Graphite Bio announced a $45 million Series A financing led by founding investor Versant Ventures and Samsara BioCapital. Graphite Bio is a gene editing company focused on targeted DNA integration to precisely insert genetic payloads to treat a broad range of severe diseases. The financing will be used to support the company’s maturing pipeline, with an upcoming IND and several other candidates advancing toward the clinic in the next 12-18 months.
Graphite Bio is focused on correcting defective genes by high-efficiency site-specific integration of new genetic sequences. This technology has the potential to precisely repair a damaged portion of a gene, completely replace a malfunctioning gene while retaining normal regulatory control, or to insert a wide range of therapeutic genetic cargoes into precise regions of the genome. In addition, Graphite Bio’s technology has the potential to provide for durable expression while minimizing toxicity from off-target insertions.
“Our flexible, site-specific approach is extremely powerful and could be used to definitively correct the underlying causes of many severe genetic diseases, and also is applicable to broader disease areas,” said Josh Lehrer, M.D., CEO of Graphite Bio. “With backing from Versant and Samsara, we look forward to progressing our novel medicines into the clinic for patients with high unmet needs.”
Graphite Bio’s technology differs from CRISPR-Cas9 gene editing technology, which can cut DNA strands to disrupt genetic controls that lead to certain disorders. However, CRISPR-Cas9 has not been able to achieve the high-efficiency insertion of new genetic cargo. Graphite Bio’s gene editing platform includes several complementary technologies that enable targeted and permanent DNA integration with high efficiency. The platform builds on seminal work led by Dr. Danny Dever in the laboratory of Dr. Matt Porteus at Stanford University demonstrating an increase in integration efficiency from less than 1% to greater than 50% across diverse genetic lesions in a wide range of cell types.
Based on progress to date, Graphite Bio expects to commence Phase 1 studies of its first development candidate in early 2021. The company’s lead program specifically corrects the single nucleotide point mutation in the sickle β globin gene. In cells from patients with the disease, Graphite Bio has shown that its gene correction approach efficiently restores healthy hemoglobin protein and eliminates sickle cell hemoglobin.
Graphite Bio is also advancing several other programs to the clinic, each with the potential to lead to a cure for serious unmet needs.