Analogy 1: Imagine a specialized Bristol-Myers Squibb, but focused on building 'smart bomb' immunotherapies that only activate inside the tumor.

Analogy 2: Like an early-stage Genentech or Merck, pioneering a new generation of cancer drugs designed to be 'off' until they reach the tumor.

• XTX101: A clinical-stage, tumor-selective anti-CTLA-4 monoclonal antibody currently in Phase 1/2 clinical trials for solid tumors.
• XTX202: A modified form of IL-2, masked with a protein domain to prevent binding activity until cleaved by tumor microenvironment-associated proteases.
• XTX301: An IL-12 product candidate, masked with a protein domain to prevent binding activity until cleaved by tumor microenvironment-associated proteases.
• XTX401: An IL-15 product candidate, masked with a protein domain to prevent binding activity until cleaved by tumor microenvironment-associated proteases.

Xilio Therapeutics (XLO) is a clinical-stage biotechnology company focused on the development of immunotherapies. As a company in the Phase 1/2 clinical trial stage with its drug candidates (e.g., XTX101, XTX202), it does not yet have any approved commercial products available for sale.

Therefore, Xilio Therapeutics does not currently have major customers, whether individuals or other companies, purchasing its products. Its primary activities are research and development and conducting clinical trials.

The key risks to Xilio Therapeutics (XLO) primarily revolve around the inherent uncertainties of clinical-stage biotechnology development and the company's financial stability.

1. Clinical Development and Regulatory Approval Risk: As a clinical-stage biotechnology company, Xilio Therapeutics' success is heavily dependent on the successful outcome of its ongoing and planned preclinical studies and clinical trials, including the Phase 1/2 clinical trials for XTX101 and the advancement of its cytokine programs (XTX202, XTX301, XTX401). There is significant uncertainty regarding the timing and results of these trials, and failure to achieve positive clinical results, encounter unexpected safety issues, or obtain necessary regulatory approvals would significantly and adversely affect the company's business.
2. Financial Position and Need for Additional Capital: Xilio Therapeutics faces substantial financial risks, characterized by a poor financial strength rating, high leverage, and negative earnings per share. The company has a history of recurring losses from operations and its Altman Z-Score indicates a potential risk of bankruptcy. While Xilio has reported an anticipated cash runway into 2027, the substantial capital requirements for ongoing drug development mean the company will likely need to secure additional financing, which could be challenging given its financial metrics and could result in dilution for existing shareholders.

Xilio Therapeutics, Inc. (NASDAQ: XLO) develops immunotherapies targeting various cancers. The addressable markets for its main product candidates are as follows:

XTX101 (tumor-selective anti-CTLA-4 mAb for solid tumors)

• The global CTLA-4 inhibitors market was valued at approximately USD 2.6 billion in 2024 and is projected to reach USD 8.7 billion by 2035, growing at a Compound Annual Growth Rate (CAGR) of 11.6% from 2025 to 2035.
• Another estimate for the global CTLA-4 inhibitor market forecasts it to reach between USD 3.0 billion and USD 4.5 billion in 2025, with a CAGR of approximately 2.5% to 4.5% through 2030.
• The broader global solid tumor therapeutics market, which XTX101 addresses, was valued at USD 362.21 billion in 2024 and is projected to reach USD 1,557.42 billion by 2032, with a CAGR of 20.00% during the forecast period of 2025 to 2032. North America dominates this market due to the high prevalence of solid tumors and advancements in treatment.

XTX202 (modified IL-2 product candidate for cancer)

• The global Human Interleukin-2 (IL-2) market was valued at USD 1.8 billion in 2023 and is projected to reach USD 4.5 billion by 2032, exhibiting a CAGR of 10.9%.
• The market size for IL-2-based/targeting therapies in the 7MM (United States, Germany, France, Italy, Spain, United Kingdom, and Japan) is expected to reach an estimated USD 4 billion by 2034. Specifically, the United States IL-2 market is projected to reach USD 4 billion by 2034.
• The global cytokine market, which includes IL-2 therapies, was valued at USD 101.8 billion in 2025 and is estimated to reach USD 173.5 billion by 2034, with a CAGR of 5.91% from 2026 to 2034. North America held approximately 62.9% of the global cytokine market in 2025.

XTX301 (IL-12 product candidate for cancer)

• The global Interleukin 12 receptor market size is projected to reach an estimated value of USD 3.2 billion by 2032, growing from USD 1.5 billion in 2023 at a CAGR of 8.5%.
• Another report indicates the global Interleukin 12 Receptor market size was recorded at $1304.5 million in 2021 and is expected to reach $1788 million by the end of 2025, and $3358.8 million by 2033, growing at a CAGR of 8.2% during 2025 to 2033.
• XTX301 targets solid tumors. The global solid tumor therapeutics market sizes mentioned for XTX101 also apply here, with the market valued at USD 362.21 billion in 2024 and projected to reach USD 1,557.42 billion by 2032.

XTX401 (IL-15 product candidate for cancer)

• Interleukin-15 (IL-15) is considered a promising immunotherapeutic agent for cancer.
• While specific market size data solely for IL-15 focused therapies are not as widely reported as for IL-2 or CTLA-4, IL-15 falls within the broader global cytokine market. This market was valued at USD 101.8 billion in 2025 and is estimated to reach USD 173.5 billion by 2034.
• The cytokine market is projected to reach USD 149.41 billion by 2031, growing at a CAGR of 7.08% from 2026.

Xilio Therapeutics (XLO), a clinical-stage biotechnology company focused on developing tumor-activated immuno-oncology therapies, anticipates several key drivers for future revenue growth over the next two to three years.

1. Milestone and Option Payments from Strategic Collaborations: A significant portion of Xilio's near-term revenue growth is expected to come from its partnerships with larger pharmaceutical companies, notably Gilead Sciences and AbbVie. The collaboration with Gilead for XTX301 (IL-12) includes a potential $75 million option fee if Gilead exercises its option in the first half of 2027, following the delivery of an option data package. Additionally, Xilio anticipates further development milestones and option fees from its AbbVie collaboration in 2026 and 2027. These partnerships have already contributed substantially to collaboration and license revenue, with a reported increase driven by both AbbVie and Gilead.
2. Advancement and Potential Commercialization of Key Pipeline Candidates: The successful progression of Xilio's lead clinical programs, particularly XTX101 and XTX301, is a crucial driver. Promising Phase 2 data for vilastobart (XTX101), a tumor-selective anti-CTLA-4 mAb, in combination therapy for metastatic colorectal cancer, showcases its potential. XTX301, a modified IL-12, has advanced to Phase 2 with Gilead and has demonstrated encouraging Phase 1 results, including partial responses in heavily pre-treated solid tumor patients. While full commercialization is likely beyond the 2-3 year horizon, positive clinical outcomes can trigger further milestone payments and enhance the value of future product sales or expanded partnerships.
3. Initiation of New Clinical Programs and Partnerships: Xilio's strategy involves expanding its pipeline by nominating new development candidates from its masked T-cell engager programs, including PSMA, CLDN18.2, and STEAP1. The company anticipates nominating these candidates in the latter half of 2025 and the first half of 2026, with plans to advance at least two into IND-enabling studies and submit Investigational New Drug (IND) applications in 2027. Successful progression of these early-stage assets could attract new collaborators or expand existing agreements, leading to additional upfront payments and milestone revenues within or shortly after the forecast period.

Share Issuance

• In October 2021, Xilio Therapeutics completed its initial public offering (IPO), raising approximately $117.6 million in gross proceeds by issuing 7,353,000 shares at $16.00 per share.
• The company received $47.0 million in net proceeds from a follow-on public offering in June 2025. Additionally, Xilio received $35.8 million in gross proceeds in late 2025 and early 2026 from the exercise of Series B warrants associated with this offering, including full exercises by key investors such as Coastlands Capital, Frazier Life Sciences, and Gilead Sciences.
• In February 2026, Xilio priced an underwritten offering of 74,780,300 pre-funded warrants, expecting to generate approximately $40.0 million in gross proceeds (approximately $37.1 million net).
• A 1-for-14 reverse stock split was announced in March 2026, effective March 13, 2026, to increase the per-share market price and regain compliance with Nasdaq listing requirements, reducing outstanding shares from approximately 73.5 million to about 5.2 million.

Inbound Investments

• In February 2025, Xilio Therapeutics entered into a collaboration and option agreement with AbbVie, receiving $52.0 million in upfront payments, consisting of a $42.0 million cash payment and a $10.0 million equity investment in Xilio common stock by AbbVie. This collaboration also provides for potential additional contingent payments and royalties up to $2.1 billion.
• In September 2025, Xilio achieved a $17.5 million development milestone under its license agreement with Gilead Sciences related to the efarindodekin alfa (XTX301) program. The company also has potential future funding, including a $75 million option fee if Gilead licenses the IL-12 program.

Capital Expenditures

• Xilio Therapeutics anticipates that its cash and cash equivalents, which were an estimated $137.5 million as of December 31, 2025 (including proceeds from warrant exercises and the February 2026 offering), will be sufficient to fund its operating expenses and capital expenditure requirements into the second quarter of 2027.
• As of September 30, 2025, with $103.8 million in cash and cash equivalents, and a $17.5 million development milestone from Gilead, the company expected to fund its operating expenses and capital expenditure requirements into the first quarter of 2027.