PET-Based Imaging of Radiolabeled CIT-013

Overview

Sponsor-declared trial summary

Key facts

Sponsor

Citryll B.V.

Participant type

Patients

Age range

18-64 years, 65+ years

Gender

Male and Female

Therapeutic area

Diseases [C] - Immune System Diseases [C20]

Trial duration

4 Nov 2025 → ongoing

Decision date (initial)

2025-10-24

Transition trial

No

Low-intervention

No

Rare-disease indication

No

Vulnerable population

No

External identifiers

EU CT number

2025-522189-60-00

ClinicalTrials.gov

NCT07147959

Trial design

CTIS Part I — objectives, methods, condition coding

Main objective

Scope: Others, Efficacy, Safety, Pharmacokinetic

The primary objective of this trial is to evaluate the distribution of radiolabeled CIT-013 in patients with IMIDs.

Secondary objectives 2

1. Evaluate the safety and tolerability of CIT-013 in patients with IMIDs.
2. Characterize pharmacokinetic profile of CIT-013 in patients with IMIDs.

Conditions and MedDRA coding

Inflammatory mediated immune diseases

Eligibility criteria

Principal inclusion / exclusion criteria as submitted by sponsor

Inclusion criteria 8

1. For male participants with female partners of child-bearing potential, an adequate form of contraception must be adhered to, and men must refrain from donating sperm, prior to entry into the trial and for a further 6 months after IP administration.
2. Willing and able to provide written, informed consent.
3. (RA specific) Diagnosed with RA according to the 2010 classification criteria of the American College of Rheumatology (ACR) and the European League Against Rheumatism (EULAR) ≥ 6 months prior to screening (diagnosis based on medical records).
4. (active RA specific) Disease Activity Score 28 (DAS28) C-Reactive Protein (CRP) (DAS28-CRP) ≥ 4.2 AND ≥ 1 Swollen Joint AND ≥ 1 Tender Joint at screening.
5. (RA in remission specific) DAS28-CRP score ≤ 2.6 AND no Swollen Joints or Tender Joints at screening.
6. (HS specific) HS of ≥ 6 months duration (diagnosis based on medical records).
7. (HS specific) International Hidradenitis Suppurativa Severity Score System (IHS4) score of ≥ 7 AND at least 1 draining tunnel at screening.
8. Female (of non-childbearing potential) or male between 60-85 years of age (inclusive).

Exclusion criteria 12

1. Known history of severe allergies, non-allergic drug reactions, or multiple drug allergies.
2. Known hypersensitivity to any of the ingredients (L-histidine, Histidine-HCl monohydrate, Sucrose, Polysorbate) of the IP, including the radioactive tracer, or to drugs of similar chemical structure or pharmacological profile.
3. Significant clinical manifestation of any metabolic, allergic, dermatological, hepatic, renal, hematological, pulmonary, cardiovascular, gastrointestinal, neurological, respiratory, endocrine, or psychiatric disorder, at discretion of the Investigator (or designee).
4. Any other multi-system autoimmune disease.
5. Any other condition which, in the Investigator’s opinion, will interfere with the trial.
6. Female participants of childbearing potential (including females that are pregnant or breastfeeding). Follicle-stimulating hormone (FSH) levels < 50 IU/L are exclusionary, unless there is a confirmed other reason for non-childbearing potential (e.g., complete hysterectomy), at discretion of the Investigator.
7. A recent (within 2 years) history of drug and/or alcohol abuse.
8. Prior treatment with CIT-013.
9. Being an employee of the Investigator or trial site, with direct involvement in the proposed trial or other studies under the direction of that Investigator or trial site or being a family member of an employee or the Investigator.
10. Active HBV, HCV, or HIV infection, as tested and confirmed during screening.
11. Evidence of active TB or being at high risk for TB, assessed according to local site procedures.
12. Male participants with a pregnant partner.

Endpoints

Primary and secondary outcome measures (English text)

Primary endpoints 1

1. This objective is measured by whole body PET-CT imaging 24 hours (D2) after IP administration. In addition to visual assessment, uptake of [89Zr]-DFO-CIT-013 will be quantified per organ(-system). In vivo distribution profiles will be evaluated per cohort to determine ranges of uptake per organ(-system) and between cohorts to compare uptake in different IMIDs.

Secondary endpoints 2

1. Frequency and severity of treatment-emergent adverse events (TEAE) throughout the trial period, including clinically relevant findings and ADAs.
2. Pharmacokinetic (PK) levels throughout the trial, per cohort.

Investigational products

Investigational medicinal products (IMPs), comparators, placebo, auxiliary

Test 1

Sponsors and contacts

Sponsor organisations, regulatory contacts, third parties

Citryll B.V.

Sponsor organisation

Citryll B.V.

Address

Rk Gebouw, Kloosterstraat 9 Kloosterstraat 9

City

Oss

Postcode

5349 AB

Country

Netherlands

Scientific contact point

Organisation

Citryll B.V.

Contact name

Maarten Kraan

Public contact point

Organisation

Citryll B.V.

Contact name

Nicole Keijzer

Locations

1 EU/EEA country · 1 investigational sites

By country

Investigational sites

Country notifications

Trial-start, recruitment-start, end and early-termination notifications submitted per Member State

Results and documents

Annex IV summary of results, Annex V layperson summary, and all documents registered in CTIS for this trial

Documents 15 files

Public protocol annexes, IB summaries, regulatory submissions and post-authorisation documents registered in CTIS.

Application history

3 submissions — initial application plus substantial / non-substantial modifications