On May 11th, ASBM submitted comments on the FDA’s recently released draft guidance and Q&As aimed at “streamlining” biosimilar development by permitting the use of data from non-U.S.-licensed comparator products and foreign clinical studies in the U.S. biosimilar approval process. While efficiency is important, ASBM is concerned that these changes may lower evidentiary standards in ways that risk undermining physician and patient confidence in biosimilars.
Biosimilars are safe and effective—but they are not generics. Reducing the role of clinical and pharmacokinetic data too aggressively, while promoting a simplified regulatory approach, risks blurring the scientific distinctions that underpin the biosimilar pathway. ASBM believes that the FDA maintaining a science-based, case-by-case approach is essential to preserving trust in biosimilars and ensuring patient safety.
From ASBM’s comments:
The FDA’s proposed approach to biosimilar approval stands in stark contrast to the rigor traditionally expected of innovator medicines, which must independently demonstrate safety and effectiveness through substantial evidence, generally grounded in well-controlled clinical investigations. For example, in Q.I.8.a, lines 164–168, the draft permits “analytical differences identified in product quality attributes between the non-U.S.-licensed comparator product used in the clinical study and the U.S.-licensed reference product included in the applicant’s comparative analytical assessment,” so long as the sponsor provides “an adequate scientific rationale” for those differences. This language could be read to suggest that if a biosimilar manufacturer offers a plausible explanation for detected quality differences, that rationale may be accepted without requirement to demonstrate its basis in fact. This raises an alarming possibility, as physicians and patients expect confidence in the quality of FDA-approved medicines, not merely adequate or plausible explanations – particularly when those medicines are complex biologics used by patients with serious and chronic conditions.
Maintaining physician and patient confidence in third-party biosimilar substitutions is critical, as biologic treatment is highly individualized and often involves patients with chronic, complex conditions. In ASBM’s national physician surveys[1], 89% of prescribers expressed high confidence in the safety and effectiveness of biosimilars[2], and 88% of U.S. physicians supported maintaining the FDA’s case-by-case approach to interchangeability, but only 11% favored treating all biosimilars as interchangeable by default.[3] This suggests that the FDA’s rigorous, evidence-based framework has been effective at building confidence in biosimilars among physicians, but that confidence could be undermined if biosimilars are treated more like generics without proper, individual evaluation.
[1] http://www.safebiologics.org/surveys
[2] https://safebiologics.org/wp-content/uploads/2023/08/ASBM-2021-US-Biologics-Prescribers-Survey-Specialty-Data.pdf
[3] https://safebiologics.org/wp-content/uploads/2024/09/ASBM-US-Physician-Survey-IC-Biosims.pdf
Read ASBM’s full comments below:
Read the FDA announcement about the new Guidance and Q&As.
