SEED Therapeutics to Present Phase 1 Trial Design for ST-01156, a First-in-Human Oral RBM39 Molecular Glue Degrader, at 2026 ASCO Annual Meeting

SEED Therapeutics has announced it will present the Phase 1 trial design for ST-01156, an orally administered RBM39 molecular glue degrader, at the 2026 ASCO Annual Meeting

The poster presentation titled "First-in-Human Clinical Evaluation of ST-01156, an Optimized and Selective Degrader of RNA-Binding Motif 39 (RBM39): A Phase 1 Study in Advanced Solid Malignancies with a Focus on RBM39-Dependent Cancers" will be presented on Saturday, May 30, 2026, from 1:30 p.m. to 4:30 p.m. CDT at McCormick Place in Chicago, IL, during the session "Developmental Therapeutics — Molecularly Targeted Agents and Tumor Biology" (Abstract Number:
TPS3164)

ST-01156 is an oral, selective, brain-penetrant molecular glue that degrades RBM39, a key regulator of RNA splicing and transcription, and is being evaluated in an ongoing first-in-human Phase 1 trial for patients with advanced solid malignancies, particularly RBM39-dependent cancers such as Ewing sarcoma, KRAS-mutant cancers, and hepatocellular carcinoma

The Phase 1 trial is open-label and dose-escalating, with the primary objective of characterizing safety, tolerability, and adverse events, identifying the recommended Phase 2 dose, and evaluating pharmacokinetics and early anticancer signals

The study is registered as NCT07197554 and is being conducted at leading cancer centers including Dana-Farber Cancer Institute, Memorial Sloan Kettering Cancer Center, MD Anderson Cancer Center, and others

The FDA has cleared the IND for ST-01156, which has received Orphan Drug and Rare Pediatric Disease designations for Ewing sarcoma, a rare pediatric cancer with no new approved therapies in over 30 years