Law360 (July 25, 2019, 6:18 PM EDT) -- The Patent Trial and Appeal Board has agreed to review a drug delivery formulation patent owned by Arbutus Biopharma Corp., a company set on curing hepatitis B.

The board on Wednesday accepted Moderna Therapeutics Inc.’s challenge to each claim in Arbutus' U.S. Patent No. 8,058,069, agreeing to consider whether it was obvious or anticipated by prior art. This marks the third inter partes review the board has open right now between the pair.

The patent itself covers a way to deliver medication, and is listed in the U.S. Food and Drug Administration's Orange Book for Alnylam Pharmaceuticals Inc.'s polyneuropathy medication Onpattro. Alnylam licenses the patent from Arbutus, which is itself focused on developing hepatitis B cures.

Arbutus, formerly known as Tekmira Pharmaceuticals Corp., had urged the board to exercise its discretion and reject the challenge. The board is already reviewing U.S. Patent No. 9,364,435, which is a continuation of the '069 one, the drugmaker said. Accepting the instant IPR would essentially be relitigating the one for the ‘435 patent, the patent owner had argued.

While the board said those concerns “resonate,” they’re “outweighed” by the different scope of each IPR.

“The sole independent claim of the ’069 patent includes specific requirements for cationic lipid, phospholipid, and cholesterol content not present in the sole independent claim of the ’435 patent,” the board wrote. “We are unaware of, and patent owner does not identify, any decision by the board relying on a previously filed petition concerning one patent as a basis for denying institution under § 314(a) of a subsequent petition challenging a second (albeit, related) patent.”

The board has also agreed to review Arbutus’ U.S. Patent No. 9,404,127, following another challenge from Moderna. The decisions to review the ‘127 and ‘435 patents came in September, and while oral arguments have been held, final written decisions have not yet been issued.

An attorney for Arbutus declined to comment. Counsel for Moderna didn’t immediately respond to a request for comment Thursday.

Administrative patent judges Christopher G. Paulraj, Jacqueline T.harlow and Timothy G. Majors sat on the panel for the Patent Trial and Appeal Board.

The patent-in-suit is U.S. Patent No. 8,058,069.

Moderna is represented by Michael Fleming and C. Maclain Wells of Irell & Manella LLP.

Arbutus is represented by Michael T. Rosato, Steven W. Parmelee and Sonja R. Gerrard of Wilson Sonsini Goodrich & Rosati PC.

The case is Moderna Therapeutics, Inc. v. Arbutus Biopharma Corporation, case number IPR2019-00554, before the Patent Trial and Appeal Board. The related cases are Moderna Therapeutics, Inc. v. Arbutus Biopharma Corporation, case numbers IPR2018-00739 and IPR2018-00680, before the Patent Trial and Appeal Board.

--Editing by Kelly Duncan.