Sickle Cell Disease: FDA Lifts Partial hold on bluebird’s Trial for Patients Under 18


One year ago, in December 2021, clinical studies of lovo-cel for patients who were eighteen or younger were put on partial hold by the FDA. At the time, bluebird bio, based in Somerville, Mass. was conducting an investigation into a young patient who had persistent anemia (non-transfusion) after being treated with lovotibeglogene autotemcel also known as lovo-cel.

Business Wire reported the results of this in-depth investigation which were presented to the Annual ASH Exposition along with a second case of acute anemia. In this instance, the blood disorder was diagnosed in a male patient after lovo-cel therapy.

The two patients were found to have alpha-thalassemia trait. However, the company emphasized that no other patients involved with the study were found to have this genotype.

As a result of the aforementioned cases, the specific genotype became part of the exclusion criteria in future studies.

The HGB-210 Trial

During the partial hold, adult patients (over 18) continued with dosing. The company resumed enrollment and treating patients in the two – 17 age group after the hold was lifted.

Bluebird remains in position as of early 2023 to submit its Biologics License Application requesting the FDA’s approval of lovo-cel for sickle cell disease.

Patients in the HGB-206 cohort C have now received their final treatment. Bluebird should complete its drug product and vector studies for lovo-cel BLA in the latter part of 2022.

The following designations have been granted to lovo-cell by the FDA:

  • orphan drug is granted to treat rare disease conditions and qualifies sponsors for various incentives
  • fast track is granted to drugs under development to fulfill unmet medical needs and expedite the FDA review process
  • regenerative medicine advanced therapy is granted to drug candidates developed to treat life-threatening conditions; it allows accelerated approval
  • rare pediatric disease program is designed for pediatric patients to stimulate new drug development; it offers incentives to obtain FDA approval

 About lovo-cel

Lovo-cel is a one-time-only gene therapy designed to increase active copies of altered forms of the β-globin gene into the patient’s blood stem cells.

The patient’s red blood cells will then produce anti-sickling hemoglobin intended to reduce sickled red blood cells as well as other complications.

When a person has sickle cell disease, their hemoglobin is abnormal rather than round as in healthy cells. Normal cells move through small blood vessels carrying oxygen to all parts of the body. Sickle cells become hard and die early, causing a continuous shortage of red blood cells.

Bluebird is conducting Phase I/II and Phase III studies as well as an efficacy and safety study for patients who have received treatment in its bio-sponsored trials.


Rose Duesterwald

Rose Duesterwald

Rose became acquainted with Patient Worthy after her husband was diagnosed with Acute Myeloid Leukemia (AML) six years ago. During this period of partial remission, Rose researched investigational drugs to be prepared in the event of a relapse. Her husband died February 12, 2021 with a rare and unexplained occurrence of liver cancer possibly unrelated to AML.

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