Decision Resources finds that the majority of U.S. and European physicians are wary of using a biosimilar for an indication for which supporting clinical data are lacking. According to new analysis, physician attitudes about indication extrapolation-where a biosimilar needs only to show similarity in a phase III study for one indication, and it will be granted approval for other indications for which the branded product is used-vary by country. French physicians are the most conservative when asked about indication extrapolation when compared to German and U.S. physicians.

Analysis from Biosimilars Advisory Service: Acceptance of Biosimilars Across Physician Specialties also finds that surveyed rheumatologists, nephrologists and gastroenterologists in particular say indication extrapolation should not be allowed or should be done carefully because of minute differences between the biosimilar and the branded product that may be clinically significant.

"It's not surprising to see that rheumatologists, nephrologists and gastroenterologists we surveyed are wary of indication extrapolation as these specialists have expressed a moderately conservative approach to biosimilars," said Decision Resources analyst Edward Wydysh, Ph.D. "To meet physician expectations, biosimilar manufacturers will most likely need to conduct clinical trials in several indications, which may be cost-prohibitive for a smaller company to enter the market. If a biosimilar manufacturer with fewer resources wants to compete with an original biologic in more indications, it should focus on therapeutic areas and drug classes that surveyed physicians find most acceptable for extrapolation, for instance granulocyte colony stimulating factors, or G-CSFs, in oncology."