent law and medical innovation may be upon us, and there seems to be some truth in that concern.'

Appearing to distinguish the claims in question from the Myriad decision in 2013, Judge Lourie differentiated patent claims drafted narrowly to be 'application claims', from those which relate to abstract claims, saying that one of the claims in question related to practical uses of performing a specific prenatal diagnosis.

'They recite innovative and practical uses for it, particularly for diagnostic testing: blood typing, sex typing, and screening for genetic abnormalities,' he said. 'Moreover, the claims here are not abstract. There is nothing abstract about performing actual physical steps on a physical material.'

Nevertheless, he added that following Mayo these 'additional steps' would add nothing inventive to the process, despite concluding that it was 'unsound' to have rules that take inventions of this kind out of the realm of patentability.  

Dissenting, Circuit Judge Pauline Newman, believed that such an 'incorrect decision' is not required by the Supreme Court's precedent. 'The new diagnostic method here is novel and unforeseen, and is of profound public benefit,' she said.

Sequenom says the latest decision was 'not unexpected', given that the Court of Appeals had already said it was bound by the decision in Mayo, but added that it was a 'necessary first step' to having the case heard by the Supreme Court.

It also says the ruling will have little impact on its business, pointing out that it has been operating under the invalidity ruling of the District Court since 2013 and that it continues to enforce equivalent patent claims in Europe, Canada, Australia and elsewhere.