Regulus Therapeutics Receives FDA Clinical Hold For Hepatitis C Drug

In after-hours trade on Monday, shares of Regulus Therapeutics (RGLS) tanked by 60% after the company announced that the FDA has placed a clinical hold on its Hepatitis C drug candidate. The hepatitis C drug candidate placed on the clinical hold is known as RG-101 which is a microRNA drug. Regulus states that the FDA should send a formal letter to the company within the next 30 days.

The company will investigate the letter and then attempt a dialogue with the FDA to seek release of the clinical hold. The reason for the clinical hold being placed was because one patient experienced a second averse event of Jaundice. This occurred in a patient who has end-stage renal disease with the Hepatitis C virus. The patient had only received a single dose of RG-101 and got sick after 117 days. 

The company will now work with the FDA and see if it can get the clinical hold released in a timely manner. Regulus stated that the trials won't be impacted because all patients have been enrolled and treated already. Therefore, the company still expects to update shareholders on the clinical results at an upcoming scientific meeting.