Prime Medicine Launches with $315 Million Financing

Prime Medicine™, a company delivering on the promise of Prime Editing to provide lifelong cures to patients, today announced its launch with $315 million in financing.

The financing comprised a $115 million Series A; based on the rapid progress of the science and the company, Prime Medicine expanded its syndicate support with a $200M Series B financing approximately nine months after the company began operations. Investors in the Series A included ARCH Venture Partners, F-Prime Capital, GV, and Newpath Partners. The Series B included all Series A investors, plus Casdin Capital, Cormorant Asset Management, Moore Strategic Ventures, Public Sector Pension Investment Board (PSP Investments), Redmile Group, Samsara BioCapital, funds and accounts advised by T. Rowe Price Associates, Inc., and a number of additional, unnamed life sciences investment funds.

“Prime Editing is a wonderful example of the revolution in genetic medicine that we are living through,” said Robert Nelsen, co-founder and Managing Director of ARCH Venture Partners. “When mature, gene editing technologies like this could totally change our conception of what’s possible in treating disease.”

“This is an opportunity to take a giant step toward cures for a much wider range of diseases than previously possible,” said Stephen Knight, MD, President and Managing Partner of F-Prime Capital.

The funds raised will be used to continue building the company, rapidly advance towards clinical indications, expand the capabilities of the platform, and to further enhance the exceptional promise of Prime Editing. By the end of 2021, Prime Medicine expects to employ more than 100 people full-time.

“Prime Editing represents an opportunity to do what no gene editing approach has yet been capable of – correcting nearly all types of pathogenic gene mutations, correcting multiple mutations at once, and bringing durable cures to patients across multiple disease areas, potentially with a single ‘once and done’ treatment approach,” said David Schenkein, MD, General Partner at GV. “We are tremendously excited about the potential of this technology, and about the talented team at Prime working to bring it to patients.”

Prime Editing is a next-generation gene editing technology that acts like a DNA word processor to “search and replace” disease-causing genetic sequences at their precise location in the genome, without resulting in double-strand DNA breaks that cause unwanted cellular changes. It is versatile, with the potential to address more than 90 percent of known disease-causing mutations, and works in a variety of dividing and non-dividing primary human cells, as well as in animals. Prime editing has been shown by multiple independent laboratories to make genome edits with high fidelity, making edits precisely at the desired location with minimal or no editing in other parts of the genome. Together, these features overcome several technical barriers attributed to earlier gene editing technologies.

“Prime Editing is a transformative technology that we believe will make a significant impact by addressing the fundamental causes of genetic disease,” said Keith Gottesdiener, MD, CEO of Prime Medicine. “Since Prime began operations in the summer of 2020, we have continued to make great progress in advancing the performance of Prime Editing, which allowed us to close our Series B financing nine months later. We are operating from a position of financial strength, and look forward to further developing the technology and progressing our preclinical programs toward the clinic, with the hope that they may cure or halt the progression of genetic diseases for patients.”

Scientific Approach

Prime Editing was developed by scientific founders David R. Liu, PhD and Andrew Anzalone, MD, PhD, at the Broad Institute of MIT and Harvard. Dr. Liu is the Richard Merkin Professor, director of the Merkin Institute of Transformative Technologies in Healthcare, core institute member and vice chair of the faculty at the Broad Institute, and a professor of chemistry and chemical biology at Harvard University. Dr. Anzalone conceived of Prime Editing and brought it to Dr. Liu’s laboratory, where it was developed. Dr. Anzalone is now advancing Prime Editing as Head of Prime Editing Platform at Prime Medicine.

Prime Medicine is currently advancing multiple drug discovery programs targeted at liver, eye, ex-vivo hematopoietic stem cell, and neuro-muscular indications.

A study describing Prime Editing’s ability to “search and replace” to restore normal genetic function almost anywhere in the genome was first published in Nature in 2019. The technology was immediately and widely recognized as a major advance in gene editing, with the potential to overcome fundamental barriers that have prohibited existing gene editing approaches from addressing many genetic diseases. Since then, Prime Editing has been validated in numerous laboratories around the world and dozens of peer-reviewed articles.

The technology works by using a prime editor protein comprising a Cas nickase domain and a reverse transcriptase domain, together with a prime editing guide RNA (pegRNA) that carries both a targeting sequence and a template for a replacement sequence. The prime editor searches for the specific DNA sequence that needs to be edited. Once located, the prime editor uses the pegRNA’s “replace” sequence to activate the reverse transcriptase domain, which makes a DNA copy of the template carried by the pegRNA, creating a corrected DNA sequence. The corrected sequence then preferentially replaces the original genomic DNA, resulting in a permanent edit of the DNA at the target location.

Prime Medicine also benefits from a relationship with Beam Therapeutics. Prime and Beam are separate companies that both emerged from the laboratory of Dr. David R. Liu. Sharing many common interests, Prime and Beam have built a partnership to form a collaborative approach to fighting disease and accelerating the development of Prime Editing to deliver therapies for patients. In the areas of partnership, Prime Medicine and Beam share research, expertise, and intellectual property for assays, know-how, delivery, and manufacturing.

The Broad Institute of MIT and Harvard has extended a license for prime editing technology to Prime Medicine for human therapeutic uses under the Broad Institute’s inclusive innovation model.

Leadership team

Biotech veteran Keith Gottesdiener, MD is president and chief executive officer of Prime Medicine. Dr. Gottesdiener helmed Rhythm Pharmaceuticals, Inc. for nine years, leading the company to FDA submission of IMCIVREE (setmelanotide), the first treatment for rare genetic diseases of obesity, which was rapidly followed by FDA approval. Over the course of Dr. Gottesdiener’s tenure, Rhythm raised approximately $700 million through both private and public financings, as well as licensing deals, and grew from 3 employees to 100. Before joining Rhythm in 2011, Dr. Gottesdiener spent 16 years at Merck Research Laboratories, where he held positions of leadership across Merck’s early and late clinical development organizations.

The Prime Medicine leadership team brings significant company building, scientific and drug development experience and also includes:

  • Jeremy Duffield, MD, PhD, Chief Scientific Officer
  • Meredith Goldwasser, ScD, SVP, Strategy and Corporate Operations
  • Andrew Anzalone, MD, PhD, Co-founder and Head of Prime Editing Platform
  • Karen Brown, PhD, JD, SVP Intellectual Property and Legal Affairs

The company’s investors and board members are life sciences leaders with extensive experience building biotech companies pioneering novel technologies, including:

  • Keith Gottesdiener, President and CEO, Prime Medicine
  • Stephen Knight, President and Managing Partner, F-Prime Capital
  • Robert Nelsen, Co-founder and Managing Director, ARCH Venture Partners
  • David Schenkein, MD, General Partner, GV
  • John Evans, Chief Executive Officer, Beam Therapeutics

About Prime Medicine

Prime Medicine is a biotechnology company founded to deliver on the promise of Prime Editing, a versatile gene editing technology that can truly “search and replace” to restore normal genetic function and address the fundamental causes of disease. Prime Medicine envisions a world where Prime Editing can cure, halt, and ultimately prevent genetic diseases, providing lifelong benefit to patients and shaping the future of gene editing. For more information, visit www.primemedicine.com or LinkedIn.