The clinical-stage next-generation gene editing company offered 1.5 million more shares than expected and priced at the top of its proposed range of $15 to $17 per share. In addition, Graphite Bio has also granted the underwriters a 30-day option to purchase up to an additional 2.1 million shares of its common stock at the initial public offering price, less underwriting discounts and commissions. The shares will trade on the Nasdaq Global Market under the ticker symbol “GRPH.”
Graphite Bio is advancing a platform that marries gene editing with gene therapy to improve targeted DNA integration and precisely insert genetic payloads to treat a variety of severe genetic diseases. The platform draws from gene-editing research from the lab of Stanford professor Matthew Porteus, an academic founder of CRISPR Therapeutics, and gene therapy expertise from Stanford professor Maria Grazia Roncarolo, who helped advance multiple gene therapy products into the clinic when she served as director of Telethon Institute for Cell and Gene Therapy at the San Raffaele Scientific Institute in Milan.
The company is focused on correcting defective genes by high-efficiency site-specific integration of new genetic sequences. Its 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 says its technology has the potential to provide for durable expression while minimizing toxicity from off-target insertions.
Graphite Bio’s gene editing platform includes several complementary technologies that enable targeted and permanent DNA integration at very high efficiency. The platform builds on seminal work led by Danny Dever in the laboratory of Matt Porteus at Stanford University demonstrating an increase in integration efficiency from less than 1 percent to greater than 50 percent across diverse genetic lesions in a wide range of cell types.
The efficiency improvements enable clinically meaningful levels of targeted integration for therapeutic applications. The company says its medicines therefore can replace defective genes, insert genetic cargo into specific loci and significantly limit undesirable, indiscriminate transgene expression.
Graphite Bio has received IND clearance from the U.S. Food and Drug Administration to initiate its first phase 1/2 clinical trial evaluating investigational candidate GPH101 in sickle cell disease, aiming to enroll the first patient in the second half of 2021 and have proof-of-concept data by the end of 2022. GPH101 is designed to specifically correct the single nucleotide point mutation in the sickle β globin gene. In cells from patients with the disease, the company has shown that its gene correction approach efficiently restores healthy hemoglobin protein and eliminates sickle cell hemoglobin.
The company is also completing IND-enabling studies to advance investigational therapies GPH201 and GPH301 in severe combined immune deficiency with IL2RG deficiency, known as x-linked SCID (XSCID), and Gaucher Disease (Types 1 and 3, respectively).