The FDA is upset with certain marketing claims related to Incyte’s chronic graft-versus-host disease (cGVHD) drug Niktimvo.
In an untitled letter published on April 24, U.S. regulators pointed to a landing page on the Niktimvo website that claims “Niktimvo may provide a prompt and durable response.”
But the FDA said in its letter that “these claims and publications suggest that Nictimbo provides greater benefit to patients with cGVHD than has been previously demonstrated.” According to the FDA, the company’s claims are “misleading that patients will experience a ‘fast’ response to the drug, when in fact they will not.”
Additionally, according to the FDA, Incyte’s claim that “more than half (60%) of those who responded to Nictimbo continued to have a response for at least one year” is misleading because “it does not include patients who experienced progression.”
This is a similar story for the claim on the “Response” webpage, namely that “people achieved responses in multiple affected organs.”
Again, when FDA reviewed the trial data, it stated that the overall response measurements were based on “assessment of cumulative response across all organs rather than specific individual organs.”
This also “misleadingly overstates the drug’s perceived benefits,” the regulator said. Incyte also said on the same page that its drug “produced symptom improvement,” but the FDA said this was simply “not substantiated” by the data.
As with all of these letters, Incyte must address the agency’s concerns within 15 business days of receipt.
In its 2025 full-year financial report, Insight said it had sales of $151.6 million in the year and saw “rapid adoption of Nictimbo.” Anti-CSF-1R antibody was approved for cGVHD in August 2024. Analysts believe the drug will eventually become a blockbuster product.

