CRISPR pioneer Prime Medicine switches CEO and lays off quarter of its staff

Boston Globe

19-05-2025

Prime was initially formed in 2019, around a
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The technology can, in theory, be used to correct about 90 percent of known disease-causing mutations. It has revolutionized the field and proved so compelling that several competitors have been accused of copying the technology. But Prime itself had fallen on much harder times.
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The company's stock is down 91 percent since its IPO. It had less than a year of cash left on its books. Last year, to conserve resources, it was forced to cut most of its pipeline of experimental treatments and conduct a small layoff. Outgoing CEO Keith Gottesdiener blamed investors that, with rising interest rates,
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However, both outside executives and former employees also blamed Prime's leadership.
Prime also faced delivery challenges, as scientists have not yet devised clear ways to send its gene editors anywhere in the body besides the liver.
And the precision of the company's technology could actually work against it from a business standpoint.
Many genetic diseases are caused by hundreds or thousands of different individual mutations. Changing one or two DNA letters at a time can mean treating only a small subset of an already rare disease.
With Monday's announcement, Gottesdiener will be replaced by Allan Reine, a longtime biotech investor and Prime's CFO since January 2024. Prime said Gottesdiener decided to step down as CEO and a member of the board. The switch is 'effective immediately.' The company also named Jeff Marrazzo, former CEO of Spark Therapeutics, as executive chair.
The reorganization will extend Prime's cash runway into 'the first half of 2026' and cut its expenses by half through 2027. As part of the move, the company is scrapping its lead program in one subtype of chronic granulomatous disease, or CGD, a rare immune deficiency that leaves patients vulnerable to life-threatening infections.
The company had only managed to dose a single patient since receiving Food and Drug Administration clearance last April, an investigator announced at a gene therapy conference last week. That's likely because of the rarity of the condition and the complexity and intensity of the treatment: Cells have to be collected from a patient, edited in a lab, and then re-infused.
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Prime said data from the patient were positive. After 30 days, 66 percent of neutrophils — a key immune cell impaired by the disease — had function restored. Only 20 percent correction is thought to be needed to benefit patients.
It's a milestone, the first proof-of-concept for prime editing. But the company will cease all efforts to advance the program, as well as a follow-on therapy meant to help more CGD patients, likely because of the rarity of the disease and the difficulty other companies have had commercializing such complex treatments.
Prime said it is working 'with urgency' to find another company who can take it forward 'to help ensure this important therapy is delivered to patients.'
The company's main focus will now be on two liver conditions: Wilson's disease and alpha-1 antitrypsin deficiency, or AATD. Both are relatively common rare diseases. But both come with drawbacks. Although Wilson's disease can progress to liver failure and cause damage to other organ systems, some in the industry fear some patients may have their condition sufficiently well managed they wouldn't opt for a gene editing treatment.
And in AATD, Prime has a
Prime 'is committed to honoring the terms of the Agreement, and confident that it has the rights to pursue AATD under the Agreement,' the company said.
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It is also competing with a slew of other biotechs developing both gene editing and non-gene editing treatments for the condition, in which a single letter misspelling leads patients' livers to secrete toxic proteins.
In addition, Prime will continue work with the Cystic Fibrosis Foundation to create one-time therapies for the rare lung disorder and with Bristol Myers Squibb to create CAR-T treatments.
Prime plans to put both its AATD and Wilson's disease programs in trials in 2026, meaning it will have to raise money before data from those efforts are in. It's not clear if any of its rivals are in a better position. The entire gene-editing industry's downturn has continued, and Tessera, the main company accused of copying Prime's technology, has stayed vague about its plans for starting trials.