FVIII + Emicizumab for Hemophilia A (PRIORITY Trial)

Palo Alto (17 mi)

Overseen byGuy Young, MD

Age: < 18

Sex: Male

Travel: May be covered

Time Reimbursement: Varies

Trial Phase: Phase 4

Waitlist Available

Sponsor: Children's Hospital Los Angeles

No Placebo Group

Prior Safety Data

Approved in 2 jurisdictions

Trial Summary

What is the purpose of this trial?This study will enroll children who have hemophilia A with inhibitors who successfully completed immune tolerance induction per the ISTH criteria (negative inhibitor titer, recovery \>66% of expected, and half-life of \>6 hours with their current FVIII concentrate). Previous to emicizumab, there was only one option for these patients which was to continue FVIII therapy in a prophylaxis mode to prevent bleeding. There was a sense that the ongoing FVIII served to maintain tolerance however no evidence for this notion exists and in fact what limited data is available suggests that continuing FVIII may not be necessary simply to maintain tolerance. To figure out this question, this will be a randomized, controlled 2 arm study which will randomize patients post-successful ITI to emicizumab plus weekly FVIII (for maintenance of tolerance) versus emicizumab alone. Patients will be followed for up to 2 years. We aim to enroll 52 subjects. The FVIII weekly arm can use any factor VIII concentrate and emicizumab is standard of care for inhibitor and non-inhibitor patients.

Eligibility Criteria

This trial is for boys aged 12 or younger with severe or moderate hemophilia A who have had a high inhibitor response (>5 BU) but achieved immune tolerance. They must be currently on emicizumab or agree to switch to it, and within one year of successful immune tolerance induction as per ISTH criteria.

Inclusion Criteria

I am 12 years old or younger.

I am a male with severe or moderate hemophilia A.

I am currently using emicizumab or open to switching to it.

I've successfully completed immune tolerance therapy for hemophilia within the last year.

Exclusion Criteria

I am older than 12 years.

I do not want to receive IV treatments for clotting.

Treatment Details

The study tests if continuing weekly FVIII therapy alongside emicizumab is necessary to maintain immune tolerance in children post-successful ITI compared to just using emicizumab alone. It's a randomized, controlled study with two groups followed for up to two years.

2Treatment groups

Active Control

Group I: Emicizumab + FVIII weeklyActive Control2 Interventions

In addition to emicizumab prophylaxis,participants will receive non-prophylactic exposure to FVIII concentrates through weekly 50 IU/kg ±10% doses - the choice of FVIII concentrate is at the discretion of the PI.

Group II: Emicizumab onlyActive Control1 Intervention

Participants will only receive emicizumab prophylaxis.

Emicizumab is already approved in United States, European Union for the following indications:

🇺🇸 Approved in United States as Hemlibra for: