Martin Shkreli, chief executive officer of Turing Pharmaceuticals AG, said he would lower the price of the drug Daraprim after being criticized for boosting it fifty-fold to $750 a pill.

"We have agreed to lower the price of Daraprim to a point that is more affordable," Shkreli said Tuesday in an interview with ABC News. He didn't say what the new price would be.

Turing acquired an older antibiotic drug, Daraprim, in August and soon after that raised the price to $750 a pill from $13.50. Shkreli was criticized by Democratic presidential candidate Hillary Rodham Clinton on Monday, who called the price hike "outrageous" on Twitter and responded with a proposal to cap consumer spending on drugs. Clinton's tweet caused the Nasdaq Biotechnology Index to slide, losing more than $40 billion in market value on Monday.

The top U.S. pharmaceutical lobby, Pharmaceutical Research and Manufacturers of America, said earlier Tuesday that New York-based Turing isn't part of the group and doesn't represent the values of its member companies. The organization's CEO, John Castellani, wrote in an e-mail that "we do not embrace either their recent actions or the conduct of their CEO."

Shkreli had defended the price increase for Daraprim, calling it a bargain even at the higher price in an interview Monday. Patients typically take the drug, which treats the parasite-caused disease toxoplasmosis, for at least several weeks, at what Shkreli said was about a $50,000 cost. Some may need it for longer.

Clinton responded to Shkreli's announcement Tuesday with a single-word tweet: "Good."