Rachel Sachs, an associate law professor at Washington University in St. Louis and expert in innovation policy, said the government had every right to seek price concessions. She noted that the government, through Medicare and Medicaid, was effectively buying its inventions back from itself. “The public is paying for the research and to the extent that many people, if not most, will pay through public insurance, we’re paying again,” she said.

Hillary Clinton, in her campaign for president, promised to set new rules for federal support of research so that Americans “get the value they deserve” for the money taxpayers spend in supporting research. It is not clear how President-elect Donald J. Trump will approach these issues; he has said he favors reducing health care costs, but Republicans, who control Congress, too, have opposed a government role in price setting.

One mechanism to control pricing already exists. It is called march-in rights, and it lets the N.I.H. take back control of a patent on an invention made with federal funding if the drug is not being made available to the public on reasonable terms. The tool has gone unused.

Earlier this year, Knowledge Ecology International and another advocacy group, the Union for Affordable Cancer Treatment, petitioned the agency to exercise march-in rights on Xtandi, a prostate cancer drug that was developed by federally funded researchers at U.C.L.A. It said the price in the United States of about $129,000 a year, two to four times that in other developed countries, meant the drug was not reasonably available. The effort was supported by other public interest groups and some Democratic members of Congress.

U.C.L.A. made more than $500 million by selling its royalty rights to the drug. But the N.I.H. declined to exercise its march-in rights on Xtandi, arguing that it was not qualified to judge whether a drug’s price is reasonable and that a high price does not mean a drug is not being made available to the public.

“N.I.H. has made it clear that its job is not to decide prices of drugs, period,” Dr. Rohrbaugh said

Kite says it has not decided what to charge for KTE-C19, but Dr. Belldegrun hinted that Kite’s therapy might be relatively expensive because ideally it would be a single treatment that would cure the patient, not a drug that would have to be taken continuously. He added that Kite would take steps to make sure that everyone who needed the drug could get it.