NICE recommends treatment with Strimvelis for adenosine deaminase deficiency severe combined immunodeficiency.- GlaxoSmithKline.

According to final guidance from NICE, Strimvelis (gene therapy), from GlaxoSmithKline, is recommended, within its marketing authorisation, as an option for treating adenosine deaminase deficiency severe combined immunodeficiency (ADA-SCID) when no suitable human leukocyte antigen-matched related stem cell donor is available. Clinical trial evidence shows that Strimvelis is effective in treating ADA-SCID.

Compared with haematopoietic stem cell transplants (HSCTs), results suggest the main benefits are that more people live after Strimvelis than after a transplant and fewer people develop graft-versus-host disease. However, the exact size of the clinical benefits are uncertain because the trials have been small and uncontrolled, and the evidence for HSCTs is limited. There are also several important uncertainties in the cost-effectiveness results associated with Strimvelis. However, there are health-related and wider benefits not included in the economic analysis but which are important to consider.

Taking these into account, and considering the additional weight that can be assigned to the benefits when the estimated health gain is large, the plausible cost-effectiveness estimates for Strimvelis are within the range that NICE normally considers acceptable for highly specialised technologies. The cost of Strimvelis is high and there are some uncertainties in the evidence. However, Strimvelis is likely to provide important benefits for people with ADA-SCID, at a cost that provides value for money in the context of a highly specialised service.

Comment: The inherited genetic condition, also known as bubble baby syndrome, affects the body's white blood cells, leaving children without a fully-functioning immune system and extremely vulnerable to infections. The current treatment is a stem cell transplant, but closely-matched donors are hard to find and the transplants may not be successful in all cases, they also carry a risk of mortality and graft-versus-host disease. Those not receiving treatment need to be kept in isolation, hence the bubble baby reference.