According to the law firm press release, Regulus is a biopharmaceutical company that focuses on the discovery and development of drugs that target microRNAs to treat and prevent various diseases, including hepatitis C infections, cardiovascular, fibrosis, oncology, immune-inflammatory, and metabolic diseases. One of its main clinical development products is RG-101, a GalNAc-conjugated anti-miR targeting miR-122 to treat patients with hepatitis C virus infection.

The Complaint alleges that throughout the Class Period, Defendants made materially false and/or misleading statements, as well as failed to disclose material adverse facts about the Company's business, operations, and prospects. Specifically, Defendants made false and/or misleading statements and/or failed to disclose that: (i) patients treated with RG-101 were at increased risk of contracting jaundice; (ii) consequently, the Company had overstated RG-101's approval prospects and/or commercial viability; and (iii) as a result of the foregoing, Regulus's public statements were materially false and misleading at all relevant times.

On June 27, 2016, post-market, Regulus announced that it had received verbal notice from the U.S. Food and Drug Administration ("FDA") that the FDA had placed RG-101 on clinical hold after a second serious adverse event of jaundice was reported in a patient treated with the drug.

On this news, Regulus's share price fell $2.47, or more than 49%, to close at $2.54 on June 28, 2016.