STTK

– Phase 1 clinical trial results for SL-325 demonstrated a favorable safety profile, a potentially best-in-mechanism immunogenicity profile, and durable DR3 blockade of TL1A binding, potentially enabling prolonged dosing intervals – – RECEPTIVE-CD1 Phase 2b clinical trial of SL-325 in patients with Crohn’s disease expected to initiate in the third quarter of 2026 – – Announced lead DR3 x IL-23 receptor blocking, half-life extended bispecific antibody product candidate, SL-846, with initial Phase 1 clinical data expected in 2027 – –Strengthened balance sheet with approximately $208.3 million in cash and cash equivalents and short-term investments as of June 30, 2026, expected to fund operations into 2029 – AUSTIN, Texas and DURHAM, N.C., Aug. 11, 2026 (GLOBE NEWSWIRE) -- Shattuck Labs, Inc. (Shattuck or the Company) (NASDAQ: STTK), a clinical-stage biotechnology company pioneering the development of potential first-in-class monoclonal and bispecific DR3 blocking antibodies for the treatment of patients with inflammatory and immune-mediated diseases, today reported financial results for the second quarter ended June 30, 2026 and provided recent business highlights. "The Phase 1 clinical data for SL-325 has checked all of the boxes and positions SL-325 as a potentially winning antibody in the TL1A/DR3 axis heading into Phase 2 clinical development," said Taylor Schreiber, M.D., Ph.D., Chief Executive Officer of Shattuck. "The RECEPTIVE-CD1 Phase 2b clinical trial in Crohn’s disease is on track to initiate in the third quarter, and is designed to establish the efficacy profile of SL-325 across three dose levels, both at induction and at maintenance time points. As we expected, clinical proof of concept for the TL1A/DR3 axis is now emerging outside of IBD. We are pleased to see this continued momentum for the class, and we believe that blocking DR3 will prove more efficacious than blocking TL1A across any indication where TL1A is implicated." DR3 Program Development in 2026 Shattuck is advancing a pipeline of DR3-targeted monoclonal and bispecific antibody product candidates for the treatment of inflammatory and immune-mediated diseases. Recent updates and anticipated upcoming milestones include: SL-325 Shattuck’s lead clinical-stage product candidate, SL-325, is a potentially first-in-class DR3 blocking antibody for the treatment of Crohn's disease, ulcerative colitis, and other inflammatory and immune-mediated diseases. Phase 1 clinical trial results for SL-325 demonstrated a potentially best-in-mechanism profile. Key findings from the Phase 1 clinical trial include: RECEPTIVE-CD1 Phase 2b clinical trial of SL-325 in patients with moderately-to-severely active Crohn's disease is expected to initiate in the third quarter of 2026. SL-846 Shattuck’s lead bispecific product candidate, SL-846, is a potentially first-in-class, half-life extended DR3 x IL-23 receptor blocking antibody for the treatment of inflammatory and immune-mediated diseases. SL-846 is currently being evaluated in an ongoing IND-enabling GLP toxicology study in non-human primates. Preclinical data for SL-846, including safety, pharmacokinetics, and receptor occupancy from the ongoing GLP toxicology study are expected to be presented in a poster at UEG Week, to be held October 17-20, 2026. Shattuck expects to initiate a Phase 1 healthy volunteer clinical trial of SL-846 and report initial data in 2027. Upcoming Events Shattuck plans to participate in the following upcoming event(s). Details will be included on the Events & Presentations section of the Company’s website. 21st Annual Wells Fargo Healthcare Conference, September 8-10, 2026. Management will participate in one-on-one meetings. Citi’s 2026 Biopharma Back to School Conference, September 9-10, 2026. Management will participate in one-on-one meetings. Cantor Global Healthcare Conference, September 9-11, 2026. Taylor Schreiber, M.D., Ph.D., CEO of Shattuck Labs will participate in a fireside chat, and management will participate in one-on-one meetings. United European Gastroenterology Week (UEGW), October 17-20, 2026. Shattuck will present posters containing preclinical and non-human primate toxicology data for SL-846. Capital Markets Update Shattuck completed an underwritten public offering with aggregate gross proceeds of approximately $86.2 million. As of July 1, 2026, all of the common stock warrants issued in the Company's August 2025 private placement have been exercised, resulting in aggregate gross proceeds of approximately $57.1 million. Second Quarter 2026 Financial Results Cash and Cash Equivalents and Investments: As of June 30, 2026, cash and cash equivalents and short-term investments were $208.3 million, as compared to $50.5 million as of June 30, 2025. Research and Development (R&D) Expenses: R&D expenses were $11.7 million for the quarter ended June 30, 2026, as compared to $8.7 million for the quarter ended June 30, 2025. General and Administrative (G&A) Expenses: G&A expenses were $4.5 million for the quarter ended June 30, 2026, as compared to $4.4 million for the quarter ended June 30, 2025. Net Loss: Net loss was $15.2 million for the quarter ended June 30, 2026, or $0.12 per basic and diluted share, as compared to a net loss of $12.5 million for the quarter ended June 30, 2025, or $0.24 per basic and diluted share. Financial Guidance As of June 30, 2026, cash and cash equivalents, and short-term investments, were approximately $208.3 million. Shattuck’s current cash and cash equivalents, and short-term investments are expected to fund operations into 2029. This cash runway guidance is based on the Company’s current operational plans and excludes any additional capital that may be received, proceeds from business development transactions, and/or additional costs associated with clinical development activities that may be undertaken. About SL-325 SL-325 is a potentially first-in-class Death Receptor 3 (DR3) blocking antibody designed to achieve a complete and durable blockade of the clinically validated DR3/TL1A pathway. Shattuck’s preclinical studies demonstrate high affinity binding and superior activity over TL1A antibodies, and offer a data-driven rationale for targeting the TNF receptor, DR3, versus its ligand, TL1A. SL-325 is a fully Fc-silenced, fully human immunoglobulin G monoclonal antibody. In a recently completed Phase 1 clinical trial, SL-325 demonstrated a favorable safety profile, a potentially best-in-mechanism immunogenicity profile, no evidence of residual DR3 agonism, and provided durable blockade of TL1A binding to DR3 at low doses. SL-325 will be evaluated in a Phase 2b clinical trial in Crohn’s disease patients, which is expected to initiate in the third quarter of 2026. About SL-846 SL-846 is a potentially first-in-class Death Receptor 3 (DR3) by IL-23 receptor (IL-23R) blocking bispecific antibody designed to achieve complete and durable blockade of the clinically validated DR3/TL1A and IL-23/IL-23R pathways. Shattuck’s preclinical studies demonstrate high affinity binding to both DR3 and IL-23R, with equivalent or superior in vitro potency in comparison to benchmark IL-23 controls (sequence equivalents of risankizumab and icotrokinra) in a variety of preclinical assays. SL-846 is an Fc-silenced, half-life extended, fully human immunoglobulin G bispecific antibody currently being evaluated for safety, tolerability, immunogenicity, and pharmacodynamics in an IND-enabling GLP toxicology study in non-human primates. About Shattuck Labs, Inc. Shattuck Labs, Inc. is a clinical-stage biotechnology company pioneering the development of potentially first-in-class monoclonal and bispecific DR3 blocking antibodies for the treatment of patients with inflammatory and immune-mediated diseases. Shattuck’s expertise in protein engineering and the development of novel TNF receptor therapeutics come together in its lead program, SL-325, a potentially first-in-class DR3 antagonist antibody designed to achieve a more complete blockade of the clinically validated DR3/TL1A pathway. The Company has offices in both Austin, Texas and Durham, North Carolina. For more information, please visit: www.ShattuckLabs.com. Forward-Looking Statements Certain statements in this press release may constitute “forward-looking statements” within the meaning of the federal securities laws, including, but not limited to, Shattuck’s expectations regarding: plans for its preclinical studies, clinical trials and research and development programs, particularly with respect to SL-325; the anticipated timing of initiation of a Phase 2 clinical trial of SL-325 in patients with Crohn’s disease; the clinical benefit, safety and tolerability of SL-325; anticipated development of additional preclinical pipeline candidates; the anticipated timing of initiation of a Phase 1 clinical trial of SL-846; the clinical benefit, safety and tolerability of SL-846; the anticipated release of data from SL-846; the potential clinical significance of clinical and preclinical data and expectations regarding the time period over which the Company’s capital resources will be sufficient to fund its anticipated operations. Words such as “may,” “might,” “will,” “objective,” “intend,” “should,” “could,” “can,” “would,” “expect,” “believe,” “design,” “estimate,” “predict,” “potential,” “develop,” “plan,” “anticipate” or the negative of these terms, and similar expressions, or statements regarding intent, belief, or current expectations, are forward-looking statements. While the Company believes these forward-looking statements are reasonable, undue reliance should not be placed on any such forward-looking statements, which are based on information available to it on the date of this release. These forward-looking statements are based upon current estimates and assumptions and are subject to various risks and uncertainties (including, without limitation, those set forth in Shattuck’s filings with the U.S. Securities and Exchange Commission (SEC)), many of which are beyond its control and subject to change. Actual results or outcomes, or the timing of actual results or outcomes, could be materially different. Risks and uncertainties include: global macroeconomic conditions and related volatility; expectations regarding the initiation, progress, and expected results of the Company’s preclinical studies, clinical trials and research and development programs, including the timing and costs thereof; the Company’s ability to enroll patients in its clinical trials; the unpredictable relationship between preclinical study results and clinical study results; the Company’s ability to advance product candidates into, and successfully complete, nonclinical studies and clinical trials; the timing or likelihood of regulatory filings and approvals; the implementation of the Company’s business model, strategic plans for its business and product candidates; the scope of protection the Company is able to establish and maintain for intellectual property rights covering its technology; liquidity and capital resources, including the time period over which current capital resources are expected to the fund the Company’s operations; and other risks and uncertainties identified in Shattuck’s Annual Report on Form 10-K for the year ended December 31, 2025, and subsequent filings with the SEC. Shattuck claims the protection of the Safe Harbor contained in the Private Securities Litigation Reform Act of 1995 for forward-looking statements. The Company expressly disclaims any obligation to update or alter any statements whether as a result of new information, future events or otherwise, except as required by law. The Company intends to use the investor relations portion of its website as a means of disclosing material non-public information and for complying with disclosure obligations under Regulation FD. Investor & Media Contact: Andrew R. NeillChief Financial OfficerShattuck Labs, [email protected]

Potentially best-in-mechanism immunogenicity profile, with only 3.7% of participants developing antidrug antibodies Complete blockade of TL1A binding to DR3 for over 3 months expected at doses of 1 mg/kg and higher Well tolerated with a favorable safety profile consistent with the TL1A inhibitor class No evidence of DR3 agonism RECEPTIVE-CD1 Phase 2b clinical trial in patients with Crohn’s disease expected to initiate in the third quarter of 2026 Lead bispecific product candidate, SL-846 (DR3xIL-23R), currently being evaluated in IND-enabling toxicology studies; Phase 1 initiation expected in the first half of 2027 AUSTIN, TX and DURHAM, NC, June 08, 2026 (GLOBE NEWSWIRE) -- Shattuck Labs, Inc. (Shattuck or the Company) (NASDAQ: STTK), a clinical-stage biotechnology company pioneering the development of potential first-in-class monoclonal and bispecific DR3 blocking antibodies for the treatment of patients with inflammatory and immune-mediated diseases, today announced data from its Phase 1 clinical trial of SL-325, Shattuck’s lead DR3 blocking antibody candidate. “SL-325 is now the first antibody that blocks the receptor for TL1A, known as DR3, to generate human clinical data. The profile of SL-325 is highly encouraging, including a potentially best-in-mechanism immunogenicity profile, saturation of DR3 at low doses of SL-325, and durable inhibition of TL1A binding for months after a single dose.” said Taylor Schreiber, M.D., Ph.D., Chief Executive Officer of Shattuck. “These data indicate that blocking DR3 with SL-325, or with our DR3 by IL-23 receptor blocking bispecific antibody candidate, SL-846, may substantially improve upon the efficacy shown to date with the TL1A inhibitor class, providing an opportunity to maximize potential efficacy for TL1A blockade in IBD and beyond.” Key Phase 1 Findings The Phase 1 trial is a first-in-human, randomized, placebo-controlled trial evaluating the safety, tolerability, pharmacokinetics (“PK”), receptor occupancy (“RO”), pharmacodynamics (“PD”), and immunogenicity of SL-325 in healthy volunteers. The study enrolled 72 participants, across six single-ascending dose cohorts, with doses ranging from 0.1 mg/kg to 30.0 mg/kg, and three multiple-ascending dose cohorts, with doses ranging from 1 mg/kg to 10 mg/kg. Immunogenicity: Antidrug antibodies (“ADA”) to SL-325 were detected in 3.7% [2/54] of participants who received SL-325. Pharmacokinetics and Receptor Occupancy: Pharmacodynamics: Clinical data now corroborate our previous preclinical findings that SL-325 is a pure DR3 blocking antibody. Safety: SL-325 was well tolerated at all dose levels and upon repeat dosing, with a favorable safety profile consistent with the TL1A inhibitor class. RECEPTIVE-CD1 Phase 2b Trial of SL-325 in Crohn’s Disease The RECEPTIVE-CD1 clinical trial is designed as a randomized, double-blind, placebo-controlled Phase 2b clinical trial to evaluate the safety and efficacy of two dose levels of SL-325 as monotherapy versus placebo in moderate-to-severe Crohn’s disease. SL-325 will be administered intravenously, and the trial will include a 12-week induction period, followed by a 40-week maintenance period, for a total of 52 weeks of treatment for each patient enrolled. RECEPTIVE-CD1 is expected to enroll approximately 174 patients, randomized 1:1:1, with patients receiving either low dose SL-325, high dose SL-325, or placebo. RECEPTIVE-CD1 will enroll patients at clinical sites in the United States, Canada, and Europe. RECEPTIVE-CD1 is expected to enroll patients with moderate-to-severe Crohn’s disease, as defined with a Crohn’s Disease Activity Index (“CDAI”) score of between 220 and 450. The primary endpoint is expected to be endoscopic response at Week 12, and the key secondary endpoint will be clinical remission at Week 12. Patients randomized to the placebo arm will be eligible to receive SL-325 after the 12-week induction period. The primary endpoint, endoscopic response at 12 weeks, is expected to be disclosed in the first half of 2028. SL-846: A Dual DR3 and IL-23 Receptor Blocking Antibody SL-846 is Shattuck’s lead bispecific product candidate and is designed to simultaneously bind to DR3 and to IL-23 receptor, blocking the interaction with TL1A and IL-23, respectively, while avoiding the risk of immune complex formation and resulting ADA challenges of the TL1A-based bispecifics. SL-846 is an Fc-silenced, half-life extended, IgG1 bispecific antibody. Preclinical data demonstrated that SL-846 was equipotent, or more potent, than sequence equivalents of risankizumab and icotrokinra controls in multiple in vitro and cell-based potency assays. SL-846 is currently being evaluated in an ongoing IND-enabling GLP toxicology study in non-human primates. Safety and immunogenicity data are expected in the second half of 2026. Shattuck expects to submit an IND for SL-846 in the first half of 2027. About SL-325 SL-325 is a potentially first-in-class Death Receptor 3 (DR3) blocking antibody designed to achieve a complete and durable blockade of the clinically validated DR3/TL1A pathway. Shattuck’s preclinical studies demonstrate high affinity binding and superior activity over TL1A antibodies, and offer a data-driven rationale for targeting the TNF receptor, DR3, versus its ligand, TL1A. SL-325 is a fully Fc-silenced, fully human immunoglobulin G monoclonal antibody with a favorable safety profile, potentially best-in-mechanism immunogenicity profile, no evidence of residual DR3 agonism capable of providing durable blockade of TL1A binding to DR3 at low doses in a recently completed Phase 1 clinical trial. SL-325 is expected to be evaluated in a Phase 2b clinical trial in Crohn’s Disease patients initiating in the third quarter of 2026. About SL-846 SL-846 is a potentially first-in-class Death Receptor 3 (DR3) by IL-23 receptor (IL-23R) blocking bispecific antibody designed to achieve complete and durable blockade of the clinically validated DR3/TL1A and IL-23/IL-23R pathways. Shattuck’s preclinical studies demonstrate high affinity binding to both DR3 and IL-23R, with equivalent or superior in vitro potency in comparison to benchmark IL-23 controls (sequence equivalents of risankizumab and icotrokinra) in a variety of preclinical assays. SL-846 is an Fc-silenced, half-life extended, fully human immunoglobulin G bispecific antibody currently being evaluated for safety, tolerability, immunogenicity, and pharmacodynamics in an IND-enabling GLP toxicology study in non-human primates. About Shattuck Labs, Inc. Shattuck Labs, Inc. is a clinical-stage biotechnology company pioneering the development of potentially first-in-class monoclonal and bispecific DR3 blocking antibodies for the treatment of patients with inflammatory and immune-mediated diseases. Shattuck’s expertise in protein engineering and the development of novel TNF receptor therapeutics come together in its lead program, SL-325, a potentially first-in-class DR3 antagonist antibody designed to achieve a more complete blockade of the clinically validated DR3/TL1A pathway. The Company has offices in both Austin, Texas and Durham, North Carolina. For more information, please visit:  www.ShattuckLabs.com. Forward-Looking Statements Certain statements in this press release may constitute “forward-looking statements” within the meaning of the federal securities laws, including, but not limited to, Shattuck’s expectations regarding: plans for its preclinical studies, clinical trials and research and development programs, particularly with respect to SL-325; the anticipated timing of release of data from the Company’s ongoing Phase 1 clinical trial of SL-325; the anticipated timing of initiation of a Phase 2 clinical trial of SL-325 in patients with Crohn’s disease; the clinical benefit, safety and tolerability of SL-325; anticipated development of additional preclinical pipeline candidates; the timing of nomination, release of preclinical data and development timelines of a lead bispecific antibody candidate; and expectations regarding the time period over which the Company’s capital resources will be sufficient to fund its anticipated operations. Words such as “may,” “might,” “will,” “objective,” “intend,” “should,” “could,” “can,” “would,” “expect,” “believe,” “design,” “estimate,” “predict,” “potential,” “develop,” “plan” or the negative of these terms, and similar expressions, or statements regarding intent, belief, or current expectations, are forward-looking statements. While the Company believes these forward-looking statements are reasonable, undue reliance should not be placed on any such forward-looking statements, which are based on information available to it on the date of this release. These forward-looking statements are based upon current estimates and assumptions and are subject to various risks and uncertainties (including, without limitation, those set forth in Shattuck’s filings with the U.S. Securities and Exchange Commission (SEC)), many of which are beyond its control and subject to change. Actual results could be materially different. Risks and uncertainties include: global macroeconomic conditions and related volatility; expectations regarding the initiation, progress, and expected results of the Company’s preclinical studies, clinical trials and research and development programs; expectations regarding the timing, completion and outcome of the Company’s preclinical studies and clinical trials; the unpredictable relationship between preclinical study results and clinical study results; the timing or likelihood of regulatory filings and approvals; liquidity and capital resources, including the time period over which current capital resources are expected to the fund the Company’s operations; and other risks and uncertainties identified in Shattuck’s Annual Report on Form 10-K for the year ended December 31, 2025, and subsequent disclosure documents filed with the SEC. Shattuck claims the protection of the Safe Harbor contained in the Private Securities Litigation Reform Act of 1995 for forward-looking statements. The Company expressly disclaims any obligation to update or alter any statements whether as a result of new information, future events or otherwise, except as required by law. The Company intends to use the investor relations portion of its website as a means of disclosing material non-public information and for complying with disclosure obligations under Regulation FD. Investor & Media Contact: Andrew R. NeillChief Financial OfficerShattuck Labs, [email protected]

Phase 1 clinical trial of SL-325 enrollment complete; data expected in the second quarter of 2026 – Phase 2 clinical trial of SL-325 in patients with Crohn’s disease expected to initiate in the third quarter of 2026 – AUSTIN, Texas and DURHAM, N.C., May 07, 2026 (GLOBE NEWSWIRE) -- Shattuck Labs, Inc. (Shattuck or the Company) (NASDAQ: STTK), a clinical-stage biotechnology company pioneering the development of potential first-in-class monoclonal and bispecific DR3 blocking antibodies for the treatment of patients with inflammatory and immune-mediated diseases, today reported financial results for the first quarter ended March 31, 2026 and provided recent business highlights. “We are pleased to have completed enrollment in our Phase 1 clinical trial of SL-325, and are looking forward to sharing a comprehensive data set on all single ascending dose and multiple ascending dose cohorts from this study in the second quarter of 2026, including safety and tolerability, pharmacokinetics, receptor occupancy, duration of receptor occupancy, pharmacodynamics, and immunogenicity data,” said Taylor Schreiber, M.D., Ph.D., Chief Executive Officer of Shattuck. DR3 Program Development in 2026 Shattuck’s lead product candidate, SL-325, is a potentially first-in-class and best-in-mechanism DR3 blocking antibody for the treatment of Crohn’s disease, ulcerative colitis, and other inflammatory and immune-mediated diseases. Recent updates and anticipated upcoming milestones for SL-325, and Shattuck’s other DR3 blocking antibodies, include: The Phase 1 trial evaluating the safety, tolerability, immunogenicity, and pharmacokinetics (PK) of SL-325 in healthy volunteers is ongoing and will determine the recommended Phase 2 dose and dosing schedule. Enrollment of all six single-ascending dose cohorts and all three multiple-ascending dose cohorts of the trial is now complete, with participant follow-up, data collection, and data analysis ongoing. Shattuck plans to present safety and tolerability, PK, receptor occupancy, duration of receptor occupancy, pharmacodynamics, and immunogenicity data from this trial in the second quarter of 2026. Subject to positive Phase 1 data and regulatory alignment, Shattuck expects to initiate a Phase 2 clinical trial of SL-325 in patients with Crohn’s disease in the third quarter of 2026. Shattuck continues to develop multiple DR3-based bispecific antibodies. Shattuck’s lead bispecific antibody has entered IND-enabling activities. This bispecific antibody was designed to inhibit both the DR3/TL1A axis and another biologically relevant target for the treatment of patients with inflammatory and immune-mediated diseases. Shattuck plans to disclose the targets of its lead bispecific product candidate, supporting preclinical data, and expected development timelines in the second quarter of 2026. Upcoming Events Shattuck plans to participate in the following upcoming event(s). Details will be included on the Events & Presentations section of the Company’s website. Leerink Partners Therapeutics Forum 2026 (Boston, MA), July 14-15, 2026. Management will participate in one-on-one meetings. First Quarter 2026 Financial Results Cash and Cash Equivalents and Investments: As of March 31, 2026, cash and cash equivalents and short-term investments were $90.4 million, as compared to $60.9 million as of March 31, 2025. Research and Development (R&D) Expenses: R&D expenses were $10.9 million for the quarter ended March 31, 2026, as compared to $9.9 million for the quarter ended March 31, 2025. General and Administrative (G&A) Expenses: G&A expenses were $4.6 million for the quarter ended March 31, 2026, as compared to $4.5 million for the quarter ended March 31, 2025. Net Loss: Net loss was $14.8 million for the quarter ended March 31, 2026, or $0.13 per basic and diluted share, as compared to a net loss of $13.7 million for the quarter ended March 31, 2025, or $0.27 per basic and diluted share. Financial Guidance As of March 31, 2026, cash and cash equivalents were approximately $90.4 million. Shattuck’s current cash and cash equivalents, assuming the full exercise of the outstanding common stock warrants, are expected to fund operations into 2029. This cash runway guidance is based on the Company’s current operational plans and excludes any additional capital that may be received (other than from the exercise of the common stock warrants), proceeds from business development transactions, and/or additional costs associated with clinical development activities that may be undertaken. About SL-325 SL-325 is a potential first-in-class Death Receptor 3 (DR3) blocking antibody designed to achieve a complete and durable blockade of the clinically validated DR3/TL1A pathway. Shattuck’s preclinical studies demonstrate high affinity binding and superior activity over TL1A antibodies, and offer a data-driven rationale for targeting the TNF receptor, DR3, versus its ligand, TL1A. SL-325 is a fully Fc-silenced, humanized immunoglobulin G monoclonal antibody with a favorable safety profile in non-human primates, currently being evaluated in a Phase 1 clinical trial. About Shattuck Labs, Inc. Shattuck Labs, Inc. is a clinical-stage biotechnology company pioneering the development of potentially first-in-class monoclonal and bispecific DR3 blocking antibodies for the treatment of patients with inflammatory and immune-mediated diseases. Shattuck’s expertise in protein engineering and the development of novel TNF receptor therapeutics come together in its lead program, SL-325, a potentially first-in-class DR3 antagonist antibody designed to achieve a more complete blockade of the clinically validated DR3/TL1A pathway. The Company has offices in both Austin, Texas and Durham, North Carolina. For more information, please visit: www.ShattuckLabs.com. Forward-Looking Statements Certain statements in this press release may constitute “forward-looking statements” within the meaning of the federal securities laws, including, but not limited to, Shattuck’s expectations regarding: plans for its preclinical studies, clinical trials and research and development programs, particularly with respect to SL-325; the anticipated timing of release of data from the Company’s ongoing Phase 1 clinical trial of SL-325; the anticipated timing of initiation of a Phase 2 clinical trial of SL-325 in patients with Crohn’s disease; the clinical benefit, safety and tolerability of SL-325; anticipated development of additional preclinical pipeline candidates; the timing of nomination, release of preclinical data and development timelines of a lead bispecific antibody candidate; and expectations regarding the time period over which the Company’s capital resources will be sufficient to fund its anticipated operations. Words such as “may,” “might,” “will,” “objective,” “intend,” “should,” “could,” “can,” “would,” “expect,” “believe,” “design,” “estimate,” “predict,” “potential,” “develop,” “plan” or the negative of these terms, and similar expressions, or statements regarding intent, belief, or current expectations, are forward-looking statements. While the Company believes these forward-looking statements are reasonable, undue reliance should not be placed on any such forward-looking statements, which are based on information available to it on the date of this release. These forward-looking statements are based upon current estimates and assumptions and are subject to various risks and uncertainties (including, without limitation, those set forth in Shattuck’s filings with the U.S. Securities and Exchange Commission (SEC)), many of which are beyond its control and subject to change. Actual results could be materially different. Risks and uncertainties include: global macroeconomic conditions and related volatility; expectations regarding the initiation, progress, and expected results of the Company’s preclinical studies, clinical trials and research and development programs; expectations regarding the timing, completion and outcome of the Company’s preclinical studies and clinical trials; the unpredictable relationship between preclinical study results and clinical study results; the timing or likelihood of regulatory filings and approvals; liquidity and capital resources, including the time period over which current capital resources are expected to the fund the Company’s operations; and other risks and uncertainties identified in Shattuck’s Annual Report on Form 10-K for the year ended December 31, 2025, and subsequent disclosure documents filed with the SEC. Shattuck claims the protection of the Safe Harbor contained in the Private Securities Litigation Reform Act of 1995 for forward-looking statements. The Company expressly disclaims any obligation to update or alter any statements whether as a result of new information, future events or otherwise, except as required by law. The Company intends to use the investor relations portion of its website as a means of disclosing material non-public information and for complying with disclosure obligations under Regulation FD. Investor & Media Contact: Andrew Neill Chief Financial Officer Shattuck Labs, Inc. [email protected] FINANCIAL INFORMATION SHATTUCK LABS, INC. CONDENSED BALANCE SHEETS (unaudited) (In thousands) SHATTUCK LABS, INC. CONDENSED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (Unaudited) (In thousands, except share and per share amounts)

Phase 1 clinical trial of SL-325 ongoing, with data expected in the second quarter of 2026 – Phase 2 clinical trial of SL-325 in patients with Crohn’s disease expected to initiate in the third quarter of 2026 – AUSTIN, Texas and DURHAM, N.C., March 05, 2026 (GLOBE NEWSWIRE) -- Shattuck Labs, Inc. (Shattuck or the Company) (NASDAQ: STTK), a clinical-stage biotechnology company pioneering the development of potential first-in-class monoclonal and bispecific DR3 blocking antibodies for the treatment of patients with inflammatory and immune-mediated diseases, today reported financial results for the fourth quarter and full year ended December 31, 2025 and provided recent business highlights. “SL-325 is now the first DR3 blocking antibody to generate human clinical data, and we are very pleased with the progress we have made in our Phase 1 clinical trial, which is nearly complete. We look forward to sharing the data from this trial in the second quarter, and anticipate initiating our Phase 2 clinical trial in Crohn’s disease in the third quarter,” said Taylor Schreiber, M.D., Ph.D., Chief Executive Officer of Shattuck. DR3 Program Development in 2025 Shattuck’s lead product candidate, SL-325, is a potentially first-in-class and best-in-mechanism DR3 blocking antibody for the treatment of Crohn’s disease, ulcerative colitis, and other inflammatory and immune-mediated diseases. Recent updates and anticipated upcoming milestones for SL-325, and Shattuck’s other DR3 blocking antibodies, include: The Phase 1 trial evaluating the safety, tolerability, immunogenicity, and pharmacokinetics (PK) of SL-325 in healthy volunteers is ongoing and progressing as planned, and will determine the recommended Phase 2 dose and dosing schedule. Enrollment of all six single-ascending dose (SAD) cohorts is now complete, and full enrollment in the final multiple-ascending dose (MAD) cohort of the trial is expected to be completed in the second quarter of 2026. Shattuck expects to disclose safety and tolerability, PK, receptor occupancy, duration of receptor occupancy, and immunogenicity data from this trial in the second quarter of 2026. Subject to positive Phase 1 data and regulatory alignment, Shattuck expects to initiate a Phase 2 clinical trial of SL-325 in patients with Crohn’s disease in the third quarter of 2026. Shattuck continues to develop multiple DR3-based bispecific antibodies. Shattuck’s lead bispecific antibody has entered IND-enabling activities. This bispecific antibody was designed to inhibit both the DR3/TL1A axis and another biologically relevant target for the treatment of patients with inflammatory and immune-mediated diseases. Shattuck plans to disclose the targets of its lead bispecific product candidate, supporting preclinical data, and expected development timelines in the first half of 2026. Appointment to Management Team Michael Choi, M.D., joined Shattuck Labs as Vice President of Clinical Development in November 2025. Dr. Choi brings extensive experience advancing inflammatory bowel disease programs, including as clinical lead at Morphic Therapeutic, where he led the development of MORF-057, its oral α4β7 antagonist. Earlier in his career, Dr. Choi served as Assistant Professor of Medicine at Harvard Medical School and Affiliated Faculty at the Harvard Stem Cell Institute. Dr. Choi received his medical degree from Cornell University, trained in Internal Medicine at UCSF, and completed his Gastroenterology Fellowship at Massachusetts General Hospital. Recent Events Shattuck participated in the Piper Sandler 37th Annual Healthcare Conference on December 2, 2025. Dr. Schreiber presented at the conference and management participated in one-on-one meetings. Shattuck participated in the Evercore ISI 8th Annual HealthCONx Conference on December 3-4, 2025. Dr. Schreiber participated in a fireside chat and management participated in one-on-one meetings. Shattuck participated in the Piper Sandler Virtual Novel Targets in Immunology Symposium on February 12-13, 2026. Dr. Schreiber, Andrew R. Neill, Chief Financial Officer, and Michael Choi, M.D., Vice President of Clinical Development participated in a fireside chat. Shattuck participated in the TD Cowen 46th Annual Health Care Conference on March 2-4, 2026. Dr. Schreiber presented at the conference and management participated in one-on-one meetings. Upcoming Events Shattuck plans to attend the following investor conference. Details will be included on the Events & Presentations section of the Company’s website. Leerink Global Healthcare Conference 2026 (Miami, FL), March 8-11, 2026. Dr. Schreiber will present at the conference and participate in one-on-one meetings. Capital Markets Update In the first quarter of 2026, Shattuck sold shares of its common stock under its at-the-market offering facility for aggregate gross proceeds of $21.4 million. As a result of these sales, accounts advised by T. Rowe Price Investment Management, Inc. reported beneficial ownership of more than 10% of the Company’s outstanding common stock. As of February 28, 2026, cash and cash equivalents and short-term investments were approximately $94.5 million (unaudited), which includes the gross proceeds of $21.4 million from sales of Shattuck’s common stock under its at-the-market offering facility, as described above. This amount is preliminary, has not been audited or reviewed by the Company’s independent registered public accounting firm, and is subject to change upon completion of the Company’s financial closing procedures. Fourth Quarter and Full-Year 2025 Financial Results Cash and Cash Equivalents and Investments: As of December 31, 2025, cash and cash equivalents and short-term investments were approximately $78.1 million, as compared to $73.0 million as of December 31, 2024. Research and Development (R&D) Expenses: R&D expenses were $9.1 million for the quarter ended December 31, 2025, as compared to $15.4 million for the quarter ended December 31, 2024. R&D expenses for the year ended December 31, 2025 were $35.3 million, as compared to $67.2 million for the year ended December 31, 2024. This full year decrease was a result of the discontinuation of the SL-172154 program and related workforce reductions and other pipeline compound costs, partially offset by an increase in SL-325 expenses primarily as a result of moving SL-325 into clinical development in 2025. General and Administrative (G&A) Expenses: G&A expenses were $4.3 million for the quarter ended December 31, 2025, as compared to $4.2 million for the quarter ended December 31, 2024. General and administrative expenses for the year ended December 31, 2025 were $17.2 million, as compared to $19.1 million for the year ended December 31, 2024. This full year decrease was primarily the result of a decrease in compensation and related benefit expenses as a result of workforce reductions in 2024 as well as a decrease in legal fees. Net Loss: Net loss was $12.6 million for the quarter ended December 31, 2025, or $0.12 per basic and diluted share, as compared to a net loss of $18.7 million for the quarter ended December 31, 2024, or $0.37 per basic and diluted share. Net loss for the year ended December 31, 2025 was $48.8 million, or $0.70 per basic and diluted share, as compared to $75.4 million, or $1.49 per basic and diluted share, for the year ended December 31, 2024. Financial Guidance As of December 31, 2025, cash and cash equivalents and short-term investments were approximately $78.1 million. Shattuck’s current cash and cash equivalents and short-term investments, including the gross proceeds from its sale of common stock under its at-the-market offering facility of $21.4 million in the first quarter of 2026, and assuming the full exercise of the outstanding common stock warrants, are expected to fund operations into 2029. This cash runway guidance is based on the Company’s current operational plans and excludes any additional capital that may be received, proceeds from business development transactions, and/or additional costs associated with clinical development activities that may be undertaken. About SL-325 SL-325 is a potential first-in-class Death Receptor 3 (DR3) blocking antibody designed to achieve a complete and durable blockade of the clinically validated DR3/TL1A pathway. Shattuck’s preclinical studies demonstrate high affinity binding and superior activity over TL1A antibodies, and offer a data-driven rationale for targeting the TNF receptor, DR3, versus its ligand, TL1A. SL-325 is a fully Fc-silenced, humanized immunoglobulin G monoclonal antibody with a favorable safety profile in non-human primates, currently being evaluated in a Phase 1 clinical trial. About Shattuck Labs, Inc. Shattuck Labs, Inc. is a clinical-stage biotechnology company pioneering the development of potentially first-in-class monoclonal and bispecific DR3 blocking antibodies for the treatment of patients with inflammatory and immune-mediated diseases. Shattuck’s expertise in protein engineering and the development of novel TNF receptor therapeutics come together in its lead program, SL-325, a potentially first-in-class DR3 antagonist antibody designed to achieve a more complete blockade of the clinically validated DR3/TL1A pathway. The Company has offices in both Austin, Texas and Durham, North Carolina. For more information, please visit: www.ShattuckLabs.com. Forward-Looking Statements Certain statements in this press release may constitute “forward-looking statements” within the meaning of the federal securities laws, including, but not limited to, our expectations regarding: plans for our preclinical studies, clinical trials and research and development programs, particularly with respect to SL-325; the anticipated timing of release of data from our ongoing Phase 1 clinical trial of SL-325; the expected timing of enrollment in the MAD cohort of our Phase 1 clinical trial of SL-325; the anticipated timing of initiation of a Phase 2 clinical trial of SL-325 in patients with Crohn’s disease; the clinical benefit, safety and tolerability of SL-325; anticipated development of additional preclinical pipeline candidates the timing of nomination, release of preclinical data and development timelines of a lead bispecific antibody candidate; and expectations regarding the time period over which our capital resources will be sufficient to fund our anticipated operations. Words such as “may,” “might,” “will,” “objective,” “intend,” “should,” “could,” “can,” “would,” “expect,” “believe,” “design,” “estimate,” “predict,” “potential,” “develop,” “plan” or the negative of these terms, and similar expressions, or statements regarding intent, belief, or current expectations, are forward-looking statements. While we believe these forward-looking statements are reasonable, undue reliance should not be placed on any such forward-looking statements, which are based on information available to us on the date of this release. These forward-looking statements are based upon current estimates and assumptions and are subject to various risks and uncertainties (including, without limitation, those set forth in our filings with the U.S. Securities and Exchange Commission (SEC)), many of which are beyond our control and subject to change. Actual results could be materially different. Risks and uncertainties include: global macroeconomic conditions and related volatility, expectations regarding the initiation, progress, and expected results of our preclinical studies, clinical trials and research and development programs; expectations regarding the timing, completion and outcome of our preclinical studies and clinical trials; the unpredictable relationship between preclinical study results and clinical study results; the timing or likelihood of regulatory filings and approvals; our expectations regarding the overall benefit of the strategic prioritization of our pipeline; liquidity and capital resources; and other risks and uncertainties identified in our Annual Report on Form 10-K for the year ended December 31, 2024, and subsequent disclosure documents filed with the SEC. We claim the protection of the Safe Harbor contained in the Private Securities Litigation Reform Act of 1995 for forward-looking statements. We expressly disclaim any obligation to update or alter any statements whether as a result of new information, future events or otherwise, except as required by law. The Company intends to use the investor relations portion of its website as a means of disclosing material non-public information and for complying with disclosure obligations under Regulation FD. Investor & Media Contact: Andrew Neill Chief Financial Officer Shattuck Labs, Inc. [email protected]

–First participants dosed in Phase 1 clinical trial of SL-325 in healthy volunteers – – Closed a private placement of up to $103 million in August 2025 to support advancement of SL-325 – – Appointments of Dan Baker, M.D., and Mona Ashiya, Ph.D. to the Board of Directors – AUSTIN, TX and DURHAM, NC, Nov. 06, 2025 (GLOBE NEWSWIRE) -- Shattuck Labs, Inc. (Shattuck or the Company) (NASDAQ: STTK), a biotechnology company pioneering the development of novel therapeutics targeting tumor necrosis factor (TNF) superfamily receptors for the treatment of patients with inflammatory and immune-mediated diseases, today reported financial results for the quarter ended September 30, 2025 and provided recent business highlights. “In the third quarter of 2025, SL-325 became the first DR3 blocking antibody to enter clinical development, and our Phase 1 trial is proceeding as we anticipated” said Taylor Schreiber, M.D., Ph.D., Chief Executive Officer of Shattuck. “With the successful closing of our private placement, and assuming the full exercise of the common stock warrants issued in the private placement, we are well-capitalized to advance SL-325 into Phase 2 trials. We are executing with discipline and remain focused on generating data that supports SL-325 as a potentially first-in-class DR3 blocking antibody.” Business Highlights Shattuck closed a private placement of up to approximately $103 million in August 2025, with proceeds from the financing, assuming full exercise of the common stock warrants issued therein, expected to fund operations into 2029 and advance SL-325 through multiple clinical milestones, including a Phase 2 clinical trial in IBD, and potentially another autoimmune disease. DR3 Program Development in 2025 Shattuck’s lead product candidate, SL-325, is a potentially first-in-class DR3 antagonist antibody for the treatment of IBD and other inflammatory and immune-mediated diseases. Recent updates and anticipated upcoming milestones for SL-325 include: IND clearance for SL-325 occurred in August 2025. First participants dosed in the single-ascending dose (SAD) portion of the Phase 1 clinical trial in the third quarter of 2025. The Phase 1 trial is evaluating safety, tolerability, immunogenicity, and pharmacokinetics (PK) of SL-325 in healthy volunteers, and will determine the recommended Phase 2 dose and dosing schedule of SL-325. Enrollment of SAD and multiple-ascending dose (MAD) portions is expected to be completed in the second quarter of 2026. Safety, tolerability, DR3 occupancy, immunogenicity, and PK data will be evaluated in this open-label study, and Shattuck expects to disclose initial results by the second quarter of 2026. Shattuck continues to develop multiple preclinical DR3-based bispecific antibodies, which are designed to inhibit both the DR3/TL1A axis and another biologically relevant target for the treatment of patients with IBD. Shattuck continues to make progress in the preclinical development of its bispecific antibodies in-line with expectations. Shattuck plans to announce a lead bispecific candidate from its preclinical pipeline in the first half of 2026. Appointments to Board of Directors Dan Baker, M.D., industry expert, and Mona Ashiya, Ph.D., Member at OrbiMed, appointed to Shattuck’s Board of Directors in August 2025. Recent Events Shattuck participated in the H.C. Wainwright 27th Annual Global Investment Conference, September 8-10, 2025. Taylor Schreiber, M.D., Ph.D., CEO of Shattuck, presented at the conference and participated in one-on-one meetings. Upcoming Events Shattuck plans to attend the following investor conference(s). Details will be included on the Events & Presentations section of the Company’s website. Piper Sandler 37th Annual Healthcare Conference (New York City, NY), December 2nd, 2025. Management will participate in one-on-one meetings. Evercore ISI 8th Annual Healthcare Conference (Miami, FL), December 3rd-4th. Taylor Schreiber, M.D., Ph.D., CEO of Shattuck Labs, will participate in a fireside chat hosted by covering analyst Jon Miller, and management will participate in one-on-one meetings. Third Quarter 2025 Financial Results Cash and Cash Equivalents and Short-Term Investments: As of September 30, 2025, cash and cash equivalents and short-term investments were $86.1 million, as compared to $90.1 million as of September 30, 2024. Research and Development (R&D) Expenses: R&D expenses were $7.6 million for the quarter ended September 30, 2025, as compared to $16.3 million for the quarter ended September 30, 2024. General and Administrative (G&A) Expenses: G&A expenses were $4.1 million for the quarter ended September 30, 2025, as compared to $4.6 million for the quarter ended September 30, 2024. Net Loss: Net loss was $10.1 million for the quarter ended September 30, 2025, or $0.14 per basic and diluted share, as compared to a net loss of $16.6 million for the quarter ended September 30, 2024, or $0.33 per basic and diluted share. Financial Guidance As of September 30, 2025, cash and cash equivalents and short-term investments were approximately $86.1 million. Shattuck’s current cash and cash equivalents and short-term investments, assuming the full exercise of the outstanding common stock warrants, are expected to fund operations into 2029. This cash runway guidance is based on the Company’s current operational plans and excludes any additional capital that may be received, proceeds from business development transactions, and/or additional costs associated with clinical development activities that may be undertaken. About SL-325 SL-325 is a potential first-in-class Death Receptor 3 (DR3) blocking antibody designed to achieve a complete and durable blockade of the clinically validated DR3/TL1A pathway. Shattuck’s preclinical studies demonstrate high affinity binding and superior activity over TL1A antibodies, and offer a data-driven rationale for targeting the TNF receptor, DR3, versus its ligand, TL1A. SL-325 is a fully Fc-silenced humanized immunoglobin G monoclonal antibody with a favorable safety profile in non-human primates. About Shattuck Labs, Inc. Shattuck Labs, Inc. (Nasdaq: STTK) is a biotechnology company specializing in the development of potential treatments for autoimmune/inflammatory diseases. The Company is developing a potentially first-in-class antibody for the treatment of inflammatory bowel disease (IBD) and other inflammatory autoimmune diseases. Shattuck’s expertise in protein engineering and the development of novel TNF receptor agonist and antagonist therapeutics come together in its lead program, SL-325, a potential first-in-class DR3 antagonist antibody designed to achieve a more complete blockade of the clinically validated DR3/TL1A pathway. The Company has offices in both Austin, Texas and Durham, North Carolina. For more information, please visit: www.ShattuckLabs.com. Forward-Looking Statements Certain statements in this press release may constitute “forward-looking statements” within the meaning of the federal securities laws, including, but not limited to, our expectations regarding: expectations regarding the timing for completion of enrollment of patients in the Phase 1 trial for SL-325; the anticipated timing for completion of the Phase 1 trial for SL-325; expectations regarding the timing for release of the results of the Phase 1 trial for SL-325; anticipated Phase 2 clinical trials for SL-325; anticipated timing for nomination of an additional development candidate from the Company’s preclinical pipeline; and the time period over which the Company’s capital resources will be sufficient to fund its anticipated operations, including whether the common stock warrants will be exercised and provide the Company with additional capital. Words such as “may,” “might,” “will,” “objective,” “intend,” “should,” “could,” “can,” “would,” “expect,” “believe,” “design,” “estimate,” “predict,” “potential,” “develop,” “plan” or the negative of these terms, and similar expressions, or statements regarding intent, belief, or current expectations, are forward-looking statements. While the Company believes these forward-looking statements are reasonable, undue reliance should not be placed on any such forward-looking statements, which are based on information available to the Company on the date of this release. These forward-looking statements are based upon current estimates and assumptions and are subject to various risks and uncertainties (including, without limitation, those set forth in Shattuck’s filings with the SEC), many of which are beyond the Company’s control and subject to change. Actual results could be materially different. Risks and uncertainties include: global macroeconomic conditions and related volatility; expected results of the Company’s preclinical studies, clinical trials and research and development programs; expectations regarding the timing, completion and outcome of the Company’s clinical trials; the unpredictable relationship between preclinical study results and clinical study results; the timing or likelihood of regulatory filings and approvals; Shattuck’s expectations regarding the overall benefit of the strategic prioritization of its pipeline; liquidity and capital resources, including whether the common stock warrants will be exercised and provide the Company with additional capital; and other risks and uncertainties identified in Shattuck’s Annual Report on Form 10-K for the year ended December 31, 2024, and subsequent disclosure documents filed with the SEC. The Company claims the protection of the Safe Harbor contained in the Private Securities Litigation Reform Act of 1995 for forward-looking statements. The Company expressly disclaims any obligation to update or alter any statements whether as a result of new information, future events or otherwise, except as required by law. The Company intends to use the investor relations portion of its website as a means of disclosing material non-public information and for complying with disclosure obligations under Regulation FD. Investor & Media Contact: Andrew R. Neill Chief Financial Officer Shattuck Labs, Inc. [email protected]

– Submitted Investigational New Drug (IND) application to evaluate SL-325 in a Phase 1 clinical trial in healthy volunteers; clearance expected in Q3 2025 – – On track to dose first participant in Phase 1 clinical trial for SL-325 in Q3 2025 – – Cash balance of approximately $50.5 million at end of Q2 2025 – – Aggregate proceeds from recent oversubscribed private placement of up to $103 million, less offering expenses, expected to fund operations into 2029 – AUSTIN, TX and DURHAM, NC, Aug. 14, 2025 (GLOBE NEWSWIRE) -- Shattuck Labs, Inc. (Shattuck or the Company) (NASDAQ: STTK), a biotechnology company pioneering the development of novel therapeutics targeting tumor necrosis factor (TNF) superfamily receptors for the treatment of patients with inflammatory and immune-mediated diseases, today reported financial results for the second quarter ended June 30, 2025 and provided recent business highlights. “The second quarter of 2025 was a productive period for Shattuck, as we prepared and successfully submitted an IND application to the U.S. Food & Drug Administration (FDA),” said Taylor Schreiber, M.D., Ph.D., Chief Executive Officer of Shattuck. “We expect to begin enrollment in our Phase 1 clinical trial, subject to regulatory alignment, in healthy volunteers later this quarter, and to complete the trial during the second quarter of 2026. Following our recent private placement, led by OrbiMed, we are in a strong position and expect to transition seamlessly into multiple Phase 2 clinical trials for our lead asset, SL-325, and fund our operations into 2029.” DR3 Program Development in 2025 Shattuck’s lead product candidate, SL-325, is a potentially first-in-class DR3 blocking antibody for the treatment of IBD and other inflammatory and immune-mediated diseases. Recent updates and anticipated upcoming milestones for SL-325 include: An IND was submitted to the FDA for SL-325 in July 2025; clearance expected in the third quarter of 2025. Phase 1 clinical trial will evaluate safety, tolerability, immunogenicity and pharmacokinetics in healthy volunteers, and determine the recommended Phase 2 dose and dosing schedule of SL-325. Subject to regulatory alignment, dosing of the first participant in the single-ascending dose (SAD) portion of the trial is expected in the third quarter of 2025, and the multiple-ascending dose (MAD) portion of the trial is expected to commence in the fourth quarter of 2025. Phase 1 enrollment of the SAD and MAD portions of the clinical trial is expected to be completed in the second quarter of 2026. Shattuck continues to develop multiple preclinical DR3-based bispecific antibodies, which are designed to inhibit both the DR3/TL1A axis and other biologically relevant targets for the treatment of patients with IBD. Shattuck plans to nominate a lead bispecific candidate from its preclinical pipeline in 2025. Recent Events Shattuck participated in the 24th Annual Needham Virtual Healthcare Conference on April 9, 2025. Taylor Schreiber, M.D., Ph.D., CEO of Shattuck Labs presented at the conference. Details are on the Events & Presentations section of the Company’s website. Shattuck participated in the Leerink Partners Therapeutics Forum: I&I and Metabolism on July 8, 2025. Taylor Schreiber, M.D., Ph.D., CEO of Shattuck Labs presented at the conference. Details are on the Events & Presentations section of the Company’s website. Upcoming Events Shattuck plans to attend the following investor conference. Details will be included on the Events & Presentations section of the Company’s website. H.C. Wainwright 27th Annual Global Investment Conference, September 8-10, 2025. Taylor Schreiber, M.D., Ph.D., CEO of Shattuck Labs will provide a corporate presentation, and management will participate in one-on-one meetings. Second Quarter 2025 Financial Results Cash and Cash Equivalents and Investments: As of June 30, 2025, cash and cash equivalents and investments were $50.5 million, as compared to $105.3 million as of June 30, 2024. Research and Development (R&D) Expenses: R&D expenses were $8.7 million for the quarter ended June 30, 2025, as compared to $19.2 million for the quarter ended June 30, 2024. General and Administrative (G&A) Expenses: G&A expenses were $4.4 million for the quarter ended June 30, 2025, as compared to $5.3 million for the quarter ended June 30, 2024. Net Loss: Net loss was $12.5 million for the quarter ended June 30, 2025, or $0.24 per basic and diluted share, as compared to a net loss of $21.6 million for the quarter ended June 30, 2024, or $0.42 per basic and diluted share. Financial Guidance As of June 30, 2025, cash and cash equivalents were approximately $50.5 million, which does not include the anticipated net proceeds from the private placement announced on August 5, 2025. The total anticipated proceeds from the oversubscribed private placement of up to approximately $103 million, less offering expenses, combined with current cash and cash equivalents, are expected to fund operations into 2029. The closing of the private placement is contingent upon the IND clearance for SL-325 and the satisfaction of other customary closing conditions. Shattuck intends to use the anticipated net proceeds from the private placement (including the potential proceeds to be received upon the full exercise of the accompanying common stock warrants) for the clinical development of SL-325, including multiple Phase 2 clinical trials in Inflammatory Bowel Disease (IBD) and potentially another autoimmune disease, and for general corporate purposes. This cash runway guidance is based on the Company’s current operational plans and excludes any additional capital that may be received, proceeds from business development transactions, and/or additional costs associated with clinical development activities that may be undertaken. About SL-325 SL-325 is a potential first-in-class Death Receptor 3 (DR3) blocking antibody designed to achieve a complete and durable blockade of the clinically validated DR3/TL1A pathway. Shattuck’s preclinical studies demonstrate high affinity binding and superior activity over TL1A antibodies, and offer a data-driven rationale for targeting the TNF receptor, DR3, versus its ligand, TL1A. Shattuck expects to commence a Phase 1 clinical trial in healthy volunteers in the third quarter of 2025. About Shattuck Labs, Inc. Shattuck Labs, Inc. (Nasdaq: STTK) is a biotechnology company specializing in the development of potential treatments for inflammatory and immune-mediated diseases. The Company is developing a potentially first-in-class antibody for the treatment of inflammatory bowel disease (IBD) and other inflammatory and immune-mediated diseases. Shattuck’s expertise in protein engineering and the development of novel TNF receptor therapeutics come together in its lead program, SL-325, a potentially first-in-class DR3 antagonist antibody designed to achieve a more complete blockade of the clinically validated DR3/TL1A pathway. The Company has offices in both Austin, Texas and Durham, North Carolina. For more information, please visit: www.ShattuckLabs.com. Forward-Looking Statements Certain statements in this press release may constitute “forward-looking statements” within the meaning of the federal securities laws, including, but not limited to, our expectations regarding: the aggregate amount of proceeds to be received from the private placement, including whether the common stock warrants will be exercised and provide the Company with additional capital; the closing of the private placement and associated satisfaction of closing conditions, including with respect to clearance of the Company’s IND; the use of proceeds from the private placement; expectations regarding the timing for enrollment of and dosing of patients in the Phase 1 trial for SL-325; the anticipated timing for completion of the Phase 1 trial for SL-325; expectations regarding the results of the Phase 1 trial for SL-325; anticipated Phase 2 clinical trials for SL-325; anticipated timing for nomination of an additional development candidate from the Company’s preclinical pipeline; and the time period over which our capital resources will be sufficient to fund our anticipated operations. Words such as “may,” “might,” “will,” “objective,” “intend,” “should,” “could,” “can,” “would,” “expect,” “believe,” “design,” “estimate,” “predict,” “potential,” “develop,” “plan” or the negative of these terms, and similar expressions, or statements regarding intent, belief, or current expectations, are forward-looking statements. While the Company believes these forward-looking statements are reasonable, undue reliance should not be placed on any such forward-looking statements, which are based on information available to the Company on the date of this release. These forward-looking statements are based upon current estimates and assumptions and are subject to various risks and uncertainties (including, without limitation, those set forth in Shattuck’s filings with the SEC), many of which are beyond the Company’s control and subject to change. Actual results could be materially different. Risks and uncertainties include: global macroeconomic conditions and related volatility; expected results of the Company’s preclinical studies, clinical trials and research and development programs; expectations regarding the timing, completion and outcome of the Company’s clinical trials; the unpredictable relationship between preclinical study results and clinical study results; the timing or likelihood of regulatory filings and approvals, including FDA clearance of our IND filing, which is a closing condition for the Company’s private placement; Shattuck’s expectations regarding the overall benefit of the strategic prioritization of its pipeline; liquidity and capital resources; and other risks and uncertainties identified in Shattuck’s Annual Report on Form 10-K for the year ended December 31, 2024, and subsequent disclosure documents filed with the SEC. The Company claims the protection of the Safe Harbor contained in the Private Securities Litigation Reform Act of 1995 for forward-looking statements. The Company expressly disclaims any obligation to update or alter any statements whether as a result of new information, future events or otherwise, except as required by law. The Company intends to use the investor relations portion of its website as a means of disclosing material non-public information and for complying with disclosure obligations under Regulation FD. Investor & Media Contact: Conor Richardson Vice President of Investor Relations Shattuck Labs, Inc. [email protected]

– Company advances SL-325 program with an IND filing expected in the third quarter of 2025 – – Cash balance of approximately $60.9 million as of March 31, 2025, expected to fund operations into 2027 – AUSTIN, TX and DURHAM, NC, May 01, 2025 (GLOBE NEWSWIRE) -- Shattuck Labs, Inc. (Shattuck) (NASDAQ: STTK), a biotechnology company pioneering the development of novel therapeutics targeting tumor necrosis factor (TNF) superfamily receptors for the treatment of patients with inflammatory and immune-mediated diseases, today reported financial results for the first quarter ended March 31, 2025 and provided recent business highlights. “All IND-enabling activities and regulatory interactions remain on-track to initiate the Phase 1 clinical trial for SL-325 in the third quarter of this year. We believe SL-325 is fundamentally differentiated in its approach to targeting the clinically validated DR3/TL1A pathway and could potentially provide best-in-class clinical remission rates for IBD patients,” said Taylor Schreiber, M.D., Ph.D., Chief Executive Officer of Shattuck. “Spending last quarter continued to come in line with expectations, and wind-down activities associated with the discontinued oncology programs have now been substantially completed. We continue to be well-positioned to fund operations into 2027, beyond the results from our Phase 1 clinical trial for SL-325.” DR3 Program Development in 2025 Shattuck’s lead product candidate, SL-325, is a potentially first-in-class DR3 antagonist antibody. SL-325 is a DR3 blocking antibody for the treatment of IBD and other inflammatory and immune-mediated diseases. IND filing expected in the third quarter of 2025. Phase 1 clinical trial will evaluate safety, tolerability, and pharmacokinetics, and determine the recommended Phase 2 dose and dosing schedule of SL-325. First patient in for the SAD portion of the trial expected in the third quarter of 2025. Phase 1 enrollment completion expected in the second quarter of 2026. Shattuck continues to develop multiple preclinical DR3-based bispecific antibodies, which are designed to inhibit both the DR3/TL1A axis and another biologically relevant target for the treatment of patients with IBD. Shattuck plans to nominate a lead bispecific candidate from its preclinical pipeline in 2025. First Quarter 2025 Business Highlights and Other Recent Developments Recent Events Shattuck participated in the 24th Annual Needham Virtual Healthcare Conference on April 9, 2025. Taylor Schreiber, M.D., Ph.D., CEO of Shattuck Labs presented at the Conference. Details are on the Events & Presentations section of the Company’s website. Shattuck Labs participated in an oral presentation at ECCO in February 2025. Full press release can be found here. Presentation can be found here. Preclinical studies of SL-325 in NHP demonstrated a favorable safety profile with no infusion-related reactions observed, no changes in clinical pathology parameters, gross pathology, or histopathology analysis, and a No Observed Adverse Effect Level determined to be 100mg/kg, the top administered dose; Full receptor occupancy at 1 mg/kg or greater, durable for >28 days, no Treg expansion or activation of CD3 T cells observed; and Differentiation from TL1A blocking monoclonal antibodies may yield a distinct profile for bispecific antibody development. Notably, by targeting DR3, immune complex formation and stabilization of TL1A is not expected with SL-325, which may improve the immunogenicity profile as compared to TL1A targeting agents and allow for the development of DR3-based bispecific antibodies. Durable blockade of constitutively expressed DR3 may translate to higher complete remission rates. Shattuck Labs presented a poster at the 2025 Crohn’s & Colitis Foundation Congress in February. Poster can be found here. Data from in vitro preclinical development and characterization of SL-325 were presented. SL-325 is a fully Fc-silenced humanized immunoglobulin G monoclonal antibody that demonstrated high affinity binding to human DR3 and potent antagonistic properties with no evidence of residual agonism. Upcoming Events Shattuck Labs to present at the PEGS Boston Summit on May 12, 2025. Taylor Schreiber, M.D., Ph.D., CEO of Shattuck Labs, will present on SL-325 in the Advances in Immunotherapy section of the conference. Details of the presentation will be on the Events & Presentations section of the Company’s website after the conclusion of the live event. Shattuck Labs to participate in the Leerink Partners Therapeutics Forum: I&I and Metabolism on July 8-9, 2025. Company management will participate in scheduled one-on-one investor meetings. First Quarter 2025 Financial Results Cash and Cash Equivalents and Investments: As of March 31, 2025, cash and cash equivalents and investments were $60.9 million, as compared to $114.6 million as of March 31, 2024. Research and Development (R&D) Expenses: R&D expenses were $9.9 million for the quarter ended March 31, 2025, as compared to $16.3 million for the quarter ended March 31, 2024. General and Administrative (G&A) Expenses: G&A expenses were $4.5 million for the quarter ended March 31, 2025, as compared to $4.9 million for the quarter ended March 31, 2024. Net Loss: Net loss was $13.7 million for the quarter ended March 31, 2025, or $0.27 per basic and diluted share, as compared to a net loss of $18.5 million for the quarter ended March 31, 2024, or $0.37 per basic and diluted share. Financial Guidance As of March 31, 2025, cash and cash equivalents were approximately $60.9 million. Shattuck’s current cash and cash equivalents are expected to fund operations into 2027. This cash runway guidance is based on the Company’s current operational plans and excludes any additional capital that may be received, proceeds from business development transactions, and/or additional costs associated with clinical development activities that may be undertaken. About SL-325 SL-325 is a potential first-in-class Death Receptor 3 (DR3) blocking antibody designed to achieve a complete and durable blockade of the clinically validated DR3/TL1A pathway. Shattuck’s preclinical studies demonstrate high affinity binding and superior activity over TL1A antibodies, and offer a data-driven rationale for targeting the TNF receptor, DR3, versus its ligand, TL1A. SL-325 has completed a GLP toxicology study in non-human primates, with an IND filing expected in the third quarter of 2025. About Shattuck Labs, Inc. Shattuck Labs, Inc. (Nasdaq: STTK) is a biotechnology company specializing in the development of potential treatments for inflammatory and immune-mediated diseases. The Company is developing a potentially first-in-class antibody for the treatment of inflammatory bowel disease (IBD) and other inflammatory and immune-mediated diseases. Shattuck’s expertise in protein engineering and the development of novel TNF receptor therapeutics come together in its lead program, SL-325, a potentially first-in-class DR3 antagonist antibody designed to achieve a more complete blockade of the clinically validated DR3/TL1A pathway. The Company has offices in both Austin, Texas and Durham, North Carolina. For more information, please visit: www.ShattuckLabs.com. Forward-Looking Statements Certain statements in this press release may constitute “forward-looking statements” within the meaning of the federal securities laws, including, but not limited to, our expectations regarding: plans for our preclinical studies, clinical trials and research and development programs, particularly with respect to SL-325; the anticipated timing of any regulatory filings for SL-325; the expected initiation and trial design of, and timing of enrollment in, our expected Phase 1 and Phase 2 clinical trial of SL-325; the clinical benefit, safety and tolerability of SL-325; anticipated development of additional preclinical pipeline candidates the timing of nomination of a lead bispecific antibody candidate; and expectations regarding the time period over which our capital resources will be sufficient to fund our anticipated operations. Words such as “may,” “might,” “will,” “objective,” “intend,” “should,” “could,” “can,” “would,” “expect,” “believe,” “design,” “estimate,” “predict,” “potential,” “develop,” “plan” or the negative of these terms, and similar expressions, or statements regarding intent, belief, or current expectations, are forward-looking statements. While we believe these forward-looking statements are reasonable, undue reliance should not be placed on any such forward-looking statements, which are based on information available to us on the date of this release. These forward-looking statements are based upon current estimates and assumptions and are subject to various risks and uncertainties (including, without limitation, those set forth in our filings with the U.S. Securities and Exchange Commission (SEC)), many of which are beyond our control and subject to change. Actual results could be materially different. Risks and uncertainties include: global macroeconomic conditions and related volatility, expectations regarding the initiation, progress, and expected results of our preclinical studies, clinical trials and research and development programs; expectations regarding the timing, completion and outcome of our preclinical studies and clinical trials; the unpredictable relationship between preclinical study results and clinical study results; the timing or likelihood of regulatory filings and approvals; our expectations regarding the overall benefit of the strategic prioritization of our pipeline; liquidity and capital resources; and other risks and uncertainties identified in our Annual Report on Form 10-K for the year ended December 31, 2024, and subsequent disclosure documents filed with the SEC. We claim the protection of the Safe Harbor contained in the Private Securities Litigation Reform Act of 1995 for forward-looking statements. We expressly disclaim any obligation to update or alter any statements whether as a result of new information, future events or otherwise, except as required by law. The Company intends to use the investor relations portion of its website as a means of disclosing material non-public information and for complying with disclosure obligations under Regulation FD. Investor & Media Contact: Conor Richardson Vice President of Investor Relations Shattuck Labs, Inc. [email protected]

– Presented preclinical non-human primate (NHP) data at the 20th Congress of European Crohn’s and Colitis Organization in Inflammatory Bowel Diseases 2025 (ECCO) for SL-325, a potentially first-in-class blocking antibody to DR3, the receptor for TL1A; data demonstrated favorable safety profile, full receptor occupancy, lack of DR3 agonism – – SL-325 advances toward Phase 1; on track for IND filing in the third quarter of 2025 – – Cash balance of approximately $73.0 million as of December 31, 2024, expected to fund operations into 2027 – AUSTIN, TX and DURHAM, NC, March 27, 2025 (GLOBE NEWSWIRE) -- Shattuck Labs, Inc. (Shattuck) (NASDAQ: STTK), a biotechnology company pioneering the development of novel therapeutics targeting tumor necrosis factor (TNF) superfamily receptors for the treatment of patients with inflammatory and immune-mediated diseases, today reported financial results for the fourth quarter and full year ended December 31, 2024 and provided recent business highlights. “Shattuck made the difficult but appropriate decision to terminate our SL-172154 program in 2024, and rapidly transitioned to our potential first-in-class DR3 blocking antibody, SL-325,” said Taylor Schreiber, M.D., Ph.D., Chief Executive Officer of Shattuck. “In February, we presented preclinical results from our IND-enabling GLP toxicology study for SL-325 at ECCO, demonstrating differentiation from TL1A blocking monoclonal antibodies, along with a favorable safety profile, full receptor occupancy, and lack of DR3 agonism. Our encouraging preclinical data underscore SL-325’s potential for DR3 blockade to provide potentially best-in-class clinical remission rates for IBD patients. We are on track for an IND filing in the third quarter of this year and are excited to begin generating data with the first-ever DR3 blocking antibody to enter clinical trials. Shattuck remains well-positioned to fund operations and clinical development of SL-325 into 2027.” DR3 Program Development in 2025 Shattuck’s lead product candidate, SL-325, is a potentially first-in-class DR3 antagonist antibody. SL-325 is a DR3 blocking antibody for the treatment of IBD and other inflammatory and immune-mediated diseases. IND filing expected in the third quarter of 2025. Phase 1 clinical trial will evaluate safety, tolerability, and pharmacokinetics, and determine the recommended Phase 2 dose and dosing schedule of SL-325, with complete enrollment expected in the second quarter of 2026. Shattuck continues to develop multiple preclinical DR3-based bispecific antibodies, which are designed to inhibit both the DR3/TL1A axis and another biologically relevant target for the treatment of patients with IBD. Shattuck plans to nominate a lead bispecific candidate from its preclinical pipeline in 2025. Fourth Quarter 2024 Business Highlights and Other Recent Developments DR3 Program Development Shattuck Labs participated in an oral presentation at ECCO in February 2025. Preclinical studies of SL-325 in NHP demonstrated a favorable safety profile with no infusion-related reactions observed, no changes in clinical pathology parameters, gross pathology, or histopathology analysis, and a No Observed Adverse Effect Level determined to be 100mg/kg, the top administered dose; Full receptor occupancy at 1 mg/kg or greater, durable for >28 days, no Treg expansion or activation of CD3 T cells observed; and Differentiation from TL1A blocking monoclonal antibodies may yield a distinct profile for bispecific antibody development. Notably, by targeting DR3, immune complex formation and stabilization of TL1A is not expected with SL-325, which may improve the immunogenicity profile as compared to TL1A targeting agents and allow for the development of DR3-based bispecific antibodies. Durable blockade of constitutively expressed DR3 may translate to higher complete remission rates. Shattuck Labs presented a poster at the 2025 Crohn’s & Colitis Foundation Congress in February. Data from in vitro preclinical development and characterization of SL-325 were presented. SL-325 is a fully Fc-silenced humanized immunoglobulin G monoclonal antibody that demonstrated high affinity binding to human DR3 and potent antagonistic properties with no evidence of residual agonism. Upcoming Events Shattuck plans to attend the following investor conference. Details will be included on the Events & Presentations section of the Company’s website. 24th Annual Needham Virtual Healthcare Conference, April 7–10, 2025. Taylor Schreiber, M.D., Ph.D., CEO of Shattuck Labs, will participate in a presentation on April 9, 2025. Fourth Quarter and Full-Year 2024 Financial Results Cash and Cash Equivalents and Investments: As of December 31, 2024, cash and cash equivalents and investments were approximately $73.0 million, as compared to $130.6 million as of December 31, 2023. Research and Development (R&D) Expenses: R&D expenses were $15.4 million for the quarter ended December 31, 2024, as compared to $15.2 million for the quarter ended December 31, 2023. R&D expenses for the year ended December 31, 2024 were $67.2 million, as compared to $74.3 million for the year ended December 31, 2023. This decrease for the full year was primarily driven by decreases in manufacturing costs associated with SL-172154 and research expenses associated with other research programs. General and Administrative (G&A) Expenses: G&A expenses were $4.2 million for the quarter ended December 31, 2024, as compared to $4.4 million for the quarter ended December 31, 2023. General and administrative expenses for the year ended December 31, 2024 were $19.1 million, as compared to $19.3 million for the year ended December 31, 2023. This decrease for the full year was primarily the result of a decrease in insurance, software, and information technology costs. Net Loss: Net loss was $18.7 million for the quarter ended December 31, 2024, or $0.37 per basic and diluted share, as compared to a net loss of $17.7 million for the quarter ended December 31, 2023, or $0.41 per basic and diluted share. Net loss for the year ended December 31, 2024 was $75.4 million, or $1.49 per basic and diluted share, as compared to $87.3 million, or $2.05 per basic and diluted share, for the year ended December 31, 2023. Financial Guidance As of December 31, 2024, cash and cash equivalents and investments were approximately $73.0 million. Shattuck’s current cash and cash equivalents are expected to fund operations into 2027. This cash runway guidance is based on the Company’s current operational plans and excludes any additional capital that may be received, proceeds from business development transactions, and/or additional costs associated with clinical development activities that may be undertaken. About SL-325 SL-325 is a potential first-in-class Death Receptor 3 (DR3) blocking antibody designed to achieve a complete and durable blockade of the clinically validated DR3/TL1A pathway. Shattuck’s preclinical studies demonstrate high affinity binding and superior activity over TL1A antibodies, and offer a data-driven rationale for targeting the TNF receptor, DR3, versus its ligand, TL1A. SL-325 has completed a GLP toxicology study in non-human primates, with an IND filing expected in the third quarter of 2025. About Shattuck Labs, Inc. Shattuck Labs, Inc. (Nasdaq: STTK) is a biotechnology company specializing in the development of potential treatments for inflammatory and immune-mediated diseases. The Company is developing a potentially first-in-class antibody for the treatment of inflammatory bowel disease (IBD) and other inflammatory and immune-mediated diseases. Shattuck’s expertise in protein engineering and the development of novel TNF receptor therapeutics come together in its lead program, SL-325, a potentially first-in-class DR3 antagonist antibody designed to achieve a more complete blockade of the clinically validated DR3/TL1A pathway. The Company has offices in both Austin, Texas and Durham, North Carolina. For more information, please visit: www.ShattuckLabs.com. Forward-Looking Statements Certain statements in this press release may constitute “forward-looking statements” within the meaning of the federal securities laws, including, but not limited to, our expectations regarding: plans for our preclinical studies, clinical trials and research and development programs, particularly with respect to SL-325; the anticipated timing of any regulatory filings for SL-325; the expected initiation and trial design of, and timing of enrollment in, our expected Phase 1 clinical trial of SL-325; the anticipated timing of our preclinical studies for SL-425; the clinical benefit, safety and tolerability of SL-325; anticipated development of additional preclinical pipeline candidates the timing of nomination of a lead bispecific antibody candidate; and expectations regarding the time period over which our capital resources will be sufficient to fund our anticipated operations. Words such as “may,” “might,” “will,” “objective,” “intend,” “should,” “could,” “can,” “would,” “expect,” “believe,” “design,” “estimate,” “predict,” “potential,” “develop,” “plan” or the negative of these terms, and similar expressions, or statements regarding intent, belief, or current expectations, are forward-looking statements. While we believe these forward-looking statements are reasonable, undue reliance should not be placed on any such forward-looking statements, which are based on information available to us on the date of this release. These forward-looking statements are based upon current estimates and assumptions and are subject to various risks and uncertainties (including, without limitation, those set forth in our filings with the U.S. Securities and Exchange Commission (SEC)), many of which are beyond our control and subject to change. Actual results could be materially different. Risks and uncertainties include: global macroeconomic conditions and related volatility, expectations regarding the initiation, progress, and expected results of our preclinical studies, clinical trials and research and development programs; expectations regarding the timing, completion and outcome of our preclinical studies and clinical trials; the unpredictable relationship between preclinical study results and clinical study results; the timing or likelihood of regulatory filings and approvals; our expectations regarding the overall benefit of the strategic prioritization of our pipeline; liquidity and capital resources; and other risks and uncertainties identified in our Annual Report on Form 10-K for the year ended December 31, 2024, and subsequent disclosure documents filed with the SEC. We claim the protection of the Safe Harbor contained in the Private Securities Litigation Reform Act of 1995 for forward-looking statements. We expressly disclaim any obligation to update or alter any statements whether as a result of new information, future events or otherwise, except as required by law. The Company intends to use the investor relations portion of its website as a means of disclosing material non-public information and for complying with disclosure obligations under Regulation FD. Investor & Media Contact: Conor Richardson Vice President of Investor Relations Shattuck Labs, Inc. [email protected]