GSK to File Leucovorin Autism Label After FDA's ~40‑Case Review - 4-6 Month Fast‑Track Could Lift Sales, Squeeze Hikma

U.S. Health Secretary Robert F. Kennedy Jr. just accelerated a potentially fast track for an old drug tied to autism treatment - and he did it with a hand from GlaxoSmithKline. The Food and Drug Administration has asked GSK (LSE: GSK) to resurrect a branded approval application for leucovorin (also called folinic acid), with the goal of adding cerebral folate deficiency to the label. That shortcut could shave months off the normal timetable.

Here's the mechanics: GSK says it will file the new-use application "as quickly as possible." Once submitted, FDA review usually runs about four to six months and could be faster in this case. The agency relied on an obscure procedural route to revive GSK's old approval and base the label change on its own review of roughly 40 patient cases published between 2009 and 2024 - an approach that's raised eyebrows among academics, lawyers and clinicians.

Why traders care: a formal label change tends to push payers toward coverage and forces generic makers to adopt the same language. That matters because the generic form of leucovorin - folinic acid - is made by Hikma (LSE: HIK), while GSK previously marketed the branded product as Wellcovorin until 1997. If insurers broaden coverage, prescriptions and sales could rise quickly; one retail price listed on Cost Plus Drugs is $34.14 for a bottle of 30 high-dose pills.

There's already been a demand spike. Publicity from a February TV segment about a nonverbal child and recent promotion by President Donald Trump pushed clinicians to say their phones are ringing. Some hospitals have limited use to clinical trials because the autism indication isn't officially approved - doctors can prescribe it off-label today, but a label update changes the optics for payers and institutional policies.

Not everyone's convinced the move is medically sound. The evidence FDA cited is thin: small studies - roughly four of them with about 50-60 patients apiece, three by the same author - and an agency review of a few dozen case reports. Several experts told colleagues that larger, independently run trials would be needed to be confident the drug helps the broader autism population. Three mid-stage trials testing a liquid form of leucovorin for early language impairment in autistic children are in progress, with data expected as early as December; each study enrolls up to about 80 participants.

The regulatory shortcut also sets a precedent. The typical route for updating labels on generics involves consultation with multiple generic manufacturers and can take up to 18 months. Using the reinstatement pathway to impose a label change could speed future repurposing moves, which is why lawyers and policy researchers are watching closely and questioning whether the FDA's internal review meets usual evidentiary standards.

Political context matters here. Kennedy, who made autism a headline issue - citing a U.S. rate now estimated at roughly 1 in 31 children by age eight - had pledged fast answers as part of the Trump administration's health agenda. He and other officials publicly backed leucovorin at a White House event in late September, and the administration also pushed warnings about acetaminophen use during pregnancy; that latter stance drew sharp criticism from medical groups.

So what's market-relevant right now? If GSK files and FDA signs off quickly, branded sales and generic volumes could rise in the near term, and insurers may be more likely to pick up the tab. But the clinical case is still unsettled and larger trials won't report for months. The regulatory maneuver itself could be the bigger story for pharmaceutical investors: a faster label-change playbook that, if repeated, would alter timelines and market expectations across drug categories.

Data point to watch: FDA processing after GSK files is normally four to six months, with some mid-stage trial readouts due around December.