The CRISPR Patent War: How a Startup's IP Dispute Rewrote Biotech Law

In the annals of modern patent litigation, few battles have been as consequential as the fight over CRISPR-Cas9 gene editing technology. The dispute pitted the Broad Institute of MIT and Harvard against the University of California, Berkeley, with billions of dollars in licensing revenue and the future of biotechnology at stake.

The Science: What CRISPR-Cas9 Does

CRISPR-Cas9 is a molecular tool derived from a bacterial immune defense mechanism. It allows scientists to cut DNA at precise locations with accuracy previously unimaginable. Jennifer Doudna at UC Berkeley demonstrated in June 2012 that CRISPR-Cas9 could edit DNA in a test tube. Feng Zhang at the Broad Institute filed a patent application in December 2012 claiming use of CRISPR-Cas9 inside living eukaryotic cells — including human cells — and paid extra for expedited examination. The Broad's patents were granted first, in April 2014.

The Interference Proceeding: Pre-AIA Law in Action

Berkeley filed for an interference proceeding under pre-AIA law. An interference proceeding is a trial before the PTAB to determine which of two parties first invented the claimed subject matter. The pre-AIA priority contest turns on two concepts: conception (the complete mental formation of the definite idea of the invention) and reduction to practice (either actual, by building and testing it, or constructive, by filing a patent application). The party with the earlier conception who exercised reasonable diligence through their own reduction to practice typically prevails. Berkeley argued it had earlier conception; the Broad argued that editing DNA in a test tube was a different invention from editing DNA inside living eukaryotic cells.

PTAB's Decision: No Interference-in-Fact

In February 2017, the PTAB held there was no "interference-in-fact." Berkeley's claims to a biochemical CRISPR system and Broad's claims to eukaryotic CRISPR editing were not directed to the same invention. The gap between making something work in a test tube and making it work inside living human cells was substantial enough to constitute distinct inventions. The Federal Circuit affirmed in 2018 — and both sets of patents could coexist.

The AIA Derivation Proceeding

After the AIA, interference proceedings were replaced with derivation proceedings (35 U.S.C. § 135). A derivation proceeding determines whether an inventor in a later-filed application derived the claimed invention from an inventor in an earlier-filed application. The standard is much harder to meet: the petitioner must show the respondent derived the invention AND filed without authorization. Under the AIA's first-inventor-to-file system, the question is usually "who filed first?" — with narrow exceptions for derivation. The CRISPR dispute, straddling both eras, illustrates exactly why Congress wanted to simplify priority disputes by moving to a file-date-based system.

Patent Eligibility and 35 U.S.C. § 101

CRISPR also raised § 101 eligibility questions after Association for Molecular Pathology v. Myriad Genetics (2013), which held that naturally occurring DNA sequences cannot be patented. CRISPR-Cas9, as engineered and applied, was distinguishable: the guide RNA had to be designed by humans to target a specific gene sequence. That human design element, combined with the transformation of living cells, put it on the patentable side of the Myriad line — but the question required careful § 101 eligibility analysis of the kind patent bar candidates must master.