Subcutaneous Infliximab May Help Recapture IBD Control After Treatment Interruption, Regardless of Antidrug Antibodies
Publication date: October 21, 2026
Study presented at: American College of Gastroenterology (ACG) Annual Scientific Meeting, October 12–14, 2026, Nashville, Tennessee
Study: Post hoc analysis of the LIBERTY-CD and LIBERTY-UC trials
1-Minute Summary
Subcutaneous infliximab may help patients with inflammatory bowel disease (IBD) regain and maintain disease control after an interruption in intravenous (IV) infliximab treatment, even when antidrug antibodies (ADAs) are present, according to a post hoc analysis presented at the 2026 ACG Annual Scientific Meeting.
The analysis evaluated data from the LIBERTY-CD and LIBERTY-UC trials, which investigated subcutaneous infliximab maintenance after an initial response to IV infliximab. Patients who had received placebo during the maintenance phase could subsequently initiate subcutaneous infliximab at a dose of 240 mg, with treatment escalation also permitted under specified circumstances.
Among patients with Crohn’s disease (CD), clinical response at approximately 8 weeks was reported in 93.3% of ADA-positive patients and 90.3% of ADA-negative patients. Clinical remission rates were 86.7% and 81.8%, respectively. Among patients with ulcerative colitis (UC), response and remission outcomes varied by the reported analysis and endpoint.
Infliximab serum concentrations increased after subcutaneous treatment initiation regardless of ADA status. C-reactive protein (CRP) and fecal calprotectin levels also improved and remained reduced through the reported follow-up period.
The findings suggest that prior ADA positivity may not invariably prevent successful reintroduction of infliximab through the subcutaneous route. However, these are post hoc findings from clinical trial data, not proof that subcutaneous infliximab is universally safer or more effective than IV reintroduction. The results were presented at a scientific meeting, and complete numerical results and a peer-reviewed publication were not provided in the supplied report.
Why This Matters
Patients with IBD may temporarily discontinue biologic therapy for several reasons. When treatment is restarted after an interruption, the immune system may have developed antibodies against the medication, potentially affecting drug exposure and treatment response.
Infliximab is a tumor necrosis factor (TNF) inhibitor used to treat inflammatory conditions, including Crohn’s disease and ulcerative colitis. Interrupting and restarting IV infliximab can pose challenges because treatment-related immunogenicity may reduce the likelihood of recapturing disease control.
The study’s central question was whether restarting infliximab through subcutaneous administration might produce favorable outcomes after an IV treatment interruption, including among patients with detectable ADAs.
The results are clinically relevant because they suggest that antibody positivity alone may not fully predict failure after subcutaneous infliximab is restarted. Nevertheless, treatment decisions should also consider disease activity, previous response, the reason for discontinuation, drug concentrations, immunogenicity testing when appropriate, and the patient’s overall clinical circumstances.
Study at a Glance
| Feature | Details |
|---|---|
| Study type | Post hoc analysis of 2 clinical trials |
| Data sources | LIBERTY-CD and LIBERTY-UC |
| Participants | Patients with Crohn’s disease or ulcerative colitis who responded to IV infliximab induction |
| Initial treatment | IV infliximab induction, with response assessed at week 10 |
| Maintenance assignment in the parent trials | Subcutaneous infliximab 120 mg every 2 weeks or placebo |
| Subsequent treatment | Subcutaneous infliximab 240 mg in specified circumstances, including placebo-to-treatment transition and treatment escalation |
| Comparator | Outcomes compared by ADA status; the supplied report does not describe a concurrent randomized comparison for the post hoc reintroduction analysis |
| Exposure of interest | ADA-positive vs ADA-negative status before subcutaneous infliximab initiation |
| Main outcomes reported | Clinical response, clinical remission, inflammatory biomarkers, serum infliximab concentrations, and ADA status over time |
| Follow-up | Outcomes reported through weeks 78–80; parent-trial treatment procedures could extend through week 102 |
| Main finding | Favorable clinical and pharmacologic outcomes were observed after subcutaneous infliximab initiation regardless of ADA status |
| Presentation | ACG Annual Scientific Meeting, October 12–14, 2026 |
| Full publication / DOI | Not provided in the supplied report |
What the Researchers Found
1. Antidrug antibodies were common after treatment interruption
The investigators assessed ADA status in patients transitioning from placebo to subcutaneous infliximab 240 mg in the LIBERTY trials.
ADA positivity was defined as antibody detection at least once from the beginning of maintenance treatment at week 10 through initiation of subcutaneous infliximab, which occurred between weeks 22 and 54.
Among patients who received placebo and subsequently initiated subcutaneous infliximab 240 mg, ADA positivity was reported in:
| Trial population | ADA-positive patients |
|---|---|
| LIBERTY-CD | 72.5% |
| LIBERTY-UC | 92.2% |
These figures indicate that ADA detection was common in the analyzed groups. The supplied report does not provide the corresponding participant counts or confidence intervals.
The median interval between the last IV infliximab infusion and initiation of subcutaneous maintenance was 16 weeks for both ADA-positive and ADA-negative patients in each trial.
2. Clinical response and remission were maintained in Crohn’s disease
Among patients with Crohn’s disease, clinical response was reported in 93.3% of ADA-positive patients and 90.3% of ADA-negative patients. Clinical remission was reported in 86.7% and 81.8%, respectively.
The reported outcomes were achieved by approximately 8 weeks and maintained through weeks 78–80.
| Outcome in Crohn’s disease | ADA-positive | ADA-negative |
|---|---|---|
| Clinical response | 93.3% | 90.3% |
| Clinical remission | 86.7% | 81.8% |
The results suggest that ADA positivity did not correspond to lower response or remission percentages in this analysis. However, without the group sizes, confidence intervals, and full statistical comparisons, it is not possible to establish equivalence between the groups.
3. Ulcerative colitis outcomes varied by endpoint
For patients with ulcerative colitis, the report provides results for partial clinical response and partial clinical remission, as well as separate clinical response and remission rates.
The reported partial response and remission results were:
| Reported outcome in ulcerative colitis | ADA-positive | ADA-negative |
|---|---|---|
| Partial clinical response | 96.2% | 100% |
| Partial clinical remission | 69.2% | 100% |
The article also reports the following clinical response and remission rates:
| Additional reported outcome in ulcerative colitis | ADA-positive | ADA-negative |
|---|---|---|
| Clinical response | 79.3% | 100% |
| Clinical remission | 62.1% | 66.7% |
These figures should be kept separate because the supplied report does not fully explain the endpoint definitions, analysis populations, or reasons for the differences between the two sets of results. The percentages should not be combined or treated as interchangeable measures.
The findings suggest that favorable outcomes occurred in both ADA groups, although some reported outcomes were numerically lower among ADA-positive patients. The available information is insufficient to determine whether these differences were statistically significant.
4. Infliximab concentrations increased after subcutaneous treatment began
Serum infliximab concentrations increased over time after subcutaneous treatment was initiated, regardless of whether patients were ADA-positive or ADA-negative.
The researchers also reported that the proportion of ADA-positive patients declined after initiation of subcutaneous infliximab 240 mg.
| Time point / outcome | Crohn’s disease | Ulcerative colitis |
|---|---|---|
| ADA-positive at weeks 78–80 | 66.7% | 65.5% |
| Direction of serum infliximab concentration change after subcutaneous initiation | Increased | Increased |
The decline in the proportion of ADA-positive patients may be relevant to understanding immunogenicity after treatment reintroduction. However, the report does not provide enough detail to determine why ADA positivity declined or whether this change directly caused better clinical outcomes.
5. Inflammatory markers improved and remained lower
In both LIBERTY-CD and LIBERTY-UC, CRP levels decreased at approximately week 8 and remained reduced through weeks 78–80, irrespective of ADA status.
Fecal calprotectin levels also remained reduced over the reported observation period; these measurements were initially assessed at week 32, according to the report.
| Biomarker | Reported finding | Timing described |
|---|---|---|
| C-reactive protein | Decreased and remained reduced | Improvement around week 8, sustained through weeks 78–80 |
| Fecal calprotectin | Remained reduced | Initially measured at week 32; sustained through the reported later period |
| Serum infliximab concentration | Increased after subcutaneous treatment initiation | Increased in ADA-positive and ADA-negative patients |
These biomarker findings support the reported clinical observations, although the supplied article does not provide absolute concentrations, percentage changes, or statistical estimates.
What the Presenter Said
Marla C. Dubinsky, MD, chief of pediatric gastroenterology and nutrition at Mount Sinai Kravis Children’s Hospital and codirector of the Susan and Leonard Feinstein Inflammatory Bowel Disease Clinical Center at the Icahn School of Medicine, described the potential challenge of restarting IV therapy after a drug holiday:
“A drug holiday for anti-TNF when given IV can be associated with increased immunogenicity and less efficacy after attempted reintroduction, impacting the likelihood of success of this strategy.”
She explained the objective of the analysis:
“The purpose of this analysis was to explore whether the reintroduction of anti-TNF delivered subcutaneously, not intravenously, improved the likelihood of success and improved efficacy outcomes.”
Summarizing the findings, Dubinsky said:
“Many people who received subcutaneous infliximab after IV induction recaptured response, and both drug concentrations and efficacy were not impacted by antidrug antibodies pre- or post-reintroduction after a drug holiday.”
She also emphasized the continued role infliximab may have for patients who previously benefited from treatment:
“Infliximab is an excellent therapy.”
She added that some patients may have tried several other treatments but felt best while receiving infliximab, and stated:
“We now may have a more effective and safer way to reintroduce the drug to patients.”
These are the presenter’s interpretations of the analysis. The reported data support further evaluation of subcutaneous reintroduction, but do not establish that the approach is safer or more effective than all alternative strategies.
Clinical Significance
The findings suggest that a history of ADA positivity should not necessarily be interpreted as definitive evidence that subcutaneous infliximab will fail after an IV treatment interruption.
For clinicians managing Crohn’s disease or ulcerative colitis, the study provides preliminary evidence that some patients can regain clinical response after transitioning back to infliximab through the subcutaneous route. The accompanying increases in serum drug concentrations and reductions in inflammatory biomarkers support the possibility of sustained disease control in the analyzed populations.
However, these results do not mean that every patient who stops IV infliximab should automatically restart subcutaneous treatment. The study does not establish the optimal restart strategy for every clinical scenario, nor does it demonstrate that subcutaneous delivery eliminates immunogenicity or infusion-related risks.
The decision to reintroduce infliximab should remain individualized and should account for the patient’s prior response, duration of interruption, reason for stopping treatment, current disease activity, previous adverse reactions, and available monitoring options.
Limitations
Several limitations should be considered when interpreting these findings.
- Post hoc analysis: The analysis examined existing data from LIBERTY-CD and LIBERTY-UC rather than testing a prospectively designed study question specifically focused on treatment interruption and ADA status.
- Incomplete sample-size information: The supplied report does not provide participant counts for the ADA-positive and ADA-negative subgroups or the denominators underlying the reported percentages.
- Limited statistical detail: Confidence intervals, P values, and complete adjusted analyses are not included in the news report. Numerical differences between ADA groups therefore cannot be interpreted as statistically meaningful without the full results.
- No direct evidence of superiority over IV reintroduction: The supplied report does not establish that restarting subcutaneous infliximab is superior to restarting IV infliximab or to alternative treatments.
- Potential differences between outcome definitions: The report provides both partial and other clinical response and remission rates for ulcerative colitis without fully detailing their definitions or analysis populations.
- Generalizability: The analysis concerns selected patients who responded to IV infliximab induction in the parent trials. The findings may not apply to patients who never responded to infliximab, those with different treatment histories, or all patients experiencing a drug holiday.
- Conference presentation: The supplied article describes findings presented at the ACG Annual Scientific Meeting. A complete peer-reviewed publication was not identified in the supplied material.
- Safety details are limited: Although the presenter characterized the strategy as potentially safer, the report does not provide comparative adverse-event data sufficient to establish a safety advantage.
What Doctors Should Know
- Assess the reason for treatment interruption: The clinical circumstances leading to a drug holiday may influence the suitability of reintroduction.
- Do not use ADA status in isolation: In this post hoc analysis, favorable outcomes occurred in both ADA-positive and ADA-negative groups. ADA results should be interpreted alongside the patient’s clinical history and other relevant findings.
- Monitor clinical response: Symptoms, disease activity, and inflammatory biomarkers may help assess whether disease control is being recaptured.
- Consider drug exposure: Serum infliximab concentrations increased after subcutaneous treatment initiation in both ADA groups in the reported analysis.
- Interpret UC results carefully: The article provides multiple response and remission measures with different percentages. The full study is needed to clarify their definitions and populations.
- Avoid assuming a safety advantage: The available report does not provide sufficient comparative safety data to prove that subcutaneous reintroduction is safer than IV treatment or alternative therapies.
- Use individualized treatment planning: The findings may inform discussion about reintroduction, but do not establish a universal protocol for restarting infliximab after a drug holiday.
Original Research / DOI
Study title: “Impact of prior anti-drug antibody status on clinical outcomes following subcutaneous infliximab initiation after intravenous infliximab interruption: A post hoc analysis of LIBERTY-CD and -UC studies.”
Presenter: Marla C. Dubinsky, MD, and colleagues.
Presentation: ACG Annual Scientific Meeting, October 12–14, 2026, Nashville, Tennessee.
Original research status: Conference-presented post hoc analysis of the LIBERTY-CD and LIBERTY-UC trials.
DOI: Not provided.
The full conference abstract or subsequent peer-reviewed publication should be consulted for the complete author list, subgroup denominators, statistical analyses, endpoint definitions, and safety results before adding a formal reference.
Bottom Line
A post hoc analysis of the LIBERTY-CD and LIBERTY-UC trials found that patients with Crohn’s disease or ulcerative colitis could regain or maintain clinical response after initiating subcutaneous infliximab following an interruption in IV treatment, including patients with detectable antidrug antibodies.
Clinical response, remission, serum infliximab concentrations, and inflammatory biomarker trends were generally favorable in both ADA groups, although some reported ulcerative colitis outcomes differed numerically by antibody status.
The findings support further investigation of subcutaneous infliximab as a reintroduction strategy after a treatment interruption. They do not establish that the approach is universally effective, safer than IV reintroduction, or appropriate for every patient. Treatment decisions should be individualized, and the complete study results should be reviewed when available.
