- The Food and Drug Administration has accepted an application for what could be the first marketed medicine based on CRISPR gene editing technology, officially starting a review of a treatment Vertex Pharmaceuticals and partner CRISPR Therapeutics have developed for two rare blood disorders.
- The companies said Thursday that the agency will issue separate verdicts on the treatment’s use in sickle cell disease and beta thalassemia. The FDA has granted the drug, exa-cel, a speedier “priority” review for sickle cell disease, with a decision expected by Dec. 8. But it’s granted the therapy a standard review in beta thalassemia, for which the FDA will make a ruling by March 30, 2024.
- The companies also released new study data on Friday that build on the results they’ve accumulated so far. The findings confirm that both Phase 3 studies met their main and key secondary goals at an interim analysis, without any new safety concerns. They’ll be presented at the European Hematology Association meeting on Sunday.
The FDA’s review of exa-cel is the latest milestone for CRISPR, for which researchers Emmanuelle Charpentier and Jennifer Doudna won a Nobel Prize in 2020. The treatment is the first of its kind to be brought to U.S. regulators and will be a test case for how the agency views the gene editing technology.
Exa-cel could also become the first gene-based treatment for sickle cell, for which there are only a few treatments.
In sickle cell, misshaped red blood cells cause painful and life-threatening blockages. Exa-cel has shown ability to durably alleviate those symptoms for most study volunteers, though it’s unclear how long those effects will ultimately last.
Wall Street analysts were closely watching the status of the review, as the company will compete with a gene therapy developed by Bluebird Bio. Bluebird finalized an application for its sickle cell treatement, lovo-cel, three weeks after exa-cel’s submission. The FDA has until late June to decide whether to accept its application.
The agency’s decision to split the review in two, granting a priority review for sickle cell only, is a “bit surprising” given the therapy has been granted other regulatory designations designed to speed an evaluation, wrote RBC Capital Markets’ Brian Abrahams.
Still, Abrahams noted the faster review in sickle cell is more consequential, as it’s a more common disease than beta thalassemia and a larger market opportunity.
The FDA likely leaned that way because of the scarcity of other treatment options for sickle cell, added Baird analyst Jack Allen in a Friday research note. Patients already have another marketed genetic medicine, Bluebird’s Zynteglo.
In the meantime, Vertex and CRISPR Therapeutics presented new results for exa-cel that’ll be described in greater detail at at a medical meeting on Sunday.
The results come from Phase 3 studies in sickle cell and beta thalassemia, both of which have met their pre-specified goals.
In the beta thalassemia study, 24 of 27 patients eligible for evaluation did not need blood transfusions for at least a year. Of the three who did, one went about three months without a transfusion while the two others have reduced needed infused blood volumes by 80% to 96%.
In the sickle cell study, 16 of 17 patients haven’t had any pain crises for at least a year, with a mean duration of about 19 months and a maximum of 37 months. The one patient who did has a complex history of comorbidities including chronic pain, the companies said.
Vertex and CRISPR have also completed applications for exa-cel in Europe and the U.K.