INTERVIEW - Human Genome calls hepatitis drug sleeper product

NEW YORK (Reuters) - As Human Genome Sciences Inc investors focus on the eagerly-anticipated experimental lupus drug Benlysta, a "sleeper product" for hepatitis C could provide additional billions in future sales, a company official said on Tuesday.

Human Genome Sciences Inc is awaiting a U.S. approval decision later this year for Zalbin, an interferon that would compete with Roche Holding AG's big-selling Pegasys and Merck & Co's Inc Pegintron.

The two current leading interferons are taken intravenously once a week for up to 48 weeks in combination with the antiviral pill ribavirin.

Zalbin by contrast is injected every two weeks, potentially cutting down on injection-related side effects and adding to convenience. Human Genome has a partnership with Novartis AG on the hepatitis C drug.

"Our thought is that any time you would use a weekly interferon, you should use Zalbin because you would have to take half as many injections and it would do the same thing," Barry Labinger, Human Genome's chief commercial officer, said in an interview at the BIO CEO & Investor conference in New York.

"The goal is to maintain the antiviral efficacy of an interferon by boosting the normal immune response, while also reducing the burden of treatment," Labinger said.

The company is also testing a once-monthly version of Zalbin, Labinger said.

Zalbin is a sleeper for two reasons.

"For us as a company, expectations are all on Benlysta right now," he said.

The other reason is that scientific and investor focus on hepatitis C is firmly on a new class of antiviral drugs being developed by Vertex Pharmaceuticals Inc, Merck and others that look set to sharply increase cure rates for the serious liver disease while potentially cutting treatment duration.

But those drugs are being tested in combination with standard treatments and Human Genome sees Zalbin as an attractive replacement for the current interferons.

Labinger expects the current annual $2 billion market for interferons to expand and he sees Zalbin eventually grabbing "a big chunk" of the market share.

"I think the market will grow largely because cure rates will go up with these new antivirals," he said, drawing more untreated patients to the clinic.

"As far as commercial performance goes, a better interferon is going to get used quite a lot, even though it's not the thing that gets the scientific juices flowing," Labinger added.

Meanwhile, the company is preparing to file its application seeking U.S. approval of Benlysta, which could become the first new lupus drug approved in half a century.

The company, which is developing the drug with GlaxoSmithKline Plc, sees the drug garnering annual peak sales of "multiple billion dollars just for lupus alone," Labinger said.

Benlysta also has the potential to treat a wide range of other autoimmune diseases such as rheumatoid arthritis, multiple sclerosis and to prevent rejection of transplanted organs, which could significantly push sales even higher.

With a priority review from the U.S. Food and Drug Administration, Benlysta could also be approved in the fourth quarter of this year.

Asked if the company could handle the simultaneous launch of both Zalbin and Benlysta, Labinger expressed little concern.

"We have cash, we've got a good team and we've got two partners that we can rely on for certain areas. We will be ready, no doubt," he said.

(Reporting by Bill Berkrot and Ransdell Pierson; editing by Andre Grenon)