The ENVISION trial is for people who:
To find out if you are eligible to participate in ENVISION some information from your medical records will be needed and additional tests will be performed.
For the first 6 months of the trial, participants will be randomly assigned to 1 of 2 groups:
A placebo looks just like the investigational medication but does not contain any active ingredients.
If participants have an attack during the study, they will be able to take hemin (if available).
Neither participants nor the study team will be able to choose which group they are assigned to. In addition, neither of them will know if they are assigned to receive the investigational medication or the placebo. This is called double-blind.
In both groups, the study medication is given as a subcutaneous injection (just under the skin). After completing the 6-month double-blind treatment period, participants will enter the open-label extension (OLE) period where all participants will receive monthly injections of the investigational medication for up to 30 months (2.5 years).
ENVISION participants will be instructed by the study doctor on how to treat any attacks that occur during the trial. The study doctor will also discuss how to manage any chronic symptoms that may be experienced, including pain.
Participants who currently take hemin on a regular basis to prevent attacks (prophylaxis usage) will need to stop taking it when they enter screening. This is to allow the researchers to see the effects of the investigational medication. It ensures that any effects that could otherwise be due to taking hemin are not attributed to the investigational medication.
Participation in ENVISION will last up to approximately 38 months.
up to 2 months
To check eligibility for the trial
Participants will be randomly assigned to 1 of the following treatment groups:
During this time participants will have 8 study visits. There is a 50% chance of receiving the investigational medication and a 50% chance of receiving a placebo, given once a month.
Up to 30 months (2.5 years)
During this time participants will have regular study visits. All participants will receive the investigational medication once a month
The study medication and all trial-related procedures are provided at no cost. In addition, transportation to and from study visits, or reimbursement for travel-related costs may also be provided.