The House of Representatives is expected to vote Tuesday on the bill, which would allow terminally ill people, or those who are likely to die prematurely, to have access to experimental medicines that the FDA has not approved.
Still, the stumble was an embarrassment for GOP leaders who pushed the bill at the behest of Mr. Trump.
The FDA's compassionate use program already approves experimental drugs for very sick patients, with a 99 percent approval rate for requests that it gets each year, Politico reported. Vice President Mike Pence also signed a "right to try" law when he was governor of Indiana.
The measure strikes a balance between safety and providing "hopeful news for patients desperately seeking the right way to try" experimental treatments, said Energy and Commerce Chairman Greg Walden of OR and Michael Burgess of Texas, another top panel Republican.
Democrats say the measure would achieve little since the federal Food and Drug Administration already approves almost all requests it receives for an existing program that lets patients use unproven treatments.
The House bill, which was released Saturday by House Energy and Commerce Committee Chairman Greg Walden, R-Ore., and Health Subcommittee Chairman Michael C. Burgess, R-Texas, is similar to legislation passed by the Senate in August.
CNBC's Cramer Says Colleague Larry Kudlow is Leader to Replace Cohn
He did, however, float the possibility of Cohn returning to the White House in a different capacity. Larry Kudlow worked at the Office of Budget and Management during the Reagan administration.
"The last thing I want to do is give patients false hope and to put them at risk" by reducing the FDA's powers, said Rep.
Holly Fernandez Lynch, a bioethics expert at the University of Pennsylvania, said the FDA acts as clearinghouse for useful information across companies, so cutting them out of the request process could be harmful.
The Pennsylvania legislature has given final approval to a bill that would allow hunters to use leashed dogs to track big game that has been legally harvested or wounded. The FDA would have to be notified of the decision and of any problems that occur.
But the agency would no longer have a supervisory role over people who use the bill's "alternative pathway" to obtaining the treatments through their doctors and drug companies. It has been working closely with lawmakers, she added, "to provide technical assistance as Congress works on this important issue to help ensure patients are also protected".
More than 70 patient and research groups sent a letter of opposition Monday to House leaders saying the bill "would not increase access to promising therapies" and "is still less safe" that the FDA's existing process. The right-to-try legislation does not compel pharmaceutical firms to provide sought-after therapies.