A Phase 3 interventional study of IV Tulisokibart and SC Tulisokibart in Crohn's Disease, sponsored by Merck Sharp & Dohme LLC. Recruiting at 499 sites in 47 countries. Open to participants aged 16 Years to 80 Years. Per ClinicalTrials.gov, last updated 2026-11-10.
Sponsored by Merck Sharp & Dohme LLC (part of Merck & Co., Inc) · Phase 3, Interventional, and Treatment
The purpose of this protocol is to evaluate the efficacy and safety of tulisokibart in participants with moderately to severely active Crohn's disease. Study 1's primary hypotheses are that at least 1 tulisokibart dose level is superior to placebo in the proportion of participants achieving clinical remission per Crohn's Disease Activity Index score (\<150, US/FDA) or per stool frequency and abdominal pain score (EU/EMA) and in the proportion of participants achieving endoscopic response at Week 52 (US/FDA and EU/EMA), and that at least 1 tulisokibart dose level is superior to placebo in the proportion of participants achieving clinical remission per Crohn's Disease Activity Index score (\<150, US/FDA) or per stool frequency and abdominal pain score (EU/EMA) and in the proportion of participants achieving endoscopic response at Week 12 (US/FDA and EU/EMA). Study 2's primary hypothesis is that at least 1 tulisokibart dose level is superior to placebo in the proportion of participants achieving clinical remission per Crohn's Disease Activity Index score (\<150, US/FDA) or stool frequency and abdominal pain score (EU/EMA) and in the proportion of participants achieving endoscopic response at Week 12 (US/FDA and EU/EMA).
The protocol consists of 2 studies. Study 1 includes induction and maintenance treatment, and Study 2 includes only induction treatment. Each study has its own hypotheses and outcome measures that will be assessed independently.
1,992 studies on the registry are indexed under Crohn Disease; 478 are open to participants now.
This study's planned enrollment of 1,200 is above the median of 67 across 1,260 interventional studies indexed under Crohn Disease.
Browse Crohn Disease studies →Merck Sharp & Dohme LLC is the lead sponsor of 2,166 studies on the registry; 132 are open to participants now.
Of its 501 completed or terminated interventional studies of FDA-regulated products, 370 (74%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
The main inclusion and exclusion criteria include but are not limited to the following:
Inclusion Criteria:
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis B tests
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis C tests
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants receive high dose intravenous (IV) tulisokibart, followed by a high dose subcutaneous (SC) tulisokibart regimen.
Drug: IV Tulisokibart · Drug: SC Tulisokibart
Participants receive high dose IV tulisokibart, followed by a low dose SC tulisokibart regimen.
Drug: IV Tulisokibart · Drug: SC Tulisokibart · Other: SC Placebo
Participants receive low dose IV tulisokibart, followed by a low dose SC tulisokibart regimen.
Drug: IV Tulisokibart · Drug: SC Tulisokibart · Other: SC Placebo
Participants receive IV placebo, followed by an SC placebo regimen.
Drug: IV Tulisokibart · Other: IV Placebo · Other: SC Placebo
Participants receive a high dose SC tulisokibart regimen. Participants may continue in this arm after completing participation in their original arm, if they meet protocol-specific prerequisites.
Drug: SC Tulisokibart
Participants receive a low dose SC tulisokibart and placebo regimen. Participants may continue in this arm after completing participation in their original arm, if they meet protocol-specific prerequisites.
Drug: SC Tulisokibart · Other: SC Placebo
Participants receive high dose IV tulisokibart.
Drug: IV Tulisokibart
Participants receive low dose IV tulisokibart.
Drug: IV Tulisokibart · Other: SC Placebo
Participants receive IV placebo.
Drug: IV Tulisokibart · Other: IV Placebo · Other: SC Placebo
Participants receive a high dose SC tulisokibart regimen. Participants may continue in this arm only after completing participation in their original arm, if they meet protocol-specific prerequisites.
Drug: SC Tulisokibart
Participants receive a low dose SC tulisokibart regimen. Participants may continue in this arm only after completing participation in their original arm, if they meet protocol-specific prerequisites.
Drug: SC Tulisokibart
Humanized monoclonal antibody that binds human tumor necrosis factor-like cytokine 1A (TL1A), administered intravenously
Also known as: PRA023, MK-7240
Humanized monoclonal antibody that binds human TL1A, administered subcutaneously
Also known as: PRA023, MK-7240
Placebo matching IV tulisokibart
Placebo matching SC tulisokibart
Study 1 [US/FDA Only]: Percentage of Participants Achieving Clinical Remission per Crohn's Disease Activity Index (CDAI) Score at Week 52
The percentage of participants achieving clinical remission, as defined by CDAI score \<150 for Study 1 will be presented.
Time frame: Week 52
Study 1 [EU/EMA Only]: Percentage of Participants Achieving Clinical Remission per Stool Frequency and Abdominal Pain Score at Week 52
The percentage of participants achieving clinical remission per stool frequency/abdominal pain score (SF/APS), as defined by average daily SF ≤2.8 and average daily APS ≤1.0 and both not greater than baseline for Study 1 will be presented.
Time frame: Week 52
Study 1: Percentage of Participants Achieving Endoscopic Response at Week 52
The percentage of participants achieving endoscopic response, as defined by a ≥50% decrease in Simplified endoscopic score for Crohn's disease (SES-CD) from baseline for Study 1 will be presented.
Time frame: Week 52
Study 1 [US/FDA Only]: Percentage of Participants Achieving Clinical Remission per CDAI Score at Week 12
The percentage of participants achieving clinical remission, as defined by CDAI score \<150 for Study 1 will be presented.
Time frame: Week 12
Study 1 [EU/EMA Only]: Percentage of Participants Achieving Clinical Remission per Stool Frequency and Abdominal Pain Score at Week 12
The percentage of participants achieving clinical remission per SF/APS, as defined by average daily SF ≤2.8 and average daily APS ≤1.0 and both not greater than baseline for Study 1 will be presented.
Time frame: Week 12
Study 1: Percentage of Participants Achieving Endoscopic Response at Week 12
The percentage of participants achieving endoscopic response, as defined by a ≥50% decrease in SES-CD from baseline for Study 1 will be presented.
Time frame: Week 12
Study 2 [US/FDA Only]: Percentage of Participants Achieving Clinical Remission per CDAI Score at Week 12
The percentage of participants achieving clinical remission, as defined by CDAI score \<150 for Study 2 will be presented.
Time frame: Week 12
Study 2 [EU/EMA Only]: Percentage of Participants Achieving Clinical Remission per Stool Frequency and Abdominal Pain Score at Week 12
The percentage of participants achieving clinical remission per SF/APS, as defined by average daily SF ≤2.8 and average daily APS ≤1.0 and both not greater than baseline for Study 2 will be presented.
Time frame: Week 12
Study 2: Percentage of Participants Achieving Endoscopic Response at Week 12
The percentage of participants achieving endoscopic response, as defined by a ≥50% decrease in SES-CD from baseline for Study 2 will be presented.
Time frame: Week 12
Study 1: Number of Participants Who Experienced an Adverse Event (AE)
An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of a study intervention. The number of participants who experience an AE for Study 1 will be presented.
Time frame: Up to approximately 52 weeks
Study 1: Number of Participants Who Discontinue Study Intervention due to an AE
An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of a study intervention. The number of participants who discontinue study intervention due to an AE for Study 1 will be presented.
Time frame: Up to approximately 52 weeks
Study 1 [US/FDA Only]: Percentage of Participants Achieving Clinical Remission per Stool Frequency and Abdominal Pain Score at Week 12
The percentage of participants achieving clinical remission per SF/APS, as defined by average daily SF ≤2.8 and average daily APS ≤1.0 and both not greater than baseline for Study 1 will be presented.
Time frame: Week 12
Study 1 [EU/EMA Only]: Percentage of Participants Achieving Clinical Remission per CDAI Score at Week 12
The percentage of participants achieving clinical remission, as defined by CDAI score \<150 for Study 1 will be presented.
Time frame: Week 12
Study 1: Percentage of Participants With Clinical Response per CDAI Score (Decrease From Baseline of ≥100 Points) at Week 12
The percentage of participants achieving clinical response, defined as decrease from baseline of ≥100 points in CDAI for Study 1 will be presented.
Time frame: Week 12
Study 1: Mean Change From Baseline in Functional Assessment of Chronic Illness Therapy - Fatigue (FACIT-Fatigue) Score at Week 12
The FACIT-Fatigue is a 13-item measure that assesses self-reported fatigue and its impact upon daily activities and function, scored on a 0 to 52-point scale, with lower scores indicating greater fatigue. The mean change from baseline in FACIT-Fatigue score for Study 1 will be presented.
Time frame: Baseline and Week 12
Study 1: Percentage of Participants Achieving Endoscopic Remission at Week 12
The percentage of participants achieving endoscopic remission, as defined by SES-CD ≤4 and at least 2-point reduction from baseline and no subscore \>1 in any individual variable for Study 1 will be presented. SES-CD evaluates 4 endoscopic variables (ulcer size, ulcerated surface, affected surface, and narrowing), each on a scale from 0 to 3, in 5 segments assessed during ileocolonoscopy (ileum, right colon, transverse colon, left colon/sigmoid, and rectum). The total score is the sum of the 4 endoscopic variable scores and ranges from 0 to 56, where higher scores indicate more severe disease.
Time frame: Week 12
Study 1 and 2: Percentage of Participants in Diagnostic Assay Positive (Dx+) Subpopulation Achieving Clinical Remission per CDAI Score at Week 12
Dx+ participants are those who meet protocol-specific diagnostic assay criteria during screening. The percentage of Dx+ participants achieving clinical remission, as defined by CDAI score \<150 for Study 1 and Study 2 will be presented.
Time frame: Week 12
Study 1 and 2: Percentage of Participants in Dx+ Subpopulation Achieving Endoscopic Response at Week 12
Dx+ participants are those who meet protocol-specific diagnostic assay criteria during screening. The percentage of Dx+ participants achieving endoscopic response, as defined by a ≥50% decrease in simplified endoscopic score for Crohn's disease (CD) from baseline for Study 1 and Study 2 will be presented.
Time frame: Week 12
Study 1: Percentage of Participants With Clinical Response (Decrease From Baseline at Least 100 Points) or Clinical Remission (<150) per CDAI Score at Week 6
The percentage of participants achieving clinical response (defined as decrease from baseline of ≥100 points in CDAI) or clinical remission (defined as CDAI \<150) for Study 1 will be presented.
Time frame: Week 6
Study 1 [US/FDA Only]: Percentage of Participants Achieving Clinical Remission per Stool Frequency and Abdominal Pain Score at Week 52
The percentage of participants achieving clinical remission per SF/APS, as defined by average daily SF ≤2.8 and average daily APS ≤1.0 and both not greater than baseline for Study 1 will be presented.
Time frame: Week 52
Study 1 [EU/EMA Only]: Percentage of Participants Achieving Clinical Remission per CDAI Score at Week 52
The percentage of participants achieving clinical remission, as defined by CDAI score \<150 for Study 1 will be presented.
Time frame: Week 52
Study 1: Percentage of Participants With Clinical Response per CDAI Score (Decreased From Baseline of ≥100 Points) at Week 52
The percentage of participants achieving clinical response, defined as decrease from baseline of ≥100 points in CDAI for Study 1 will be presented.
Time frame: Week 52
Study 1: Percentage of Participants Achieving Endoscopic Remission at Week 52
The percentage of participants achieving endoscopic remission, as defined by SES-CD ≤4 and at least 2-point reduction from baseline and no subscore \>1 in any individual variable for Study 1 will be presented. SES-CD evaluates 4 endoscopic variables (ulcer size, ulcerated surface, affected surface, and narrowing), each on a scale from 0 to 3, in 5 segments assessed during ileocolonoscopy (ileum, right colon, transverse colon, left colon/sigmoid, and rectum). The total score is the sum of the 4 endoscopic variable scores and ranges from 0 to 56, where higher scores indicate more severe disease.
Time frame: Week 52
Study 1: Percentage of Participants Achieving Sustained Clinical Remission per CDAI at Both Week 12 and Week 52
The percentage of participants achieving sustained clinical remission, as defined by CDAI score \<150 for Study 1 will be presented.
Time frame: Week 12 and Week 52
Study 1 [US/FDA Only]: Percentage of Participants Achieving Corticosteroid-Free Clinical Remission per CDAI Score at Week 52
The percentage of participants who are in clinical remission as defined by CDAI score \<150 and without corticosteroid use for CD at least 90 days prior to that assessment for Study 1 will be presented.
Time frame: Week 52
Study 1 [EU/EMA Only]: Percentage of Participants Achieving Corticosteroid-Free Clinical Remission per Stool Frequency and Abdominal Pain Score at Week 52
The percentage of participants who are in clinical remission per SF/APS, as defined by average daily SF ≤2.8 and average daily APS ≤1.0 and both not greater than baseline and without corticosteroid use for CD at least 90 days prior to that assessment for Study 1 will be presented.
Time frame: Week 52
Study 1: Percentage of Participants Achieving Clinical Remission per Stool Frequency, Abdominal Pain Score, and Endoscopic Remission at Week 52
The percentage of participants achieving clinical remission per SF/APS, as defined by average daily SF ≤2.8 and average daily APS ≤1.0 and both not greater than baseline, and achieving endoscopic remission, as defined by SES-CD ≤4 and at least 2-point reduction from baseline and no subscore \>1 in any individual variable for Study 1 will be presented.
Time frame: Week 52
Study 1: Percentage of Participants Achieving Clinical Remission per CDAI Score and Endoscopic Remission at Week 52
The percentage of participants achieving clinical remission as defined by CDAI score \<150, and achieving endoscopic remission, as defined by SES-CD ≤4 and at least 2-point reduction from baseline and no subscore \>1 in any individual variable for Study 1 will be presented.
Time frame: Week 52
Study 1: Mean Change From Baseline in FACIT-Fatigue Score at Week 52
The FACIT-Fatigue is a 13-item measure that assesses self-reported fatigue and its impact upon daily activities and function, scored on a 0 to 52-point scale, with lower scores indicating greater. The mean change from baseline in FACIT-Fatigue score for Study 1 will be presented.
Time frame: Baseline and Week 52
Study 1 [EU/EMA Only]: Mean Change From Baseline in Inflammatory Bowel Disease Questionnaire (IBDQ) Score at Week 52
The IBDQ measures health related quality of life in participants with inflammatory bowel disease. It consists of 32 questions each with a graded response of 1 (worst) to 7 (best). The score ranges between 32 to 224, with higher scores indicating a better quality of life. The mean change from baseline in IBDQ score for Study 1 will be presented.
Time frame: Baseline and Week 52
Study 1: Percentage of Participants With Ulcer-Free Endoscopy at Week 52
The percentage of participants achieving ulcer-free endoscopy (mucosal healing), as defined by SES-CD ulcerated surface subscore of 0 in participants with SES-CD ulcerated surface subscore ≥1 at baseline for Study 1 will be presented.
Time frame: Week 52
Study 2: Number of Participants Who Experienced an AE
An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of a study intervention. The number of participants who experience an AE for Study 2 will be presented.
Time frame: Up to approximately 12 weeks
Study 2: Number of Participants Who Discontinue Study Intervention due to an AE
An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of a study intervention. The number of participants who discontinue study intervention due to an AE for Study 2 will be presented.
Time frame: Up to approximately 12 weeks
Study 2 [US/FDA Only]: Percentage of Participants Achieving Clinical Remission per Stool Frequency and Abdominal Pain Score at Week 12
The percentage of participants achieving clinical remission per SF/APS, as defined by average daily SF ≤2.8 and average daily APS ≤1.0 and both not greater than baseline for Study 2 will be presented.
Time frame: Week 12
Study 2 [EU/EMA Only]: Percentage of Participants Achieving Clinical Remission per CDAI Score at Week 12
The percentage of participants achieving clinical remission, as defined by CDAI score \<150 for Study 2 will be presented.
Time frame: Week 12
Study 2: Percentage of Participants With Clinical Response per CDAI Score (Decreased From Baseline of ≥100 Points) at Week 12
The percentage of participants achieving clinical response, defined as decrease from baseline of ≥100 points in CDAI for Study 2 will be presented.
Time frame: Week 12
Study 2: Mean Change From Baseline in FACIT-Fatigue Score at Week 12
The FACIT-Fatigue is a 13-item measure that assesses self-reported fatigue and its impact upon daily activities and function, scored on a 0 to 52-point scale, with lower scores indicating greater. The mean change from baseline in FACIT-Fatigue score for Study 2 will be presented.
Time frame: Baseline and Week 12
Study 2: Percentage of Participants Achieving Endoscopic Remission at Week 12
The percentage of participants achieving endoscopic remission, as defined by SES-CD ≤4 and at least 2-point reduction from baseline and no subscore \>1 in any individual variable for Study 2 will be presented. SES-CD evaluates 4 endoscopic variables (ulcer size, ulcerated surface, affected surface, and narrowing), each on a scale from 0 to 3, in 5 segments assessed during ileocolonoscopy (ileum, right colon, transverse colon, left colon/sigmoid, and rectum). The total score is the sum of the 4 endoscopic variable scores and ranges from 0 to 56, where higher scores indicate more severe disease.
Time frame: Week 12
Study 2 [EU/EMA Only]: Mean Change From Baseline in IBDQ Score at Week 12
The IBDQ measures health related quality of life in participants with inflammatory bowel disease. It consists of 32 questions each with a graded response of 1 (worst) to 7 (best). The score ranges between 32 to 224, with higher scores indicating a better quality of life. The mean change from baseline in IBDQ score for Study 2 will be presented.
Time frame: Baseline and Week 12
Study 2: Percentage of Participants With Clinical Response (Decreased From Baseline of ≥100 Points) or Clinical Remission (<150) per CDAI Score at Week 6
The percentage of participants achieving clinical response (defined as decrease from baseline of ≥100 points in CDAI) or clinical remission (defined as CDAI \<150) for Study 2 will be presented.
Time frame: Week 6
Study 2: Percentage of Participants With Ulcer-Free Endoscopy at Week 12
The percentage of participants achieving ulcer-free endoscopy (mucosal healing), as defined by SES-CD ulcerated surface subscore of 0 in participants with SES-CD ulcerated surface subscore ≥1 at baseline for Study 2 will be presented.
Time frame: Week 12
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Showing the first 100 of 499 sites across 47 countries. Choose a country and city above to see the rest.
Plan to share: Yes — https://trialstransparency.msdclinicaltrials.com/pdf/ProcedureAccessClinicalTrialData.pdf
Data sharing details ↗ · externaldatasharing-msd.com
Started Jun 2024 (actual). Primary completion is estimated for Oct 2028, 52 months after the start.
Of 70 industry-sponsored phase 3 interventional studies under Crohn Disease, half reached primary completion within 46 months of starting (the median), counting those still running; a quarter within 35 and three quarters within 69. This study's planned 52 months is above that.
Counting every sponsor, half of 88 studies reached it within 49 months; a quarter within 36 and three quarters within 69.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
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Studies of the drug tested here: Tulisokibart