The most expensive drug in the U.S. is now Lenmeldy, a $4.25 million gene therapy the FDA approved March 18 for children with a rare genetic disease.

Metachromatic leukodystrophy manifests into the loss of motor and cognitive function, and early death, according to the FDA. The first and only one-time medicine for patients is Lenmeldy (atidarsagene autotemcel). Its manufacturer, Orchard Therapeutics, said the drug’s wholesale acquisition cost is $4.25 million. 

In a March 20 news release, Orchard said the price tag “is reflective of the value the therapy may deliver to eligible patients and their families, as well the potential long-term impact [the] treatment may have on overall healthcare utilization, minimization of productivity loss for caregivers and life opportunities for patients.”

In a trial, 37 children received Lenmeldy and experienced a significant reduction in the risk of severe motor impairment and death compared to untreated children. At 5 years old, 71% of treated children could walk without assistance. All study participants who had pre-symptomatic late infantile MLD were alive at 6 years old, compared to 58% of children in the control group. 

Before its approval, the Institute for Clinical and Economic Review said the drug would be cost effective if priced between $2.3 million and $3.9 million. 

Other chart-topping medications include Hemgenix, a $3.5 million hemophilia B therapy; Elevidys, a $3.2 million muscular dystrophy drug; and Skysona, a $3 million medicine for adrenoleukodystrophy.