Precision BioSciences Announces Publication of its Preclinical In Vivo Gene Editing Abstract on Duchenne Muscular Dystrophy Program for the American Society of Gene & Cell Therapy 26th Annual Meeting

Precision BioSciences, Inc. (Nasdaq: DTIL), a clinical stage gene editing company developing ARCUS®-based ex vivo allogeneic CAR T and in vivo gene editing therapies, today announced that its late-breaking abstract presenting preclinical in vivo gene editing data for its PBGENE-DMD program, being developed for the potential treatment of Duchenne muscular dystrophy (DMD), is available through the American Society of Gene & Cell Therapy (ASGCT) 26^th Annual Meeting website at https://annualmeeting.asgct.org/abstracts/abstract-details?abstractId=15227.

An oral presentation, ARCUS-Mediated Excision of the "Hot Spot" Region of the Human Dystrophin Gene for the Treatment of Duchenne Muscular Dystrophy (DMD), will be presented as part of the Late-breaking Abstracts 2 Session on May 19, 2023.

About ARCUS
ARCUS is a proprietary genome editing technology discovered and developed by scientists at Precision BioSciences. It uses sequence-specific DNA-cutting enzymes, or nucleases, that are designed to either insert (knock-in), excise (knock-out), or repair DNA of living cells and organisms. ARCUS is based on a naturally occurring genome editing enzyme, I-CreI, that evolved in the algae Chlamydomonas reinhardtii to make highly specific cuts in cellular DNA and stimulate gene insertion at the cut site by homologous recombination. Precision's platform and products are protected by a comprehensive portfolio including nearly 100 patents to date.

About DMD
DMD is a genetic disorder associated with mutations in the dystrophin gene that prevent production of the dystrophin protein. Dystrophin stabilizes the cell membrane during muscle contraction to prevent damage, and the absence of intact dystrophin protein leads to inflammation, fibrosis, and progressive loss of muscle function and mass. Over time, children with DMD will develop problems walking and breathing, eventually leading to death in the second or third decade of life due to progressive cardiomyopathy and respiratory insufficiency. DMD occurs in 1 in 3,500 to 5,000 male births, and currently there are limited approved therapies available for patients.

About Precision BioSciences, Inc.
Precision BioSciences, Inc. is a clinical stage biotechnology company dedicated to improving life (DTIL) with its novel and proprietary ARCUS® genome editing platform. ARCUS is a highly precise and versatile genome editing platform that was designed with therapeutic safety, delivery, and control in mind. Using ARCUS, the Company's pipeline consists of several in vivo gene editing candidates designed to cure genetic and infectious diseases where no adequate treatments exist and multiple ex vivo clinical candidates. For more information about Precision BioSciences, please visit www.precisionbiosciences.com.

Forward-Looking Statements
This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. All statements contained in this press release that do not relate to matters of historical fact should be considered forward-looking statements, including, without limitation, statements regarding expected conference participation and disclosure of preclinical data, the clinical development, nomination, and goals of our PBGENE-DMD program, and therapeutic potential of an ARCUS gene editing approach for the treatment of DMD. In some cases, you can identify forward-looking statements by terms such as "aim," "anticipate," "approach," "believe," "contemplate," "could," "estimate," "expect," "goal," "intend," "look," "may," "mission," "plan," "possible," "potential," "predict," "project," "pursue," "should," "target," "will," "would," or the negative thereof and similar words and expressions.

Forward-looking statements are based on management's current expectations, beliefs and assumptions and on information currently available to us. Such statements are neither promises nor guarantees, but involve a number of known and unknown risks, uncertainties and assumptions, and actual results may differ materially from those expressed or implied in the forward-looking statements due to various important factors, including, but not limited to, the important factors discussed under the caption "Risk Factors" in our Quarterly Report on Form 10-Q for the quarterly period ended March 31, 2023, as any such factors may be updated from time to time in our other filings with the SEC, which are accessible on the SEC's website at www.sec.gov and the Investors page of our website under SEC Filings at investor.precisionbiosciences.com.

All forward-looking statements speak only as of the date of this press release and, except as required by applicable law, we have no obligation to update or revise any forward-looking statements contained herein, whether as a result of any new information, future events, changed circumstances or otherwise.