ICER: Sickle Cell Gene Therapies Could be Cost-Effective

Two potential gene therapies for sickle cell disease would be cost-effective if priced between $1.35 million and $2.05 million, according to the Institute for Clinical and Economic Review (ICER) in a recently released evidence report. Exagamglogene autotemcel (exa-cel) and lovotibeglogene autotemcel (lovo-cel) are being assessed by the FDA, and they could be approved by the end of the year.

David Rind, M.D.

“Sickle cell disease can affect nearly every organ system in the body, and severe sickle cell disease affects nearly every aspect of a person’s life,” said ICER’s Chief Medical Officer, David Rind, M.D., said in a press release “From the earliest days of gene therapy, patients, families, and clinicians have imagined that someday it might be possible to address the underlying genetics of sickle cell to achieve a cure. These first two genetic therapies, using different technologies and altering different genetic targets may mean that day has nearly arrived.”

Sickle cell disease results from mutations in a gene that encodes a key component of hemoglobin, the oxygen carrying molecule in blood. Current treatments include blood transfusions and the use of medication that helps prevent sickling of red blood cells, reduce complications and manage pain. But a blood and bone marrow transplant is currently the only cure. This involves the use of donor cells, which carries a risk of rejection.

The healthcare costs associated with sickle cell are high, about $1.7 million and patients have out-of-pocket costs of $44,000 over their lifetime, according to a study published in Blood Advances earlier this year of patients with commercial insurance.

ICER found that both exa-cel and lovo-cel are likely to improve quality and length of life, using a $2 million placeholder price for both therapies. The organization rated lovo-cel as incremental or better compared with standard of care and exa-cel as comparable or better compared with standard of care. Reviewers said that the improvement seen with lovo-cell and exa-cell needs to be balanced against the potential harms of myeloablative conditioning, which is the use of high-dose chemotherapy before a stem-cell transplant, as well as the uncertainties about the duration of effect.

Developed by Vertex Pharmaceuticals and CRISPR Therapeutics, exa-cel is a one-time therapy that uses a patient’s own hematopoietic stem cells that are edited to produce high levels of fetal hemoglobin in red blood cells. The FDA has set the target action dates of Dec. 8, 2023, for exa-cel for use in patients who have severe sickle cell disease and March 30, 2024, for patients with transfusion-dependent beta thalassemia.

Bluebird bio’s lovo-cel is a one-time treatment that is designed to add functional copies of a modified form of the β-globin gene into a patient’s own blood stem cells, enabling the body to produce its own hemoglobin. The FDA has set an action date of Dec. 20, 2023.

But ICER officials said long-term safety and efficacy remain uncertain for both gene therapies. During trials, the had FDA placed a clinical hold on lovo-cel because of concerns about hematologic malignancies, and two deaths from hematologic malignancies occurred. There was one death in the exa-cel trial. In addition, ICER officials said some patients in the trials of exa-cel continued to have episodes of pain.