The CBO initially projected that the provision, known as the ORPHAN Cures Act, would cost around $5 billion over the next decade. But the office said Monday that its earlier assessment did not take into account several major, high-priced drugs that will be exempted from Medicare price negotiations as a result of the Trump-GOP law.

Among the drugs included in the new CBO analysis is Keytruda, a cancer medication sold by Merck that carries a list price of $24,062 every six weeks. The Trump GOP-budget law delays Keytruda’s eligibility for Medicare price negotiations by at least a year, postponing significant potential savings for taxpayers and patients.

Merith Basey, executive director of Patients for Affordable Drugs Now, said in response to the updated CBO analysis that “the ORPHAN Cures Act is a wildly expensive handout to Big Pharma that will harm patients, drain taxpayer dollars, and weaken the government’s ability to rein in high drug prices.”