The US Food and Drug Administration has roughly five weeks of funding left to review new drug applications during the shutdown, commissioner Dr. Scott Gottlieb said Monday on Twitter.
Experts say this could have a ripple effect, bogging down the approval and manufacture of new drugs, delaying patients from getting these treatments and adding to a host of other crucial FDA actions and oversight that have taken a hit during the shutdown.
The partial government shutdown began on December 22 after Congress and the White House failed to reach a spending deal. On January 12, it became the longest government shutdown in US history.
In order to keep reviewing applications for the next five weeks, Gottlieb said the agency has stretched its remaining funds, which came from user fees paid by drug companies before the shutdown. The FDA is not allowed to accept new fees or applications until the shutdown is over.
"We're shifting operating dollars to payroll dollars in order to maximize our runway and preserve program functions," Gottlieb said.
This does not include blood and allergy-related products which are not covered by a user fee program, "so routine review activity ceased related to new products in these categories," Gottlieb also said . For medical devices, the FDA has about three months on the clock, though "we're still working through the final numbers," he said .
"There are lots of innovative new compounds in the pipeline now that may be delayed," said Kenneth Kaitin, director of the Tufts Center for the Study of Drug Development , which works with pharmaceutical companies, academic institutions, nonprofits and government entities to assess the impact of regulations and policies on the drug development process.
"In a very grim view of this, there are lives that are going to be lost because patients won't get access to these drugs," he said.
Kaitin described a domino effect that could result from delays in new drug approvals: It could disrupt companies' plans to scale up production and launch new drugs. Investors might grow hesitant to put their dollars behind these drugs. Shifting resources could curb research on other pharmaceuticals. And this impact will likely be greatest on smaller companies with only one or two drugs in the pipeline, whose products have earned a growing share of FDA approvals in recent years, he added.
"You have to plan these activities in advance because you don't just suddenly have a building that's making drugs," said Kaitin, also a professor at Tufts University School of Medicine.
"When this shutdown ever ends, there's going to be, I think, a formidable backlog of applications that's going to slow everything down to a crawl for a while," Kaitin added. "The inability to get new drugs to the marketplace is a very significant issue for the public -- and for public health."
Drug applications take months to review. For a completed drug application with priority review , the FDA typically plans to take action within six months. Under standard review, it's 10 months.
During these reviews , experts review the science behind the drug. Routine inspections are performed on clinical trial sites to check for any evidence of false or manipulated data. Once a drug is deemed safe and effective, the agency must work with companies to fine tune the product's labeling and prescribing information.
If any drugs get approved during the shutdown, Kaitin said, they'll likely be limited to those nearing the very end of the process.
"It's not very hard to do the math and realize five weeks is going to get you very little," he said.
Pharmaceutical industry group PhRMA declined CNN's request for comment.
Some of the drugs impacted will be generics, according to Gottlieb. In 2018, the agency granted full or tentative approval to more than 1,000 generic drugs, he said .
"Our generics and biosimilars programs will however be impacted should the lapse in funding continue," said Gottlieb. "We continue to operate the programs using carryover user fees, and we'll prioritize work that impacts public safety, as this is our foremost priority."
The FDA's review of drug applications is just one of the agency's many vital capacities affected by the shutdown, according to Dr. Joshua Sharfstein, a former FDA principal deputy commissioner.
"The fact that there are people still reviewing applications is not reflective of the sweep of activities that the agency is usually working on," said Sharfstein, a professor at the Johns Hopkins Bloomberg School of Public Health. "The FDA does so many more things that affect clinical medicine."
For example, the agency monitors drugs currently on the market, puts out safety communications and talks with professional societies to make sure drugs are used in the best possible way, Sharfstein said.
"If it takes the FDA an extra month to figure out that there was a major safety problem, well then that's an extra month of a safety problem people had to endure," Sharfstein said.
"How many scientists have missed meetings where they might have learned something that could really have influenced the development of products five or 10 years from now?" he added.
When it comes to evaluating new drugs, the FDA must answer "really critical questions" about how it defines what makes a drug safe and effective, Sharfstein said.
"Even as they're applying those standards to a completed application, they're also coming up with the standards for the products of the future."
The FDA has continued some of its vital operations with a pared-down staff, some working without pay -- including overseeing food recalls, monitoring for and responding to outbreaks, and investigating consumer safety concerns. But it's hardly business as usual, agency employees told CNN last week.
"If someone calls and says they've had a bad reaction to a drug, we can't analyze it," said furloughed FDA employee Cheryl Monroe, who works at a lab in Detroit that tests pharmaceuticals. With only a couple people left in her part of the lab, she said there is limited routine analysis of drugs that are already on the market.
Sharfstein said the FDA "is going to extraordinary lengths to try to minimize the [shutdown's] impact on public health," but it's no substitute for a fully functional agency.
"The agency does important work, and it's really essential that people get back to work to be able to do it."