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Evaluating ALN-6400 in healthy adults

InsigHHT: A Phase 1/2, Randomized, Double-blind, Placebo-controlled, 2-part Study of the Safety, Tolerability, Efficacy, Pharmacokinetics, and Pharmacodynamics of Single Dose ALN-6400 in Adult Healthy Volunteers and Multiple Dose ALN-6400 in Adult Patients With Hereditary Hemorrhagic Telangiectasia (HHT)

PHASE1; PHASE2 · Alnylam Pharmaceuticals · NCT06659640

This study is testing a new treatment called ALN-6400 in healthy adults to see if it's safe and how it works in the body.

Quick facts

PhasePHASE1; PHASE2
Study typeInterventional
Enrollment120 (estimated)
Ages18 Years and up
SexAll
SponsorAlnylam Pharmaceuticals (industry)
Locations16 sites (Birmingham, Alabama and 15 other locations)
Trial IDNCT06659640 on ClinicalTrials.gov

What this trial studies

This study aims to assess the safety, tolerability, pharmacokinetics, and pharmacodynamics of ALN-6400 by administering single ascending doses to healthy volunteers. Participants will receive either the ALN-6400 treatment or a placebo. The study will monitor various health parameters to ensure the treatment's safety and effectiveness. This phase 1 trial is crucial for understanding how the drug behaves in the human body.

Who should consider this trial

Good fit: Ideal candidates for this study are healthy adult volunteers without significant liver or kidney issues.

Not a fit: Patients with liver disease, chronic viral infections, or those who do not meet the health criteria may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to new RNAi therapeutics that improve treatment options for various diseases.

How similar studies have performed: While this approach is relatively novel, previous studies of RNAi therapeutics have shown promising results.

Eligibility criteria

Show full inclusion / exclusion criteria 
Inclusion Criteria -

Part A:

* Is a healthy adult volunteer

Part B:

* Is an adult patient with a clinical diagnosis of HHT

Exclusion Criteria -

Part A:

* Has alanine aminotransferase (ALT) or aspartate aminotransferase (AST) \> upper limit of normal (ULN)
* Has known human immunodeficiency virus (HIV) infection; or known current or chronic hepatitis C virus or hepatitis B virus infection
* Has an estimated glomerular filtration (eGFR) of \<90 mL/min/1.73m\^2 at screening

Part B:

* Has ALT or AST \>2×ULN
* Has total bilirubin \>1.5×ULN
* Has eGFR of \<30 mL/min/1.73m\^2 at screening

Parts A and B:

* Is not willing to comply with the contraceptive requirements during the study period

Note: other protocol defined inclusion / exclusion criteria apply

Where this trial is running

Birmingham, Alabama and 15 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.

View on ClinicalTrials.gov →

Conditions: Hereditary Hemorrhagic Telangiectasia, siRNA, RNAi therapeutic, Plasminogen, PLG, HHT, Osler-Weber-Rendu, epistaxis

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.