Biointron x KACTUS Webinar: Precision Antibody Engineering

Biointron’s latest Lunch & Learn, held at CIC Cambridge on May 8, 2026, featured expert presentations from SeromYx Systems and Visterra on two critical areas of antibody and biologic development: Fc-effector function profiling and cell-based neutralizing antibody (NAB) assay design.

This session highlighted how early, mechanism-informed testing can help developers better understand therapeutic function, reduce development risk, and support safer, more effective biologic candidates.

Featured Talks:

Comprehensive Fc-Effector Function Profiling of Approved Anti-CD20 mAbs and Anti-HER2 ADCs

Shashi Jatiani, PhD
Director of Strategic Partnerships, SeromYx Systems

Dr. Jatiani discussed the importance of measuring Fc-mediated antibody functions early and comprehensively, especially as antibody formats become more complex. His talk covered how Fc interactions with Fc receptors, FcRn, and complement proteins can influence efficacy, pharmacokinetics, and safety. Case studies included approved anti-CD20 antibodies, HER2-targeting ADCs, and Fc-modified antibodies designed to direct CAR-T cells.

Key topics included:

• Why Fc biology is difficult to predict and should be tested empirically

• How antigen-specific Fc profiling can correlate with ADCC, ADCP, ADCD, CDC, and other functional outcomes

• How ADC conjugation chemistry, payload properties, and drug-to-antibody ratio can affect Fc-mediated biology

• How Fc profiling can support safer design of complex antibody formats and CAR-T directing antibodies

Critical Decisions for the Design of a Cell-Based NAB Assay: The Story of VIS171

Lee Andrews
Associate Director of Bioanalytical Development, Visterra

Lee Andrews presented a practical case study on designing a cell-based neutralizing antibody assay for VIS171, a fusion protein containing a human IgG Fc domain and two tethered human IL-2 mutein domains. The presentation focused on how assay design decisions should reflect the molecule’s mechanism of action, immunogenicity risks, and clinical relevance.

Key topics included:

• Why immunogenicity and NAB assessment are essential for biologic development

• How a cell-based reporter assay can detect neutralizing antibodies against VIS171

• Why intact VIS171 was selected as the assay agonist over recombinant human IL-2

• How surrogate positive control selection affects assay performance and reagent continuity

• Why clinically meaningful assay data matters beyond simply meeting guidance

Watch the recording now >>