Press Release

February 17, 2021
1 min read

Manufacturer suspends clinical trials for gene therapy to treat sickle cell disease


Press Release

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Gene therapy developer bluebird bio suspended clinical trials using its LentiGlobin product for sickle cell disease due to reported cases of hematologic malignancies among patients who received the treatment.

The temporary suspension applies to a phase 1/phase 2 trial (HGB-206) and phase 3 trial (HGB-210) of bb1111, bluebird bio’s LentiGlobin-based investigational therapy for patients with sickle cell disease.

 Clumps of sickle cell block the blood vessel.
Source: Adobe Stock.

The company implemented the suspension after a report that a patient treated more than 5 years ago in HGB-206 was diagnosed with acute myeloid leukemia. Additionally, a patient treated in the same study developed myelodysplastic syndrome.

The manufacturer is investigating the suspected unexpected serious adverse reactions “to determine if there is any relationship to the use of BB305 lentiviral vector in the manufacture of LentiGlobin gene therapy for [sickle cell disease],” a company-issued press release stated.

These reports also led bluebird bio to suspend marketing of betibeglogene autotemcel (Zynteglo), an autologous gene therapy manufactured with the same BB305 lentiviral vector used in LentiGlobin.

Betibeglogene autotemcel was previously approved for use in the European Union for patients with transfusion-dependent beta-thalassemia. The gene therapy has not been approved for use in the United States, but the FDA granted orphan drug status and breakthrough therapy designation, and the therapy is being evaluated in two phase 3 trials.

There have been no reported cases of hematologic malignancies among patients who received betibeglogene autotemcel for transfusion-dependent beta-thalassemia, according to the manufacturer.

The cases among the two patients in the HGB-206 trial have been reported to the FDA and European Medicines Agency. The studies will continue to be monitored by an independent safety review board, and bluebird bio will work with regulators to complete the investigations, according to the press release.

“The safety of every patient who has participated in our studies or is treated with our gene therapies is the utmost priority for us,” Nick Leschly, CEO of bluebird bio, said in the release. “We are committed to fully assessing these cases in partnership with the health care providers supporting our clinical studies and appropriate regulatory agencies. Our thoughts are with these patients and their families during this time.”