Vertex CEO sees "historic launch" for Hep-C drug

* CEO says uptake of Incivek very strong

* CEO says will be very proud to show results

* Says doesn't know if latest IMS data is correct

By Ros Krasny

BOSTON, Oct 20 (Reuters) - The chief executive of Vertex Pharmaceuticals Inc , Matthew Emmens, said on Thursday that adoption of its recently-launched hepatitis C drug, Incivek, has been "very very fast."

The first full quarter of U.S. sales of Incivek will emerge when the biotechnology company reports its quarterly earnings later this month.

"We'll be very proud at what we show you," said Emmens, speaking at a Greater Boston Chamber of Commerce breakfast."

The Incivek launch, he said, "will be a historic launch in terms of acceptance."

Shares of Vertex have lurched in recent weeks afer IMS Health, which provides prescription data and other services to the pharmaceutical industry, revised its estimates of the number of prescriptions written in late Steptember.

Initially investors had thought demand was flattening. It then emerged that IMS had failed to include certain data, which sent the prescription number up again.

Emmens declined to comment on the snafu, or speculate on whether IMS now has its figures correct.

"I'm confident of our internal data and that's how we drive the company," he said.

Incivek is one of two new breakthrough hepatitis C drugs to be launched recently. The other is Victrelis, made by Merck & Co . Both drugs promise a higher cure rate for the disease, which infects the liver and can lead eventually to cirrhosis and liver failure.

Vertex's shares were up nearly 1 percent at $40.52 in early trading on Nasdaq.