Gilead unveils promising hepatitis C, fatty liver data; setbacks elsewhere

Gilead Sciences Inc announced high cure rates across all types of hepatitis C in late stage studies testing a triple drug combination, and said another experimental drug showed promise in reducing liver scarring known as fibrosis in a mid stage trial.

The company said it planned to advance the drug, called GS-4997 or selonsertib, into Phase III trials against the fatty liver disease known as NASH, or nonalcoholic steatohepatitis, that is reaching epidemic proportions in the United States and elsewhere. The drug was tested in combination with Gilead's experimental anti-fibrotic drug simtuzumab.

Gilead shares rose more than 1 percent to $74.18.

But GS-4997 failed to achieve the main goal of midstage trials for pulmonary arterial hypertension or diabetic kidney disease based on preliminary data analysis, the company said.

"Due to insufficient evidence of efficacy, Gilead has decided not to pursue Phase III studies of GS-4997 in PAH or DKD at this time," Gilead said in a statement.

A quartet of Phase III trials tested Gilead's Sovaldi in combination with experimental antiviral drugs velpatasvir and voxilaprevir across hepatitis C genotypes 1 through 6 in previously untreated patients and those who failed prior therapy. The trials included patients with and without advanced liver damage known as cirrhosis.

Across the four trials, the pangenotypic triple combination achieved cure rates of between 95 percent and 97 percent over either eight or 12 weeks of treatment.

The three drugs each use different mechanisms to prevent the virus from replicating in the blood. Gilead's big-selling two-drug combination Harvoni, which also includes Sovaldi, treats genotype 1, the most common in the United States, as well as genotypes 4, 5 and 6 with one pill a day.

In the trial of 72 patients with NASH and moderate to severe fibrosis, 43 percent who got 18 milligrams of GS-4997 plus simtuzumab achieved at least a one-stage improvement in fibrosis. With a 6 mg dose of GS-4997 plus simtuzumab, 30 percent experienced such a fibrosis improvement, according to preliminary data after 24 weeks of treatment.

"We believe this data, which raises the likelihood Gilead participates in multi-billion dollar markets beyond HIV and hepatitis C in the medium-term, should start to improve sentiment" for the company, Jefferies analyst Brian Abrahams said in a research note.

Overall, GS-4997 was well tolerated with no dose-related increase in the incidence of treatment-related adverse events or serious adverse events, the company said.