Merck raised prices five drugs including Keytruda in November

The list price increases are the first that the U.S. drugmaker has made since pledging in July that it would not raise the average net price of all of its medicines by more than the inflation rate.Merck raised the price of cancer immunotherapy Keytruda,which is forecast to bring in more than $7 billion in sales this year, by around 1.5 percent.It also raised the price of its human papillomavirus (HPV) vaccine Gardasil, which protects against cancers related to the virus, by around 6 percent.