June 20 (Reuters) - The U.S. Food and Drug

Administration has proposed that biosimilar drugs seeking

agency's interchangeable designation will no longer need studies

showing the impact of switching between them and the branded

drug.

WHY IT'S IMPORTANT

The designation allows pharmacists to substitute branded

drugs with their close copies easily.

AbbVie's ( ABBV ) top-selling arthritis drug Humira has held

onto its share of more than 80% of patients even after facing

competition from nine lower-priced biosimilar rivals in the U.S.

in the last year.

That has raised questions about whether the market for

prescription biosimilars can survive in its current form, drug

pricing experts and analysts have said.

Regulatory reform is needed so patients can more easily

access biosimilars and draw rival drugmakers to develop them.

CONTEXT

The FDA has generally recommended switching studies to show

evidence of interchangeability of a biosimilar.

But recent studies showed no differences in the risk of

death, serious adverse events, and treatment discontinuations

between participants who switched between biosimilars and those

who did not.

The agency said analytical tools available today can

accurately evaluate the structure and effects of biologic

products with more precision than switching studies.

The agency will seek comments from the industry before

finalizing the proposed guidance.

BY THE NUMBERS

Out of the 13 approved interchangeable biosimilars in the

past, nine were approved without additional switching study

data, the FDA said.

KEY QUOTES

"Both biosimilars and interchangeable biosimilars meet the

same high standard of biosimilarity for FDA approval and both

are as safe and effective as the reference product," said Sarah

Yim, director of the Office of Therapeutic Biologics and

Biosimilars at the FDA.

(Reporting by Mariam Sunny and Bhanvi Satija in Bengaluru;

Editing by Anil D'Silva)