Introduction
The phase 2b GALAXI 1 and phase 3 GALAXI 2&3 studies evaluated guselkumab (GUS), a dual-acting IL-23p19 subunit inhibitor, in participants (pts) with moderately to severely active CD.1 Pts treated with ustekinumab (UST) who met inadequate response criteria during the long-term extension (LTE) could cross over to GUS 200 mg SC q4w. Here, we present efficacy and safety results in pts who received GUS after experiencing an inadequate response to UST in the pooled GALAXI LTE.
Aims & Methods
Individuals with prior inadequate response or intolerance to UST were excluded from GALAXI; however, during the LTE, pts treated with UST 90 mg SC q8w who met inadequate treatment response criteria (not in clinical response [≥100-point reduction in CDAI score from baseline or CDAI<150] and CDAI ≥220) between Wks 52-80 of LTE were eligible for a treatment switch to GUS 200 mg SC q4w, without IV induction. Clinical response and clinical remission (CDAI<150) were both assessed 16 weeks after treatment switch. Endoscopic response (≥50% improvement from baseline SES-CD or SES-CD≤2) and endoscopic remission (SES-CD≤4 and ≥2-point reduction from baseline and no subscore >1 in any individual component) were assessed at Wk 96. Safety was assessed through Wk 96.
Results
In total, 80 pts treated with UST underwent treatment switch to GUS 200 mg SC q4w maintenance therapy due to meeting inadequate treatment response criteria between Wks 52-80 of the LTE. Of these 80 pts, 75 were included in the efficacy analyses (baseline mean age, 35.2yrs; male, 64.0%; mean CD disease duration, 8.21yrs; mean CDAI, 291.5; mean SES-CD, 12.8; history of inadequate response/intolerance to biologics [BIO-IR], 60.0%).
The proportions of pts achieving clinical response and clinical remission 16 weeks after treatment switch from UST to GUS 200 mg SC q4w were 61.3% and 52.0%, respectively. These results were comparable to the proportions of pts treated with GUS 200 mg IV q4w induction in the BIO-IR subgroup of the total LTE population who achieved clinical response and clinical remission at Wk 12 (61.7% and 46.7%, respectively).
The proportions of pts achieving endoscopic response and endoscopic remission at Wk 96 (ie, ~1 year after treatment switch from UST to GUS 200 mg SC q4w) were 49.3% and 30.7%, respectively. These results were similar to the proportions of pts in the BIO-IR subgroup receiving GUS 200 mg SC q4w maintenance who achieved endoscopic response and endoscopic remission at Wk 48 (57.2% and 35.5%, respectively).
Safety results are summarized in the Table.
Table. Safety Summary From Treatment Switch Through Week 96
| Ustekinumab 90 mg SC q8w → Guselkumab 200 mg SC q4wa
|
N
| 80
|
Average duration of follow-up, weeks
| 34.8
|
Average exposure, number of administrations
| 8.4
|
Participants with 1 or more:
AEs, n (%)
SAEs, n (%)
AEs leading to DC of study agent, n (%)
Serious infections,b n (%)
Malignancies, n (%)
Injection site reaction, n (%)
|
50 (62.5%)
6 (7.5%)
2 (2.5%)
0
1 (1.3%)
5 (6.3%)
|
AE= adverse event; DC= discontinuation; SAE= serious adverse event; SC= subcutaneous.
a Participants who were randomized to ustekinumab at Week 0 or who switched from placebo to ustekinumab at Week 12 and continued SC maintenance dosing of ustekinumab in the maintenance period and switched to guselkumab 200 mg SC q4w dosing during the long-term extension.
b Infections are based on MedDRA system organ class “Infections and Infestations”.
Note: Participants are counted only once for any given event, regardless of the number of times they actually experienced the event. |
Conclusion
Among pts who experienced inadequate response to UST in the LTE, more than half achieved clinical remission 16 weeks after treatment switch to GUS 200 mg SC q4w, and approximately 50% were in endoscopic response ~1 year after treatment switch. These data suggest pts with an inadequate treatment response to UST may benefit from GUS treatment. Results should be interpreted considering that pts received GUS SC maintenance therapy directly without IV induction. Key safety event rates were consistent with the known safety profile of GUS in approved indications.
References
1) Sachen K, Hammaker D, Sarabia I, et al. Frontiers in Immunology. 2025; doi:10.3389/fimmu.2025.1532852.
Disclosure
AA reports potential conflicts of interest with AbbVie, Bristol Myers Squibb/Celgene, DiaSorin, Eli Lilly, Gilead, IBD Horizons, Janssen, Pfizer, Takeda, and TLL Pharmaceuticals
DW reports consulting fees from AbbVie, Bristol Myers Squibb, Janssen, Lilly, Pfizer, Takeda
RL reports having received advisory board fees from AbbVie, Aspen, BMS, Celgene, Celltrion, Chiesi, Ferring, Glutagen, Hospira, Janssen, Lilly, MSD, Novartis, Pfizer, Prometheus Biosciences, and Takeda; received research grants from Celltrion, Shire, Janssen, Takeda, Joanna Tiddy grant from University of Sydney, McCusker Charitable Trust, Gastroenterological Society of Australia, NHMRC, Gutsy Group, and Pfizer
RVR, WvD, and CB are employees of Johnson & Johnson and own company stock/stock options.
TH received grant support from Mitsubishi Tanabe Pharma Corporation, EA pharma Co. Ltd., AbbVie GK, JIMRO Co. Ltd., Zeria Pharmaceutical Co. Ltd., Kyorin Pharmaceutical Co. Ltd., Nippon Kayaku Co. Ltd., Takeda Pharmaceutical Co. Ltd., Pfizer Inc., Mochida Pharmaceutical Co. Ltd., Boston Scientific Corporation, Kissei Pharmaceutical Co. Ltd., consulting fees from Mitsubishi Tanabe Pharma Corporation, EA pharma Co. Ltd., AbbVie GK, Janssen Pharmaceutical K.K., Pfizer Inc., Nichi-Iko Pharmaceutical Co. Ltd., Eli Lilly, Gilead Sciences, Bristol Myers Squibb, and lecture fee from Mitsubishi Tanabe Pharma Corporation, AbbVie GK, EA pharma Co. Ltd., Kyorin Pharmaceutical Co. Ltd., JIMRO Co., Janssen Pharmaceutical K.K., Mochida Pharmaceutical Co., Ltd., Takeda Pharmaceutical Co. Ltd., Pfizer Inc. Kissei Pharmaceutical Co. Ltd.
JP reports consultancy fees/honorarium from AbbVie, Alimentiv, Athos, Atomwise, Boehringer Ingelheim, Celsius, Ferring, Galapagos, Genentech/Roche, GlaxoSmithKline, Janssen, Mirum, Nimbus, Pfizer, Progenity, Prometheus, Protagonist, Revolo, Sanofi, Sorriso, Surrozen, Takeda, and Wasserman, and has served on a data safety monitoring board for Alimentiv, Mirum, Sorriso, Sanofi, and Surrozen.
