* FDA advisory panel to vote on drug Thursday afternoon
* Analysts expect panel backing, more than $1 bln in sales
* Vertex shares halted on Nasdaq
By Lisa Richwine
SILVER SPRING, Md., April 28 (Reuters) - Vertex Pharmaceuticals Inc (VRTX.O) urged U.S. advisers on Thursday to back its experimental drug that cured nearly 80 percent of newly treated patients with hepatitis C, a virus that can destroy the liver.
The advisory panel unanimously recommended approval of a rival Merck & Co (MRK.N) drug on Wednesday. Analysts expect Vertex to win an endorsement when the committee votes on its drug, telaprevir, on Thursday afternoon. They forecast blockbuster sales of more than $1 billion a year for each medicine.
In Merck and Vertex studies, the pills have cured more patients than standard therapies and in half the time in some cases. Doctors say tens of thousands of patients have delayed treatment in anticipation of the new medicines.
Telaprevir “produces substantial clinical benefit compared to the current treatment,” Vertex Chief Medical Officer Robert Kauffman told the panel, a group of outside experts that advises the Food and Drug Administration.
The Vertex drug wiped out the virus in 79 percent of patients not previously treated for hepatitis C, almost twice the 40 percent cure rate with current therapies. Merck’s drug cured as many as 66 percent of patients.
Analysts expect telaprevir to draw more patients with its higher cure rate.
Both the Merck and Vertex medicines must be taken with the current combination therapy of the injectable drug interferon and a pill called ribavirin. The older drugs require almost a year of treatment and often cause flu-like symptoms that are tough to tolerate. Many patients who took the newer medicines were able to end treatment after about six months.
About 170 million people around the world and 3.2 million in the United States are infected with hepatitis C, a blood-borne disease that can lead to chronic liver problems, liver cancer, cirrhosis and death.
The infection has spread mainly through sharing needles, such as those used for illegal drugs and tattoos, or through blood transfusions before 1992, when screening began. Many people who are infected do not know they have the virus and show no symptoms.
In a preliminary analysis, FDA reviewers agreed the Vertex drug was effective and raised few safety concerns. The main side effects reported, anemia and rashes, are not expected to derail approval.
Both of the new medicines work by blocking a protein called protease that the virus needs to replicate. They could be approved for sale as early as May.
Vertex shares were halted on Nasdaq as the panel met. (Reporting by Lisa Richwine; Editing by Lisa Von Ahn)