Genexine’s First-in-Class SOX2 Degrader GX-BP1 Demonstrates Up to 96% TGI and Eliminates Tumor Regrowth in Preclinical Models

SEOUL, South Korea--(BUSINESS WIRE)--Genexine, Inc. (KOSDAQ: 095700), a clinical-stage biotechnology company, today announced new preclinical data for its SOX2-targeting bioPROTAC candidate, GX-BP1, presented at the American Association for Cancer Research (AACR) Annual Meeting 2026 in San Diego.

GX-BP1 is a first-in-class bioPROTAC drug candidate designed to selectively degrade SOX2, a transcription factor widely recognized as a key driver of tumor progression, cancer stemness, and therapeutic resistance, yet historically considered undruggable. By directly eliminating SOX2 via the ubiquitin-proteasome system, GX-BP1 targets a central driver of tumor relapse, metastasis, and resistance to standard therapies.

Preclinical data demonstrated strong anti-tumor activity across multiple models. GX-BP1 monotherapy achieved approximately 70% tumor growth inhibition (TGI), confirming meaningful standalone efficacy.

In combination settings, GX-BP1 restored sensitivity in chemotherapy-resistant models and enhanced the efficacy of EGFR-targeted therapies, including osimertinib, by suppressing SOX2-driven resistance mechanisms.

Notably, the combination of GX-BP1 with carboplatin and paclitaxel showed a clear dose-dependent response, achieving 87% to 96% TGI, with near-complete tumor growth suppression at higher doses. In addition, while tumor regrowth was observed in the osimertinib monotherapy group, the combination of GX-BP1 with osimertinib completely prevented tumor relapse, accompanied by effective elimination of cancer stem cell populations.

These findings position GX-BP1 as a potential backbone therapy for combination strategies, with broad applicability across chemotherapy, targeted therapy, and immunotherapy settings, particularly in resistant or refractory disease.

Genexine has also established a clinically relevant delivery approach using a lung-targeted lipid nanoparticle (LNP) system, enabling efficient systemic delivery of over 70% GX-BP1 mRNA to lung tissues within 24 hours.

GX-BP1 has demonstrated a comprehensive preclinical profile, including in vivo efficacy, pharmacokinetics, biodistribution, and safety, supporting advancement into IND-enabling studies. Genexine is actively pursuing global licensing and strategic partnership opportunities for GX-BP1 and its bioPROTAC platform-based pipelines.

“GX-BP1 represents a differentiated therapeutic approach that directly targets a central driver of cancer resistance,” said Jaehyun Choi, Ph.D., Chief Executive Officer and Head of R&D at Genexine. “We believe its strong combination potential, and GX-BP1’s robust preclinical profile position it as a promising next-generation therapeutic candidate, and we are advancing discussions with global partners.”

About Genexine

Genexine is one of the first-generation biotechnology companies in South Korea, dedicated to developing innovative biologics to address unmet medical needs in patients with serious diseases. The company leverages its proprietary technology platforms, including the long-acting hyFc® platform, DNA vaccine technology, and the next-generation bioPROTAC platform, to develop novel therapeutics.

In particular, Genexine is advancing a pipeline of global first-in-class drug candidates based on its bioPROTAC platform, including GX-BP1 for lung cancer and GX-BP2 for atopic dermatitis. In addition, the company is progressing late-stage bio-better assets toward commercialization. Efesa® (GX-E4), a long-acting treatment for anemia in chronic kidney disease, is currently under regulatory review in Korea and other global markets for non-dialysis patients. GX-H9, a long-acting growth hormone, is also preparing for regulatory approval in China.

About EPDeg™ bioPROTAC

EPDeg™ bioPROTAC is a next-generation targeted protein degradation (TPD) technology that directly fuses a synthetic nanobody-based target-binding moiety with an E3 ligase. This design overcomes key limitations of conventional small molecule-based PROTAC approaches, enabling improved development efficiency and enhanced tissue specificity. By selectively degrading disease-causing proteins, EPDeg™ bioPROTAC offers a novel therapeutic strategy with the potential to address previously undruggable targets.