The FDA calls for a shortened approval process for Generic drugs. However, because of the enormously high number of applications that are submitted even years before the expiration of the drug’s original patent, it takes almost thrice as long as when FDA reviews new experimental drugs.
Currently, there are more than 2,400 generic drug applications that are pending FDA approval since many widely used drugs will soon foresee patent expiration.
Because generic drugs are as good as brand-name “innovator” drugs with respect to performance, intended use, strength, dosage form, route of administration, and quality, their safety and efficacy is not tested in animals and people.
As an alternative, the manufacturer must demonstrate that the performance of the generic drug is comparable to that of the original one in people by scientifically proving that identical amounts of active ingredients are released into the bloodstream in the same amount of time. This is frequently performed by administering the generic drug to a group of healthy volunteers and testing the drug levels over time by repeatedly drawing blood samples.
In addition to reviewing chemistry and sterility data of the proposed generic, the FDA staff also examines the detailed package insert information and inspects the manufacturing unit.
A generic can make an entry into the market only when the “innovator” drug’s patent has expired, as seen quite frequently, or when the generic company challenges and proves the invalidity of the patent in court. In such cases, the generic company winning the proceedings acquires an exclusive right to individually have only the generic drug in the market for a 6-months exclusive period. Subsequently, the generic versions can be marketed by other companies whose applications are approved by the FDA.
Acting director of FDA’s Office of Generic Drugs, Keith Webber, says that his office has been receiving around 850 annual applications and the number is expected to exceed 850 this year. Surprisingly, this is about 10 times the number of NDAs submitted.
He said that many applications are replicas of the same innovator drug or different dosage forms filed by various generic drugmakers. A few have been reviewed and returned to the applicant because of deficits.
Webber said: “We do prioritize the review of applications where there is no generic yet on the market. It’s extremely rare” for the original drug’s patent to expire and not have a generic approved in the interim.
The average approval time is around 30 months considering the typical back and forth between FDA reviewers and companies.
Webber said: “We’re working to shorten that, looking for efficiencies and additional resources. I hesitate to say we don’t have a problem, because we are short on staff.”
Similar to new prescription drugs, the FDA plans to levy a charge for reviewing applications for generic medicines, to help the agency employ and remunerate more staff.