Lenmeldy becomes world’s most expensive drug


The gene therapy for metachromatic leukodystrophy (MLD), Lenmeldy (atidarsagene autotemcel; also branded as Libmeldy in some markets), has become the most expensive drug on the market. (UK), which was recently acquired by (Japan), set the US wholesale acquisition cost (WAC) of Lenmeldy at a staggering $4.25m for a one-time treatment.

This is the highest cost of any treatment that has been approved by the FDA to date. Orchard Therapeutics launched Lenmeldy in the US as the first FDA-approved therapy for the treatment of children with MLD on 20 March 2024. This WAC price was based on an assessment by the Institute for Clinical and Economic Review (ICER), which determined the health benefit price benchmark (HBPB) for Lenmeldy to be up to $3.

94m. This beats out the now second most expensive drug, CSL Behring’s (US) Hemgenix (etranacogene dezaparvovec), by almost $1m, which was priced at roughly $3.5m.

The high price was based on the benefit of the therapy concerning clinical, social, and economic factors. Despite MLD being a rare disease, with a diagnosis prevalence of 0.0001% in the US according to GlobalData databases, the availability of this gene therapy will vastly improve the lifespan of those affected.

Lenmeldy is indicated for children with pre-symptomatic late infantile (PSLI), pre-symptomatic early juvenile, (PSEJ), or early symptomatic early juvenile (ESEJ) MLD, which are collectively referred to as early-onset MLD. The illness is caused by a deficiency of an enzyme .