BioPharma, Pharma

Prime Medicine pulls off $175M IPO and sketches out plans to reach the clinic

Prime Medicine has yet to test prime editing in humans, but the biotech company garnered enough investor interest to boost the size of its IPO, raising $175 million. Prime claims its technology has key advantages over other gene-editing technologies and the IPO cash will support a pipeline that currently spans 18 programs.

dna, genomics

Prime Medicine projects it could begin the first human test of its gene-editing technology in 2024 with multiple programs on its heels in the following year. The biotech company now has $175 million in IPO cash to finance that research.

In a year of mostly stagnant stock market debuts, Prime pulled off a rare feat: not only did the biotech surpass the $100 million mark for an IPO, but it was also able to boost the deal size to raise even more. Prime priced its offering of nearly 10.3 million shares at $17 apiece, which was the midpoint of its planned $16 to $18 per share range. That’s 1.4 million more shares than the Cambridge, Massachusetts-based company initially planned to sell—an indication that investors are interested in the technology despite the lack of human data. Prime’s shares are set to begin trading on the Nasdaq Thursday under the stock symbol “PRME.”

Like many gene-editing companies, Prime Medicine aims to develop one-time treatments that offer potential disease cures. But Prime claims its prime-editing approach is more precise, efficient, and versatile than other gene-editing technologies. Its prime editors are comprised of a Cas protein—the same protein used in CRISPR Cas editing. But this protein is modified to nick the DNA rather than make the double-stranded cut that happens with the CRISPR system. Guide RNA target the prime editor to a specific location in the genome. This more targeted approach is intended to avoid off-target edits and their complications. Prime describes its technology as a “word processor” of gene editing.

In addition to better precision, Prime claims prime editing can address a broader range of diseases, disorders that cannot be addressed by currently available gene-editing technologies. Reflecting that breadth, Prime has built a pipeline of 18 programs spanning diseases “where the unique characteristics of Prime Editing could offer advantages over current standard-of-care and novel therapeutic modalities in development,” the company said in the IPO filing. Disclosed programs include prime editors for retinitis pigmentosa, Usher’s syndrome, Friedreich’s ataxia, myotonic dystrophy type 1, and Huntington’s disease.

Prime’s most advanced program is a sickle cell disease gene-editor that has reached preclinical proof of concept under a partnership with Beam Therapeutics. The rest of the pipeline is in much earlier-stages of development, but the company plans to use the IPO cash to advance unspecified programs to the preclinical research that could support the filing of an investigational new drug (IND) application with the FDA.

“All our in vivo studies are preliminary to date,” Prime said in the filing. “We will continue to expand preclinical proof-of-concept in vivo, including data from in vivo rodent studies and non-human primate studies in several programs in 2023. If successful, we expect to next initiate IND-enabling studies for several of our lead programs, with the first IND filing potentially as early as 2024, and with the potential for additional IND filings as early as 2025.”

Without specifying programs, the updated IPO filing lays out plans to spend $90 million to advance research through preclinical proof-of-concept. About $65 million is estimated for IND-enabling studies and the potential start of clinical studies. Another $65 million is earmarked for further developing the prime editing platform technology and discovery-stage research for more potential programs. And finally, Prime said it will spend about $50 million to develop its early-stage manufacturing processes and build out a dedicated chemistry facility. The company estimates that its cash will support the company into 2025.

Prime’s $175 million IPO follows the $183 million stock market debut of Third Harmonic Bio, an inflammation and allergy biotech that waited until it had some Phase 1 data before proceeding with plans for taking the company public. A handful of other biotech companies have passed the $100 million mark in IPOs this year. But most of the IPO activity this year has come from small deals, according to IPO research firm Renaissance Capital.

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