• Pfizer has locked down an exclusive option to acquire all outstanding shares of Vivet Therapeutics, a privately held gene therapy biotech based in France.
• The option was part of a larger deal in which Pfizer paid 45 million euros, or $51 million, for a 15% stake in Vivet. The big pharma may hand over an additional 560 million euros if it decides to purchase the rest of Vivet’s shares, though that payment is subject to certain clinical, regulatory and commercial milestones.
• Pfizer can exercise its option to acquire all of Vivet once the biotech’s lead candidate, which targets a rare disorder known as Wilson disease, generates certain data from a planned Phase 1/2 clinical trial. A Pfizer spokesperson told BioPharma Dive the companies intend to file in the first quarter of 2020 applications with U.S. and European regulators to start in-human testing of the candidate.

Gene therapy is quickly embedding itself into the DNA of many big pharmas and biotechs. Novartis last year spent $8.7 billion to acquire AveXis for its adeno-associated virus technology and for its spinal muscular atrophy treatment, which may receive Food and Drug Administration approval by May.

Roche and Biogen also recently purchased gene therapy developers, with the former snagging Spark Therapeutics and the latter buying Nightstar Therapeutics.

AveXis, Spark and Nightstar all received takeover bids from multiple suitors, suggesting at least a few companies didn’t get the deal they were hoping for and may be on the lookout for other gene therapy opportunities.

Pfizer is another company to have demonstrated a growing interest in the technology. The pharmaceutical giant got its hands on a gene therapy manufacturing facility through a $150 million acquisition of Bamboo Therapeutics in 2017. It has also entered research collaborations with Spark and Sangamo Therapeutics for gene therapies aimed at a variety of diseases, from hemophilia B to ALS.

Vivet’s research, meanwhile, centers on liver diseases.

The biotech is aiming to cure Wilson disease with its lead candidate, VTX-801, which in theory works by correcting defective copper transporters. Patients with the disease don’t properly metabolize copper, which causes the metal to build up in body tissues — particularly in the liver and central nervous system.

Symptoms of the disease often aren’t expressed for decades, but when they arise they can vary widely in type and severity. Patients may experience depression, seizure or acute liver failure, according to Vivet. By the company’s estimates, about 1 in 30,000 people worldwide have Wilson disease.

Vivet isn’t alone in targeting the disease. Last April, Alexion paid $855 million to acquire Wilson Therapeutics and its late-stage therapeutic for the rare condition.

While Pfizer’s new stake provides Vivet with an infusion of cash, the small developer and its novel adeno-associated virus technology had already attracted investments from big pharma prior to Wednesday’s announcement. The company has received funding from venture arms of Novartis and Roche, for instance.