Financial Performance - For the nine months ended September 30, 2024, the company reported a net loss of $45.1 million, compared to a net loss of $58.7 million for the same period in 2023[114]. - The accumulated deficit as of September 30, 2024, was $370.7 million, indicating significant ongoing operating losses[114]. - The company incurred a net loss of $45.1 million during the nine months ended September 30, 2024, with net cash used in operating activities of $4.2 million[148]. - Net loss for the three months ended September 30, 2024, was $14.0 million, an improvement of $2.7 million compared to a net loss of $16.7 million in Q3 2023[129]. - The company experienced a net cash used in operating activities of $55.2 million during the nine months ended September 30, 2023, primarily driven by a net loss of $58.7 million[149]. - Total operating expenses for the nine months ended September 30, 2024, were $51.6 million, a decrease of $9.4 million from $61.0 million in the same period in 2023[136]. Revenue Generation - The company has not generated any revenue from product sales since inception and does not expect to do so for at least the next several years[116]. - License revenue for the three months ended September 30, 2024, was $2.3 million, a significant increase from $0 for the same period in 2023[130]. - Total revenue for the three months ended September 30, 2024, was $2.3 million, compared to $0 in the same period in 2023[129]. - License revenue for the nine months ended September 30, 2024, was $4.6 million, compared to $0 for the same period in 2023[137]. Cash and Funding - As of September 30, 2024, the company had cash and cash equivalents of $61.3 million, which is expected to fund operations through the end of the second quarter of 2025[115]. - The company raised an aggregate of $430.5 million in gross proceeds through various financing activities, including $225.5 million from preferred units and convertible preferred stock[143]. - During the nine months ended September 30, 2024, net cash provided by financing activities was $21.0 million, primarily from the sale of common stock and prefunded warrants[151]. - The company anticipates that its existing cash will be sufficient to fund operations through the end of the second quarter of 2025, but there is substantial doubt about its ability to continue as a going concern[157]. - The company plans to raise additional capital through equity or debt financings, collaborations, or licensing transactions to fund its operations[157]. Research and Development - The company is advancing clinical development for vilastobart in a Phase 2 trial, with initial data expected in Q4 2024 for approximately 20 patients[110]. - The company plans to report safety, pharmacokinetic, and pharmacodynamic data for XTX301 in Q4 2024 as part of its Phase 1 clinical trial[110]. - The company anticipates that research and development expenses will remain approximately the same or continue to increase as it advances its programs[121]. - Total research and development expenses for the nine months ended September 30, 2024, were $32.4 million, down $8.0 million from $40.4 million in the same period in 2023[138]. - Research and development expenses decreased by $0.3 million from $11.1 million in Q3 2023 to $10.8 million in Q3 2024[131]. - The company has devoted substantially all financial resources to research and development, with significant expenses expected to continue for the foreseeable future[189]. Workforce and Restructuring - A strategic portfolio reprioritization in March 2024 led to a workforce reduction of 15 employees, approximately 21% of the workforce[126]. - Restructuring expenses for the nine months ended September 30, 2024, were $0.9 million, associated with workforce reduction announced in March 2024[141]. Regulatory and Compliance Risks - The company received a deficiency letter from Nasdaq regarding its stock price falling below $1.00 per share, with a compliance period until March 10, 2025[184]. - If compliance is not regained by March 10, 2025, the company may qualify for an additional 180-day compliance period by transferring its listing to the Nasdaq Capital Market[185]. - The company may consider a reverse stock split to regain compliance with Nasdaq listing requirements, but there is no guarantee of success[187]. - The company has substantial doubt about its ability to continue as a going concern if it cannot secure additional capital[176]. - Regulatory authorities may impose additional requirements or restrictions on product candidates post-approval due to safety concerns[232]. Clinical Trials and Product Development - The company is currently evaluating vilastobart in combination with atezolizumab in Phase 1 and Phase 2 clinical trials for advanced solid tumors and microsatellite stable colorectal cancer[201]. - The company is also evaluating XTX301 in a Phase 1 clinical trial, including ongoing monotherapy dose escalation and expansion[201]. - The company has not yet demonstrated the ability to successfully complete late-stage clinical trials or obtain regulatory approvals[196]. - The risk of failure for current and future product candidates is high, with significant uncertainty in preclinical studies and clinical trials[212]. - Clinical trials may experience substantial delays, increasing costs and limiting revenue generation capabilities[215]. - The company may face difficulties in patient enrollment for clinical trials, which could lead to significant delays or abandonment of trials[227]. Competition and Market Risks - If vilastobart is approved, it may face competition from established anti-CTLA-4 therapies such as Yervoy and Imjudo, as well as several other companies with similar programs[304]. - Currently, there are no approved IL-12 therapies for cancer treatment, but multiple companies are developing modified IL-12 delivery programs, posing potential competition for XTX301[306]. - The company is aware of several competitors developing bispecific PD-1 targeted IL-2 therapies, which could impact the development of its research-stage product candidate XTX501[307]. - The company competes in the immunotherapy market for cancer treatment, facing competition from major pharmaceutical and biotechnology companies, as well as academic institutions and research organizations[302]. Manufacturing and Supply Chain Risks - Manufacturing biologics is complex, and the company may experience production issues that could delay development or commercialization[259]. - The company relies on third-party contract development and manufacturing organizations (CDMOs), which are subject to significant regulation and may face capacity limitations or supply interruptions[263]. - A significant disruption in supply from WuXi Biologics could adversely affect the company's business and lead to delays in clinical trials and regulatory approvals[270]. - The company relies on WuXi Biologics for manufacturing processes, exposing it to risks such as price increases and manufacturing delays[268]. Environmental and Geopolitical Risks - Compliance with environmental, health, and safety laws is critical, as failure to comply could result in substantial fines and adversely affect the company's operations[274]. - The company is exposed to geopolitical risks, particularly related to operations in China, which could disrupt manufacturing and supply chains[273].

Exhibit 99.1 Xilio Therapeutics Announces Pipeline and Business Updates and Third Quarter 2024 Financial Results Will present initial Phase 1C dose escalation data for vilastobart (XTX101), a tumoractivated, Fc-enhanced anti-CTLA-4, in combination with atezolizumab, in a late-breaker poster presentation at the SITC Annual Meeting Expect to report initial Phase 2 data in microsatellite stable colorectal cancer (MSS CRC) for vilastobart in combination with atezolizumab in the fourth quarter of 2024 Expect to ...

Combination of vilastobart and atezolizumab demonstrated encouraging early evidence of anti-tumor activity, including unconfirmed partial responses observed in two patients with difficult-to-treat, immunologically “cold” tumors Complete resolution of a metastatic liver lesion observed in a patient with microsatellite stable colorectal cancer (MSS CRC) Safety data indicated combination of vilastobart and atezolizumab was generally well-tolerated and support the potential of vilastobart to be a differentiated ...

Will present initial Phase 1C dose escalation data for vilastobart (XTX101), a tumor-activated, Fc-enhanced anti-CTLA-4, in combination with atezolizumab, in a late-breaker poster presentation at the SITC Annual Meeting Expect to report initial Phase 2 data in microsatellite stable colorectal cancer (MSS CRC) for vilastobart in combination with atezolizumab in the fourth quarter of 2024 Expect to report Phase 1 data for XTX301, a tumor-activated IL-12, in the fourth quarter of 2024 WALTHAM, Mass., Nov. 07, ...

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2024 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 | --- | --- | |----------------------------------------------------------------------------------------------------------|-------------------------------------------------- ...

Exhibit 99.1 Xilio Therapeutics Announces Pipeline and Business Updates and Second Quarter 2024 Financial Results Initiated enrollment in Phase 2 clinical trial of XTX101, a tumor-activated, Fc-enhanced anti-CTLA-4, in combination with atezolizumab in patients with microsatellite stable colorectal cancer (MSS CRC) Initiated enrollment in Phase 1B monotherapy dose expansion for XTX301, a tumor-activated IL-12, in patients with advanced solid tumors; Phase 1A monotherapy dose escalation ongoing with no dose-l ...

Initiated enrollment in Phase 2 clinical trial of XTX101, a tumor-activated, Fc-enhanced anti-CTLA-4, in combination with atezolizumab in patients with microsatellite stable colorectal cancer (MSS CRC) Initiated enrollment in Phase 1B monotherapy dose expansion for XTX301, a tumor-activated IL-12, in patients with advanced solid tumors; Phase 1A monotherapy dose escalation ongoing with no dose-limiting toxicities observed to date Expect to report clinical data for XTX101 and XTX301 in the fourth quarter of ...

(Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2024 Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-40925 Xilio Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 85-1623397 (St ...

Exhibit 99.1 Xilio Therapeutics Announces Pipeline and Business Updates and First Quarter 2024 Financial Results WALTHAM, Mass., May 14, 2024 -- Xilio Therapeutics, Inc. (Nasdaq: XLO), a clinical- stage biotechnology company discovering and developing tumor-activated immuno-oncology therapies for people living with cancer, today announced pipeline progress and business updates and reported financial results for the first quarter ended March 31, 2024. Plan to report clinical data for XTX101 and XTX301, a tum ...

Table of Contents ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from ________ to ________. Commission file number: 001-40925 XILIO THERAPEUTICS, INC. (Exact name of registrant as specified in its charter) (State of Other Jurisdiction of incorporation or Organization) (I.R.S. Employer Identification No.) 828 Winter Street, Suite 300, Waltham, MA 02451 (Address of principal executive offices) (Zip code) Delaware 85-1623397 UNITED STATES SE ...