Sapience Therapeutics Presents Positive ST101 Phase 2 GBM Data at ASCO 2024

Sapience Therapeutics, a clinical-stage biotechnology company, has presented new clinical and biomarker data from its ST101 Phase 2 study on Glioblastoma Multiforme (GBM) at the 2024 American Society of Clinical Oncology (ASCO) Annual Meeting. ST101, a pioneering antagonist of C/EBPβ, is being tested in patients with recurrent and newly diagnosed GBM in a Phase 1-2 clinical study (NCT04478279).

Dr. Fabio M. Iwamoto, Principal Investigator of the ST101-101 clinical study from the Division of Neuro-Oncology at New York-Presbyterian/Columbia University Irving Medical Center, expressed optimism about ST101’s effectiveness in GBM patients. The treatment demonstrated durable responses, significant survival benefits, and an alteration of the tumor microenvironment to an immune-active state. Dr. Abi Vainstein-Haras, Sapience's Chief Medical Officer, highlighted the positive clinical outcomes and favorable safety profile of ST101, reinforcing the potential of C/EBPβ as a target for GBM treatment. She emphasized the importance of further exploring ST101 in combination with immune-oncology agents, like checkpoint inhibitors, to improve patient outcomes.

Key findings from the oral presentation, titled "Efficacy and biomarker analysis of phase 2 (P2) and window-of-opportunity (WoO) cohorts of patients with glioblastoma (GBM) treated with ST101, an inhibitor of the transcription factor C/EBPβ," were shared by Dr. Iwamoto. The data showed ST101’s potential as a well-tolerated treatment option for GBM patients.

In the main study, 30 patients with recurrent GBM were treated with ST101 monotherapy. This group had 2 patients with partial responses (PRs), with treatment durations of 55 weeks and over 59 weeks, respectively. Additionally, 7 patients experienced stable disease (SD) with treatment durations ranging from 13 to 79 weeks. The overall survival (OS) rates were 53% at 9 months and 40% at 12 months.

A window-of-opportunity study evaluated ST101 monotherapy in 6 patients with recurrent GBM, resulting in 2 partial responses (one unconfirmed) and 2 stable disease cases. The median overall survival was approximately 12 months, with 3 out of 6 patients still alive between 41 to 62 weeks.

Another window-of-opportunity study explored the combination of ST101 with standard-of-care treatments (radiation and temozolomide) in 6 newly diagnosed GBM patients. This cohort saw 1 complete response (CR) lasting about a year and ongoing, and 4 stable disease cases, with 3 still ongoing. Notably, 5 out of 6 patients were alive between 25 to 57 weeks.

Biomarker data from these studies indicated that ST101 could cross the blood-brain barrier and infiltrate tumor tissue. Immunohistochemistry (IHC) results confirmed target engagement and degradation and showed modulation of the tumor immune microenvironment to support anti-tumor activity.

ST101, an innovative antagonist of C/EBPβ, is being tested in both newly diagnosed and recurrent GBM patients in the Phase 2 stage of an ongoing clinical study. Additionally, ST101 is being assessed as a monotherapy and in combination with radiation and temozolomide in a sub-study. The U.S. FDA has granted Fast Track designation for recurrent GBM and orphan designations for glioma from both the U.S. FDA and the European Commission.

Sapience Therapeutics, based in Tarrytown, New York, is a clinical-stage biotechnology company dedicated to developing peptide therapeutics that address oncogenic and immune dysregulation driving cancer. The company's pipeline includes SPEARs™ (Stabilized Peptides Engineered Against Regulation) and SPARCs™ (Stabilized Peptides Against Receptors on Cancer) designed to disrupt intracellular protein-protein interactions and target cancer cells. Sapience’s lead programs, ST316 and ST101, are currently in Phase 1-2 clinical trials.