Gilead looks beyond Trodelvy with Tubulis alliance

Gilead Sciences has shored up its antibody-drug conjugate pipeline by licensing a candidate from German biotech Tubulis in a deal worth up to $415 million.

The agreement includes an upfront payment of $20 million to Munich-based Tubulis for opt-in rights to the ADC, which will carry a topoisomerase I inhibitor payload and is directed at an undisclosed solid tumour target. There's another $30 million on the table if it takes the programme forward and $365 million in possible milestone payments.

The move comes after Gilead has been struggling to extend the indications for its TROP2-targeting ADC Trodelvy (sacituzumab govitecan), which was the crown jewel in its $21 billion acquisition of Immunomedics in 2020.

Trodelvy has been approved by the FDA for breast and bladder cancer, with sales topping $1 billion a year, although it recently failed a confirmatory trial in the latter and was withdrawn for that use.

Meanwhile, Gilead's efforts to extend its use into the big lung cancer market have so far been unsuccessful, denting the company's plan to make one-third of revenues from cancer drugs in 2030. It took a hefty $1.75 billion charge related to Trodelvy in its third-quarter financial results.

The deal with Tubulis gives Gilead access to the German biotech's ADC technology platform, designed to make ADCs more stable, reducing the toxicity that can occur if, for example, the payload drug is released from the molecule before it reaches the site of a tumour.

At the heart of the platform is its Tubutecan topoisomerase I inhibitor payload, which can be joined to targeting antibodies using a proprietary conjugation chemistry linker Alco5.

In a statement, Gilead said getting access to those technologies will allow it to design an ADC candidate with "superior biophysical properties and stability to address current treatment challenges such as durability and off-target toxicity."

Tubulis' technologies have also attracted Bristol-Myers Squibb which agreed a $1 billion-plus deal with the biotech last year and helped the company raise €128 million ($138 million) in an upscaled second-round financing in March.

In June, Tubulis dosed the first patient in the phase 1/2a NAPISTAR 1-01 trial of its lead in-house ADC candidate TUB-040 in ovarian and non-small cell lung cancer. The NaPi2b-targeting drug was awarded a fast-track designation from the FDA in platinum-resistant ovarian cancer later that month.

It also hopes to start a phase 1/2 trial of its next candidate – 5T4-targeting TUB-030 – in solid tumours before the end of the year.