RG-101 combined with antivirals reduces HCV treatment duration

Regulus Therapeutics announced interim results from one of its ongoing phase 2 studies of RG-101, an anti-miR targeting miR-122, which indicated that the drug in combination with Harvoni, Olysio or Daklinza, was safe and effective for reducing hepatitis C virus infection over 4 weeks.

In the clinical trial, researchers enrolled 79 treatment-naive patients with HCV genotype 1 and 4 and sought to evaluate a shortened, 4-week treatment regimen containing a subcutaneous administration of 2 mg/kg of RG-101 (Regulus Therapeutics) at days 1 and 29, combined with either Harvoni (ledipasvir/sofosbuvir, Gilead Sciences; n = 27), Olysio (simeprevir, Janssen Therapeutics; n = 27) or Daklinza (daclatasvir, Bristol-Myers Squibb; n = 25), according to a press release.

To date, 38 patients have been evaluated through 8 weeks of follow-up, of which 97% had HCV RNA viral load below the limit of quantification (n = 37). For patients who have been through 12 weeks of follow-up, 100% have had HCV RNA viral loads remain below the limit of quantification (14/14), according to the release.

“These sustained virologic responses demonstrate the potential ability of RG-101 to successfully reduce currently marketed oral treatment regimens to just four weeks, a major clinical breakthrough that the HCV field has not been able to achieve until today and I look forward to future results,” Eric J. Lawitz, MD, vice president of scientific and research development at The Texas Liver Institute and clinical professor of medicine at the University of Texas Health Science Center, said in the release. “In addition, I believe this novel approach might allow treating physicians to overcome compliance issues in a wide variety of patient populations.”

Eric J. Lawitz

According to Regulus, RG-101 has been generally well-tolerated with the majority of adverse events being mild or moderate in nature. In addition, no patients have discontinued the study due to RG-101 treatment.

“The potent antiviral activity and sustained, durable responses observed from this interim analysis, provide evidence that RG-101 may have clinical utility as a potential backbone agent in combination with oral therapies to treat a wide range of HCV patients,” Paul Grint, MD, president and CEO of Regulus, said in the release. “Based on the results announced, Regulus intends to accelerate development of RG-101 given its promising potential to shorten treatment regimens.”

The primary endpoint of the analysis is 12 weeks of follow-up for all 79 patients. These results are expected to be reported in the second quarter of the year.

Disclosure: Grint is employed by Regulus Therapeutics. Healio.com/Hepatology was unable to confirm relevant financial disclosures of Lawitz at the time of publication.