A former U.S. hedge fund manager is defending a recent decision to raise the price of a drug used to treat deadly parasitic infections in pregnant mothers, people with AIDS and cancer patients from US$13.50 a pill to US$750 a pill.

Martin Shkreli, founder and CEO of Turing Pharmaceuticals, recently purchased the U.S. rights to Daraprim, which was developed in 1953 and is one of the main drugs used to treat toxoplasmosis.

The Infections Diseases Society of America raised the alarm about the company’s 5,000-per-cent price increase in an open letter sent to Turing earlier this month.

The group of prominent doctors wrote that there is “no justification for an increase of this magnitude” and warned of “severe consequences” for patients.

Shkreli went on U.S. television on Monday and argued that the much higher price is reasonable. The interview was later posted to Turing’s website, along with a written statement.

Shrklei told the TV interviewer that a course of treatment for toxoplasmosis is about 100 pills, so at $13.50 a pill, “the price to save your life was only $1,000.”

“Cancer drugs can cost $100,000 or more,” Shkreli added. “Daraprim is still underpriced relative to its peers.”

At the new price, 100 pills would cost about $75,000.

Turing’s online statement says “our number one concern is ensuring that patients with toxoplasmosis have efficient and affordable access to Daraprim.”

It goes on to say that “the status quo” for toxoplasmosis “is not an option,” and that, “Turing hopes to change that by targeting investments that both improve on the current formulation and seek to develop new therapeutics with better clinical profiles.”

The company also said it offers the medication free of charge to “qualified, uninsured patients” and that it will “will work with any patient, hospital, clinic and financial institution – on a case-by-case basis – to help secure access to Daraprim.”

Shkreli also took to Twitter to address the controversy, where promised better access to and lower prices for the drug.