Genethon and Hansa Biopharma announce initiation of a Phase 2 trial of imlifidase as a pre-treatment to GNT-0003 in severe Crigler-Najjar syndrome
The trial will be conducted in patients with pre-existing anti-AAV antibodies which limit use of gene therapy treatment
Lund, Sweden and Evry, France 3 December 2024. Hansa Biopharma, “Hansa” (Nasdaq Stockholm: HNSA) and Genethon, a pioneer and a leader in gene therapy research and development for rare genetic diseases, today announced initiation of GNT-018-IDES, a Phase 2 trial in patients with Crigler-Najjar syndrome with pre-existing antibodies against adeno-associated virus (AAV) vectors. The trial will evaluate the efficacy and safety of a single intravenous administration of Genethon’s gene therapy GNT-0003 following pre-treatment with imlifidase, Hansa’s first-in-class immunoglobulin G (IgG) antibody cleaving enzyme therapy, in patients with severe Crigler-Najjar syndrome and pre-formed antibodies to AAV serotype 8 (AAV8).
Søren Tulstrup, President and CEO, Hansa Biopharma said, “We know that anti-AAV antibodies prevent up to 1 in 3 people from benefitting from gene therapies using AAV-vectors.1-4 That’s why our collaboration with Genethon and the initiation of the Phase 2 clinical trial in Crigler-Najjar syndrome is so important. This collaboration with Genethon is the second of our three partnerships with leading gene therapy companies to have reached the clinical stage, marking an important milestone in our efforts to enable a much larger group of patients to benefit from potentially lifesaving gene therapies.”
Antibodies against AAV vectors remain a major challenge, as their presence in patients excludes them from entering clinical studies with potentially curative gene therapy treatments and from access to currently marketed and future gene therapies.
Frédéric Revah, CEO, Genethon added: “This new clinical trial reflects Genethon’s commitment in pursuing innovative strategies to ensure and broaden access to gene therapies for patients suffering from rare diseases. Patients with pre-existing neutralizing antibodies against AAV vectors cannot today benefit from gene therapy. The initiation of this clinical trial and the collaboration with Hansa Biopharma is a crucial step for Genethon and highlights several years of pioneering research to understand and control the immune response to AAV in order to make gene therapy more effective and to increase the number of patients able to access it.”
GNT-018-IDES, sponsored by Genethon, is a single arm Phase 2 trial with a total of three patients aged ≥18 years with Crigler-Najjar syndrome and pre-formed anti-AVV8 antibodies and requiring phototherapy. Once screened, patients will undergo a three-month observational period before being dosed with imlifidase followed by GNT-0003. Genethon and Hansa expect to communicate data from the trial in 2025.
GNT-0003 is currently being evaluated in a pivotal clinical trial following the positive results of the phase 1-2 dose escalation study showing safety and efficacy of GNT-0003, and was granted PRIME priority drug status from the EMA. If successful, GNT-0003 would be the first gene therapy treatment for Crigler-Najjar syndrome.
