Vanda Pharmaceuticals on Thursday announced that the regulator declined to approve its application, a decision the company says was delayed by more than 185 days and failed to satisfy the requirements of the Federal Drug and Cosmetic Act.
The FDA on Thursday denied to approve Vanda Pharmaceuticals’ drug application for tradipitant, an investigational NK-1R antagonist that the biopharma was proposing for the treatment of gastroparesis.
The company did not reveal the regulator’s reasoning for the rejection, though claimed that the agency’s Complete Response Letter “was conclusory in nature” and that it “generally disregarded the evidence provided.” According to Vanda, the FDA asked that it to run additional studies “with a design and duration inconsistent with the advice of key experts in the field.”
Jefferies analyst Andrew Tsai in a note to investors said that the rejection was “unsurprising,” especially given a failed Phase III study and an outstanding and unaddressed request from the FDA for additional animal and long-term safety analyses. Vanda also expected a negative outcome, noting in its second-quarter business report that the regulator issued a “preliminary notice” flagging “deficiencies” in its application.
Still, the company stands by its application for tradipitant, arguing that the data package includes “substantial evidence” of the drug candidate’s efficacy and shows a favorable benefit-risk profile for gastroparesis. Vanda said it will continue to seek approval for tradipitant in this indication and will sustain its expanded access program for gastroparesis patients.
Vanda is also working on a separate drug application for tradipitant to prevent vomiting in motion sickness, scheduled for filing “later this year,” according to the announcement.
In response to the FDA’s rejection, Vanda delivered a scathing assessment of the agency. According to the company, the regulator’s verdict was delayed by more than 185 days, which is in violation of the Federal Drug and Cosmetic Act’s (FDCA) 180-day leeway for the FDA to review an application and issue an approval or provide an opportunity for a hearing.
“In this case the FDA has failed to do either,” Vanda said.
The biopharma also slammed the FDA’s inaction in seeking external guidance regarding tradipitant’s application—despite the company “repeatedly requesting” that the regulator convene an advisory committee.
Tradipitant is a small molecule antagonist of neurokinin (NK)-1 receptors, which are largely localized in the gastrointestinal tract and in brain regions involved in the vomit reflex. Through this mechanism of action, tradipitant helps counter the nausea and vomiting symptoms that typically occur with gastroparesis.
Vanda supported tradipitant’s regulatory bid with data from various clinical efficacy studies, supplemented by a 12-week open-label study, findings from its expanded-access program and non-animal preclinical studies.
According to the company, “a number of patients” currently on tradipitant treatment have field a citizen petition requesting that the FDA approve tradipitant for gastroparesis.
Tradipitant’s rejection comes days after the biotech sued the FDA, alleging in its complaint earlier this month that the regulator’s process for approving drugs is unconstitutional, according to Bloomberg. The biopharma also took aim at the FDA’s alleged violations of the FDCA in February 2024, when the agency rejected the expansion of Vanda’s Hetlioz (tasimelteon) into insomnia.
