By Michael Calia 

Merck & Co. said Thursday that a pair of its hepatitis C virus treatments showed a cure rate of 98% in a mid-stage trial, supporting advancement of the study.

The drug maker said it has initiated a Phase 3 trial after analyzing the study results of the 12-week regimen using the oral treatment, which combines MK-5172 and MK-8742. The company said the study also showed a 94% cure rate for patients receiving those treatments, plus ribavirin.

Merck's announcement comes as Bristol-Myers Squibb Co. on Tuesday said its hepatitis C treatment demonstrated efficacy in a study, achieving positive results in as much as 90% of certain patient groups. Gilead Sciences Inc. also said data from a phase two study of its all-oral hepatitis C treatment, Sovaldi, demonstrated efficacy, supporting initial findings from phase three trials.

Bristol-Myers and Gilead, among others, have been in a race to bring all-oral hepatitis C treatments to the market, which is expected to be worth billions of dollars. Gilead's drug costs $1,000 a day.

Merck said there were no early discontinuations of its investigational hepatitis C treatment due to adverse effects, nor were any significant abnormalities detected. The most common side effects were fatigue, headache, nausea, diarrhea and insomnia, the company added.

Merck has taken some hits lately as it contends with patent expirations on lucrative drugs, as well as issues with bringing new products to the marketplace. Last year, the company said it would cut its workforce by 20% over two years, including cutting positions in its research-and-development operations. The company has also said it would consider shedding some products and businesses.

The company in February said it agreed to collaborate with other drug makers to study its investigational cancer treatment.

Shares of Merck rose 1.8% to $58.10 in recent premarket trading. Through Wednesday's close, the stock was up 14% so far this year.

Write to Michael Calia at michael.calia@wsj.com

Subscribe to WSJ: http://online.wsj.com?mod=djnwires

Merck (NYSE:MRK)
Historical Stock Chart
From Mar 2024 to Apr 2024 Click Here for more Merck Charts.
Merck (NYSE:MRK)
Historical Stock Chart
From Apr 2023 to Apr 2024 Click Here for more Merck Charts.