A Phase 2 interventional study of ALN-6400 in Von Willebrand Disease (VWD) and Heavy Menstrual Bleeding (HMB), sponsored by Alnylam Pharmaceuticals. Recruiting at 21 sites in 5 countries. Open to female participants aged 16 Years to 45 Years. Per ClinicalTrials.gov, last updated 2026-10-26.
Sponsored by Alnylam Pharmaceuticals · Phase 2, Interventional, and Treatment
The purpose of this study is to evaluate the safety, tolerability, efficacy, and pharmacodynamics (PD) of multiple doses of ALN-6400 in adult and adolescent patients with VWD and HMB
96 studies on the registry are indexed under von Willebrand Diseases; 25 are open to participants now.
This study's planned enrollment of 24 is close to the median of 25 across 41 interventional studies indexed under von Willebrand Diseases.
Browse von Willebrand Diseases studies →Alnylam Pharmaceuticals is the lead sponsor of 84 studies on the registry; 19 are open to participants now.
Of its 18 completed or terminated interventional studies of FDA-regulated products, 15 (83%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria -
Note: other protocol defined inclusion / exclusion criteria apply
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Platelets
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ALT and AST (liver enzymes)
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ULN (upper limit of normal)
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Bilirubin
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants will be administered multiple doses of ALN-6400.
Drug: ALN-6400
Participants will be administered multiple doses of ALN-6400.
Drug: ALN-6400
ALN-6400 will be administered subcutaneously (SC).
Frequency of Adverse Events
Time frame: Up to Week 72
Change from Baseline in Plasminogen (PLG) Plasma Activity Levels
Time frame: Screening and up to Week 72 postdose
Change from Baseline in PLG Plasma Protein Levels
Time frame: Screening and up to Week 72 postdose
Change from Baseline in Menstrual Blood Loss Via Pictorial Blood Assessment Chart (PBAC)
Time frame: Screening and up to Week 72 postdose
Patient-reported Outcome (PRO) assessed by Patient Global Impression of Change (PGI-C) Score
Time frame: Week 4 up to Week 72
Change from Baseline in PRO assessed by Patient Global Impression of Severity (PGI-S) Score
Time frame: Baseline up to Week 72
Plan to share: Yes — Phase 2-4: Access to Anonymized individual participant data that support these results is made available 12 months after study completion and not less than 12 months after the product and indication have been approved in the United States (US) and/or the European Union (EU). Data will be provided contingent upon the approval of a research proposal and the execution of a data sharing agreement. Requests for access to data can be submitted via the website www.vivli.org.
No publications or documents are linked to this record.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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