Vivet Therapeutics Announces Multiple Projects Update, Including New VTX-803 Preclinical data To Be Presented At 2021 American Society Of Gene And Cell Therapy Annual Meeting

Compelling additional preclinical data further support therapeutic potential of gene therapy product to treat Progressive Familial Intrahepatic Cholestasis Type 3 (PFIC3).

Paris, France, May 10, 2021 – Vivet Therapeutics (“Vivet”), a clinical stage biotech company dedicated to developing gene therapy treatments for inherited liver disorders with high unmet medical need, today announced that new data regarding VTX-803, Vivet’s AAV-based gene therapy in development for the treatment of PFIC3, will be presented during the ASGCT 24th Annual Meeting, May 11 - 14, 2021.

New findings from the recently completed preclinical studies of VTX-803 will be presented by Dr. Nicholas D. Weber, Research Scientist at Vivet. VTX-803 was already shown to normalize key serum biomarkers, hepatosplenomegaly and liver fibrosis in two-week-old (pre-fibrotic liver) or five-week-old (fibrotic liver) PFIC3 mice.

Dr Weber will present new animal data expanding those results: “AAV-Based Gene Therapy for PFIC3 (VTX-803) Shows Further Promise with Durable Efficacy in PFIC3 Mice at Different Disease Stages” (Tuesday May 11, 2021; 8:00-10:00 AM EST – Abstract 503).

These data show VTX-803 therapeutic effect in older animals (16 weeks) presenting severely fibrotic/cirrhotic livers, without an increase in dose. Dr. Weber will also present VTX-803 long-term studies showing the vector to be safe and the effect to be durable at least up to 6 months and comparable between 5-week-old and 16-week-old mice.

Dr. Gloria González-Aseguinolaza, Vivet Therapeutics CSO and Deputy Director of Cima center of the Fundación para la Investigación Médica Aplicada (FIMA) will co-chair a session: “Gene Therapy for Inborn Errors of Metabolism” (Tuesday May 11, 2021; 5:30-7:30 PM EST), where Dr. Nick Weber will also be presenting additional data on VTX-803.

Vivet is also developing an AAV-based gene therapy product, VTX-802 for Progressive Familial Intrahepatic Cholestasis Type 2 (PFIC2), currently at preclinical stage.

Vivet and Mirum Pharmaceuticals recently announced an exclusive worldwide option, collaboration and license agreement for Vivet’s Gene Therapy programs targeting Progressive Familial Intrahepatic Cholestasis, VTX-802 and VTX-803.

In addition, compelling data from a new animal proof of concept study for VTX-804, one of Vivet’s portfolio indications, an AAV-based gene therapy for Citrullinemia Type 1 (CTLN-1) will be presented by Andrea Bazo, PhD Student at Cima center-FIMA: “rAAV-Mediated Gene Therapy in Combination with Short-Term Nitrogen-Scavenger Treatment Corrects Biochemical and Behavioral Abnormalities and Increases Lifespan in Infant Citrullinemia Type 1 (CTLN-1) Mice” (Tuesday May 11, 2021; 8:00-10:00 AM EST – Abstract 520).

CTLN-1 is a rare autosomal recessive urea cycle defect characterized biologically by hyperammonemia and clinically by progressive lethargy, poor feeding and vomiting in the neonatal form and by variable hyperammonemia in the later-onset form patients.

These preclinical data show that a single dose of VTX-804 administered intravenously to infantile CTLN-1 mice in association with Standard of Care (SOC) normalized lifespan and corrected biochemical and behavioral abnormalities up to 6 months post administration, making VTX-804 a potentially very promising therapeutic strategy for young CTLN-1 patients.

The abstracts listed above can be found online at: https://www.cell.com/action/showPdf?pii=S1525-0016%2821%2900206-9

About Vivet Therapeutics

Vivet Therapeutics is a clinical stage emerging biotechnology company developing novel gene therapy treatments for rare, inherited metabolic diseases.

Vivet is building a diversified gene therapy pipeline based on novel recombinant adeno-associated virus (rAAV) technologies developed through its partnerships with, and exclusive licenses from, the Fundación para la Investigación Médica Aplicada (FIMA), a not-for-profit foundation at the Centro de Investigación Medica Aplicada (CIMA), University of Navarra based in Pamplona, Spain.

Vivet’s lead program, VTX-801, currently under IND clinical development with the GATEWAY clinical trial, is a novel investigational gene therapy for Wilson disease which has been granted Orphan Drug Designation (ODD) by the Food and Drug Administration (FDA) and the European Commission (EC). This rare genetic disorder is caused by mutations in the gene encoding the ATP7B protein, which reduces the ability of the liver and other tissues to regulate copper levels causing severe hepatic damage, neurologic symptoms and potentially death.

Vivet’s second gene therapy product, VTX-803 for PFIC3, received US and European Orphan Drug Designation in May 2020.

Vivet is supported by international life science investors including Novartis Venture Fund, Roche Venture Fund, HealthCap, Pfizer Inc., Columbus Venture Partners, Ysios Capital, Kurma Partners and Idinvest Partners.

Please visit us at www.vivet-therapeutics.com and follow us on Twitter at @Vivet_tx and LinkedIn.

About PFIC

Progressive Familial Intrahepatic Cholestasis (PFIC) is a rare genetic disorder that causes progressive liver disease typically leading to liver failure. In people with PFIC, liver cells are less able to secrete bile or essential components into the bile. The resulting dysregulation in the bile processing causes liver disease in affected individuals. Signs and symptoms of PFIC typically begin in infancy. Patients experience severe itching, jaundice, failure to grow at the expected rate (failure to thrive), and an increasing inability of the liver to function (liver failure). The disease is estimated to affect one in every 50,000 to 100,000 births in the United States and Europe. Six types of PFIC have been genetically identified, all of which are similarly characterized by impaired bile flow and progressive liver disease. The PFIC2 patient population accounts for approximately 60% of the PFIC patient population. PFIC2 is caused by a mutation in the ABCB11 gene, which normally encodes a bile salt export pump protein that moves bile acids out of the liver. PFIC3, is caused by a genetic defect in the ABCB4 gene (also designated MDR3) which encodes a phospholipid translocator involved in biliary phospholipid (phosphatidylcholine) excretion. In PFIC3, cholestasis results from the toxicity of bile in which detergent bile salts are not inactivated by phospholipids, leading to bile canaliculi and biliary epithelium injuries.