The Federal Circuit today issued a key biotechnology opinion, holding that isolated human DNA sequences are patentable subject matter under 35 U.S.C. § 101. Ass’n for Molecular Pathology v. USPTO, No. 2010-1406 (July 29, 2011).

The opinion was a panel decision written by Judge Lourie. The underlying subject matter involved compound claims to isolated human DNA related to the BRCA pair genes. BRCA mutations are implicated in the increased risk of breast and ovarian cancer.

The panel held that complementary DNA (cDNA) sequences are patentable subject matter under 35 U.S.C. § 101. In particular, cDNA is synthesized as complementary to messenger RNA (mRNA) and does not contain the introns found in naturally occurring gene sequences. Therefore, cDNA does not exist in nature.

The panel split on whether isolated DNA sequences identical to naturally-occurring sequences, such as the whole gene, are patent-eligible. Judge Lourie reasoned that isolated DNA is per se patent eligible subject matter, because human intervention in cleaving or synthesizing a portion of a native chromosomal DNA imparts on isolated DNA a distinctive chemical identity from that possessed by native DNA. Judge Moore concurred in the result but for different reasons; in her view, shorter sequences are patentable because they have expanded utility compared to the natural sequence. Regarding longer sequences as more problematic because they do not have any new and different utility from the naturally occurring sequence, Judge Moore nonetheless regarded them as patentable out of deference to people’s settled expectations. Judge Bryson, in dissent, would have held that “the isolation of the naturally occurring genetic material does not make the claims to the isolated BRCA genes patent-eligible.”

The panel held as invalid method claims that involved comparing a patient’s BRCA sequence with the naturally-occurring sequence to identify the presence of cancer-predisposing mutations. These claims were viewed as pure mental steps or abstract ideas (the only step was “comparing” or “analyzing”) and as failing the machine or transformation-step test. On the other hand, a method claim to screening potential cancer therapeutics via changes in cell growth rates was held to be patentable.

Finally, the court held that all but one of the declaratory judgment plaintiffs lacked standing because they had not suffered any constitutional injury-in-fact.