In May, Gilead pledged to donate 2.4 million bottles of its HIV drug Truvada to the U.S. government’s effort to eradicate the disease, partly by preventing new infections. Gilead even promised it would donate its newer drug, Descovy, if the FDA approves it for prevention as it did for Truvada.

But now Gilead is facing accusations that its largesse may have suspicious underpinnings.

On Wednesday the House Oversight Committee’s chairman, Rep. Elijah E. Cummings (D-MD), and three colleagues sent a letter (PDF) to Gilead demanding details about what led to the company’s generous offer. Specifically, the committee wants to know if the Truvada donation involved negotiations between Gilead and the Department of Health and Human Services (HHS) over patents on the product.

A spokesperson for Gilead said in an email to FiercePharma that the company is "reviewing the full scope of the request and will respond to the committee in a timely manner."

Gilead has been under fire from the House Oversight Committee since May, when new CEO Daniel O’Day was called before Congress to be grilled about Truvada’s use in HIV prevention, known as PrEP. Much of the four-hour discussion focused on cost.

One expert who testified during the sometimes-contentious hearing said that Truvada is available in Australia for $8 per month but that it costs $1,780 per month in the U.S. Hence only 10% of people who could benefit by using the drug for HIV prevention are receiving it, the committee concluded.

Now, Cummings is focused on determining whether there’s a link between Gilead’s deal with the U.S. government to provide Truvada for PrEP and its efforts to protect the patents on the product—and by extension its ability to push through price hikes on it. 

Wednesday's letter came close on the heels of a June 17 letter (PDF) Cummings and a colleague sent to the Government Accountability Office (GAO) expressing concerns that Gilead may be infringing on patents owned by the U.S. government that are relevant to the use of Truvada in PrEP. The letter requested that the GAO conduct a review of how HHS detects and prevents the infringement of patents owned by the government "to ensure that any private enterprises that make use of government-owned intellectual property properly compensate the government."

In the letter sent to Gilead yesterday, Cummings noted that patents owned by the government based on early discovery work on Truvada had been deemed "not valid" by Gilead. "We would like to understand whether these patents played any role in negotiations between the company and [HHS] and whether Gilead has otherwise engaged in negotiations with the U.S. government regarding these patents," the letter states.

Gilead was asked to provide copies of all documents and communications between the company and the federal government regarding the donation of Truvada or Descovy for PrEP. The representatives also requested details about the cost of goods sold for the products for each year going back to 2004, as well as documents related to nine price increases for Truvada since 2012.

The U.S. reps are far from alone in their concern about Gilead’s behavior as it relates to HIV treatments. In May, a federal judge waved through a lawsuit filed by 140 patients in 31 states that alleges Gilead protected Truvada and several other of its older HIV drugs by shelving the development of safer alternatives. The patients allege they suffered kidney and bone problems as a result of not being able to access safer alternatives.

A separate lawsuit, also filed in May, alleges Gilead worked with Bristol-Myers Squibb, Johnson & Johnson and Japan Tobacco to stifle generic competition on its older HIV drugs. That lawsuit was filed by HIV and AIDS activists.

Meanwhile, Gilead acknowledged that it will face Truvada generics in 2020—a year earlier than expected—a disclosure that came just one day before it agreed to donate those millions of bottles of Truvada to the government’s PrEP push.

Was it a coincidence, or did Gilead strike a deal with HHS that’s somehow tied to government-owned patents on Truvada? Cummings and his colleagues are hoping the reams of documents they’ve requested from Gilead will help answer that question and more.