Shattuck Labs reports Q3 2026 financial results

Item 2.02 Results of Operations and Financial Condition.

On November 5, 2026, Shattuck Labs, Inc. issued a press release announcing its financial results for the quarter ended September 30, 2026.¹ A copy of the press release is furnished as Exhibit 99.1 to this Current Report on Form 8-K.

As provided in General Instruction B.2 of Form 8-K, the information in this Item 2.02 and Exhibit 99.1 incorporated herein shall not be deemed to be "filed" for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the "Exchange Act") or otherwise subject to the liabilities of that section, nor shall such information or Exhibit 99.1 be deemed to be incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

Item 9.01 Financial Statements and Exhibits.

Exhibits

Exhibit

Number Description of Exhibit

99.1 Press release issued by Shattuck Labs, Inc. regarding its financial results for the quarter ended September 30, 2026, dated November 5, 2026.²

104 The cover page from the Company's Current Report on Form 8-K formatted in Inline XBRL.

2

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

Shattuck Labs, Inc.

Date: November 5, 2026

By: /s/ Dr. Taylor Schreiber

Dr. Taylor Schreiber

Chief Executive Officer (principal executive officer)

3

Shattuck Labs Reports Third Quarter 2026 Financial Results and Recent Business Highlights

– Presented preclinical data for SL-846 at UEG Week 2026, including data from a chronic toxicology study in non-human primates –

AUSTIN, TX and DURHAM, NC, Nov. 05, 2026 -- 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 third quarter ended September 30, 2026 and provided recent business highlights.

"We are very excited to begin Phase 2 clinical development with SL-325 in both Crohn's disease and hidradenitis suppurativa. We believe these two studies will allow direct comparisons with the TL1A antibody class and evaluate the efficacy that may be left on the table due to the potential immunogenicity liabilities of TL1A antibodies," said Taylor Schreiber, M.D., Ph.D., Chief Executive Officer of Shattuck. "In addition, SL-846 has demonstrated a compelling profile in preclinical studies, and we expect to share initial Phase 1 clinical data for what we expect to be a first-in-class DR3 by IL-23 receptor blocking antibody in 2027."

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, hidradenitis suppurativa (HS), and other inflammatory and immune-mediated diseases. Phase 1 clinical trial results demonstrated favorable safety and tolerability, potentially best-in-mechanism immunogenicity with an antidrug antibody rate of 3.7%, and highly durable inhibition of TL1A binding to DR3 that may enable quarterly maintenance dosing.

• Initiated the RECEPTIVE-CD1 Phase 2b clinical trial of SL-325 in patients with moderately-to-severely active Crohn's disease.

◦ Randomized, double-blind, placebo-controlled trial designed to evaluate three dose levels of SL-325 compared with placebo in approximately 232 patients, randomized 1:1:1:1.

◦ Primary endpoint is endoscopic response at 12 weeks. These data are expected in the first half of 2028.

• Announced plans to initiate the RECEPTIVE-HS1 Phase 2 clinical trial of SL-325 in patients with moderate to severe hidradenitis suppurativa, with trial initiation expected in the fourth quarter of 2026.

◦ HS is the second Phase 2 indication for SL-325 and expands development beyond IBD.

◦ Submitted an Investigational New Drug (IND) application to the FDA in October 2026.

◦ Designed RECEPTIVE-HS1 as a randomized, double-blind, placebo-controlled Phase 2 clinical trial evaluating two dose levels of SL-325 compared with placebo in approximately 150 patients, randomized 1:1:1.

◦ Primary endpoint is HiSCR50 response at Week 16, with data expected in the first half of 2028.

• Appointed Shoba Ravichandran, M.D., as Senior Vice President, Clinical Development, to lead the clinical development of SL-325 in HS. Dr. Ravichandran brings more than 20 years of drug development experience, including leading the global approval of Cosentyx in HS at Novartis.

SL-846

Shattuck's lead bispecific product candidate, SL-846, is a potentially first-in-class, half-life extended DR3 x IL-23 receptor (IL-23R) blocking antibody for the treatment of inflammatory and immune-mediated diseases.

• Presented preliminary preclinical data for SL-846 at UEG Week 2026, including data from the GLP toxicology study in non-human primates, which showed the following:

◦ Well tolerated through the top dose of 100 mg/kg.

◦ No evidence of DR3 or IL-23R agonism.

◦ Full and durable blockade of TL1A binding to DR3, and complete blockade of IL-23 signaling.

◦ Data from the NHP study support potential quarterly subcutaneous dosing in humans.

◦ NHP and in silico analyses suggest that SL-846 may have a superior immunogenicity profile to TL1A directed bispecific antibodies; projected human anti-drug antibody rate of between 8-12%.

• 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 events. Details will be included on the Events & Presentations section of the Company's website.

• Evercore ISI 9th Annual Healthcare Conference, November 30-December 1, 2026 . Management will participate in a fireside chat, and in one-on-one meetings.

• Piper Sandler 38th Annual Healthcare Conference, December 2-3, 2026. Taylor Schreiber, M.D., Ph.D., CEO of Shattuck Labs will present at the conference, and management will participate in one-on-one meetings.

Third