Conatus says data supports moving forward with liver disease drug

Last Updated: 2015-01-08

By Bill Berkrot

(Reuters) - Conatus Pharmaceuticals Inc said on Thursday initial results from small early stage trials supported continued development of its experimental drug for patients with cirrhosis and liver impairment.

In one of the studies, the company tested its drug, emricasan, at three doses in 21 patients with cirrhosis and acute liver failure - the sickest patients on the liver disease spectrum.

The data through seven days showed no dose limiting toxicities and no serious adverse events related to the oral drug given twice a day, providing reassurance on the safety of emricasan, the company said.

There was a nearly 50% death rate among patients who began in the study, but a high mortality rate is common with acute liver failure.

The study looked for reductions in biomarkers associated with cell death and inflammation, considered drivers of progressive liver disease, for indication that the first-in-class drug was having an effect. The biomarkers are specific to the mechanisms of action of the drug, the company said.

There were sustained reductions in key biomarkers seen with the highest 50 milligram dose, Conatus reported.

"That reduction tells us that we're getting effective concentrations of drug in the liver," Conatus Chief Executive Steven Mento said in a telephone interview. "The only time you see them is if the target for emricasan is activated."

At 25 mg, there was an initial but fading response, and little or no response to 5 mg compared with placebo, the company said.

Conatus believes the lower doses could be effective in patients with less severe liver impairment.

The company expects to have more complete data and results of other emricasan studies by the end of this year.

By then, "we will have a sufficient data base of clinical information ... to outline more definitively what we think is the most efficient and rapid approval pathway for this drug in cirrhotic patients," Mento said.

Cirrhosis is a severe scarring caused by all manner of assaults on the liver that over time destroys function of the organ. An estimated 2 million people in the United States and five largest European markets have cirrhosis and varying degrees of liver impairment, Conatus said.

In patients facing liver failure and awaiting a transplant, the hope is emricasan could help them survive until a liver becomes available.

"Buying them more time would be a tremendous benefit," Mento said, "because the alternative is dying."