Overlapping Claim Language in Recent CRISPR Patents

I love CRISPR! I think it's the coolest recent molecular biology technology. Here's a quick summary for those who don't know (or forgot) the science. CRISPR stands for Clustered Regularly Interspaced Short Palindromic Repeats. Many bacteria have repeating sections in the genomes. These sequences came from viral particles that had previously infected the lineage of bacterial cells. There's are enzymes called CRISPR associated proteins (Cas) that can open the bacterial genome at CRISPR sites, incorporate nucleic acid sequences complementary to the viral sequences, and then code for new Cas that can target and inactivate the viral genome. So the CRISPR Cas system is a way for bacterial to prevent viral infection - it's a part of the bacterial immune system.

The key discoveries of the CRISPR Cas systems started in the 1980s. By the 2000s, scientists were learning how to use Cas9 to edit genomes in vivo. Scientists now have ways of editing living humans' genomes, and can cure genetic diseases like sickle cell anemia with new treatment technologies. It's really amazing stuff, so I'm always excited to see new CRISPR patents coming out.

Patent 12,460,190 (the '190 patent): CRISPR DNA Targeting Enzymes and Systems. The inventors were all at Arbor Biotechnologies back when the provisional application was filed on September 9th, 2019, although some of them have moved to or started new companies since then. They are David Scott, David Cheng, Winston Yan, and Tia Ditommaso. It looks like during the prosecution of this application, the inventors submitted another application for CRISPR RNA Targeting Enzymes and Systems and Uses Thereof (emphasis mine), which issued as patent 12,460,203 ('203) on the same date at the '190 patent, November 4th, 2025. The filing date of the '203 patent is November 8th, 2021. Overall, it was about six years from initial filing to patent issuance, and almost four years to the day for the '203 patent from filing to issue.

Remember that I’m not a lawyer, and nothing in this post is legal advice. While I am a registered patent agent, nothing in this post constitutes advice for a client.

These patents cover engineered CRISPR-CAS systems. Let's look at Claim 1 from each patent. From the '190 patent:

"An engineered, non-naturally occurring Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR)-associated (Cas) system comprising: (a) an RNA guide or a nucleic acid encoding the RNA guide, wherein the RNA guide comprises a direct repeat sequence and a spacer sequence capable of hybridizing to a target nucleic acid in a eukaryotic cell; and (b) a CRISPR-Cas effector protein or a nucleic acid encoding the CRISPR-Cas effector protein, wherein the CRISPR-Cas effector protein comprises an amino acid sequence with at least 95% identity to SEQ ID NO: 10, wherein the CRISPR-Cas effector protein binds to the RNA guide, and wherein the spacer sequence binds to a target nucleic acid"

And from the '203 patent:

"An engineered, non-naturally occurring Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR)-associated (Cas) system comprising: (a) an RNA guide or a nucleic acid encoding the RNA guide comprising a direct repeat sequence of SEQ ID NO: 65 and a spacer sequence capable of hybridizing to a target nucleic acid in a eukaryotic cell; and (b) a nucleic acid encoding a CRISPR-Cas effector protein, or the CRISPR-Cas effector protein, wherein the CRISPR-Cas effector protein binds to the RNA guide, and wherein the spacer sequence binds to a target nucleic acid"

These claims are quite similar. I bolded the meaningful differences that I could identify. I have not highlighted the change in phrase order of Claims 1b. How one of the patents issued as "DNA Targeting" when both of their Claims 1 are directed to RNA guides escapes me. SEQ ID NO: 10 from the '190 patent is about amino acids, and does not bear on this issue. SEQ ID NO: 65 from the '203 pertains to the repeats in the RNA guide. There is also an RNA guide in the '190 patent, although it isn't required to be the same as the RNA guide in the '203 patent. But I don't see why it couldn't be! It's hard for me to see how both of these inventions are novel. For example, Claim 1a in the '203 patent means that the RNA guide must include the repeats of SEQ ID NO:65, and Claim 1a in the '190 patent means that that RNA guide must include a direct repeat sequence. I don't see a reason why the "direct" repeat sequence must not be SEQ ID NO:65 from the '203 patent. In that sense, the two claims can at least be for the same thing some of the time.

A claim in a patent is like staking out a little piece of territory. The patent needs to use language to clearly delineate the boundaries of that territory. The way this is supposed to work is that an inventor cannot receive a patent to a piece of territory that is already marked off as someone else's turf. When that isn't the case, the patent with the later filing date ought to be rejected for a lack of novelty - that's going to show up from the Patent Office as a rejection under 35 USC 102.

What's especially surprising to me is that these claims are written with the term "comprising." In patents, "comprising" is an open-ended term, meaning that the claim is staking out territory that includes the listed term in addition to other stuff. Because both claims are written with "comprising," I read them both as claim at least some of the same territory as each other.

At this point, I'm a little mystified as to how these two patents both issued as written. I would certainly love to hear any feedback that sheds light on what's going on here! My goal for my clients is to always use claim language that clearly and firmly defends their invention, without any room for ambiguity or overlap in claim language that could cut into what their patent protects.