In the glare of an intense gene therapy spotlight, bluebird continues to tout each small step forward for its pioneering LentiGlobin
As one of the pioneers in the new wave of gene therapy developers, bluebird bio $blue has spent considerable time providing incremental evidence that it can step up results for LentiGlobin, improving the manufacturing process and beefing up positive outcomes for a therapy that’s had its problems along the way.
Today, the research team has two new updates to offer on a handful of patients afflicted by an inability to produce sufficient quantities of healthy hemoglobin, couched in the relentlessly optimistic terms that has helped CEO Nick Leschly build their market cap to close to $10 billion. Preparing for an update this weekend at the 23rd Congress of the European Hematology Association, they need to impress analysts in the lead-up to a crucial marketing application.
Bluebird’s shares inched up to the $200 mark in early trading Friday, with a generally positive spin on the latest data. But they couldn’t hold on in the short run. By mid-morning the stock was down 4% as the EHA generated a touch crowd of observers.

In sickle cell disease, their focus is on Group C, where 4 patients past the 3-month followup stage are making more than 30% of anti-sickling HbAT87Q — their definition of success. And one of those patients who’s gone past 6 months has a normal total hemoglobin level of 14.2 g/dL with 60%-plus production.
These patients are getting the new and improved version of the gene therapy after the original fell well short of a cure, and investigators are staying on each patient as bluebird builds its case for the steep price they have in mind for LentiGlobin.
Durability is key here.
Bluebird has made enough progress with its two studies for transfusion-dependent β-thalassemia that CMO David Davidson says today that they are on track to file for European approval later this year — even though it isn’t perfect.
The key data point here: Seven of 8 patients are producing ≥ 7.6 g/dL of HbAT87Q and are maintaining total hemoglobin levels of 11.1 – 13.3 g/dL by 6 months.
Bluebird has become a favorite target for some observers, ready to catch them out for hyping less-than-perfect numbers in a field trying to achieve a near-perfect record for a once-and-done therapy. Their latest round of data on the leading BCMA-targeting CAR-T caught some early flak at ASCO a few days ago, dinging the stock. But the underlying positives turned it around with investors who remain believers.
“Consistently higher in vivo vector copy numbers and HbAT87Q hemoglobin levels in patients indicate that LentiGlobin manufacturing refinements have resulted in improved gene therapy characteristics and may enable sustained transfusion independence for a great majority of patients,” said Professor Franco Locatelli, the lead investigator of the Northstar-2 study.