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Regenxbio, Inc. v. Sarepta Therapeutics. Inc. – The Long Reach of Funk Bros. Seed Co.

Regenxbio [Regen], a company developing gene therapy, sued Sarepta [Sar] in D. Del. for infringement of claims of U.S. Pat. No. 105,526,417:

  1. A cultured host cell containing a recombinant nucleic acid molecule encoding an AAP vp 1 capsid protein having a sequence comprising nucleic acids 1 to 738 of SEQ ID NO 81 (AAvrh.10) or a sequence at least 95% identical to the full length of amino acids 1 to 738 of SEQ ID NO: 81, wherein the recombinant nucleic acid molecule further comprises a heterologous non-AA sequence.

Most of my comments that follow will come from my reading of AIPLA’s amicus brief to the Fed. Cir. in support of neither party. I also read Regenxbio’s brief to the Fed. Cir., but it is 50 pages long and includes the patent, which adds about 200 pages of sequence listings. Also, the key arguments are present in both briefs. (The only decisions of importance are “Myriad” [“Myr”], “Chakrabarty” [“Chak”] and “Funk Brothers Seed Co. v. Kalo” (333 U.S. 127 (1948) [“Funk”]).

When I read the AIPLA brief, all I could think was “How could Regenxbio have lost this suit?” or, put another way, “How did Sarepta ever win?” The D.Del. judge found claim 1 to be patent ineligible for patenting, a ruling that flies in the face of some heavy precedent. In Chak, four plasmids had been inserted into a live bacterium, allowing the bacterium to digest oil spills. The altered bacterium was not “naturally occurring “ or a “natural phenomenon”. Rather it was “markedly different” from any bacterium found in nature.

Instead, the court relied on its reading of Myr in which the isolation of a gene did not impart patent eligibility, even when bonds were severed in the isolation process. Thus, the court gave claims to the newly isolated stretch of DNA more weight to its information content than to its chemical structure per se. However claims to easily prepared cDNA from the gene’s sequence was found to be patent eligible.

Surprisingly, the court relied on its reading of Funk that collection and combination of cultured bacterial inoculants that did not interfere with each other was, at best, a packaging technique that did not rise to the level of patentable subject matter. The Funk court reasoned that the bacteria exhibited no more useful properties in simple combination than they would in the wide world of nature.

The District Court Judge took the same rationale and applied it to a much more complicated biosystem based on adeno-associate viruses (AAV). Please read claim I supra and you can see the components and steps that Regen used to make the modified “cultured cell”. This is a composition claim but the central step is introducing a recombinant nucleic acid molecule encoding a AAvp1vpl capsid protein into the cultured cell that is 738 amino acids long, or a sequence that is 95% identical to said amino acid sequence 1 – 738. However, the same 1-738 recombinant sequence must also further comprise heterologous non-AAV sequence.

In brief, the claim is directed to a host cell that contains a nucleic that can in turn encode a capsid protein that is 1-738 amino acids long, or at least 95% of its sequence, and the recombinant nucleic acid [remember that element?] can also comprise a heterologous non-AAV sequence.

But when amici start to stumble, the Examiner is ready to strike. For instance amici start by arguing that the cultured host cells are neither human made nor occur in nature. This would be a good place to wrap it up. Amicus then argues that cells with the recited DNA and a heterologous non-AAA sequence are not naturally occurring, but concedes that the AAV capsid sequence was derived from a primate. Amicus argues that the claims recited host cell DNA must contain both the natural sequence and a different sequence derived from another species or type of organism.

This post is getting too long, but let’s read the Judge’s mind for just a second—which is not the mind that thinks that Funk Bros. is relevant here. Our prospective judge considers that in Myriad, the main claim was to a gene related to cancer. The isolated (gene) sequence was found to be a natural product and Judge Lourie’s argument that chemical bonds must be broken to isolate the gene was ignored. But what about constructing the cell that you want by altering a single strand of DNA, e.g.,or cut and pasting the single strain to yield the claimed nucleic acid? Who says that the AAV vpl capsid-encoding DNA is not a natural product? And who says that the heterological sequence is not derived from a natural source? It is a very broad claim element and the Fed. Cir. may want to discuss the written description requirement. Stay tuned in on this one.

© 2024 Schwegman, Lundberg & Woessner, P.A. All Rights Reserved.
by: Warren Woessner of Schwegman, Lundberg & Woessner, P.A.
For more news on Gene Therapy Patent Claims, visit the NLR Intellectual Property section.

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