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Crohn's DiseasePhase 2CALLISTONCT06681324

Study Evaluating AZD7798 for Treatment in Crohn's Disease Patients With an Ileostomy

A Phase 2 study testing AZD7798 in people with Crohn's Disease, run by AstraZeneca at 17 sites in 7 countries.

Active, not recruiting

Under way, not looking for participants. Everyone needed has enrolled. The study is still running.

Official record
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Trial summary

The purpose of this study is to evaluate safety, tolerability, and effect on mucosal repair of AZD7798 compared with placebo in participants with active ileal Crohn's disease and an ileostomy. Read more about this study

Who is it for?
Ages 18 to 80 years
Conditions the study is for
Crohn's Disease
What is being tested?
AZD7798
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
24 participants
Where
17 sitesin 7 countries
Study dates
11 Dec 2024to 3 Sep 2027
Phase
Phase 2
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 80 years
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • 18 to 80 years of age.
  • Diagnosis of Crohn's disease established with clinical AND at least one of imaging, endoscopic, and/or histopathologic evidence.
  • Ileostomy (including Kock pouch) for at least 3 months.
  • Prior to screening endoscopy, clinical suspicion of active ileal inflammation based on at least one of the following: previous endoscopy, imaging (CT, MRI, IUS), or FCP above upper reference limit.
  • Active ileal Crohn's disease as determined by active intestinal mucosal inflammation, as demonstrated on video recorded ileoscopy performed during the screening period and scored by a blinded central reader with agreement on the SES CD ≥ 4 of the ileal segment from 5 to 25 cm (20cm length) proximal to the stoma. Participants with inflammation in additional intestinal segments are not excluded.
  • Capable of giving signed informed consent.

Who cannot join

  • Concomitant additional gastrointestinal luminal inflammatory diseases including, but not limited to, infectious enteritis, ischaemic bowel, inflammation and strictures caused by previous radiation therapy
  • Strictures/stenoses preventing passage of endoscope throughout the specified segment (up to 25 cm of ileum)
  • Short bowel syndrome
  • Within 3 months prior to screening:
  • Diagnosis of peritonitis or need treatment of peritonitis
  • Bowel perforation or evidence of obstruction
Show all 71Show fewer
  • All intrabdominal, cutaneous and perianal/perirectal abscesses and fistulae are excluded with exception of: cutaneous and perianal/perirectal abscesses and/or fistulae which are adequately drained 4 weeks prior to randomization, and intra-abdominal fistulae between bowel segments only without complications
  • Ongoing or expected nutritional dependency on total enteral or parenteral nutrition during study (partial nutrition acceptable).
  • In participants with any remaining colon and/or rectum, evidence of an increased risk of colorectal cancer, including:
  • Adenomatous colonic/rectal polyps that have not been removed
  • Intestinal dysplasia
  • Not undertaking appropriate surveillance, if indicated, for colorectal dysplasia/malignancy
  • Family history of early onset colorectal cancer, established diagnosis of HNPCC pancolitis for >8years duration without up-to-date colorectal cancer surveillance (can be performed during screening endoscopy if considered clinically appropriate by Investigator)
  • Reversal of ileostomy or formation of J-pouch planned prior to end of study period.
  • High-output stoma (eg, > 2000 mL/24 hours) associated with volume depletion and/or electrolyte disturbance to the extent that, in the opinion of the Investigator, it may put the participant at undue risk because of participation in the study, or impact their ability to participate in the study or interfere with the interpretation of study data.
  • Any of the following treatments within the specified time period:
  • An anti-TNF biologic within 8 weeks prior to randomization, unless therapeutic drug monitoring is performed, and drug concentrations are undetectable.
  • Any biologic targeting immune response other than an anti-TNF (including vedolizumab and ustekinumab) within 12 weeks prior to randomization unless validated therapeutic drug monitoring is performed, and drug concentrations are indetectable. Biologics not targeting immune response (eg, denosumab) will not be contraindicated.
  • Other advanced small molecule treatments for Crohn's disease (including JAK inhibitors or S1P modulators) within 4 weeks prior to randomization
  • Cyclosporine, mycophenolate mofetil, sirolimus (rapamycin), thalidomide, or tacrolimus within 4 weeks prior to randomization
  • Treatment with apheresis (eg, Adacolumn, Cellsorba) within 4 weeks prior to randomization
  • Administration of any live vaccine within 4 weeks prior to randomization, or planned administration of any such vaccine during the study
  • Faecal microbiota transplantation within 4 weeks prior to randomization
  • Regular intake of NSAIDs within 12 weeks prior to screening ileoscopy and during the study (defined as at least times per week for more than 3 months; not applicable to daily aspirin use up to 325 mg per day)
  • Lymphocyte-depleting treatment, including, but not limited to rituximab, within 12 months prior to randomization
  • Any changes in dosing of the following medications prior to screening ileoscopy as outlined
  • 5-aminosalicylates within 2 weeks
  • Oral corticosteroids within 2 weeks. Also excluded if on stable dosing of steroids exceeding the following dose equivalents:
  • Systemic steroids > 20 mg/day prednisolone dose or equivalent (ii) Locally targeted steroids exceeding maximum budesonide dose or equivalent [9 mg/day] (c) Immunomodulators (thiopurines or methotrexate) within 4 weeks (d) Antibiotic therapy for the treatment of Crohn's disease, eg, ciprofloxacin or metronidazole within 2 weeks (e) Probiotics within 2 weeks
  • Evidence of recent or currently active infection, including use of IV or oral antibiotics for documented infection within 30 days prior to screening. Topical antimicrobials or antimicrobials for the treatment of uncomplicated urinary tract infection may be allowed at the Medical Monitor's discretion.
  • Evidence of chronic hepatitis B or C infection defined as:
  • HBV: HBsAg positive or HBcAb positive
  • HCV: Positive result for HCV Ab is exclusionary unless HCV RNA is undetectable, and at least 12 weeks post anti-viral treatment of HCV (if treated).
  • History of TB (active or latent) unless an appropriate course of treatment has been completed.
  • Positive diagnostic TB test at screening (defined as positive QuantiFERON test). In cases where the QuantiFERON test is indeterminate, the patient may have the test repeated once and if their second test is negative, they will be eligible. In the event a second test is also indeterminate, the Investigator has the option to undertake PPD testing. If the PPD reaction is <5mm, then the patient is eligible. If the reaction is ≥ 5 mm, or PPD testing is not undertaken, the patient is not eligible. If there has been a history of completed treatment for TB and, per specialist opinion, a positive QuantiFERON test reflects previous infection only and no current active or latent infection, the participant could be included.
  • History of serious opportunistic infection (eg, histoplasmosis, listeriosis, coccidioidomycosis, pneumocystosis, aspergillosis) within 12 months prior to screening
  • Symptomatic herpes zoster infection within 3 months prior to screening.
  • Positive C. difficile toxin test at screening.
  • Any identified immunodeficiency, congenital and/or acquired aetiologies, including, but not limited to:
  • HIV infection (patients with positive results of HIV testing by the central laboratory will be excluded)
  • Splenectomy
  • Previous allogenic bone marrow transplant or history of organ or cell-based transplantation (eg, islet cell transplantation or autologous stem cell transplantation) with the exception of corneal transplant
  • Primary immune deficiency diseases, excluding selective IgA deficiency.
  • Abnormal laboratory results at screening:
  • Haemoglobin < 8 g/dL
  • Neutrophil count < 1,500/μL (or < 1.5 × 109/L); a re-test is allowed during screening in cases of mild neutropenia clinically suspected to be transient
  • Lymphocytes < 500/μL (or < 0.5 × 109/L)
  • Liver function tests: AST/ALT/ALP > 2 × ULN; or TBL ≥ 1.5 × ULN (isolated bilirubin > 1.5 × ULN is acceptable if bilirubin is fractionated and direct bilirubin < 35%)
  • eGFR according to CKD-EPI formula < 30 mL/min
  • Any other abnormal laboratory results at screening, which, in the opinion of the Investigator, will prevent the participant from completing the study or will interfere with the interpretation of the study results
  • Prolonged QTcF interval > 450 ms (or > 480 ms for patients with bundle branch block) or congenital long-QT syndrome or family history of long-QT syndrome or sudden cardiac death in age < 40 years. In case of borderline result or concern for artifact, triplicate ECGs should be collected within a 10-minute period, and the averaged value calculated for decision making.
  • Clinically significant cardiovascular conditions including:
  • Acute coronary syndrome (acute myocardial infarction, unstable angina), coronary intervention with percutaneous coronary intervention/coronary artery bypass surgery, stroke, transient ischaemic attack within 6 months prior to screening
  • Decompensated heart failure requiring hospitalisation, or Class III/IV heart failure, within 6 months prior to screening
  • Untreated second degree, Mobitz II or third degree atrioventricular-block, significant sinus node dysfunction/pause or therapy-requiring tachyarrhythmia. Patients with atrial fibrillation/flutter and optimally controlled ventricular rate (resting rate < 100 bpm) may be eligible as judged by the Investigator
  • Hypertrophic cardiomyopathy or clinically significant valvular heart disease which, in the opinion of the Investigator, will prevent the patient from completing the study or will interfere with the interpretation of the study results.
  • Reproduction:
  • Pregnant and breastfeeding participants, or those planning to breastfeed during the study
  • FOCBP, unless they agree to complete abstinence or to use a highly effective contraceptive method AND barrier method from enrollment until 18 weeks following last drug administration. FONCBP may be included.
  • Current malignancy or history of malignancy, except for:
  • Basal cell carcinoma, localised squamous cell carcinoma of the skin, or in situ carcinoma of the cervix are eligible provided the patient is in remission and curative therapy was completed at least 12 months prior to screening;
  • Other non-gastrointestinal malignancies are eligible provided that the patient is in remission and curative therapy was completed at least 5 years prior to screening.
  • Current significant major or unstable respiratory disease, heart disease, cerebrovascular disease, haematological disease, hepatic disease including large duct primary sclerosing cholangitis with jaundice, recurrent cholangitis or cirrhosis, renal disease, gastrointestinal disease, or other major disease other than active Crohn's disease. Gilbert's syndrome is not exclusionary. Small duct primary sclerosing cholangitis is not exclusionary if liver biomarkers are normal and there is no concern for cirrhosis.
  • Current enrolment in another interventional study or treatment with any investigational drug within 4 months (or 5 half-lives, whichever is longer) prior to screening
  • Unstable lifestyle factors, such as alcohol use to excess or recreational drug use, to the extent that in the opinion of the Investigator they would interfere with the ability of a patient to complete the study.
  • Patients committed to an institution by virtue of an order issued either by the judicial or the administrative authorities.
  • Involvement in the planning and/or conduct of the study (applies to both AstraZeneca staff and/or staff at the study site)
  • Judgement by the Investigator that the participant should not participate in the study if the participant is unlikely to comply with study procedures, restrictions, and requirements.
  • Previous randomization in the present study.
  • Investigator concerns regarding patient's willingness and ability to attend all study visits, comply with the study procedures, read in order to complete questionnaires, or to complete the study period.
  • Hypersensitivity to the IMP or any of its excipients.

Trial locations and contacts

17 sites in 7 countries.

17 sites in 7 countries

United Kingdom5 sites
  • Research Site

    Birmingham, B15 2GW

  • Research Site

    Cambridge, CB2 0XY

  • Research Site

    London, E1 1FR

  • Research Site

    London, NW10 7NS

  • Research Site

    London, WC1E 6AG

Other trials in United Kingdom

Italy3 sites
  • Research Site

    Padova, 35121

  • Research Site

    Roma, 00168

  • Research Site

    Rozzano, 20089

Other trials in Italy

Ukraine3 sites
  • Research Site

    Kyiv, 02002

  • Research Site

    Kyiv, 04210

  • Research Site

    Vinnytsia, 21029

Other trials in Ukraine

Netherlands2 sites
  • Research Site

    Amsterdam, 1081 HV

  • Research Site

    Nijmegen, 6525 GA

Other trials in Netherlands

Sweden2 sites
  • Research Site

    Linköping, 581 85

  • Research Site

    Stockholm, 17176

Other trials in Sweden

Belgium1 site
  • Research Site

    Leuven, 3000

Other trials in Belgium

Poland1 site
  • Research Site

    Warsaw, 04-501

Other trials in Poland

About this study

Official title: A Participant- and Investigator-blind, Randomized, Placebo-controlled Phase II Study to Evaluate Safety, Tolerability, and Mucosal Repair With AZD7798 in Patients With Active Ileal Crohn's Disease and an Ileostomy (CALLISTO)

The purpose of this study is to evaluate safety, tolerability, and effect on mucosal repair of AZD7798 compared with placebo in participants with active ileal Crohn's disease and an ileostomy.

Read the detailed description

This is a participant-and investigator-blind, randomized, parallel-group, placebo controlled phase II study designed to evaluate safety, tolerability, and mucosal repair with AZD7798 in participants with active ileal Crohn's disease and an ileostomy. This study will include a screening period, an induction period, an open-label maintenance period, and a follow-up period. Approximately 30 participants will be randomized globally to receive either AZD7798 or placebo during 12-week participant- and investigator- blind induction period. At week 12 after induction period, all eligible participants will enter 40-week open label maintenance period. Follow-up visits will take place 8 weeks and 18 weeks after the last dose of study intervention, whether this occurs during the induction period or the open-label maintenance period.

Conditions
Crohn's Disease
Being tested
AZD7798, Placebo
Keywords
Crohn's disease, ileostomy, inflammation, small bowel, stoma
Medical subject headings
Crohn Disease, Inflammation

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • AZD7798Drug

    AZD7798

  • PlaceboOther

    Placebo

Study groups in NCT06681324
Study groupRoleWhat they receive
AZD7798ExperimentalAZD7798
Receives: Drug: AZD7798
PlaceboPlacebo comparatorPlacebo
Receives: Other: Placebo

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Number of participants with adverse events

    Summary of any adverse events and also by MedDRA SOC and Preferred term

    Measured: from Week 0 to Week 12

  2. Number of participants with abnormal Vital signs: Blood pressure

    Systolic and diastolic blood pressure will be summarized by descriptive statistics

    Measured: from Week 0 to Week 12

  3. Number of participants with abnormal Vital signs: Pulse rate

    Pulse rate will be summarized by descriptive statistics

    Measured: from Week 0 to Week 12

  4. Number of participants with abnormal values in haematology: complete blood count (CBC)

    The variables platelet count, red blood cell (RBC) count, haemoglobin, haematocrit will be summarized with descriptive statistics

    Measured: from Week 0 to Week 12

  5. Number of participants with abnormal values in haematology: white blood cell (WBC) count

    The variables neutrophils, lymphocytes, monocytes, eosinophils, and basophils will be summarized with descriptive statistics

    Measured: from Week 0 to Week 12

  6. Number of participants with abnormal values in haematology: RBC

    The variables mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and percentage of reticulocytes will be summarized with descriptive statistics

    Measured: from Week 0 to Week 12

  7. Number of participants with abnormal values in clinical chemistry: kidney function

    The variables creatinine and blood urea nitrogen (BUN) will be summarized with descriptive statistics

    Measured: from Week 0 to Week 12

  8. Number of participants with abnormal values in clinical chemistry: electrolytes

    The variables potassium, sodium, and calcium will be summarized with descriptive statistics

    Measured: from Week 0 to Week 12

  9. Number of participants with abnormal values in clinical chemistry: liver function

    The variables ALT (Alanine Aminotransferase), AST (Aspartate Aminotransferase), and ALP (alkaline phosphatase), and albumin will be summarized with descriptive statistics

    Measured: from Week 0 to Week 12

  10. Number of participants with abnormal values in clinical chemistry: hs-CRP

    The variable hs-C-reactive protein will be summarized with descriptive statistics

    Measured: from Week 0 to Week 12

  11. Number of participants with abnormal values in clinical chemistry: glucose

    The variable glucose will be summarized with descriptive statistics

    Measured: from Week 0 to Week 12

  12. Number of participants with abnormal values in ECG readings

    12-lead ECGs will be obtained using an ECG machine, that automatically measures RR/HR, PR, QRS, QT and Corrected QT (QTc) intervals, and summarized with descriptive statistics

    Measured: from Week 0 to Week 12

Secondary outcomes (18)
  1. Difference in mean change from baseline in endoscopic score between active and placebo

    Simple Endoscopic Score for Crohn's Disease (SES-CD) is based on the evaluation of ileum, and the presence and size of ulcerations and the extent of the inflammatory area and stenosis are assessed. The segment is scored from 0 to 12, higher scores indicating more active disease

    Measured: Week 12

  2. Number of participants with endoscopic response

    Endoscopic response is defined as ≥ 50% decrease from baseline in SES-CD total score and based on the evaluation of ileum and the presence and size of ulcerations and the extent of the inflammatory area and stenosis are assessed. The segment is scored from 0 to 12, higher scores indicating more active disease

    Measured: Week 12

  3. Number of participants with endoscopic remission

    Endoscopic remission is defined as SES-CD total score < 4 and at least 2 point reduction from baseline with no sub score > 1 in any individual variable. SES-CD is based on the evaluation of ileum, and the presence and size of ulcerations and the extent of the inflammatory area and stenosis are assessed. The segment is scored from 0 to 12, higher scores indicating more active disease

    Measured: Week 12

  4. Serum AZD7798 concentration

    Serum AZD7798 concentration (PK)

    Measured: up to 52 Weeks

  5. Incidence of anti-drug antibody response

    Incidence of anti-drug antibody (ADA) response - number and percentages with a positive ADA result

    Measured: up to 52 Weeks

  6. Titre of anti-drug antibody response

    Titre of anti-drug antibody (ADA) response - immunogenicity titre will be summarized descriptively as a continuous variable, only for ADA positive tests

    Measured: up to 52 Weeks

  7. Number of participants with adverse events in active treatment

    Summary of any adverse events and also by MedDRA SOC and Preferred term

    Measured: from Week 12 to Week 52

  8. Number of participants with abnormal vital signs: Blood pressure

    Systolic and diastolic blood pressure will be summarized by descriptive statistics

    Measured: from Week 12 to Week 52

  9. Number of participants with abnormal vital signs: Pulse rate

    Pulse rate will be summarized by descriptive statistics

    Measured: from Week 12 to Week 52

  10. Number of participants with abnormal values in haematology: complete blood count (CBC)

    The variables platelet count, red blood cell (RBC) count, haemoglobin, haematocrit will be summarized with descriptive statistics

    Measured: from Week 12 to Week 52

  11. Number of participants with abnormal values in haematology: white blood cell (WBC) count

    The variables neutrophils, lymphocytes, monocytes, eosinophils, and basophils will be summarized with descriptive statistics

    Measured: from Week 12 to Week 52

  12. Number of participants with abnormal values in haematology: RBC

    The variables mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and percentage of reticulocytes will be summarized with descriptive statistics

    Measured: from Week 12 to Week 52

  13. Number of participants with abnormal values in clinical chemistry: kidney function

    The variables creatinine and blood urea nitrogen (BUN) will be summarized with descriptive statistics

    Measured: from week 12 to week 52

  14. Number of participants with abnormal values in clinical chemistry: electrolytes

    The variables potassium, sodium, and calcium will be summarized with descriptive statistics

    Measured: from Week 12 to Week 52

  15. Number of participants with abnormal values in clinical chemistry: liver function

    The variables ALT (Alanine Aminotransferase), AST (Aspartate Aminotransferase), and ALP (alkaline phosphatase), and albumin will be summarized with descriptive statistics

    Measured: from Week 12 to Week 52

  16. Number of participants with abnormal values in clinical chemistry: hs-CRP

    The variable hs-C-reactive protein will be summarized with descriptive statistics

    Measured: from Week 12 to Week 52

  17. Number of participants with abnormal values in clinical chemistry: glucose

    The variable glucose will be summarized with descriptive statistics

    Measured: from Week 12 to Week 52

  18. Number of participants with abnormal values in ECG readings

    12-lead ECGs will be obtained using an ECG machine, that automatically measures RR/HR, PR, QRS, QT and Corrected QT (QTc) intervals, and summarized with descriptive statistics

    Measured: from week 12 to week 52

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted8 Nov 2024
  2. Study start11 Dec 2024
  3. Primary completion10 Aug 2026
  4. Study completion3 Sep 2027 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 2
Primary purpose
Other
Allocation
Randomised
Intervention model
Parallel groups
Model description
Participants will be randomized 2:1 to receive either AZD7798 or placebo during 12-week participant- and Investigator- blind induction period. At week 12 after induction period, all eligible participants will enter 40-week open label maintenance period.
Masking
Triple blind
Who is masked
Participant, Care provider, Investigator
Enrolment
24 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT06681324
Sponsor's protocol ID
D9690C00006
Acronym
CALLISTO
Status last verified
Oct 2026
First submitted
25 Sep 2024
Last updated
28 Oct 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Yes: Qualified researchers can request access to anonymized individual patient-level data from AstraZeneca group of companies sponsored clinical trials via the request portal Vivli.org. All requests will be evaluated as per the AZ disclosure commitment: https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure. Yes, indicates that AZ are accepting requests for IPD, but this does not mean all requests will be shared.

Questions about this trial

What is this clinical trial studying?

A Phase 2 study testing AZD7798 in people with Crohn's Disease, run by AstraZeneca at 17 sites in 7 countries.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 6 inclusion and 71 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: under way, not looking for participants, as of the sponsor's last update on 28 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 17 sites in United Kingdom, Italy, Ukraine, Netherlands, Sweden and 2 more countries. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Number of participants with adverse events (time frame: from Week 0 to Week 12). The study lists 12 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 28 Oct 2026.

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