- Editas said its experimental gene editing treatment for sickle cell disease showed promise in the first two patients treated, an early step in the company’s efforts to catch up to rivals much further along in development.
- The treatment, EDIT-301, is designed to edit regions of two genes involved in production of fetal hemoglobin, boosting levels to reduce the misshaping — or sickling — of red blood cells. Sickle cells have a shorter lifespan and can clump together, resulting in clogs in blood vessels that can cause painful episodes known as vaso-occlusive crises and a range of other health effects.
- Editas researchers have so far followed one of the two patients treated with EDIT-301 for five months and the other for 1.5 months. After five months, the first patient’s hemoglobin levels have risen, exceeding the level needed to suppress sickling, Editas said Tuesday. In both patients, the therapy so far appears to be generally well tolerated, the company said.
After years of little progress, sickle cell disease research has drawn new interest from gene therapy developers who see a path to curing the inherited disease.
Vertex Pharmaceuticals and CRISPR Therapeutics have already started a rolling application for approval of their treatment, called exa-cel, for both sickle cell disease and beta thalassemia. They expect to complete the submission in the first quarter of next year. Bluebird bio also plans to seek approval for its lovo-cel therapy for sickle cell in the first quarter.
Editas executives said they expect there will be plenty of room for their product, if further clinical studies succeed. The vast majority of patients will still be untreated, they told investors on a conference call Tuesday. And they believe that the technology behind EDIT-301 may differentiate it from other treatments. It’s the first to use a gene-editing nuclease called AsCas12a in humans.
Initial results for the two patients in the RUBY trial are promising, analysts said. Neither patient has experienced a vaso-occlusive event since treatment, though both had typically experienced three or four such episodes a year before enrolling in the trial, according to Editas.
Still, analysts cautioned that it’s far too early to draw any conclusions about how well the therapy will perform. The initial data is “compelling,” RBC Capital Markets analyst Luca Issi wrote to clients. But whether EDIT-301 ends up being a unique product or a “me-too” following rivals late to the market is unclear, Issi said.
Editas is counting on EDIT-301 to succeed after a series of corporate setbacks, including research delays and changes in its executive suite. In November, the company said it would stop enrolling new patients in a trial of its most advanced therapy — a treatment for a genetic form of blindness — and instead seek a partner to continue development.