08:53 AM EDT, 09/09/2025 (MT Newswires) -- Xilio Therapeutics ( XLO ) said Tuesday it started phase 2 of an ongoing phase 1/2 clinical trial assessing efarindodekin alfa, a potential monotherapy for patients with certain advanced solid tumors.

The company said that in connection with beginning of phase 2, it achieved a $17.5 million development milestone under its exclusive global license agreement with Gilead Sciences ( GILD ) to develop and commercialize efarindodekin alfa.

Xilio said it expects to receive the $17.5 million by Q4, an amount that will help it fund its operating expenses and capital expenditure needs into Q1 of 2027.

The company said that based on phase 1 data, efarindodekin alfa showed "promising" anti-tumor activity.

Shares of Xilio were up 2% and Gilead rose 0.5% in recent premarket activity.