By Ben Butkus
This article has been updated from a previous version to clarify comments attributed to Enzo.
The US Patent and Trademark Office ruled recently that a patent owned by Siemens Healthcare Diagnostics and relating to nucleic acid signal-amplification technology is predated and invalidated by a patent application owned by Enzo Biochem.
The decision paves the way for Enzo to be issued a patent based on its prior application, the company said, and as such it plans to "rapidly" develop and market products based on the technology for a wide variety of applications, Enzo Chairman and CEO Elazar Rabbani told PCR Insider this week.
In addition, with a new patent in hand, Enzo may be able to claim infringement by a number of clinical diagnostics and life sciences research products that use Enzo's technology. While the company did not say that any particular products might infringe, it did say that the technology is used in a number of third-party products, including Siemens' Versant branched DNA assays.
"This technology is the basis for several significant products in clinical diagnostics and in the life sciences field [that] are currently marketed or licensed by various commercial entities," Enzo President Barry Weiner said in a statement.
Enzo added that according to various trade reports, industry-wide sales of diagnostic products that use the nucleic acid signal amplification technology are estimated to exceed $100 million in the US.
However, besides the Versant assays, Enzo declined to name any products that use its technology; and Rabbani told PCR Insider that Enzo hopes to establish relationships with various industry partners to use the technology in various applications.
"The technology has a broad range of applications, and Enzo is fully committed to exploring not only nucleic acid amplification, but all areas," Rabbani said. "We hope to have collaborations with industry, as well, because this is nicely applicable to a lot of areas, particularly with multiplex [applications]."
For instance, the technology can also be applied to immunological studies, protein detection, and small-molecule and ligand studies, Rabbani said. "I believe this is a very important platform technology … and we fully intend to explore and expand [its] application to all areas," he added.
The nucleic acid signal-amplification technology is marketed as an alternative to PCR-based methods. Specifically, Enzo said that it enables direct detection of nucleic acids without the need for target amplification and without compromising assay sensitivity.
"We are intent to apply it not only to signal amplification in enzymatic-mediated signal generation, but also to fluorescence and other types of signals," Rabbani said.
But, Rabbani added, Enzo put off introducing its own products based on the amplification technology while the interference was proceeding, "because that would have been inappropriate. We are very respectful of IP, and even if we have a dispute, we'd rather see that dispute resolved, clarified, or licensed before we introduce a product into the market. But now we fully intend to rapidly introduce products to the market."
Enzo's patent dispute started nearly two decades ago with Siemens Healthcare Diagnostics predecessor Chiron. According to Enzo, Chiron filed a patent application on Oct. 15, 1987, around the so-called branched DNA technology. This patent was eventually awarded to Chiron in 1992 as US Patent No. 5,124,246, "Nucleic acid multimers and amplified nucleic acid hybridization assays using same."
But Enzo said that it had filed a patent application (serial no. 06/491,929, not published online) almost four and a half years before Chiron filed its application. The USPTO declared an interference proceeding on Aug. 7, 2006, to determine if Enzo or Bayer Healthcare (which had since acquired Chiron) had made the invention first, Enzo said.
Last month, the USPTO issued a ruling that Enzo's application and invention had indeed pre-dated Chiron's. The diagnostic division of Bayer Healthcare, which has since been acquired by Siemens, markets the Versant branched DNA assays for HIV and hepatitis viral load monitoring.
Enzo said that, subject to any requests for rehearing or appeals that Bayer/Siemens might file, as a result of the USPTO's decision Enzo will receive a 17-year patent for all inventions covered by the claims in its patent application. The term of the patent will commence on the date of its issuance.
It is unclear whether Siemens plans to appeal the USPTO's decision. A spokesperson for the company confirmed that the company owns the '246 patent, but declined comment on the patent interference decision at this time.