The liver disease hepatitis C is the new battleground for lawsuits intended to slash the cost of life-saving medicines. In February alone, five suits were filed in India and Argentina claiming that the latest class of antiviral drugs does not warrant the 20-year patent monopoly that manufacturers have sought in those countries. Roughly 177.5 million adults worldwide are infected with the hepatitis C virus, which can cause liver cancer and cirrhosis if left untreated — but the latest antiviral medications have revolutionized care. The first to reach the market was sofosbuvir, sold under the name Sovaldi by Gilead Sciences of Foster City, California; clinical trials of the drug in combination with other medications have shown a cure rate of 95% or more. Four of the lawsuits filed in February target Indian patents on sofosbuvir and two related drugs, Gilead’s velpatasvir (sold in combination with sofosbuvir under the name Epclusa) and Daklinza (daclatasvir) from Bristol-Myers Squibb in New York City. The fifth challenges Gilead’s application to patent sofosbuvir in Argentina. Some of the suits argue that sofosbuvir, velpatasvir and daclatasvir are not sufficiently inventive to warrant a patent. Others challenge Gilead’s attempts to obtain additional patents on sofosbuvir by modifying it slightly, to extend the company’s intellectual-property rights — a practice called evergreening.

To know more, click Hepatitis C Drugs.