(CNN) Sen. Bernie Sanders sent a blistering letter to a pharmaceutical company on Monday, demanding answers about its decision to charge $375,000 for a formerly low-cost drug and calling it corporate greed at its worst.
"Catalyst's decision to set the annual list price at $375,000 is not only a blatant fleecing of American taxpayers, but is also an immoral exploitation of patients who need this medication," the independent senator from Vermont wrote. "Simply put, it is corporate greed.
"I am profoundly concerned that Catalyst's actions will cause patients to suffer or die."
Sanders sent the letter to Patrick McEnany, president and CEO of Calayst Pharmaceuticals, about the pricing of its drug Firdapse, which is used to treat a rare neuromuscular disease called Lambert-Eaton myasthenic syndrome, also known as LEMS.
Sanders asked the pharmaceutical company to describe the financial and non-financial factors that led to the decision to raise the price so dramatically.
"How many patients will suffer or die due to Catalyst's decision to set the list price at $375,000?" Sanders asked.
However, Sanders' letter also notes that the company has said many Firdapse patients will pay about $10 out of pocket each month, and he asked for more detail about that claim.
Sanders asked Catalyst to respond by February 18.
The company said in a statement Monday, "Catalyst's top priority is improving patient care in the LEMS community and potentially elsewhere within the neuromuscular community. We will respond to Senator Sanders' letter in a timely manner and provide information about Firdapse and the programs that we have in place to raise awareness of LEMS, facilitate accurate and timely diagnosis, and broaden affordable patient access to an FDA-approved treatment."
Patients had been able to get a version of the drug for free through a compassionate use program through the US Food and Drug Administration. In November, Catalyst acquired the North American license for Firdapse and then announced, in a December 13 phone call with investors, its intention to set the list price at $375,000, according to the letter.
"By setting such a high price and forcing production and distribution of the older, inexpensive version to cease, you are threatening access that patients had to a cheap version of this product, and handing a completely unwarranted bill to American taxpayers," Sanders wrote.
The letter comes at a time when Americans have grown wary of the increasing prices of pharmaceuticals, with President Trump and lawmakers on both sides of the aisle saying more needs to be done to curb skyrocketing prices.