Vivet is currently evaluating the two programs, VTX-803 (for PFIC subtype 3) and VTX-802 (for PFIC subtype 2), in preclinical studies. The two AAV gene therapy programs correct the defective multidrug resistance protein 3 (MDR3) transporter for PFIC3 and bile salt export pump (BSEP) functions for PFIC2.

The gene therapies may ultimately provide a cure for patients living with rare liver diseases. The therapies have the potential to restore physiological bile secretion and prevent severe hepatic complications of the disease, according to the firms.

Vivet received orphan drug designation for VTX-803 by the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA) in May 2020.

Under the agreement, Vivet will continue to advance the preclinical studies. Mirum has the exclusive option to license the programs after which Mirum would lead the clinical development and any future commercialization of the programs. Until the option has been exercised, Mirum will provide funding to support the continued research and development costs associated with the two gene therapy programs.

Financial details of the license agreement were not disclosed.