CRISPR Therapeutics Highlights Promising In Vivo Gene Editing Data

While its partner Vertex Pharmaceuticals spearheads the market launch, CRISPR Therapeutics is witnessing encouraging progress in the rollout of its approved gene therapy Casgevy and demonstrating promising early results in its in vivo gene editing programs.

Vertex, responsible for the commercialization of Casgevy for sickle cell disease and beta-thalassemia, reported this week that over 65 treatment centers have now been activated for the therapy. This development offers a positive signal for the gene therapy field, which has recently faced headwinds. William Blair analysts noted that Vertex’s reported revenue of $14.2 million for Casgevy in the first quarter, a modest 4% increase, suggests that the initial phase of patient referrals and cell collection is beginning to translate into actual cell infusions.

The journey for Casgevy, approved in December 2023, has been a gradual process, with the first patient infusions occurring in September 2024. The complexities and costs associated with gene therapies, along with the need to establish specialized treatment centers, have contributed to a slower market penetration compared to traditional pharmaceuticals. However, Vertex remains optimistic, with Chief Operating Officer Stuart Arbuckle stating a goal of 75 activated treatment centers globally. He reported that approximately 90 patients have undergone initial cell collection, and over twice that number have been referred for treatment, with eight patients having completed the full treatment course. Arbuckle highlighted the transformative impact of Casgevy on patients’ lives, enabling them to experience newfound freedom and improved quality of life.

Meanwhile, CRISPR Therapeutics has been laser-focused on advancing its clinical program, particularly its in vivo liver editing program, CTX310. The company presented initial data from a Phase 1 trial involving just 10 patients with elevated low-density lipoprotein (LDL) and triglyceride (TG) levels. A single dose of CTX310, delivered using CRISPR’s proprietary lipid nanoparticle (LNP) technology, resulted in a decrease in the expression of the ANGPTL3 gene, a key regulator of LDL and TG levels. Consequently, both LDL and TG levels were reduced in the treated patients. Notably, one patient with severe hypertriglyceridemia experienced an 82% reduction in TG, while another with heterozygous familial hypercholesterolemia showed an 81% reduction in LDL-C.

William Blair analysts described this early data as “competitive” with existing and investigational therapies targeting ANGPTL3. Furthermore, CTX310 demonstrated a favorable safety profile, with no severe adverse events or elevations in liver enzymes reported across the tested doses. CRISPR Therapeutics hailed these results as a “significant milestone” for its in vivo LNP delivery platform. The company plans to present more comprehensive data from the Phase 1 trial at an upcoming medical meeting later this year. CRISPR is also progressing CTX320, another in vivo candidate targeting cardiovascular disease, with a Phase 1 readout anticipated in the second quarter. Additionally, the company has several preclinical programs in development and expects readouts from a Phase 1 oncology trial (CTX131) and an update on its regenerative medicine diabetes treatment (CTX211) before the end of 2025.

William Blair analysts concluded that CRISPR Therapeutics has a “catalyst-rich 12-month period ahead” as it advances its diverse portfolio of ex vivo and in vivo gene editing candidates through clinical development.