Four Rituximabs, One Name: A Biosimilar Deep-Dive

About this webinar

Same skin. Different fruit.

That's the position a biosimilar developer is in the day a regulator asks them to prove their molecule is "highly similar" to a reference product — because "highly similar" is a legal phrase that only means something if you have instruments sharp enough to see what different actually looks like. And for a monoclonal antibody, different rarely shows up in the sequence. It shows up in the decorations.

Youngseo Na and the Schwendeman Lab at the University of Michigan — in collaboration with MS Bioworks — just published a study that puts that idea on the bench. Biosimilar comparability is almost always done pairwise: one proposed biosimilar measured against its reference product, one regulatory decision at a time. The Michigan team ran a different experiment. They took Rituxan and all three FDA-approved rituximab biosimilars — Truxima, Ruxience, and Riabni — three lots of each — and pushed every sample through three orthogonal Byos workflows on the same platform: native intact mass, released glycan HILIC-FLR, and LC-MS/MS peptide mapping. Three independent measurements of the same set of molecules, cross-checked against each other. What came back reframes where biosimilar variation actually lives — and how characterization data should be shaped to see it.

What you'll learn in this webinar:

• Where biosimilar variation actually lives.Why the largest glycoform and afucosylation differences in this four-product set surfaced between biosimilars — not between biosimilar and reference — and what that means for the way comparability is usually reported.
• How to build orthogonal confidence into a PTM characterization package.How the Michigan team used three independent Byos workflows — intact MS, released glycan, and peptide mapping — with three independent quantification strategies, so every finding could be corroborated module to module before it was called.
• How glycan microheterogeneity maps onto ADCC potency.The direct, measurable relationship between total afucosylated glycan content and in-vitro ADCC activity across the four products — and why that link makes glycan profiling a load-bearing piece of any biosimilar characterization story.