(Reuters) - Gilead Sciences Inc said a late-stage trial testing its experimental hepatitis C drug showed no detectable virus level in 73 percent of study patients after 16 weeks of therapy.
The study tested Gilead's sofosbuvir, in combination with a standard drug for the infection, ribavirin, in patients with genotype 2 or 3 of the virus who did not respond to prior treatments.
The study, named FUSION, showed that half of the patients in the 12-week arm and 73 percent in the 16-week arm could suppress the virus. The main goal was for the virus to be undetectable in more than 25 percent of the study patients.
Fatigue, headache, insomnia and nausea were the most common adverse effects reported in less than 15 percent of patients, the biotechnology company said in a statement.
"With positive results from all four Phase 3 trials now in hand, Gilead is on track to meet its goal of filing regulatory applications in the United States and Europe in the second quarter," Gilead Chief Scientific Officer Norbert Bischofberger said.
Earlier in the month, Gilead said the drug combination also achieved main goals set in two other late-stage trials of treating patients who have chronic hepatitis C virus infection and have never been treated for it.
Sofosbuvir also showed promise in another late-stage study called Positron in patients who were unable or unwilling to take interferon -- a standard hepatitis C drug known for its unpleasant side effects.
Gilead said it will present full data from the four studies at a future scientific conference.
Shares of the company rose 2.5 percent to $42.60 in early trade on the Nasdaq on Tuesday.