KING OF PRUSSIA, PA, May 18,2026 — SEED Therapeutics, Inc. (“SEED”), a clinical-stagebiotechnology company developing rationally designed molecular glue degraders,today announced that it will present a poster on ST-01156, its orallyadministered, selective RBM39 molecular glue degrader currently in afirst-in-human Phase 1 study, at the 2026 American Society of ClinicalOncology (ASCO) Annual Meeting, taking place May 29 through June 2 inChicago, IL. The poster will describethe trial design and preclinical rationale for the ongoing Phase 1 study ofST-01156 in patients with advanced solid malignancies, with a focus on RBM39-dependentcancers.

"RBM39 is acompelling oncology target whose therapeutic potential has been constrained byprior chemical matter. ST-01156 was designed as an oral, selective,brain-penetrant molecular glue degrader to test that hypothesis with thepharmacologic profile required for patients with advanced solid tumors. ThisPhase 1 study is structured to rigorously characterize its safety,pharmacology, and early signals of activity in patients with RBM39-dependent cancers,including those who have exhausted standard treatment options," said EricK. Rowinsky, M.D., clinical and medical lead at SEED and presenting author ofthe poster.

Presentation details are as follows:

·       Title: First-in-Human Clinical Evaluation of ST-01156, an Optimized and Selective Degrader of RNA-Binding Motif39 (RBM39): A Phase 1 Study in Advanced Solid Malignancies with a Focus onRBM39-Dependent Cancers

·       Presenter/Authors: Eric K. Rowinsky, GregoryM. Cote, George D. Demetri, Robert G. Maki, Suzanne George, Daneng Li, Alain C.Mita, Monica M. Mita, Jordi Rodon Ahnert, Dan Lu, Dong Liu, Lan Huang, JamesTonra

·       Presentation Time: Saturday, May 30,2026, from 1:30 p.m. to 4:30 p.m. CDT

·       Location: McCormick Place, Chicago, IL

·       Session: Developmental Therapeutics — MolecularlyTargeted Agents and Tumor Biology

·       Abstract Number: TPS3164

·      Poster Board Number: 296b

About SEED Therapeutics

SEED Therapeutics is a clinical-stage biotechnology company developing rationally designed molecularglue degraders to treat diseases driven by proteins previously consideredundruggable. Its proprietary RITE3™ platform enables selective targeted proteindegradation with a defined therapeutic window, supporting a pipeline of sixmolecular glue programs across oncology, neurodegeneration, and immunology.

SEED was co-founded by four preeminent scientists:

·      NobelLaureate Prof. Avram Hershko, co-discoverer of the ubiquitin-proteasome system, the cellularmachinery that SEED’s molecular glue degraders harness to eliminatedisease-causing proteins.

·      Dr. LanHuang, a pioneering structural biochemistwho determined the first high-resolution structure of an E3 ligasesubstrate-binding domain, providing foundational insight into how targetedprotein degradation can be rationally designed.

·      Prof. NingZheng (University of Washington, HHMIInvestigator), structural biologist and pioneer of RING-finger E3 ligasemechanisms, and the scientist who coined the term “molecular glue” to describesmall molecules that redirect E3 ligases to degrade neo-substrates.

·       Prof. Michele Pagano (NYU Grossman School of Medicine, HHMIInvestigator), one of the world’s foremost authorities on ubiquitin-mediatedproteolysis and its role in cell cycle control and cancer, whose work hasdefined how E3 ligase dysregulation drives tumor development.

Eli Lilly and Company andEisai Co., Ltd. serve as strategic investors and research collaborators,providing both financial investments and scientific partnerships in support ofSEED’s mission to unlock undruggable disease targets. Additional information isavailable at www.seedtherapeutics.com.

Forward-LookingStatements

This press release contains forward-looking statements regarding SEEDTherapeutics, including statements about the design and progress of itsclinical and preclinical programs. Actual results may differ materially due tovarious risks, including those inherent to drug development. SEED undertakes noobligation to update these statements except as required by law.

Media & InvestorContact

Investor Relations: IR@seedtherapeutics.com

Media Relations: PR@seedtherapeutics.com

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