Galecto to Highlight GB3226 Program at ASH 2025

• Two Presentations at ASH 2025 to highlight preclinical data and clinical development plans for GB3226, a novel dual ENL-YEATS and FLT3 inhibitor for the treatment of acute myeloid leukemia (AML)
  
  

Galecto, Inc. (NASDAQ: GLTO), a clinical-stage biotechnology company focused on the development of novel treatments for oncology and liver diseases, today announced that preclinical data and clinical development plans for its investigational candidate GB3226 will be featured in two poster presentations at the 67 th American Society of Hematology (ASH) Annual Meeting and Exposition, being held December 6 9, 2025, in Orlando, Florida.

GB3226 is a first-in-class, orally bioavailable, small-molecule inhibitor designed to simultaneously target ENL-YEATS, an epigenetic driver of leukemogenesis, and FLT3, a key oncogenic kinase mutated in approximately 30% of adult AML patients. The unique dual inhibition of these pathways may offer greater therapeutic benefit than FLT3 or menin inhibition alone. In preclinical studies, GB3226 demonstrated potent activity across AML patient-derived samples with diverse genotypes, and induced rapid tumor regression and significantly prolonged survival in xenograft models. GB3226 also exhibited favorable pharmacokinetics and tolerability in animal studies, and demonstrated additive or synergistic effects with current standard-of-care agents. These findings support further clinical development of GB3226 as a novel, differentiated therapeutic approach for patients with AML.

Poster Presentation Details

Title: A Phase 1 Study of GB3226, a Novel Dual Inhibitor of ENL-Yeats and FLT3, in Patients with Relapsed/Refractory Acute Myeloid Leukemia

Presenting Author: Abhishek Maiti, MD Anderson Cancer Center, University of Texas, USA

Session Date and Presentation Time: December 6, 2025, 5:30 PM - 7:30 PM EST

Session Title: 616. Acute Myeloid Leukemias: Investigational Drug and Cellular Therapies: Poster I

Location: Orange County Convention Center (OCCC) - West Halls B3-B4

Publication Number: 1652

Title: GB3226, A Novel, Orally Active, First-in-Class Small Molecule Inhibitor of ENL-Yeats and FLT3 Kinase for the Treatment of Relapsed/Refractory Acute Myeloid Leukemia

Presenting Author: Louis Renzetti, Galecto Inc., Copenhagen, Denmark

Session Date and Presentation Time: December 8, 2025, 6:00 PM - 8:00 PM EST

Session Title: 802. Chemical Biology and Experimental Therapeutics: Poster III

Location: Orange County Convention Center (OCCC) - West Halls B3-B4

Publication Number: 6106

About GB3226
GB3226, an investigational candidate, is a potent and selective, orally administered, ENL-YEATS and FLT3 inhibitor of multiple genetic subsets of AML. It disrupts key oncogenic pathways by inhibiting these domains, showing potent activity in MLLr and NPM1c cell lines. Promising preclinical and in vivo results highlight its efficacy in inhibiting leukemia cell growth and extending survival in AML models. In animal models, GB3226 exhibited superior efficacy to both FLT3 and menin inhibitors and was shown to inhibit cell proliferation in primary AML patient samples across multiple genotypes, including MLL-r, NPM1m, cKIT+, FLT3+, and TET2+. These mutations are often seen in AML and, in total, could account for greater than 30% of the AML patient population. Many of these mutations have proven difficult to treat with currently available regimens and therefore represent a significant unmet medical need. Based on preclinical data, the Company believes GB3226 has the potential to be additive or synergistic when used in combination with the current standard of care (azacitidine, venetoclax, cytarabine, gilteritinib, and revumenib).

About Galecto
Galecto is a clinical-stage biopharmaceutical company committed to realizing the promise of novel treatments for cancer and liver diseases. The Company's pipeline consists of first-in-class small molecule drug candidates that target cancer and fibrosis signaling pathways, including (i) an orally active galectin-3 inhibitor (GB1211) for the treatment of liver cirrhosis; (ii) an orally active galectin-3 inhibitor (GB1211) in combination with a checkpoint inhibitor for various oncology indications; and (iii) a preclinical dual inhibitor of ENL-YEATS and FLT3 (GB3226) for the treatment of multiple genetic subsets of AML. Galecto intends to use its website as a means of disclosing material non-public information. For regular updates about Galecto, visit www.galecto.com .

Forward-Looking Statements
Certain statements in this press release are forward-looking statements that involve a number of risks and uncertainties. Such forward-looking statements include statements about Galecto's preclinical and clinical development plans for GB3226 and its potential to address challenging genetic subsets of AML. The words "may," "will," "could," "would," "should," "expect," "plan," "anticipate," "intend," "believe," "estimate," "predict," "project," "potential," "continue," "target" and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. For such statements, Galecto claims the protection of the Private Securities Litigation Reform Act of 1995. Actual events or results may differ materially from Galecto's expectations. Factors that could cause actual results to differ materially from the forward-looking statements include risks and uncertainties related to the development of Galecto's product candidates and their therapeutic potential, having adequate funds and their use, and those disclosed in Galecto's filings with the Securities and Exchange Commission (SEC), including, but not limited to, Galecto's Annual Report on Form 10-K, as filed with the SEC on March 19, 2025, and Galecto's Quarterly Report on Form 10-Q, as filed with the SEC on May 8, 2025. These forward-looking statements represent Galecto's judgment as of the time of this release. Galecto disclaims any intent or obligation to update these forward-looking statements, other than as may be required under applicable law.

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