Bluebird beats a path to early approval for its pioneering gene therapy

bluebird's David Davidson

Bluebird bio ($BLUE), developing a potential cure for a rare blood disorder, is angling for an accelerated approval as it works through clinical trials, setting out a regulatory framework that could get the gene therapy on the market sooner than expected.

After meetings with the FDA and the European Medicines Agency, bluebird believes it has identified parallel paths forward for its lead candidate, plotting to tackle Europe first before making its case to U.S. regulators.

The treatment, LentiGlobin BB305, is designed to reverse the effects of beta-thalassemia major, a disease resulting from a defective beta-globin gene that stops patients from producing the hemoglobin they need, often leading to severe anemia. Bluebird's candidate uses a modified lentivirus to correct the genetic defect through a one-time infusion, ideally getting beta-thalassemia major patients back to manufacturing beta-globin on their own and freeing them from the need for constant blood transfusions.

Bluebird's therapy has thus far performed well in two ongoing trials, and the plan now is to enroll two 15-patient trials that will follow subjects for two years with a primary endpoint of transfusion independence, the company said. Bluebird believes it can qualify for conditional EMA approval with results from the studies already underway, using the two trials yet to be launched to secure a permanent OK in the future. In the U.S., the company plans to hold off on filing an application until it has results from all four studies. The FDA has already granted its breakthrough-therapy designation to bluebird's gene therapy, promising access to top agency officials and a speedy review process.

"We are very pleased with the outcome of these recent regulatory interactions," bluebird Chief Medical Officer David Davidson said in a statement. "... This feedback brings us closer to achieving our vision of delivering one-time, potentially transformative gene therapy to patients."

Bluebird's continued progress comes amid some recent jitters in the gene therapy world, as last month's resounding failure of Celladon's ($CLDN) Mydicar spooked investors slow to forget the field's checkered past. Safety and deliverability concerns hampered innovation in gene therapy for years, but a more recent string of early-stage successes has reinvigorated the field and brought VCs, bankers and retail investors back to the table. Now, as the new class of gene therapy hopefuls faces clinical scrutiny, bluebird and LentiGlobin BB305 have become bellwethers of what many describe as gene therapy 2.0.

Bluebird's lead treatment differs from many of the other gene therapies in development around the world, which involve inserting corrective genes directly into a patient. Instead, bluebird's method works by removing a patient's hematopoietic stem cells, equipping them with a functional beta-globin gene and then reinserting them through infusion.

- read the statement