Bluebird Bio One Step Closer to its First Approved Drug
Bluebird bio, headquartered in Cambridge, Massachusetts, announced interim data from two different two-year clinical trials of LentiGlobin gene therapy for transfusion-dependent beta-thalassemia (TDT).
The two studies are Northstar (HGB-204), which was recently completed, and HGB-205, which is still proceeding. They are Phase I/II clinical trials. Both have reported that a one-time treatment of LentiGlobin in the majority of 22 patients have remained free from transfusions for two years or longer. In the 13 patients with a non-beta0/beta0 genotype, 12 stopped receiving regular red blood cell transfusions, with a median time since the last infusion of 27 months. In nine patients with beta0/beta0 genotype, median transfusion volume dropped by 73 percent, and transfusions were halted in three patients.
“These interim data demonstrate the potential of LentiGlobin gene therapy to address the underlying genetic cause of TDT and increase production of functional red blood cells,” said David Davidson, bluebird’s chief medical officer, in a statement. “Nearly all patients in the two studies with a non-beta0/beta0 genotype achieved freedom from chronic blood transfusions and, importantly, several of these patients reached normal or near-normal total hemoglobin levels and sustained those levels throughout the interim study period. We hope the refined manufacturing process implemented in our ongoing pivotal trials of LentiGLobin will translate into further normalization of total hemoglobin levels across genotypes.”
Transfusion-dependent thalassemia is a severe genetic disease noted by reduced or absent hemoglobin production. This causes severe anemia and ineffective red blood cell production. Patients require regular blood transfusions to stay alive, but chronic transfusions lead to iron overload that can cause damage to multiple organs and a shorter life span. About 60,000 children are born with beta-thalassemia annually, about 1,500 in the U.S.
Andrew Obenshain, Head of Europe for bluebird, told Labiotech, “What bluebird’s therapy allows is to modify the patient’s own cells to introduce a normal copy of hemoglobin. So the patients get a bone marrow transplant from their own cells.”
This should cut possible transplant rejection and infusion-related inflammation reactions. The company plans to file for approval in Europe later this year. Fox News notes, “The interim data is from bluebird bio’s Northstar and HGB 205 studies. That’s important to know because EU regulators have said they’ll consider a conditional approval of LentiGlobin based on the final results from these two trials.”
On the other hand, the U.S. Food and Drug Administration (FDA) and bluebird have decided to wait until there is data from bluebird’s HGB-207 and HGB-212 trials before filing. The estimated completion data for HGB-207, according to Clinicaltrials.gov, is January 2020, and for HGB-212, April 2021.
Bluebird currently has three gene therapies getting closer to approval. The others are bb2121 for multiple myeloma and Lenti-D, for a rare genetic disease called cerebral ALD (CALD). The company hopes to file for those by the end of 2019, and if all goes well, all three drugs could be creating revenue in 2020.
In 2015, the company stumbled when its first version of the treatments didn’t behave the same way in all patients. The company changed various manufacturing processes in hopes of making it work more effectively, which it appears to have accomplished.
Other companies working on gene therapy for blood disorders include Vertex Pharmaceuticals, which has a deal with CRISPR Therapeutics for beta-thalassemia and sickle cell disease.