Ariosa Diagnostics this week filed a petition with the US Patent and Trademark Office for an inter partes review of a broad patent held by Sequenom in the field of prenatal diagnostics.
The patent in question, US Patent No. 6,258,540, which was issued to Dennis Lo of the Chinese University of Hong Kong and licensed by Sequenom, is also the subject of an ongoing lawsuit between Sequenom and Ariosa.
In the suit, Sequenom alleges that Ariosa's Harmony Prenatal test, which uses a targeted sequencing method to detect fetal aneuploidies from maternal plasma, infringes on the '540 patent. Sequenom offers a competing test, MaterniT21, which uses a whole-genome shotgun sequencing approach to detect fetal aneuploidies in maternal plasma.
Ariosa's CEO Ken Song told Clinical Sequencing News today that the company filed the petition for re-examination to try and get "resolution" on the patent dispute "as efficiently as possible."
"We continue to hold very firm that our test does not infringe upon the '540 patent. And we feel very confident in that," he said.
According to Ariosa's petition, the claims of the '540 patent should be deemed invalid because the patent "does not provide an enabling disclosure of or written descriptive support for the claimed subject matter."
The petition asserts that the '540 patent is invalid because it is anticipated by prior publications; experts in the field would have considered it "obvious to use then-conventional PCR techniques to detect fetal DNA in maternal serum;" and the presence of fetal DNA in maternal plasma is a natural phenomenon and therefore not patentable according to the Supreme Court's ruling in Mayo v. Prometheus.
The reexamination petition is separate from the ongoing litigation between Sequenom and Ariosa, which has been working its way through the courts.
Ariosa originally sued Sequenom last December for being overaggressive in the enforcement of its '540 patent, and Sequenom subsequently sued Ariosa for infringing the '540 patent when Ariosa launched its Prenatal Harmony Test (CSN 12/21/2011, CSN 1/25/2012).
Most recently, the US District Court for the Northern District of California denied Sequenom's motion for a preliminary injunction against Ariosa, which Sequenom subsequently appealed.
Aside from Ariosa, Sequenom is also embroiled in lawsuits with Verinata Health and Natera over the '540 patent. Verinata Health offers a competing test to MaterniT21, which also uses whole-genome shotgun sequencing of maternal plasma to detect fetal trisomies. Natera, meantime, has said it is developing a targeted sequencing-based test for the same indication.