Gilead pays $50M to team up with synthetic lethality startup Tango

Gilead is paying $50 million upfront to enter into an immuno-oncology collaboration with Tango Therapeutics. The agreement gives Gilead the option to pick up the worldwide rights to five targets discovered and validated by Tango.

Massachusetts-based Tango, a 2017 Fierce 15 winner, is a Third Rock Ventures-backed startup that uses CRISPR and other tools to discover synthetic lethal gene pairs. Around 12 months ago, Tango CEO Barbara Weber said the approach had uncovered more targets than the startup could handle internally, driving it to enter into discussions with potential partners.

Now, Gilead has signed up to take some of Tango’s projects going forward. Tango is retaining the full rights to its lead programs but granting Gilead an option on up to five other targets that it will discover and validate. 

Details of the targets are yet to emerge, but Gilead is interested in Tango’s work on immune evasion. This approach sees Tango go after targets in tumor cells that render them invisible to immune cells. By inhibiting evasion signals, Tango thinks it can destroy the cloaking devices used by tumor cells and thereby facilitate anticancer immune attacks. 

Reflecting the early-stage nature of the deal, Gilead is paying a fairly small upfront fee and putting up a sizable amount of milestones. If the programs hit all their goals, Gilead will hand over $1.7 billion in preclinical fees and development, regulatory and commercial milestones. Tango is also in line to take home low double-digit royalties and has the option to co-develop two programs in a 50/50 split.

The potential payoff from the deal for Gilead is years away but the agreement is indicative of how the company is trying to position itself for long-term growth. Gilead has long seen oncology as a way to expand beyond HIV and hepatitis C, but its efforts in the area have been mixed. Zydelig won FDA approval in 2014 but faltered commercially following patient deaths. JAK inhibitor momelotinib never made it that far.

Gilead has moved more forcefully into the field over the past year by acquiring Kite Pharma for $11.9 billion and following up with a string of smaller deals. The Tango agreement adds another avenue for Gilead to explore in the coming years. If the immune evasion idea delivers on its promise, Gilead could emerge with candidates capable of boosting the efficacy of other drugs by turning cold tumors hot.