Pfizer secures exclusive option to acquire gene therapy company Vivet Therapeutics

Vivet Therapeutics (“Vivet”), a privately held gene therapy biotech company dedicated to developing gene therapy treatments for inherited liver disorders with high unmet medical need, and Pfizer Inc. (NYSE: PFE) announced today that Pfizer has acquired a 15% equity interest in Vivet and secured an exclusive option to acquire all outstanding shares. Pfizer and Vivet will collaborate on the development of VTX-801, Vivet’s proprietary treatment for Wilson disease.

Wilson disease is a devastating, rare, chronic, and potentially life-threatening liver disorder of impaired copper transport that causes serious copper poisoning. In patients with Wilson disease, a monogenetic mutation disables the normal copper biliary excretion pathway leading to excess copper accumulation in the liver and other organs including the central nervous system. Untreated, Wilson disease results in various combinations and severity of hepatic (fibrosis and cirrhosis), neurologic and psychiatric symptoms, which can be fatal and that can only be cured by liver transplantation. Existing therapies for Wilson disease have sub-optimal efficacy or significant side effects for many patients.

Jean-Phillippe Combal, Co-Founder & CEO of Vivet, said, “We welcome Pfizer as a shareholder and partner that can help us advance our efforts to develop therapies for patients burdened with inherited liver disorders. This investment demonstrates the clear value of Vivet’s innovative approaches to gene therapy.”

Mikael Dolsten, Pfizer Chief Scientific Officer and President, Worldwide Research, Development, and Medical, said, “Pfizer strives to provide meaningful enhancements to the lives of patients with rare diseases. Our partnership with Vivet offers an important expansion of Pfizer’s commitment to collaborate with the scientific community and to accelerate our leading AAV-directed gene therapy portfolio.”

Bringing together Pfizer’s and Vivet’s expertise in liver-directed AAV gene therapy for metabolic diseases creates an opportunity to develop a breakthrough medicine that can meaningfully improve the lives of patients with Wilson disease. “VTX-801 could provide a potentially transformative therapeutic option for patients with Wilson disease by directly addressing the underlying cause of the disease—the inability to excrete copper owing to a mutation in the gene that codes for that function,” said Seng Cheng, Senior Vice President and Chief Scientific Officer of Pfizer’s Rare Disease Research Unit.

Under the terms of the transaction, Pfizer paid approximately €45 million (US$51 million) upon signing and may pay up to €560 million (US$635.8 million) inclusive of the option exercise payment and subject to certain clinical, regulatory, and commercial milestones. Pfizer can exercise its option to acquire 100% of Vivet following the company’s delivery of certain data from the Phase I/II clinical trial for VTX-801. As part of the transaction, Pfizer senior executive Monika Vnuk, M.D., Vice President, Worldwide Business Development, will join Vivet’s Board of Directors. Other terms of the transaction were not disclosed.

Vivet Co-Founder and Chief Scientific Officer Gloria Gonzalez-Aseguinolaza said, “The potential of VTX-801 has already been demonstrated in preclinical models and our partnership with Pfizer will help accelerate development of VTX-801 and expand our other innovative technologies.”

In addition to its Wilson disease program, Vivet is also advancing liver-directed gene therapy programs for progressive familial intrahepatic cholestasis (PFIC) for bile excretion defects and citrullinemia for defects in the urea cycle, which leads to the buildup of ammonia and other toxic substances in the blood.

This release was first published 20 March 2019 by Pfizer.