A Study to Evaluate the Safety and Tolerability, and the Efficacy of Si-544 in Adults With Psoriasis Vulgaris or Psoriatic Arthritis

NCT06191042 | Completed Phase 1

• 2 other identifiers: SEL-0022023-507393-40
• Study Type: interventional
• Target: 45
• Locations: 1 country
• Sites: 4

Brief Summary

The main objective of this study is to investigate the safety and tolerability of si-544. Other objectives are to study the metabolism of si-544 in the body and to assess the effects of si-544 on cells of the body's immune system (immune cells) that have been chronically activated by the disease. Likewise, the effect of si-544 on inflammatory responses in the body triggered by the disease and other disease symptoms will be investigated.

Conditions

Psoriasis Vulgaris; Psoriatic Arthritis

Outcome Measures

Primary Outcomes (2)

• Determination of safety and tolerability of treatment with si-544

  Occurrence of adverse events (AEs) and serious AEs (SAEs), including description of type, frequency, severity, and causal relationship of adverse events (AEs) and serious AEs

  From Day -35 to Day 106

• Determination of safety and tolerability of treatment with si-544

  Change in clinical laboratory, electrocardiogram (ECG), vital signs, and peripheral oxygen saturation from Baseline to all assessed timepoints

  From Day 1 (Baseline) to Day 106

Secondary Outcomes (16)

• Determination of the plasma concentrations of free si-544

  Day 1 (Baseline) and Day 25

• Determination of the pharmacodynamics (PD) of si-544 as assessed by the number of T cells in peripheral blood

  From Day 1 (Baseline) to Day 29 (Week 5), Week 8, Week 12 and Week 16

• Determination of the pharmacodynamics (PD) of si-544 as assessed by immunophenotypes of T cell subsets

  From Day 1 (Baseline) to Day 29 (Week 5), Week 8, Week 12 and Week 16

• Determination of the pharmacodynamics (PD) of si-544 as assessed by serum cytokine levels

  From Day 1 (Baseline) to Day 29 (Week 5), Week 8, Week 12 and Week 16

• Determination of the immunogenicity of si-544 treatment

  From Day 1 (Baseline) to Day 29 (Week 5) and Week 16

Study Arms (2)

si-544

EXPERIMENTAL

Drug: si-544

Placebo

PLACEBO COMPARATOR

Drug: Placebo

Interventions

si-544 DRUG

Subcutaneous injection in the abdomen

si-544

Placebo DRUG

Subcutaneous injection in the abdomen

Placebo

Eligibility Criteria

• Age: 18 Years - 75 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Subject has the capacity for consenting, was informed about the nature, the scope, and the relevance of the clinical study, voluntarily agrees in participation and in the study provisions, and duly signed the ICF approved by the ethics committee before any study-related procedure is performed
• Men and women aged ≥18 to 75 years
• Willing and able to adhere to the protocol requirements
• Women of childbearing potential must:
• have a negative pregnancy test (blood) at Screening and a negative pregnancy test (urine) at Day 1
• agree to use, and be able to comply with, highly effective measures of contraceptive control (failure rate less than 1% per year when used consistently and correctly) without interruption, from Screening through 30 days after the last IMP injection
• Reliable methods for this study are:
• i. combined (estrogen and progestogen containing) hormonal contraception associated with inhibition of ovulation (oral, intravaginal, transdermal) ii. progestogen-only hormonal contraception associated with inhibition of ovulation (oral, injectable, implantable) iii. intrauterine device iv. intrauterine hormone-releasing system v. bilateral tubal occlusion vi. vasectomized sexual partner (provided that the partner is the sole sexual partner of the woman of childbearing potential and has received medical assessment of the surgical success) vii. sexual abstinence (only if defined as refraining from heterosexual intercourse during the entire period of risk associated with the study treatment) Abstinence is only accepted as true abstinence: when this is in line with the preferred and usual lifestyle of the subject (periodic abstinence \[eg, calendar, ovulation, symptothermal, postovulation methods and withdrawal\] is not an acceptable method of contraception).
• c. agree to abstain from breast feeding during the study participation and for 90 days after the last IMP injection
• Postmenopausal (no menses for at least 1 year without alternative medical cause) or surgically sterile women (tubal ligation, hysterectomy, or bilateral oophorectomy)
• Men must agree to practice true abstinence or to use a condom during sexual contact with a pregnant woman or a woman of childbearing potential during study participation and for at least 90 days after the last IMP injection, even after undergoing a successful vasectomy.
• Diagnosis of Ps at least 3 months before Screening
• Active Ps with ≥3% BSA involved and with at least 1 psoriatic plaque (other than nail change)
• \. Diagnosis of PsA based on the classification for psoriatic arthritis criteria (CASPAR) at least 3 months before Screening
• \. Diagnosis of active Ps with at least 1 psoriatic plaque (other than nail change)

You may not qualify if:

• Known history of hypersensitivity to constituents or excipients in the pharmaceutical formulation of the IMP
• Uncontrolled hypertension or uncontrolled diabetes, as judged by the investigator
• Chronic disease other than Ps or PsA not adequately controlled by stable treatment (ie, no changes or initiation of treatment within 4 weeks before Screening and Day 1)
• History of seizures
• Presence or history of paresthesia or neuropathy
• Clinically significant ECG abnormalities, as judged by the investigator
• Clinically relevant disease which could affect the safety of the subject during the study or impede the subject's ability to complete the study, as assessed by the investigator
• Presence of acute infection within 7 days before Screening or Day 1, as judged by the investigator
• Known or active infection with Mycobacterium tuberculosis and/or positive tuberculosis interferon γ release assay result at Screening
• Known or active infection with HIV, hepatitis B virus, or hepatitis C virus
• Known or suspected abuse of alcohol, drugs, or medicinal products
• Therapy with biologics used for the treatment of Ps and/o PsA (including those under investigation) within 1 year before Day 1
• UV phototherapy or systemic therapy (except methotrexate for the treatment of PsA) within 4 weeks of Day 1
• Vaccination within 2 weeks (for live vaccines within 4 weeks) before Day 1 and/or planned vaccination during the treatment period
• Current or previous (within 4 weeks before Day 1) participation in another clinical study with an IMP or a medical device

Sponsors & Collaborators

• selectION Therapeutics GmbH: lead
• FGK Clinical Research GmbH: collaborator

Study Sites (4)

selectION Clinical Trial Site

Bad Bentheim, Germany

Location

selectION Clinical Trial Site

Berlin, Germany

Location

selectION Clinical Trial Site

Blankenfelde-Mahlow, Germany

Location

selectION Clinical Trial Site

Hamburg, Germany

Location

MeSH Terms

Conditions

Arthritis, Psoriatic

Condition Hierarchy (Ancestors)

Spondylarthropathies; Spondylarthritis; Spondylitis; Spinal Diseases; Bone Diseases; Musculoskeletal Diseases; Arthritis; Joint Diseases; Psoriasis; Skin Diseases, Papulosquamous; Skin Diseases; Skin and Connective Tissue Diseases

Study Officials

• Andreas Klostermann, Dr.

  selectION Therapeutics GmbH

  STUDY DIRECTOR

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: December 10, 2023
• First Posted: January 5, 2024
• Study Start: January 22, 2024
• Primary Completion: June 23, 2025
• Study Completion: June 23, 2025
• Last Updated: July 3, 2025

Record last verified: 2025-06

Data Sharing

• IPD Sharing: Will not share

Locations

DE (4)