ATHN Transcends: Hemophilia Gene Therapy Outcomes Arm

The Hemophilia Gene Therapy Outcomes Arm is part of the Hemophilia cohort in the ATHN Transcends protocol. The study arm was formerly known as ATHN 14: A Longitudinal Cohort Study of the Safety and Effectiveness of Gene Therapy for People with Hemophilia. It is a pragmatic study designed to understand the outcomes of gene therapy with real-world practices across a wide range of products, including the safety of adeno-associated viral vector or lentiviral vecto-mediated factor VIII and factor IX therapies when used for participants with hemophilia.

The study aims to enroll all people with hemophilia A or B of any severity with or without inhibitors having received or will receive a gene transfer product in the next 6 months. Data for the study is to be collected from participants at the time of enrollment and at the following timepoints relative to vector infusion: 3 months, 6 months, 1 year, 18 months, 2 years, and annually thereafter. Participants will be followed longitudinally for at least 15 years after vector infusion.

Safety is measured according to medical events in the European Haemophilia Safety Surveillance (EUHASS) protocol, which includes:

  • Allergic or other acute events
  • Treatment-emergent side effects of therapy
  • Transfusion transmitted infections
  • Inhibitor development
  • Thrombosis
  • Cardiovascular events
  • Malignancies
  • Neurological events
  • Death

In addition to the EUHASS endpoints, the study will collect data for the following adverse event of special interest (AESI): liver toxicity, defined as transaminase elevation (progressive elevation of hepatic tranaminases of greater than or equal to 1.5 times baseline level), and confirmation on repeat testing.

The central lab for testing is Versiti Blood Center of Wisconsin, which will cover factor level, inhibitor, and genetic testing.

Enrollment planned for late 2021
ATHN Transcends is being implemented at HTCs in phases. The Hemophilia Gene Therapy Outcomes Arm is scheduled to begin enrollment in 2021. Treatment centers with gene therapy patients and those that have expressed an interest in participating are invited to participate in this study.

To learn more about ATHN Transcends and the Hemophilia Gene Therapy Outcomes Arm, email