FDA plan will cut testing requirements for biosimilars

The FDA has proposed a radical change to the regulatory requirements for bringing biosimilars to market, in a bid to accelerate the rollout of cheaper versions of off-patent biologic drugs.

Draft guidance from the US regulator would do away with the need for biosimilar developers to run comparative efficacy studies (CES) to prove their drugs work as well as the reference product.

At a press conference announcing the move, Health and Human Services (HHS) Secretary Robert Kennedy Jr said the new framework "reflects modern science and common sense," avoiding expensive trials when "advanced testing can already prove that biosimilars work just as effectively and just as safely as the original drug."

Kennedy suggested the requirement for CES is one reason why the US is lagging behind other parts of the world in the rollout of biosimilars, with only 76 approved for marketing by the FDA so far - less than half the number available in Europe, for example.

Other aspects of US regulation of biosimilars are also under scrutiny, including a plan to make it easier for developers to show interchangeability with the reference drug, meaning that the biosimilar can be substituted for the brand by a dispenser without the need for prescriber intervention.

Last year, the Biden administration published a proposal that would allow pharmacies to automatically substitute biosimilar drugs for the reference product, and the FDA issued guidance relaxing the need for 'switching' studies that are used to demonstrate interchangeability.

In a statement, the FDA said that biologic drugs made up only 5% of prescriptions in the US last year, but accounted for 51% of total drug spending. It also said that only about 10% of biologic drugs expected to lose patent protection in the next decade currently have a biosimilar in clinical development.

"Biosimilars are often far more affordable to patients and have the promise to significantly lower health care costs in America," said FDA Commissioner Marty Makary, who is expecting to finalise the new guidance within the next three to six months.

"By streamlining the biosimilar development process and helping advance interchangeability, we can achieve massive cost reductions," he added.

The guidance lays out the conditions for a CES to be unnecessary, for example if both the reference product and proposed biosimilar product are manufactured from clonal cell lines, are highly purified, and can be well-characterised analytically. The studies may still be required if comparative pharmacokinetic studies are not feasible or clinically relevant, it notes.