SUMMARY

• Please refer to the TREMFYA Prescribing Information for relevant information regarding immunogenicity with TREMFYA. Summarized in this response are relevant data on immunogenicity from the QUASAR and GALAXI/GRAVITI clinical programs in adult patients with moderately to severely active ulcerative colitis (UC) or Crohn’s disease (CD), respectively.¹

Clinical Data

Ulcerative colitis

QUASAR Studies

The safety and efficacy of TREMFYA in adult patients with moderately to severely active UC was evaluated through two phase 3 clinical studies, including a 12-week induction study and a 44-week maintenance study.

• Up to week 56, 11% (n=48) of patients treated with TREMFYA at the recommended dosage developed antidrug antibodies.¹
• Of these patients who tested positive for anti-guselkumab antibodies and were evaluable for neutralizing antibodies, 16% (n=6) had antibodies that were classified as neutralizing antibodies.¹
• Most of the patients who were positive for antibodies to guselkumab had low titers. Two patients with the highest antibody titers exhibited low trough levels of guselkumab.¹
• There was no identified clinically significant effect of antidrug antibodies on injection site reactions, or effectiveness of guselkumab, over the treatment duration of 56 weeks.¹

Crohn’s Disease

The safety and efficacy of TREMFYA in adult patients with moderately to severely active CD was evaluated through two randomized, double-blind clinical trial programs (GALAXI and GRAVITI) for a total duration of up to 48 weeks.

GALAXI and GRAVITI Clinical Programs

• Up to Week 48 in the GALAXI program; 5% (30/634) of patients treated with TREMFYA at the recommended dosage developed antidrug antibodies.¹ 
• Of these patients who tested positive for anti-guselkumab antibodies and were evaluable for neutralizing antibodies, 5% (1/22) had antibodies that were classified as neutralizing antibodies.¹ 
• Up to Week 48 in the GRAVITI program; 9% (24/273) of patients treated with TREMFYA at the recommended dosage developed antidrug antibodies.¹ 
• Of these patients who tested positive for anti-guselkumab antibodies and were evaluable for neutralizing antibodies, none had antibodies that were classified as neutralizing antibodies.¹ 
• Most of the patients who were positive for antibodies to guselkumab had low titers.¹ 
• There was no identified clinically significant effects of antidrug antibodies on pharmacokinetics, injection site reactions, or effectiveness of guselkumab, over the treatment duration of 48 weeks.¹ 

Literature Search

A literature search of MEDLINE^®, EMBASE^®, BIOSIS Previews^®, and DERWENT^® (and/or other resources, including internal/external databases) was conducted on 9 April 2025.