A Microdose Trial Investigating Binding of [68Ga]Ga-DOTA-CYS-ATH001 in Healthy Subjects and Different Patient Groups.

Inclusion Criteria:

1. Willing and able to give written informed consent for participation in the trial andable to comply with all trial procedures and requirements.

2. Male or female participant aged 18 to 75 years, inclusive, at the screening visit.

3. Body mass index (BMI) ≥ 19 and < 40.0 kg/m2 at the time of the screening visit.

4. Women of childbearing potential (WOCBP) must practice abstinence from heterosexualintercourse (only allowed when this is the preferred and usual lifestyle of theparticipant) or must agree to use a highly effective method of contraception with afailure rate of < 1 % to prevent pregnancy from at least 2 weeks prior toadministration of tracer for at least 1 week after the PET imaging examination (orfor at least 1 weak after the last PET imaging examination for those participantsundergoing test/retest PET imaging). In addition, any male partner of a femaleparticipant must, unless he has undergone vasectomy, agree to use a condom duringthe same time period. The following are considered highly effective methods of contraception:

• combined (estrogen and progestogen-containing) hormonal contraceptionassociated with inhibition of ovulation (oral, intravaginal, transdermal),

• progestogen-only hormonal contraception associated with inhibition of ovulation (oral, injectable, implantable),

• intra-uterine device [IUD]or intra-uterine hormone-releasing system [IUS])WOCBP must refrain from donating eggs until 3 months after the last traceradministration. WOCBP with an exclusive male partner who has undergone vasectomy may choose not touse contraceptives. Women of non-childbearing potential are pre-menopausal females who have undergoneany of the following surgical procedures; hysterectomy, bilateral salpingectomy, orbilateral oophorectomy, or who are post-menopausal defined as 12 months ofamenorrhea (in questionable cases a blood sample with detection offollicle-stimulating hormone [FSH] >25 IU/L is confirmatory). Male participants must be willing to use condom or be vasectomized or practicesexual abstinence from heterosexual intercourse (only allowed when this is thepreferred and usual lifestyle of the participant) to prevent pregnancy and drugexposure of a partner and refrain from donating sperm from the administration oftracer until 3 months after the administration of tracer. Any female partner of anon-vasectomized male participant who is of childbearing potential must usecontraceptive methods with a failure rate of < 1% to prevent pregnancy (see above)from at least 2 weeks prior to administration of tracer to 4 weeks afteradministration of tracer. Cohort-specific inclusion criteria: Cohort 1 (healthy participants)

5. Medically healthy participant without abnormal clinically significant medicalhistory, physical findings, vital signs, ECG, and laboratory values at the time ofthe screening visit, as judged by the Investigator. Cohort 2 (presumed MASH patients) MASH diagnosis based on non-invasive assessments.Participants should have a high level of disease activity with regards topro-peptide of type III collagen (ProC3) as a marker of ongoing fibrogenesis.

6. Steatosis according to biopsy, radiology, or controlled attenuation parameter (CAP) (≥ 280 dB/M 8), assessments ≤ 24 weeks prior to the screening visit.

7. At least 1 cardiometabolic criteria from the following list: A. BMI ≥ 25 kg/m2 [23 Asia] OR waist circumference (WC) > 94 cm (M) 80 cm (F) ORethnicity adjusted, B. Fasting serum glucose ≥ 5.6 mmol/L [100 mg/dL] OR 2-hourpost-load glucose levels ≥ 7.8 mmol/L [≥ 140 mg/dL] OR HbA1c ≥ 5.7% [39 mmol/L) ORtype 2 diabetes OR treatment for type 2 diabetes, C. Blood pressure ≥ 130/85 mmHg ORspecific antihypertensive drug treatment, D. Plasma triglycerides ≥ 1.70 mmol/L [150mg/dL] OR lipid-lowering treatment, E. Plasma high-density lipoprotein (HDL)-cholesterol ≤ 1.0 mmol/L [40 mg/dL] (M) and ≤ 1.3 mmol/L [50 mg/dL] (F) ORlipid-lowering treatment.

8. ProC3 ≥ 12.6 ng/mL. Cohort 3 (verified MASH patients) MASH diagnosis based onhistorical liver biopsy. Participants should have a high level of disease activitywith regards to ProC3 as a marker of ongoing fibrogenesis, to allow for correlationto PET-tracer uptake.

9. Evidence of steatosis according to biopsy, radiology, or CAP (≥ 280 dB/M) orMRI-PDFF, assessments ≤ 24 weeks prior to the screening visit.

10. At least 1 cardiometabolic criteria from the following list: A. BMI ≥ 25 kg/m2 [23 Asia] OR WC > 94 cm (M) 80 cm (F) OR ethnicity adjusted, B.Fasting serum glucose ≥ 5.6 mmol/L [100 mg/dL] OR 2-hour post-load glucose levels ≥ 7.8 mmol/L [≥ 140 mg/dL] OR HbA1c ≥ 5.7% [39 mmol/L) OR type 2 diabetes OR treatmentfor type 2 diabetes, C. Blood pressure ≥ 130/85 mmHg OR specific antihypertensivedrug treatment, D. Plasma triglycerides ≥ 1.70 mmol/L [150 mg/dL] lipid-loweringtreatment, E. Plasma HDL-cholesterol ≤ 1.0 mmol/L [40 mg/dL] (M) and ≤ 1.3 mmol/L [50 mg/dL] (F) OR lipid-lowering treatment.

11. Historical liver biopsy 24 weeks to 4 weeks prior to inclusion with histologicallyproven metabolic dysfunction-associated steatotic liver disease (MASLD).

12. ProC3 ≥ 12.6 ng/mL. Cohort 4 (fibrostenotic CD patients)

13. Fibrostenotic CD as evidenced by persistent luminal narrowing with or withoutobstructive symptoms as assessed with MRI, ≤ 24 weeks prior to the screening visitOR fibrostenotic CD by positive colonoscopy up to 24 weeks prior to the screeningvisit.

14. Crohn's disease activity index (CDAI) < 150

15. Calprotectin < 250

16. C-reactive protein (CRP) < 20 Cohort 5 (PSC patients)

17. Large duct PSC, including intrahepatic bile duct involvement, according to MRI/MRCP.

18. ProC3 ≥ 12.6 ng/mL

Exclusion Criteria:

1. Any contraindication for MRI according to a standard checklist used in clinicalpractice, including claustrophobia, metallic implants or internal electrical devices (e.g., cochlear implant, nerve stimulator, gastric pacemaker, bladder stimulator,cardiac pacemaker, defibrillator, artificial valves in heart, aneurysm clips orcoils, etc.), inability to stay in supine position for 90 minutes, and permanentmakeup or tattoos which in the Investigator's opinion might jeopardize theparticipant's safety or interfere with the imaging assessments.

2. Having worked as a metal worker or welder.

3. History of any clinically significant disease or disorder which, in the opinion ofthe Investigator, may either put the participant at risk because of participation inthe trial or influence the results or the participant's ability to participate inthe trial.

4. Any clinically significant illness, medical/surgical procedure, or trauma within 4weeks of the screening visit.

5. Any malignancy within the past 12 months before the screening visit, with theexception of successfully treated basal cell carcinoma of the skin or in situprostate cancer under active surveillance, with no interventions scheduled duringthe period of trial participation.

6. Any planned major surgery within the duration of the trial participation.

7. Participants who are pregnant, currently breastfeeding, or intend to become pregnantduring the course of the trial.

8. Any positive result at the screening visit for serum hepatitis B surface antigen,hepatitis B or C antibodies and/or human immunodeficiency virus (HIV).

9. Any chronic active infection (e.g., HIV, Hepatitis B or C, tuberculosis, etc.).

10. Poor peripheral venous access, as judged by the Investigator.

11. After 10 minutes of supine rest at the screening visit, any vital signs valuesoutside the following ranges:

• Systolic blood pressure: < 90 or >165 mmHg, or

• Diastolic blood pressure < 50 or >100 mmHg, or

• Pulse < 40 or > 90 bpm

12. The participant has a change in body weight ≥5%, 3 months before the screeningvisit.

13. The participant has any laboratory abnormality or condition that, in theInvestigator's opinion, could adversely affect the safety of the participant orimpair the assessment of trial results.

14. Clinically significantly abnormal 12-lead ECG recording result or cardiac symptomsas judged by the Investigator.

15. The participant is using any prohibited concomitant medications as described in theprotocol, at the discretion of the Investigator.

16. Current use of any hormone therapy at doses that may cause metabolic interference asjudged by the Investigator. Stable hormonal replacement therapy is allowed.

17. Currently participating, or previous participation in another clinical trial within 30 days prior to the screening visit or previous participation in another PETimaging trial within the last 12 months.

18. Positive screening result for alcohol at the screening visit (cohorts 1a and 1bonly).

19. Ongoing or previous alcohol abuse, or long-standing excessive intake of alcohol, asjudged by the Investigator.

20. Presence or history of drug abuse, as judged by the Investigator.

21. History of, or current use of anabolic steroids, as judged by the Investigator.

22. Plasma donation within 1 month of screening or blood donation (or correspondingblood loss) during the last 3 months prior to screening.

23. The Investigator considers the participant unlikely to comply with trial procedures,restrictions, and requirements. Additional exclusion criteria for all participants (cohorts 2-5):

24. The participant is receiving treatment with vitamin E, thiazolidinediones, orglucagon-like peptide-1 receptor agonists unless on a stable dose for 3 monthsbefore the screening Visit and is anticipated to maintain the same dosing regimenthroughout trial participation.

25. Participants with HbA1c ≥48 mmol/mol (6.5%) at screening without a previousdiagnosis of T2D must not take part in the study. Participants with a previousdiagnosis of T2D are permitted to enter the study if on a stable regimen ofantidiabetic therapy for at least 3 months before screening. Participants who are ona stable regimen of antidiabetic therapy for at least 3 months before screening andhave HbA1c of ≥ 63 mmol/mol (9%) at screening should be excluded.

26. Clinically significant disease, apart from T2D, which in the opinion of theInvestigator might interfere with the interpretation of the trial results and/or thesafety of the participant, or in any other way unsuitable for participation in thisclinical trial.

27. The participant has a severe immune-mediated inflammatory disease (IMID) (e.g.,rheumatoid arthritis, spondylarthritis disease spectrum, connective tissuedisorders, cutaneous inflammatory conditions such as psoriasis, atopic dermatitis,hidradenitis suppurativa, asthma, multiple sclerosis). Participants with inactiveIMID or active IMID of mild to moderate severity are permitted to enter the trial. Additional exclusion criteria for MASH and PSC participants (cohorts 2-3, and 5)

28. Liver stiffness > 25 kPa by transient elastography or any sign of decompensation.For cohorts 2 and 3, based on the FibroScan® evaluation on the screening visit, andfor cohort 5 based on routine elastography performed ≤ 12 months.

29. For participants with biopsy-confirmed fibrosis stage F2 or F3, the participant hasany of the following during the screening period:

• Aspartate aminotransferase (AST) levels > 5 x the upper limit of normal (ULN).

• Alanine aminotransferase (ALT) levels > 5 x ULN.

• Alkaline phosphatase (ALP) ≥ 2 x ULN (cohorts 2 and 3) and ALP ≥ 10 (cohort 5).

• Serum creatinine ≥1.5 x ULN or has an estimated glomerular filtration rate (eGFR) < 45 mL/min/1.73m2 (the revised Lund-Malmö GFR estimating equation willbe used).

• International normalized ratio (INR) &gt;1.3.

• Total TBL ≥ULN (except for patients with a documented history of Gilbert'ssyndrome if direct bilirubin is within the normal reference range).

• Direct bilirubin ≥ 3 x ULN.

• Platelet count < 60 x 109/L.

• Presence or history of ascites, hepatic encephalopathy, or variceal bleeding.

• Presence or history of Child-Pugh > 6 (Class B or C), unless due to therapeuticanticoagulation.

• Presence or history of Model for End-Stage Liver disease (MELD) score >12 (onlyfor cohorts 2-3). Note: It is the Investigator's decision, in consultation with the Sponsor, to allowparticipants to enter the study who have clinically meaningful rising tendencies inliver chemistries or significantly elevated liver chemistries that do not yetsatisfy but could be interpreted as clinically concerning (i.e., AST or ALT > 4 xULN) at any visit during the screening period.

30. The participant has a change in body weight ≥ 5% after qualifying liver biopsy.Additional criteria for fibrostenotic CD participants (cohort 4)

31. MRI findings consistent with only inflammation, i.e., edema, hyperemic intestinalwall, restricted diffusion, mesenteric lymphadenopathy etc.