Australian expressed RNAi shop Benitec this week announced that it received a notice of allowance from the US Patent and Trademark Office for a patent application covering the use of multiple-promoter expression cassettes for simultaneous delivery of RNAi.
Separately last week, the company provided an update on its efforts to overcome rejections to its core US patent, stating that the USPTO won’t likely decide on a company appeal until the third quarter of next year.
The allowed patent application, No. 20050197313, specifically claims “a multi-promoter expression cassette comprising at least three promoter/RNAi/terminator components wherein each … component comprises a promoter element, a terminator element, and an RNAi species operably linked to the promoter element and the terminator element.” Each of the RNAi species of the invention “is different from one another,” the application notes.
The application also claims the use of the cassettes to inhibit the hepatitis C virus.
Meanwhile, Benitec’s US Patent No. 6,573,099, which has long been the centerpiece of the company’s intellectual property estate, continues to face scrutiny at the USPTO.
In 2004, the company filed lawsuits against two reagent firms, GenScript and Ambion, and the RNAi therapeutics company Nucleonics, claiming that each infringed the ‘099 patent (see RNAi News, 4/2/2004).
Although Ambion and GenScript licensed the IP, Nucleonics chose to fight the issue in court. As part of that effort, Nucleonics either opposed the patent or requested re-examinations of Benitec’s IP in several nations, including the US.
Amid financial troubles, Benitec ultimately withdrew the suit against Nucleonics, which last year shut down (see RNAi News, 11/6/2008), and restructured as a smaller firm after closing its US facility.
Still, the Nucleonics-triggered reexamination proceeded, culminating in the USPTO rejecting the patent’s claims based on objections related to the fundamental Fire and Mello patent held by the Carnegie Institute.
Last week, Benitec said that earlier this year it met with patent office officials to “better understand this rejection,” and in May launched an appeal of the decision.
“As part of this appeals process, an appeal brief was filed in late July 2009,” Benitec said. “This detailed appeals brief focused on the obviousness rejections put forward by the [patent] examiner and argued that these rejections are unsupported by the evidence and the controlling law.”
Benitec said that the USPTO is now slated to review the brief, and that the patent examiner has the option to respond, which is expected later this year. The next step would be to file a reply to the examiner’s answer, with the reexamination process then proceeding to an oral hearing before the USPTO’s appeals board, the company noted.
Due to a “backlog at the USPTO,” an oral hearing is not expected until the second quarter of 2010, with a decision “likely in the following quarter,” Benitec added.