IBD Briefs: Upadcitinib in Children with Severe Colitis and Timing of Infliximab Switch to SC Route in Adults

Posted on January 7, 2026 by gutsandgrowth

A Yerushalmy-Feler et al. Inflammatory Bowel Diseases, 2025, 31, 3320–3326. Real-World Experience with Upadacitinib for Pediatric Acute Severe Ulcerative Colitis: An International Multicenter Retrospective Study from the Pediatric IBD Porto Group of ESPGHAN

In this study of 22 pediatric patients with ASUC refractory to infliximab, key findings:

By week 26, 14 (64%) were in corticosteroid-free clinical remission and 16 (73%) patients remained colectomy-free
Two serious AEs of an appendiceal neuroendocrine tumor and cytomegalovirus colitis

My take: It is good to see more pediatric data. The availability of upadacitinib will likely lead to lower colectomy rates.

L Bertani et al. Inflammatory Bowel Diseases, 2025, 31, 3363–3369. When to Switch to Subcutaneous Infliximab? The RE-WATCH Multicenter Study

Methods: The RE-WATCH study was an observational, multicenter, retrospective study performed in four IBD referral centers. Inclusion criteria meant that only patients receiving on label SC-IFX at a dosage of 120 mg every other week were included in the study. The initiation of IFX therapy as the baseline timepoint.

Key findings:

There were no statistical differences between the two groups, early vs. late switch, after one year in terms of the respective endoscopic response (71.4% vs 70.8%, P = .95), steroid-free clinical remission (62.5% vs 68.7%, P = .51), or IFX retention rate (75.0% vs 66.7%, P = .35).
There was higher endoscopic remission rates in early switch patients as compared to late switch patients; however, this trend was not significant (69.6% vs 52.1%, P = .07).
A return to IV-IFX was required in 1 of 43 early switch patients and in 3 of 44 late switch patients (2.3% vs 6.8%, P = .31)
While the early switch group appears to fare a little better, there is likely a selection bias. For example, the early group had a much lower rate of severe endoscopic score at baseline (20% vs. 54%) and lower rate of Crohn’s fistulizing disease (8% vs 33%).

My take: These results indicate that outcomes are similar between patients switching from to IFX SC at both early (after induction) and late (after 6 months).

It is worth noting that prior studies have shown that home-based therapies (eg. home infusion), compared to office-based therapies, have been “associated with suboptimal outcomes including higher rates of nonadherence and discontinuation of infliximab.” This is a concern for SC biologics as well.

Related blog posts:

Effectiveness of Switch to Subcutaneous Infliximab

Posted on January 2, 2026 by gutsandgrowth

N Mathieu et al. Clin Gastroenterol Hepatol 2025; 23: 2597 – 2606. Open Access! PErsistence and Safety of Subcutaneous Infliximab 1 Year After Switch From Intravenous Route in IBD Patients in REMission

Methods: The PEREM (PErsistence, effectiveness and safety of subcutaneous infliximab after switch from intravenous infliximab in IBD patients in REMission) study, a prospective national French cohort trial, enrolled 426 patients with IBD. Participants were in steroid-free clinical remission for at least 6 months on IV-IFX when they switched to SC-IFX. 56% were on IV-IFX standard dosing (5 mg/kg 8-weekly) and 16% received combination therapy with an immunomodulator drug at baseline. All patients were switched to SC-IFX standard dosing (ie, 120 mg every other week). The treatment could be intensified during follow-up, either to 120 mg every week or 240 mg every other week.

Key Findings:

At week 48, SC-IFX persistence was 95.4%
86.9% of patients were in steroid-free clinical remission
Mean infliximab levels were 8.0 μg/mL at inclusion and 18.0 μg/mL at week 48 (P < .0001)
Among the 19 (4.5%) patients who stopped SC-IFX, 6 (1.4%) switched back to IV-IFX
23 (5.4%) patients required SC-IFX dose escalation
Dosing at 10 mg/kg/Q4W had 100% SC IFX persistence compared to 95% for 5 mg/kg/Q8W; however, at the 48 week followup, there were only 6 patients in the higher dose compared to 149 in the lower dose
Ongoing use of combination therapy was not associated with better persistence. Though, only 7 patients were receiving combination therapy at the 48 week followup

From the discussion:

“The high persistence observed in the PEREM study is partly explained by the long-term control of the disease by the time of switch, the median time since last flare being over 5 years before inclusion. Henceforth, the persistence observed here is in accordance with results on long term maintenance of IV-IFX, the yearly persistence of IV-IFX without intervention being 87%.”
SC-IFX was associated with higher levels. However, this was expected and higher levels are needed with SC administration. The “different bioavailability of SC-IFX compared with IV-IFX is responsible for different goals of infliximab blood levels depending on its route. In particular, a level above 20 μg/mL has been associated with higher rates of remission²⁰” with SC-IFX.

My take: This study shows that SC-IFX is a good option for patients in long-term remission. With SC-IFX therapy, more effort is needed to make sure patients are adherent with therapy and monitoring in order to achieve optimal outcomes.

Related blog posts:

Infliximab Thresholds with Subcutaneous vs Intravenous Administration for Crohn’s Disease

Posted on December 12, 2024 by gutsandgrowth

SN Hong et al. AP&T 2024; 0:1–10. doi.org/10.1111/apt.18354. Subcutaneous Infliximab Concentration Thresholds for Mucosal and Transmural Healing in Patients With Crohn’s Disease

Background: The exposure–response relationship for the intravenous (IV) formulation of infliximab is well established, with multiple studies demonstrating that higher trough concentrations (C-trough) are associated with improved patient outcomes…However, the 2-week cycle of subcutaneous administration showed many-fold higher C-trough than the 8-week cycle of IV-IFX. Direct comparison of C-trough between SC- and IV-IFX is not appropriate because of different bioavailability and concentration–time profile. It is also not appropriate to apply the C-trough thresholds that predict achieving the therapeutic targets for IV.

This was a cross-sectional retrospective study with 124 patients with Crohn’s disease (CD) who had received SC-IFX maintenance therapy for ≥6 months. SC-IFX C-trough was measured immediately before SC-IFX injection. Key findings:

Mucosal healing (MH) was noted in 77.9% (74/95) and transmural healing (TH) in 36.3% (37/102).
SC-IFX C-trough was significantly higher in patients with MH (24.1 vs.16.9 μg/mL; p=0.001) and TH (26.0 vs. 20.5 μg/mL; p=0.007) than in those without.

Discussion:

Target trough levels: In this study, the authors found that “the C-trough thresholds for clinical remission, biochemical remission, MH and TH were 12, 16, 18 and 30 μg/mL, respectively, based on ROC analysis. The C-trough of SC-IFX increased with the depth of remission.”

Why trough level targets may differ between IV administration and SC: Administration via the IV route results in early and rapid peak concentration followed by a steady decline to trough, whereas administration via the SC route has slower absorption, lower bioavailability, lower peak concentration and smaller differences between peak and trough concentrations.

The authors note that a study by Ye et al (United European Gastroenterology Journal; 2020: 8: 385–386) with 55 patients found that a C-trough >26.6 mcg/mL achieved clinical remission and fecal calprotectin levels <250 mcg/g at week 54 in 79% and 91% respectively compared to 46% and 62% in those with with C-trough <16.4 mcg/g.

These C-trough levels are significantly higher that the median C-trough levels of standard dosing (120 mg biweekly) in a phase 1 dosing RCT which was only 13.3 mcg/mL (S Schreiber et al. Gastroenterology 2018; 154: 1371). The dosing of 180 mg and 240 mg biweekly resulted in C-trough levels of 19.9 mcg/mL and 26.5 mcg/mL respectively.

My take: This study suggests that therapeutic drug monitoring will have different targets with SC-IFX than with IV-SC. SC formulations will offer more convenience. However, more effort will be needed to make sure patients are adherent with therapy in order to achieve optimal outcomes.

Related study: S. N. Hong, J. Hye Song, S. Jin Kim, et al. Inflammatory Bowel Diseases 30 (2024): 517–528. One-Year Clinical Outcomes of Subcutaneous Infliximab Maintenance Therapy Compared With Intravenous Infliximab Maintenance Therapy in Patients With Inflammatory Bowel Disease: A Prospective Cohort Study. In this prospective study with 61 patients, SC IFX switch induced a higher 1-year durable remission rate than continuing IV IFX in patients with IBD during scheduled maintenance therapy.

Related blog posts:

Disclaimer: This blog, gutsandgrowth, assumes no responsibility for any use or operation of any method, product, instruction, concept or idea contained in the material herein or for any injury or damage to persons or property (whether products liability, negligence or otherwise) resulting from such use or operation. These blog posts are for educational purposes only. Specific dosing of medications (along with potential adverse effects) should be confirmed by prescribing physician. Because of rapid advances in the medical sciences, the gutsandgrowth blog cautions that independent verification should be made of diagnosis and drug dosages. The reader is solely responsible for the conduct of any suggested test or procedure. This content is not a substitute for medical advice, diagnosis or treatment provided by a qualified healthcare provider. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a condition.

REMSWITCH: Infliximab IV to SC Study

Posted on August 28, 2023 by gutsandgrowth

A Buisson et al. Clin Gastroenterol Hepatol 2023; 21: 2338-2346. Open Access! Effectiveness of Switching From Intravenous to Subcutaneous Infliximab in Patients With Inflammatory Bowel Diseases: the REMSWITCH Study

In this study, 133 ot 184 patients in clinical remission agreed to switch to subcutaneous infliximab. Key findings:

At visit 3, a relapse occurred in 10.2% (n = 6 of 59), 7.3% (n = 3 of 38), 16.7% (n = 3 of 18), and 66.7% (n = 10 of 15) (P < .001) of patients receiving 5 mg/kg every 8 weeks (5Q8W), 10Q8W, 10Q6W, and 10Q4W, respectively.
Dose escalation to 240 mg every other week led to recapture clinical remission in 93.3% (n = 14 of 15).
Infliximab serum levels increased after the switch (P < .0001) except for patients receiving 10 mg/kg every 4 weeks.
Conclusion (borrowed from authors): Switching from intravenous to subcutaneous infliximab 120 mg every other week is safe and well accepted, leading to a low risk of relapse in IBD patients except for those receiving 10Q4W; these patients likely require 240 mg every other week

EV Loftus et al. Clin Gastroenterol Hepatol 2023; 21: 2193. Open Access! Therapeutic Drug Monitoring for Subcutaneous Infliximab? Too Early to Conclude (Editorial) This editorial provides a terrific analysis of the above-mentioned study. A few of the points:

Reduced (41.7%) or stable (36.8%) serum levels of IFX after the switch (difference: V1-V0) were associated with higher risk of relapse than increased serum levels (>1 μg/mL; 12.7%; P = .020 and P = .019, respectively)
Patients receiving IV infusion of IFX 10Q4W had a higher risk of relapse (odds ratio, 12.4; P = .017). In addition to having significantly higher serum levels than in other IFX IV regimens, this group of patients did not see a rise in IFX concentrations at V1, in contrast to other IFX regimens.
Being overweight increases the clearance of CT-P13 SC, with an increase in clearance of 43.2% for a weight increase from 70 to 120 kg. The presence of antibodies to IFX also increases clearance by 39%. Finally, a decrease in serum albumin level (42 g/L vs 3.2 g/L) increases the clearance by 30.1%.

My take:

Monitoring IFX levels would be helpful in patients switching from IV to SC administration, especially in higher risk groups (eg. high baseline dosing, positive anti-drug antibodies, low serum albumin, overweight individuals)
My experience with SC biologics has been that there is a much higher rate of non-adherence than with IV infusions. If/when SC biologics are used more often, I will need to implement more intensive followup to assure patients receive both the needed medication and the needed monitoring.

Related blog posts:

Infliximab Injections Coming Soon

Posted on August 9, 2023 by gutsandgrowth

L Gianolio et al JPGN 2023; 77(2):p 235-239, August 2023. Effectiveness of Switching to Subcutaneous Infliximab in Pediatric Inflammatory Bowel Disease Patients on Intravenous Maintenance Therapy

Key findings: After switching from IV infliximab to SC 120 mg every other week, 6 of 7 patients remained in clinical remission with no significant changes in laboratory markers and median infliximab trough levels (12.3 µg/mL at baseline; 13.9 and 14.0 µg/mL at 6 and 40 weeks respectively).

2. Gastroenterology & Endoscopy News (7/31/23) Safety, Efficacy of Subcutaneous Infliximab Supported by Trial

Excerpt:

In this multinational trial, called LIBERTY-CD, the median trough level was 16 mcg/mL, which is higher than that typically associated with IV dosing, according to Dr. Hanauer, who presented the results at Digestive Disease Week 2023 (abstract 1028)… “most professional societies to recommend a trough of 10 mcg/mL,” Dr. Hanauer said….

All patients received induction doses of infliximab by IV at weeks 0, 2 and 6. Those who achieved at least a 100-point reduction in the Crohn’s Disease Activity Index (CDAI), which accounted for 86% of the 396 patients initially enrolled, were randomized in a 2:1 ratio to receive 120 mg of subcutaneous infliximab (CT-P13) or placebo every two weeks.

The proportion of patients meeting the end point of clinical remission, defined on the basis of CDAI, was 62.3% for active therapy and 32.1% for placebo (P<0.0001). The proportion of patients in the active treatment arm achieving an endoscopic response was nearly three times higher than the proportion in the placebo arm (51.1% vs. 17.9%; P<0.0001).

My take: This study shows that SC infliximab (after IV induction) should be effective. A study showing that the SC product is not inferior to the IV dosing would be helpful. It is likely that vedolizumab will receive approval in U.S. for a similar IV induction followed by maintenance subcutaneous therapy in the next year.

gutsandgrowth

Pediatric Gastroenterology

Tag Archives: subcutaneous infliximab