Pfizer, Genentech Warn Against Requiring ‘Impractical’ Switching Studies for Biosimilar Interchangeability
Some of the FDA’s draft guidance on biosimilar interchangeability is impractical, according to Pfizer and Genentech.
In a draft guidance published in January, the agency said sponsors looking to demonstrate interchangeability should plan a switching study using a U.S.-licensed comparator to assess clinical pharmacokinetics and pharmacodynamics. Switching studies evaluate the effects of alternating treatment between a biosimilar and its reference product.
Given the anticipated size and duration of switching studies involving more than 200 patients, recruitment would be difficult if the company is required to complete the study solely in the U.S. using a U.S.-licensed product, Pfizer said.
Genentech said switching studies may become impractical to design with the advent of multiple biosimilars being approved for the same reference product — as happened recently with the FDA’s approval of Samsung Bioepis’ Renflexis, the second approved biosimilar of Janssen’s Remicade.