Current Edition

In gene editing milestone, first patient treated in Vertex, CRISPR Therapeutics study

  • A patient with a severe form of beta thalassemia recently became the first individual treated with a CRISPR-based gene editing therapeutic in a company-sponsored clinical study, a notable milestone for a technology that’s rapidly moved from scientific discovery to human testing.
  • Vertex and partner CRISPR Therapeutics, which together are developing the experimental treatment, announced the news. The early-stage study is enrolling patients with the inherited blood disorder across multiple sites in Canada and Europe.​
  • CTX001, as the companies’ treatment is known, is built from hematopoietic stem cells extracted from patients and engineered ex vivo using CRISPR/cas9 to produce high levels of fetal hemoglobin in red blood cells. By inducing fetal hemoglobin production, CRISPR and Vertex hope to lessen the need for blood transfusions in beta-thalassemia patients.

For CRISPR and Vertex, treatment of the first patient with CTX001 reflects the progress CRISPR-based gene editing has made since the companies first inked a research partnership in 2015.

“In a way, you could see this as the beginning of the beginning,” said David Altshuler, chief scientific officer at Vertex, in an interview Monday with BioPharma Dive.

“There was a period in which this technology had been described and was suitable for use in a laboratory,” Altshuler added, contrasting that to the present, when the field “now can figure out what value this has for patients and families.”

European regulators first gave the green light for Vertex and CRISPR to proceed with treating patients in the Phase 1/2 beta-thalassemia study last year.

Another trial, testing CTX001 in sickle cell disease, has begun in the U.S., and the companies announced Monday that the first patient is now enrolled. Treatment of that patient with CTX001 is expected in mid-2019.

Enrollment and treatment will proceed slowly, at first. The first two patients in each study with be dosed sequentially, allowing time for the companies to confirm the edited stem cells engraft safely.

After that, both studies will open to broader concurrent enrollment of up to 12 patients initially. If results look promising, Vertex and CRISPR can expand the studies to 45 patients, which could potentially form a registrational data set, CRISPR Therapeutics CEO Samarth Kulkarni said in an interview.

After collecting data on multiple patients, the companies plan to present at scientific conferences. Kulkarni indicated initial presentations would likely focus on safety, as well as early engraftment and biomarker results.

“The two companies, Vertex and CRISPR, want to present data in a responsible fashion and not jump the gun with one or two patients very early, but rather look at a set of patients with sufficient follow-up before we present these data at scientific conferences,” Kulkarni said.

Other companies in the space are advancing clinical testing of CRISPR-based gene editing treatments. Most notably, Editas Medicine expects to begin dosing patients in a Phase 1/2 study of its inherited eye disease therapy in the second half of this year.

Vertex and CRISPR Therapeutics’ announcement also comes as the pharmaceutical industry takes greater interest in the potential of one-time gene-based treatments. On Monday, Swiss drug giant Roche announced it would buy Spark Therapeutics and its gene therapy pipeline for $4.8 billion, drawn by the biotech’s success in securing approval for the first gene therapy for an inherited disease.