Gilead is also provided with an exclusive option to purchase the remaining stake in Tizona for up to an additional $1.2bn. The deal is also comprised of an option exercise fee and potential future milestone payments.
Tizona has discovered TTX-080, which is a potential first-in-class investigational antibody designed to target HLA-G, a novel immune checkpoint expressed across multiple tumour types.
Tizona has secured clearance from the US Food and Drug Administration (FDA) for its TTX-080. It intends to begin a phase 1 clinical trial in the third quarter of this year to assess TTX-080 both as a monotherapy and in combination with other agents in patients with advanced cancers.
The company has the flexibility to purchase the remaining stake in Tizona following the readout of a phase 1b study of Tizona’s TTX-080 or earlier if Gilead is interested.
Tizona CEO Scott Clarke said: “Gilead’s support will enable Tizona to accelerate and broaden our TTX-080 clinical program while also enabling us to rapidly advance our rich, first-in-class preclinical portfolio and target validation efforts.”
Subject to antitrust clearance under the Hart-Scott-Rodino Antitrust Improvements Act and other customary closing conditions, the deal is expected to be completed in the third quarter of this year.
Tizona will spin-off TTX-030, the firm’s investigational, first-in-class anti-CD39 antibody partnered with AbbVie, into a separate entity before the completion of the deal.
Cowen is serving as a financial advisor, while Ropes & Gray is acting as legal counsel to Gilead. Latham & Watkins is serving as legal counsel, while Squire Patton Boggs is acting as IP counsel to Tizona.
Gilead Sciences chairman and CEO Daniel O’Day said: “Tizona is pursuing first-in-class cancer immunotherapies that could make an important difference in oncology by helping patients who don’t respond to current checkpoint inhibitors.”
In June this year, Gilead Sciences agreed to acquire 49.9% equity stake in Pionyr Immunotherapeutics for $275m. The deal also provides Gilead with an exclusive option to acquire the remaining stake in Pionyr for around $315m.