FDA AdCom endorses bluebird’s CALD gene therapy

An FDA Advisory Committee has unanimously agreed bluebird bio’s gene therapy elivaldogene autotemcel (eli-cel) outweigh the risks in treating early active cerebral adrenoleukodystrophy (CALD).

The US Food and Drug Administration’s (FDA) Cellular, Tissue, and Gene Therapies Advisory Committee (CTGTAC) met yesterday to evaluate bluebird bio’s eli-cel as a treatment of early active cerebral adrenoleukodystrophy (CALD) in patients less than 18 years of age who do not have an available and willing human leukocyte antigen (HLA)-matched sibling hematopoietic stem cell (HSC) donor.

When asked: ‘Do the benefits of eli-cel outweigh the risks, for the treatment of any sub-population of children with early active cerebral adrenoleukodystrophy (CALD)?’ all 15 members of the AdCom said they did.

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However, the FDA raised multiple questions on the efficacy and safety of the gene therapy. “Data had multiple limitations, but in the context of a devastating disease where kids die within five years of diagnosis (except for the 10% with a matched sibling donor), all 15 panelists argued that the benefits outweigh the risks,” RBC Capital analyst Luca Issi wrote in a note.

Issi, therefore, expects eli-cel to be approved by the September 16th PDUFA date, but while this is clearly a positive and important win for bluebird – which has been forced to reduce its workforce and prioritize late phase gene therapy projects in efforts to cut costs of late – “CALD remains a very modest commercial opportunity given only ~30 eligible patients in the US per year (incidence is ~40 patients, 70% eligible).”

The therapy is already approved in Europe under the name Skysona, where it is produced in partnership with Minaris. In the US, bluebird entered a contract with CDMO Lonza in 2016 for both eli-cel and Zynteglo (autologous CD34+ cells encoding βA-T87Q-globin gene, LentiGlobin) from its facilities in Houston, Texas.

The AdCom is meeting again today to discuss the efficacy and safety of another bluebird gene therapy: betibeglogene autotemcel (beti-cel), for patients with beta-thalassemia who require regular red blood cell transfusions.