The Cystic Fibrosis Foundation announced an additional investment of up to $24 million in Prime Medicine to continue developing gene editing therapies for people with cystic fibrosis, building on an initial $15 million commitment made in January 2024. The expanded funding reflects growing confidence in prime editing technology as a potentially curative approach for this devastating genetic disease.
Prime Editing Technology Shows Promise for CF Treatment
Prime Medicine utilizes prime editing, a gene editing technology that enables precise DNA modifications with high accuracy. Founded by Drs. David Liu and Andrew Anzalone, who pioneered this editing technology, the company is investigating whether prime editing could treat several diseases, including cystic fibrosis.
"We believe gene editing offers the best hope for a cure for cystic fibrosis because it could permanently correct the mutations that cause this disease," said Michael P. Boyle, MD, president and chief executive officer of the Cystic Fibrosis Foundation.
The technology's versatility allows it to correct a wide range of genetic mutations, potentially addressing the underlying cause of CF across diverse genotypes. Prime Medicine intends to leverage this modularity to treat multiple disease-causing mutations, potentially benefiting the vast majority of people with CF.
Targeting G542X Mutation and Delivery Challenges
The additional CF Foundation investment will focus specifically on developing a prime editing therapy targeting the G542X nonsense mutation, one of the most prevalent CF-causing nonsense mutations for which no therapies are currently available. This represents a significant unmet medical need in the CF community.
Prime Medicine faces the major challenge of delivering gene editing treatments to the lungs of people with CF. The thick, sticky mucus that clogs airways and the body's natural immune response create barriers to foreign entities entering cells. However, if successful, the gene editing cargo would enter lung cells that normally produce CFTR protein and correct the CFTR mutation in the cell's DNA, potentially providing a permanent fix to the CFTR gene.
Multiple Approaches for Comprehensive CF Treatment
The company is advancing several complementary strategies to maximize treatment potential. Prime Medicine is developing "hotspot" approaches that use prime editing to make smaller corrections to specific CFTR mutations, as well as PASSIGE technology, which enables large gene insertions. These combined strategies eliminate the need to develop separate prime editing therapies for each individual mutation.
According to Prime Medicine, multiple hotspot Prime Editors may benefit more than 93% of people with CF, representing a potentially transformative treatment approach for the CF community.
Strategic Funding Structure and Future Development
The CF Foundation will provide the $24 million funding in two tranches, subject to certain closing conditions and scientific milestones. The first tranche includes a $6 million equity investment in Prime Medicine, demonstrating the Foundation's commitment to the technology's development.
"We are honored to receive continued support from the CF Foundation, whose longstanding commitment to driving innovation has reshaped the treatment landscape for people living with CF," said Allan Reine, M.D., Chief Executive Officer of Prime Medicine. "This additional funding reflects our shared belief in the transformative potential of Prime Editing therapy for people with this devastating genetic disease, especially for those where the current standard of care is either ineffective or poorly tolerated."
Addressing Unmet Medical Needs in CF
Cystic fibrosis affects approximately 100,000 people globally, including over 40,000 in the United States. The disease is caused by mutations in the CFTR gene, resulting in reduced or absent function of the CFTR protein, which is critical for maintaining salt and fluid balance across epithelial surfaces in organs such as the lungs, pancreas, and gastrointestinal tract.
While disease-modifying therapies have improved outcomes for many individuals, they are not curative and remain ineffective for some people with certain mutations. This creates a significant unmet need for a one-time, potentially curative treatment that can address the underlying genetic cause of CF across diverse genotypes.
The continued investment in prime editing technology represents a strategic approach to developing next-generation treatments that could fundamentally change the treatment landscape for cystic fibrosis patients worldwide.
