Shares of Mylan fell Friday, slipping as much as 5 percent, after a Wells Fargo Securities analyst said he was worried about the pharmaceutical firm's pricing practices.
The stock ended the day down more than 2 percent.
In the last six months, Mylan raised prices more than 20 percent on 24 of its products, and more than 100 percent on seven products, according to Wells Fargo analyst David Maris, who cited Medi-Span pricing data for his statistics, in a research note to clients.
But Mylan spokeswoman Nina Devlin, in a written statement, called the analysis "flawed."
"Mylan has always been known to have one of the industry's broadest and most globally diversified business models and portfolios, which we have successfully managed by balancing numerous variables, including the natural price reductions that have always been inherent to the generics industry," Devlin said.
Devlin said the analysis focused on a small number of products out of the company's more than 1,400 products Mylan sells globally and the about 600 products it sells in North America, which she said was "self-serving and misleading to investors."
"This is especially true given that these generic products represent an extremely small percentage of Mylan's approximately $4 billion North American generics business," she said.
In the research note, Maris cited examples that included "a 542 percent increase for ursodiol, a generic medication used to treat gallstones, a 444 percent increase in metoclopramide, a generic medication commonly used to treat gastroesophageal reflux disease (GERD) and gastroparesis, and a 400 percent increase in dicyclomine, a medication used to treat irritable bowel syndrome. Mylan also raised the price of tolterodine by 56 percent in 2016."
The report also noted Mylan has not limited price increases to its smaller drugs either. In May, the company increased the price of Epi-Pen, its largest product, by 15 percent. The analyst noted the price increases could come at a cost to patients and impact their reputation to shareholders.
In the past year, Valeant, Turing and other pharmaceutical companies have faced scrutiny over their pricing actions, prompting senate hearings, proposed legislation and discussion in the presidential election cycle.
"We believe that given the regulatory environment, these pricing actions could bring greater regulatory scrutiny and headline risk," Maris wrote. "Additionally, we wonder if aggressive price increases are being used to make EPS targets or to offset disappointing sales in other areas."
But Mylan disagreed.
"Mylan's business model is not today, nor has it ever been, premised on price hikes," Devlin said.
Mylan's stock has dropped sharply this year, falling 17 percent.
MYL 2016 Chart
Disclosure: Wells Fargo maintains a market in the common stock of Mylan.
(UPDATE: This story was updated to include the company's comments.)