Industry perspective on regulatory authority (RA) quality reviews of biosimilar applications - an evaluation of RA guidance and expectations for chemical, manufacturing, and controls information through in-depth query analysis.

Purpose: Evaluate the type and quantity of quality information (i.e. Chemistry, Manufacturing, and Control) requested by the US FDA and EMA in queries pertaining to biosimilar applications.

Methods: Numbers/types of queries received following regulatory submissions (FDA/EMA, = 7/ = 5) for seven biosimilars (PF-filgrastim [Nivestym], PF-rituximab [Ruxience®], PF-trastuzumab [Trazimera®], PF-bevacizumab [Zirabev®], PF-pegfilgrastim [Nyvepria®], PF-adalimumab [Abrilada™/Amsparity®], PF-infliximab [Ixifi]) from a single product portfolio were analyzed considering published regulatory authority (RA) guidance and in relation to sections/subsections of Module 3: Quality from the Common Technical Document regulatory dossier and topics based on keyword assignment.

Results: Queries were most frequently assigned (FDA/EMA %, range) to Drug Substance Manufacture (subsection 3.2.S.2; 21-35%/13-50%), Control of Drug Substance (3.2.S.4; 3-11%/5-17%), Drug Product Pharmaceutical Development (3.2.P.2; 1-12%/1-15%) and Manufacture (3.2.P.3; 17-41%/2-13%), and Analytical Similarity (3.2.R; 4-21%/4-20%). The proportion of Drug Substance and Drug Product queries was significantly different between RAs (n1 = 952, n2 = 468, p-value <0.001; two-sample proportion z-test). Topic assignments included: Control (12-27%/12-28%), Manufacturing (56-72%/34-66%), Stability (1-12%/2-24%), Biosimilarity (5-16%/5-25%), and Container Closure (0-3%/0-9%).

Conclusion: The focus of both RAs on topics related to manufacturing and controls is valuable in understanding expectations for scientific and technical content related to gaining biosimilar approval.