Background/Purpose: Nipocalimab is a human IgG1 monoclonal antibody targeting the neonatal Fc receptor (FcRn) that selectively reduces IgG levels without impacting antigen presentation, T- and B-cell functions. This study investigated the effect of nipocalimab on IgG response to T-cell–dependent/independent vaccines (tetanus, diphtheria, pertussis vaccine [Tdap]; pneumococcal polysaccharide vaccine [PPSV^®23], respectively) in healthy participants.

Methods: This open-label, parallel, interventional study randomized participants 1:1 to receive intravenous 30 mg/kg nipocalimab at Week (Wk) 0 and 15 mg/kg at Wk2 and Wk4 (active) or no drug (control). On Day 3, participants received Tdap and PPSV^®23 vaccinations and were followed through Wk16. The primary endpoint was the percentage of participants with a positive anti-tetanus IgG response (2-fold increase from baseline) at Wk4.

Results: Twenty-nine participants completed the study and were included in this analysis (active, n=15; control, n=14). The percentage of participants with a positive anti-tetanus IgG response was comparable between groups at Wk2 and Wk16, but lower in the nipocalimab versus control group at Wk4 (3/15 [20%] vs 7/14 [50%]; P=0.089). All participants maintained anti-tetanus IgG above the protective threshold (0.16 IU/mL) through Wk16. While anti-pneumococcal-capsular-polysaccharide (PCP) IgG levels were lower during nipocalimab treatment, the percent increase from baseline at Wk2 and Wk16 was comparable between groups. Post-vaccination, anti-PCP IgG remained above 50 mg/L and showed a 2-fold increase from baseline throughout the study in both groups. Nipocalimab co-administration with Tdap and PPSV^®23 was safe and well-tolerated. 

Conclusion: These findings suggest that nipocalimab does not impact the development of an adequate IgG response to T-cell–dependent/independent vaccines and that nipocalimab-treated patients can follow recommended vaccination schedules.

ACR Meeting Abstracts - https://acrabstracts.org/abstract/a-randomized-open-label-study-on-the-effect-of-nipocalimab-on-vaccine-responses-in-healthy-participants/