Xilio Stock Jumps 8% On Cancer Drug Data; Gilead Boost Extends Cash Runway Into 2027 — Retail Says Stock Undervalued

Shares of Xilio Therapeutics ended nearly 8% higher on Tuesday after the company reported positive early trial results for its cancer drug XTX301, began dosing patients in Phase 2, and secured a $17.5 million milestone payment from Gilead Sciences.

Xilio said Phase 1 data for XTX301, a tumor-activated IL-12 therapy, showed anti-tumor activity in patients with advanced solid tumors, including two partial responses, while most side effects were mild or moderate. 

The treatment also sustained interferon gamma signaling across cycles, supporting the company’s approach of reprogramming “cold” tumors into inflamed “hot” ones.

Based on the findings, Xilio selected a recommended Phase 2 dose and schedule and has begun treating patients in the Phase 2 portion of its ongoing Phase 1/2 trial in the U.S, which will enroll about 40 participants. 

Enrollment in Phase 1A has been completed, and Phase 1B expansion is still underway.

The milestone payment from Gilead, tied to the start of Phase 2, extends Xilio’s cash runway into the first quarter of 2027. As of June 30, the company held $121.6 million in cash and equivalents and expects to receive the Gilead payment in the fourth quarter of 2025.

Under their March 2024 global license agreement, Gilead may take over development and commercialization of XTX301 after reviewing clinical data, with an option fee of $75 million. 

Xilio could receive up to $500 million in additional development, regulatory and sales milestones, plus tiered royalties ranging from high single digits to mid-teens on global net sales.

On Stocktwits, retail sentiment for Xilio was ‘bullish’ amid a 2,333% surge in 24-hour message volume.

One user said that the stock had “solid news” but needed more trading volume to push through the $0.80 level.

Another user predicted the shares would climb quickly, noting it was “super hard to get shares.” 

They highlighted that Xilio held about $140 million in cash against a roughly $38 million market cap, arguing the market had assigned little to no value to its partnerships, assets, or even its cash balance, and suggesting a reprice was likely.

Xilio’s stock has declined 21.5% so far in 2025.

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