By Deena Beasley

(Reuters) - Shares of Valeant Pharmaceuticals International Inc fell on Thursday after the campaign of Democratic presidential contender Hillary Clinton posted a blog from an Iowa event detailing exorbitant price hikes for a migraine drug made by the company.

At an Iowa town hall over the weekend, Clinton read from a letter saying that the list price for 10 vials of migraine drug D.H.E. 45 had increased to more than $14,000 in December, compared with just over $3,000 in June of 2014.

"This is predatory pricing. It is unjustified. It is wrong," Clinton said, according to the post.

Officials at Valeant did not immediately respond to requests for comment.

Shares of Valeant fell nearly 9 percent to close at $86.12 on the New York Stock Exchange. More than 3 million shares of Valeant traded in the last hour of trading; total volume on the day was 7.9 mln shares.

Valeant, based in Canada, has been under pressure since last year as cracks appeared in its business model of acquiring older drugs, steeply increasing their U.S. price, and using aggressive methods to overcome insurer barriers to reimbursing its medicines.

D.H.E. 45, or dihydroergotamine, is a generic, injectable analgesic.

Clinton, fellow Democratic candidate Bernie Sanders, and Republican presidential front-runner Donald Trump have hammered away at drug costs in recent months, raising investor concerns that future price cuts could hurt pharmaceutical and biotech companies.

"I'm going after them. We are going to stop this," Clinton said at the Iowa town hall.

Trump said earlier this week that Medicare, the government-run healthcare plan for the elderly, could reap huge savings by negotiating with drugmakers on price. Medicare by law cannot directly negotiate drug prices.

A U.S. congressional committee last week subpoenaed former Turing Pharmaceuticals Chief Executive Officer Martin Shkreli to testify at a hearing about that company's decision last year to raise by 5,000 percent the price of a decades-old treatment for a rare, but dangerous, parasitic infection.

(Reporting By Deena Beasley; Editing by Tom Brown and Grant McCool)

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