Medical Information Only. Always consult your healthcare provider before enrolling in any clinical trial.
NCT03338816 · ClinicalTrials.gov registry record · Phase 3
ENVISION: A Study to Evaluate the Efficacy and Safety of Givosiran (ALN-AS1) in Patients With Acute Hepatic Porphyrias (AHP)
A Phase 3 study of Acute Hepatic Porphyria and Acute Intermittent Porphyria, sponsored by Alnylam Pharmaceuticals.
- Completed
- Registry status
- Phase 3
- Development phase
- 94
- Enrollment target
- 20
- Study locations
NCT03338816: Completed Phase 3 study of Acute Hepatic Porphyria and Acute Intermittent Porphyria, sponsored by Alnylam Pharmaceuticals.
NCT03338816 is a Phase 3 study of Acute Hepatic Porphyria and Acute Intermittent Porphyria that has completed, run by Alnylam Pharmaceuticals. The registered enrollment target is 94 participants, below the 772-participant average among 15,282 other Phase 3 trials with a reported enrollment target (88% lower). The trial reports 20 study locations across 12 states. According to ClinicalTrials.gov, the official US trial registry.
The verdict
NCT03338816, a Phase 3 study of Acute Hepatic Porphyria and Acute Intermittent Porphyria, has completed, sponsored by Alnylam Pharmaceuticals.
- COMPLETED
- Registry status
- Phase 3
- Development phase
- 94 participants
- Enrollment target
- 20
- Study locations
Study Summary
The purpose of this study is to evaluate the effect of subcutaneous givosiran (ALN-AS1), compared to placebo, on the rate of porphyria attacks in patients with Acute Hepatic Porphyrias (AHP).
Primary Outcome
Porphyria attacks were defined as meeting all of the following criteria: an acute episode of neurovisceral pain in the abdomen, back, chest, extremities and/or limbs, no other medically determined cause, and required treatment with intravenous (IV) dextrose or hemin, carbohydrates, or analgesics, or other medications such as antiemetics at a dose or frequency beyond the participant's usual daily porphyria management. The annualized rate of porphyria attacks is a composite endpoint which included
Conditions Studied
Interventions
- DRUG Placebo
- DRUG Givosiran
Study Locations (20)
Other
- Clinical Trial Site - Auchenflower
- Clinical Trial Site - Camperdown
- Clinical Trial Site - Sofia
- Clinical Trial Site - Edmonton
- Clinical Trial Site - Odense
- Clinical Trial Site - Helsinki
- Clinical Trial Site - Paris
- Clinical Trial Site - Chemnitz
- Clinical Trial Site - Munich
Arkansas
- Clinical Trial Site - Little Rock
California
- Clinical Trial Site - San Francisco
Massachusetts
- Clinical Trial Site - Boston
Michigan
- Clinical Trial Site - Ann Arbor
New York
- Clinical Trial Site - New York
North Carolina
- Clinical Trial Site - Winston-Salem
Pennsylvania
- Clinical Trial Site - Philadelphia
Trial Details
| Field | Value |
|---|---|
| Enrollment Target | 94 participants |
| Start Date | 2017-11-16 |
| Est. Completion | 2021-05-31 |
| Phase | Phase 3 |
What the finished NCT03338816 record still lists
NCT03338816 is an interventional study that assigns participants to a tested intervention. The registry caps enrollment at 94 participants, a relatively small participant target, below the 772-participant average among 15,282 other Phase 3 trials with a reported enrollment target (88% lower).
The record links to 7 conditions, with Acute Hepatic Porphyria appearing as the primary indexed condition, and to 2 interventions - of which Placebo is the first listed.
NCT03338816 names 20 study sites across 12 states, led by Other, Arkansas, California.
Frequently Asked Questions
What is clinical trial NCT03338816 about?
NCT03338816 is a clinical study titled "ENVISION: A Study to Evaluate the Efficacy and Safety of Givosiran (ALN-AS1) in Patients With Acute Hepatic Porphyrias (AHP)". The purpose of this study is to evaluate the effect of subcutaneous givosiran (ALN-AS1), compared to placebo, on the rate of porphyria attacks in patients with Acute Hepatic Porphyrias (AHP).
What is the current status of trial NCT03338816?
This trial is currently completed. It is a Phase 3 study. The enrollment target is 94 participants. The study started on 2017-11-16. Estimated completion is 2021-05-31.
What conditions does trial NCT03338816 study?
This clinical trial studies the following conditions: Acute Hepatic Porphyria, Acute Intermittent Porphyria, Porphyria, Acute Intermittent, Acute Porphyria, Hereditary Coproporphyria (HCP).
What interventions are being tested in trial NCT03338816?
The interventions under investigation include: Placebo (DRUG), Givosiran (DRUG).
Who is sponsoring clinical trial NCT03338816?
This trial is sponsored by Alnylam Pharmaceuticals, which has 49 total clinical trials registered on ClinicalTrials.gov.
Where is trial NCT03338816 being conducted?
This trial has 20 study locations across Arkansas, California, Massachusetts, Michigan, New York. Contact the study sites directly through ClinicalTrials.gov for enrollment availability.
Learn More About Clinical Trials
Similar trials for Acute Hepatic Porphyria
Matched on the same primary condition, ranked to surface studies in the same phase first, then by recruiting status, no relevance scoring or editorial curation.
Where NCT03338816's enrollment target sits among peer trials
94 1719th of 2000 higher than 279 of 2,000 other Phase 3 trials
participants (enrollment target), bucketed by value
Each bar is a band; taller bars hold more other Phase 3 trials. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.
Source ClinicalTrials.gov registry export · 2026-08-08
Nationwide trials with similar profiles
Cross-condition peers matched on enrollment target and registry start date, not the same-condition list above.
Similar enrollment target
- NCT03747146 · 94 participants · NA
Enhanced Recovery After Surgery (ERAS) Total Knee Replacement (TKR) With a Transitional Pain Service
- NCT04061421 · 94 participants · Phase 1
Active Myeloid Target Compound Combinations in MDS/MPN Overlap Syndromes Overlap Syndromes (ABNL-MARRO)
- NCT04205968 · 94 participants · Phase 2
Ramucirumab and Paclitaxel or FOLFIRI in Advanced Small Bowel Cancers
- NCT04464759 · 94 participants · Phase 1
A Study of Nivolumab and Hydroxychloroquine or Nivolumab/Ipilimumab and Hydroxychloroquine in Advanced Melanoma
Similar registry start date
- NCT05962346 · started 2026-12 · NA
Fetal Endoscopic Tracheal Occlusion for Congenital Diaphragmatic Hernia
- NCT07125183 · started 2026-12 · Phase 2
Study on Efficacy and Tolerability of Weekly Doxorubicin in Elderly Patients With Advanced or Metastatic Leiomyosarcoma
- NCT07292298 · started 2026-11 · Phase 2
Phase 2 Single-Arm Rectal Cancer Brachytherapy for Patients With Low-Lying Residual Adenocarcinoma After Total Neoadjuvant Therapy to Improve Organ Preservation Rates
- NCT04263285 · started 2026-10 · NA
Treatment of Depression Post-SCI