RAPT Therapeutics on Tuesday announced that the U.S. FDA has placed a clinical hold on two mid-stage trials of the company’s drugs after a case of liver failure observed in one patient in the atopic dermatitis trial.
The FDA puts a hold on mid-stage trials of RAPT Therapeutic company’s two drugs used to treat eczema and asthma. FDA holds on to the trial of the drug Zelnecirnon in atopic dermatitis and a trial in asthma.
The shares of the immunology-based company plunged 66% to $8.92 in premarket trading.
In a conference call, RAPT CEO Brian Wong said that patient safety is their top priority, and they intend to work closely with the agency to resolve this as quickly as possible. They anticipate a formal letter from the FDA with more details, including information needed to lift the hold. This formal feedback will be critical to direct their investigation and identify the best path forward, and also said that they are undertaking a thorough investigation of this case.
RAPT enrolled around 350 patients across three trials, the two mid-stage trials and zelnecirnon, a previous early-stage study of the drug, but there is no evidence of liver toxicity noticed in any other patient or nonclinical studies. The dosing and enrollment of the two trials have been stopped. However, the FDA clinical hold does not apply to RAPT’s ongoing trial drug tirumecirnon in oncology.
The company said that they were studying the patient's history and called the liver toxicity an isolated event.
The RAPT CEO also said that the patient in question had a particularly complex medical history. The patient had an autoimmune condition called Hashimoto's Disease, he had also undergone thyroid replacement therapy for that, and he also had a drug allergy to Dupixent, Regeneron, and Sanofi’s drug. The patient had a history of using an herbal supplement called ashwagandha which has been associated with liver failure and he also had a COVID-19 infection during the time of the event. The CEO enunciates that the patient received a liver transplant and is recovering.
In November the company said that in mid-2024 it was foreseeing to announce the outcomes of the trial in patients with atopic dermatitis or eczema, while it was bringing in advancements in enrollment in its asthma study.
Alex Thompson, Stifel analyst said that the clinical hold represents a major setback for RAPT and could result in a meaningful delay in trial timelines.
RAPT CEO said that they continue to diligently investigate the matter and work with the agency to resolve the hold as quickly as possible.
(Input from various sources)
(Rehash/Lavanya Beeraboina/MSM)