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TerminatedNCT05256810Updated Mar 29, 2024

A Study to Evaluate ALN-XDH in Healthy Subjects and Patients With Gout

A Phase 1/2 interventional study of ALN-XDH and Placebo in Gout, sponsored by Alnylam Pharmaceuticals. Terminated at 1 site in United Kingdom. Open to participants aged 18 Years to 65 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2024-03-29.

Sponsored by Alnylam Pharmaceuticals · Phase 1/2, Interventional, and Treatment

Why this study was terminated
The Sponsor elected not to continue with the study
Phase
Phase 1/2
Study type
Interventional
Enrollment
44
Allocation
Randomized
Ages
18 Years to 65 Years
Sex
All
01

Study summary

The purpose of this study is to:

  • Part A: Evaluate the safety and tolerability of single ascending doses of ALN-XDH in healthy adult participants
  • Part B: Evaluate the safety, tolerability and efficacy of ALN-XDH as monotherapy in adult patients with gout
  • Part C: Evaluate the safety, tolerability and efficacy of ALN-XDH as add-on therapy in adult patients with gout
02

Conditions studied

  • Gout

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Keywords

  • Serum uric acid
  • siRNA
03

In context

Gout

232 studies on the registry are indexed under Gout; 45 are open to participants now.

This study's enrollment of 44 is below the median of 121 across 202 interventional studies indexed under Gout.

Browse Gout studies →

Lead sponsor

Alnylam Pharmaceuticals is the lead sponsor of 82 studies on the registry; 20 are open to participants now.

Of its 17 completed or terminated interventional studies of FDA-regulated products, 14 (82%) have results posted.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 65 Years
Sexes eligible
All
Accepts healthy volunteers
Yes

Inclusion criteria

  • Part A: has serum uric acid (sUA) level ≥4 mg/dL and ≤7 mg/dL
  • Parts B and C: meets the American College of Rheumatology criteria for acute arthritis of primary gout
  • Part B: has an sUA level ≥8 mg/dL while not receiving urate-lowering therapy (ULT) or following a 1-week washout period of prior ULT
  • Part C: has been on a stable dose of allopurinol for gout for ≥6 weeks prior to screening
  • Part C: has an sUA level ≥6 mg/dL

Exclusion criteria

Exclusion Criteria:

  • Parts A, B and C: Has received an investigational agent within the last 30 days
  • Parts A, B and C: Has experienced or is being treated for acute gout flare(s) within 14 days prior to randomization
05

Study design

Phase
Phase 1 / Phase 2
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Quadruple (Participant, Care provider, Investigator, Outcomes assessor)
Enrollment
44 participants (actual)

Study arms

  • Experimental
    Part A: ALN-XDH

    A single dose of ALN-XDH administered by subcutaneous (SC) injection.

    Drug: ALN-XDH

  • Placebo comparator
    Part A: Placebo

    A single dose of placebo administered by SC injection.

    Drug: Placebo

  • Experimental
    Part B: ALN-XDH Single Dose

    A single dose of ALN-XDH administered by SC injection.

    Drug: ALN-XDH

  • Experimental
    Part B: ALN-XDH Multiple Dose

    Multiple doses of ALN-XDH administered by SC injection.

    Drug: ALN-XDH

  • Placebo comparator
    Part B: Placebo

    Multiple doses of placebo administered by SC injection.

    Drug: Placebo

  • Experimental
    Part C: ALN-XDH

    A single dose of ALN-XDH administered by SC injection.

    Drug: ALN-XDH

  • Placebo comparator
    Part C: Placebo

    A single dose of placebo administered by SC injection.

    Drug: Placebo

Interventions

  • DrugALN-XDH

    ALN-XDH administered by SC injection

  • DrugPlacebo

    Placebo administered by SC injection

06

What researchers measure

Primary outcomes

  1. Part A: Frequency of Adverse Events

    Time frame: Up to 10 months

  2. Parts B and C: Frequency of Adverse Events

    Time frame: Up to 14 months

  3. Parts B and C: Percentage of Participants with Serum Uric Acid (sUA) <6 mg/dL

    Time frame: Up to 12.25 months

Secondary outcomes

  1. Part A: Area Under the Plasma Concentration-time Curve (AUC) for ALN-XDH and Potential Metabolites

    Time frame: Day 1 predose and up to 48 hours postdose

  2. Part A: Maximum Plasma Concentration (Cmax) for ALN-XDH and Potential Metabolites

    Time frame: Day 1 predose and up to 48 hours postdose

  3. Part A: Time to Maximum Plasma Concentration (tmax) for ALN-XDH and Potential Metabolites

    Time frame: Day 1 predose and up to 48 hours postdose

  4. Part A: Fractional Excreted in Urine (fe) for ALN-XDH and Potential Metabolites

    Time frame: Day 1 predose and up to 24 hours postdose

  5. Part A: Percent Change from Baseline in sUA

    Time frame: Baseline through Month 9

  6. Parts B and C: Percentage of Participants with sUA <5 mg/dL

    Time frame: Up to 12.25 months

  7. Parts B and C: Percentage Change from Baseline in sUA Level

    Time frame: Up to 12.25 months

  8. Parts B and C: Plasma Concentrations of ALN-XDH and Potential Major Metabolite(s)

    Time frame: Day 1 and Day 85 predose and up to 4 hours postdose

  9. Parts B and C: Frequency of Treatment-associated Gout Flares

    Treatment-associated gout flares are defined as gout flares that occur within 6 months of study drug initiation.

    Time frame: Up to 6 months

  10. Parts B and C: Percent Change from Baseline in 24-hour Urine Uric Acid (uUA)

    Time frame: Baseline through Month 6

  11. Parts B and C: Percent Change from Baseline in Serum Xanthine

    Time frame: Baseline through Month 6

  12. Parts B and C: Percent Change from Baseline in 24-hour Urine Xanthine

    Time frame: Baseline through Month 6

  13. Parts B and C: Percent Change from Baseline in Serum Hypoxanthine

    Time frame: Baseline through Month 6

  14. Parts B and C: Percent Change from Baseline in 24-hour Urine Hypoxanthine

    Time frame: Baseline through Month 6

07

Study locations

1 site
  • Clinical Trial Site
    London, United Kingdom
08

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Mar 29, 2024, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT05256810
Lead sponsor
Alnylam Pharmaceuticals
Responsible party
Sponsor
First posted
Feb 25, 2022
Start date
Feb 25, 2022
Primary completion
Jan 25, 2023
Completion
Jan 25, 2023
Last update
Mar 29, 2024

Study contacts

Medical Director
study director · Alnylam Pharmaceuticals

Oversight

FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is terminated, as verified in Mar 2024. You cannot join it, but the record below documents what was studied.

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