Regulus Therapeutics ($RGLS), at work on a microRNA approach to hepatitis C, watched its shares skyrocket on positive early data for its lead candidate, which significantly reduced viral loads with a single dose.
In interim results from a proof-of-concept study, one subcutaneous administration of Regulus' RG-101 led to an average viral load reduction of 4.1 Log10, a substantial decrease in the amount of hep C virus per milliliter of blood. However, after 29 days of observation, only 6 of the 14 patients in the trial reported viral levels below the study's prespecified threshold for quantification, a rapid virologic response of just 43%.
Still, Regulus believes the results affirm the potential of RG-101, and investors agree--at least for the most part. The biotech's shares soared nearly 150% in premarket trading on Wednesday, reaching above $18 each before calming down to around $11.50 by mid morning.
In addition to its promising efficacy, RG-101 has thus far demonstrated itself safe and well-tolerated with no serious adverse events, Regulus said. In response to the strong response in interim results, the biotech is expanding its study to follow patients for up to 6 months to examine the potential for a sustained virological response--or cure--based on a single dose of the treatment. The company plans to post additional results in 2015.
Next, Regulus plans to kick off Phase II development for its therapy, planning to file an IND with the FDA early next year and launch a study combining RG-101 with Johnson & Johnson's ($JNJ) antiviral Olysio in the second quarter of 2015.
"We believe these interim data are exceptional and provide strong evidence to support the rapid advancement of RG-101 into future clinical studies, while presenting a clear opportunity for a potentially disruptive therapy to the current HCV treatment paradigm," Regulus CEO Kleanthis Xanthopoulos said in a statement.
RG-101 is injectable therapy that targets microRNA-122, which is found in liver hepatocytes and used by hep C as a viral replication factor, according to Regulus. By standing in the way of that interaction, RG-101 can halt hep C's proliferation and limit the development of treatment resistance, the company said.
The biotech, formed in 2007 with microRNA assets from Isis ($ISIS) and Alnylam ($ALNY), is also working on preclinical candidates for cancer, fibrosis and metabolic disease alongside partners including GlaxoSmithKline ($GSK), Sanofi ($SNY) and AstraZeneca ($AZN).
- read the results