Payers are so far covering the new HCV drugs from Gilead Sciences Inc. and Johnson & Johnson, but they are already looking forward to new drugs expected to hit the market in the next 18 months in the hope that competition will help them negotiate lower prices.

Payers are eager for new entrants because the two newest drugs, even when they are not more expensive than standard of care, are likely to be used by vastly more patients, driving up total spending to treat HCV.