Benitec last week experienced another setback in its attempts to maintain its core US patent after the US Patent and Trademark Office opted not to accept the company's most recent response to the ongoing re-examination of the intellectual property.
According to Benitec, the patent office decided not to enter into the re-examination proceedings the company's proposed amendments to the patent, as well as related arguments and evidence. The expressed RNAi shop said it may appeal the decision, which it said the agency made based purely on procedural grounds.
The USPTO's decision "does not substantively address the extensive arguments presented in support of [the IP's] patentability, does not substantively address evidence in the form of a declaration from a technical expert, and provides no explanation" as to why the proposed amendments would not be allowed, Benitec said last week.
Benitec said that it will "seek recourse" through the proper USPTO channels and will "receive further advice on other available options before ultimately deciding whether to proceed with an appeal, if necessary."
Benitec's patent, No. 6,573,099, claims gene-expression knockdown using DNA that transcribes double-stranded RNA. As one of the first RNAi-related patents issued in the US, it was the centerpiece of Benitec's technology portfolio.
But the value of the patent came into question after the company filed a series of patent-infringement suits in 2004 (see RNAi News, 4/2/2004). One of the defendants, now-defunct expressed RNAi shop Nucleonics, fought the case in court and, as part of its legal strategy, either opposed the patent or requested re-examinations of Benitec’s IP in several nations including the US.
Although Benitec ultimately withdrew patent-infringement suit and Nucleonics has since shut down its operations (see RNAi News, 11/6/2008), the US re-examination proceeded.
After appealing previous rejections of the '099 patent by the USPTO, Benitec announced last November that the agency had again rejected claims within the '099 patent in light of one example of prior art, US patent No. 5,578,716, which was granted in 1996 to McGill University researcher Moshe Szyf (see RNAi News, 12/4/2008).
The ‘716 patent covers “tumorigenicity-inhibiting antisense oligonucleotide sequences complementary to mRNA or double-stranded DNA that encodes mammalian DNA methyl transferase,” as well as “methods for inhibiting tumorigenicity and [a] pharmaceutical composition [that] comprises the tumorigenicity-inhibiting antisense nucleotide,” according to its abstract.
At the time, Benitec said it had asked to meet with the USPTO official conducting the re-examination and said that it would file a written response to the rejection. Those efforts appear now to have had no effect given the patent office's latest action.
Benitec and Australia's Commonwealth Scientific and Industrial Research Organization, which owns the '099 patent, "are fully committed to this patent and will take this matter to appeal with the USPTO … if necessary," the company said. "If the matter proceeds to an oral hearing before the [agency's] board of appeal, this would be expected towards the end of 2009 [or] early 2010 due to the backlog of appeals."