The Food and Drug Administration placed a clinical hold on Regulus Therapeutics' investigational drug to treat chronic hepatitis C virus infection, according to Reuters.
RG-101 was put on hold after the Carlsbad, Calif.-based company reported a second serious adverse event of jaundice. A patient in the Phase 1 trial got jaundice 117 days after receiving a single dose of RG-101.
While the FDA verbally notified the company about its decision, Regulus says it expects to receive a formal letter from the FDA within a month and plans to work with the agency to release the clinical hold.
The company has three other ongoing studies for RG-101 that will not be impacted since the trials are fully enrolled and participants have finished dosing.
Regulus' shares dropped 60 percent in extended trading in response to news of the clinical hold.
More articles on the drug market:
BMS' bladder cancer drug granted breakthrough therapy designation
Cannabis-based epilepsy drug shows positive results in late-stage trial
Allergy drug launch postponed after failed dosage study