• Truvada’s $2,000 monthly cost criticized by AIDS activists
• Letter comes month after CEO O’Day appeared before House panel

House Democrats sent a letter to Gilead Sciences Inc. seeking documents on pricing and patents for its HIV drug Truvada, whose high cost has drawn the ire of lawmakers and AIDS activists.

The letter from the Committee on Oversight and Reform comes over a month after Gilead Chief Executive Officer Daniel O’Day went before the committee and defended the company’s roughly $2,000 monthly price tag for Truvada, which is used for pre-exposure prophylaxis, or PrEP. A generic version of the treatment can be bought for as little as $210 a month in other countries, the committee said.

Among the information being sought are communications with any federal agency about donations of Truvada and another drug, Descovy, to the U.S. government; any communications with federal agencies about patents related to Truvada; how much it costs to make Truvada and Descovy; and documents regarding Truvada price increases since 2012. The committee set a deadline of late July for Gilead to respond.

“The Committee is seeking to understand if the company’s price increases for Truvada were made with innovations in mind,” lawmakers said in the letter, which was signed by Chairman Elijah Cummings, Alexandria Ocasio-Cortez, Ro Khanna and Ayanna Pressley, all Democrats.

Gilead didn’t immediately respond to a request for comment.

Truvada accounted for $3 billion in revenue for Gilead last year, and the price has risen 50% since it was approved for prevention in 2012, according to data compiled by Bloomberg Intelligence.

In the May 16 hearing, O’Day said that if Gilead had lowered the price of its medicine even a decade ago, “we wouldn’t be sitting here today with the innovations that are changing the face of HIV/AIDS.”

Read more: Gilead’s $21,000 Drug gets blame for plateau in HIV prevention

While Gilead said it spent $1.1 billion to develop the drug, which was first approved for patients with HIV in 2004, the U.S. Centers for Disease Control and Prevention did early experiments that contributed to its creation. The federal government also received patents for the use of the compounds in Truvada, but O’Day said the CDC’s patents are invalid.

AIDS activists say the U.S. government should leverage patents held by CDC to push down the price, perhaps by seeking royalties from Gilead.

O’Day said at the hearing that the company is working to make the drug more accessible, donating free drugs for uninsured patients and providing assistance to patients who struggle to afford the copay. He said those steps ensure that “price doesn’t get in the way during this period of time of patent exclusivity.”