Generic drugs go through what the Food and Drug
Administration calls an abbreviated approval process.
But it takes three times as long as FDA reviews of new
experimental drugs because of the sheer volume of applications, many of which
are submitted years before the original drug’s patent will expire.
Because so many widely used drugs are approaching the end of
their patents, there are now more than 2,400 generic drug applications awaiting
FDA approval.
Generic drugs are comparable to brand-name
“innovator” drugs in performance, intended use, strength, dosage
form, route of administration and quality. Because of that, their effectiveness
and safety aren’t tested in animals and people.
Instead, the manufacturer must prove scientifically that a
generic drug performs the same as the original one in people, meaning the same
amount of active ingredients enters the bloodstream in the same amount of time.
Often, that’s done by giving a few dozen healthy volunteers the generic drug,
then taking repeated blood samples to test the level of the drug over time.
FDA staff also review chemistry and sterility data on the
proposed generic, plus information that would go on the detailed package
insert, and inspect the factory where it would be made.
Generics cannot come to market unless the
“innovator” drug’s patent has expired or, as happens increasingly, a
generic company challenges the patent in court and proves it is in some way
invalid. In those cases, the generic company winning the lawsuit gets to have
the sole generic drug on the market for a six-month exclusivity period. After
that, other companies whose applications are approved by the FDA can market
their own generic versions.
Keith Webber, acting director of FDA’s Office of Generic
Drugs, says his office has been getting about 850 applications a year — about
10 times the number of new drug applications submitted — and expects to top 850
this year.
Many are duplicates of the same innovator drug filed by
different generic drugmakers, or different dosage forms. Some have been
reviewed and sent back to the applicant because of deficiencies, he said.
“We do prioritize the review of applications where
there is no generic yet on the market,” Webber said. “It’s extremely
rare” to not have a generic approved by the time the original drug’s
patent expires.
Given the usual back and forth between FDA reviewers and
companies, average approval time is 30 months.
“We’re working to shorten that, looking for
efficiencies and additional resources,” Webber said. “I hesitate to
say we don’t have a problem, because we are short on staff.”
For that reason, the FDA is planning to charge fees for
reviewing applications for generic medicines, as it does for new prescription
drugs, to help pay for more staff.
