Martin Shkreli
Credit: Bloomberg

A huge overnight price increase for an important tuberculosis drug has been rescinded after the company that acquired the drug gave it back to its previous owner under pressure, it was announced on Monday.

However, outrage over a gigantic price increase for another drug spread into the political sphere on Monday, causing biotechnology stocks to fall broadly as investors worried about possible government action to control pharmaceutical prices. The Nasdaq Biotechnology Index fell more than 4 percent.

“Price-gouging like this in the specialty drug market is outrageous,” Hillary Rodham Clinton, a contender for the Democratic presidential nomination, said in a tweet on Monday. She said she would announce a plan on Tuesday to deal with rising drug prices.

Ms. Clinton was referring to the actions of Turing Pharmaceuticals, which last month acquired Daraprim, a 62-year-old drug used to treat a serious parasitic infection, and raised its price to $750 per […]