|Incivek by Vertex competes with Victrelis by Merck & Co. (The Boston Globe/File 2006)|
IMS Health Inc. said Thursday its report last month on sales of Incivek, a hepatitis C drug made by Cambridge-based Vertex Pharmaceuticals, was incomplete. The prescription-data company may have underestimated prescriptions for Incivek, said Mark Schoenebaum, an analyst at ISI Group in New York. IMS data on the drug, approved by US regulators in May, suggested sales had stopped growing last month, Schoenebaum said. IMS said the figures it released for the last two weeks of September were adjusted based on estimates to account for missing data.