A Single Ascending Dose Study to Assess the Safety, Tolerability, Pharmacokinetics and Pharmacodynamics of CITY-FXI in Healthy Adults and Adults With FV Leiden or Prothrombin G20210A Mutation
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: CITY-FXI, Placebo.
- Who it may be relevant to
- Registry conditions: Factor V Leiden, Prothrombin G20210A. Basic parameters: 18 years — 60 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- United Kingdom
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
Unsure about the terms? Read our patient guide →
Official title
A Phase 1, Randomised, Double-Blind, Placebo-Controlled Single Ascending Dose Study to Evaluate the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of CITY-FXI, a FXI Targeting siRNA, Administered Subcutaneously in Healthy Adults and Adults With Factor V Leiden or Prothrombin G20210A Mutation
Overview
This is a first-in-human (FIH), single-center, randomised, double-blind, placebo-controlled, single ascending dose (SAD) study evaluating the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of CITY-FXI in healthy adults and adults with Factor V Leiden (FVL) or prothrombin G20210A mutation.
Detailed description
The study will be conducted in two parts:
* Part A: Single Ascending Dose in Healthy Adults * Part B: Single Ascending Dose in Adults with Factor V Leiden (FVL) or Prothrombin G20210A Mutation
Interventions
- Drug CITY-FXI
siRNA (subcutaneous injection) - Drug Placebo
Saline (subcutaneous injection)
Primary outcome measures
- Incidence, severity, and relationship of treatment-emergent adverse events (TEAEs) [Time frame: Through study completion, up to Day 360]
Secondary outcome measures (6)
- Maximum plasma concentration (Cmax) [Time frame: Day -1 to Day 3]
- Area under plasma concentration time curve (AUC) of CITY-FXI [Time frame: Day -1 to Day 3]
- Amount excreted in urine (Ae) of CITY-FXI [Time frame: Day -1 to Day 3]
- Change from baseline in levels of plasma Factor XI (FXI) [Time frame: Up to Day 360]
- Change from baseline of Factor XI (FXI) activity [Time frame: Up to Day 360]
- Change from baseline in activated partial thromboplastin time (aPTT) [Time frame: Up to Day 360]
Eligibility criteria
Inclusion criteria
- Males and women of non-childbearing potential (WONCBP) aged 18 to 45 years (Part A only)
- Male and female participants aged 18 to 60 (Part B only)
- Body Mass Index (BMI) between 18 and 25 kg/m2 (inclusive) and a minimum weight of 50 kg
- Ability and willingness to comply fully with all study procedures and lifestyle considerations
- Confirmed diagnosis of FVL or prothrombin G20210A mutation via genetic testing (Part B only)
- Women of childbearing potential (WOCBP) must agree to use acceptable highly effective contraceptive methods (Part B only)
Exclusion criteria
- Any clinically significant systemic disease or disorder, including but not limited to cardiovascular, hepatic, or oncological conditions
- History or evidence of any bleeding disorders
- History of clinically significant spontaneous bleeding
- Prior treatment with an investigational agent
- Confirmed diagnosis of homozygous mutations, or combined thrombophilic defects of (Part B only)
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: Yes
Study design
- Allocation
- Randomized
- Model
- Sequential
- Masking
- Double blind
- Primary purpose
- Treatment
Study locations
United Kingdom · 1 center
- Richmond Pharmacology — London
Identifiers
NCT: NCT07430397 · FXI-1101 · C24027