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News|Articles|April 29, 2026

Genexine’s GX-BP1 Shows Potent Preclinical Activity, Targeting ‘Undruggable’ SOX2 to Overcome Cancer Resistance

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Key Takeaways

  • GX-BP1 applies targeted protein degradation to SOX2, reframing an “undruggable” transcription factor as actionable through elimination rather than occupancy-based inhibition.
  • Monotherapy yielded ~70% tumor growth inhibition, indicating SOX2 degradation can materially suppress proliferation despite incomplete tumor eradication.
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Genexine’s first-in-class SOX2 degrader GX-BP1 demonstrated up to 96% tumor growth inhibition in preclinical models presented at AACR 2026. The bioPROTAC candidate also prevented tumor relapse and restored drug sensitivity, positioning it as a promising next-generation oncology therapy.

At the American Association for Cancer Research Annual Meeting 2026, Genexine, Inc. unveiled preclinical data for GX-BP1, a novel bioPROTAC designed to degrade SOX2—a transcription factor long considered “undruggable.” SOX2 plays a central role in tumor progression, cancer stem cell maintenance, and resistance to therapy.

GX-BP1 leverages the company’s EPDeg bioPROTAC platform to directly eliminate SOX2 via the ubiquitin-proteasome system rather than merely inhibiting it. This targeted protein degradation strategy represents a shift from traditional small-molecule inhibition, offering a way to address core drivers of relapse and metastasis, according to trial investigators.

How effective is GX-BP1 as a standalone therapy?

In preclinical models, GX-BP1 monotherapy achieved approximately 70% tumor growth inhibition, indicating meaningful standalone anti-tumor activity. While not curative on its own, this level of efficacy demonstrates that degrading SOX2 can significantly suppress tumor proliferation, Genexine stated in a press release.

Importantly, these findings validate SOX2 as a viable therapeutic target when approached through degradation rather than inhibition (TGI), reinforcing broader interest in targeted protein degradation technologies across oncology.

Can GX-BP1 overcome drug resistance in combination therapies?

The most striking results emerged in combination settings. GX-BP1 enhanced the efficacy of standard treatments and reversed resistance mechanisms:

  • In chemotherapy-resistant models, GX-BP1 restored sensitivity to treatment.
  • When combined with osimertinib, it suppressed resistance pathways driven by SOX2.
  • In combination with carboplatin and paclitaxel, GX-BP1 achieved 87%–96% TGI.

Notably, while tumors regrew in osimertinib-only models, the GX-BP1 combination completely prevented relapse. This effect was associated with elimination of cancer stem cell populations, which are often implicated in recurrence and treatment failure.

What role does delivery technology play in GX-BP1’s development?

A key challenge for mRNA-based therapeutics is efficient delivery. Genexine addressed this by developing a lung-targeted lipid nanoparticle system, enabling over 70% of GX-BP1 mRNA to reach lung tissue within 24 hours of systemic administration.

This targeted delivery is particularly relevant for lung cancer applications, in which localized expression of the therapeutic payload may improve efficacy while minimizing systemic toxicity.

What are the next steps for GX-BP1?

GX-BP1 has demonstrated a comprehensive preclinical profile, including favorable pharmacokinetics, biodistribution, and safety data. These results support progression into investigational new drug-enabling studies.

This targeted protein degradation strategy represents a shift from traditional small-molecule inhibition, offering a way to address core drivers of relapse and metastasis, according to trial investigators.

Genexine is also pursuing global licensing and partnership opportunities, positioning GX-BP1 as a potential backbone therapy across multiple treatment modalities, including chemotherapy, targeted therapy, and immunotherapy.

The broader implication is significant: if successful in clinical trials, GX-BP1 could validate bioPROTACs as a scalable platform for targeting previously inaccessible proteins in cancer and beyond, according to Genexine.

References

  1. Genexine’s First-in-Class SOX2 Degrader GX-BP1 Demonstrates Up to 96% TGI and Eliminates Tumor Regrowth in Preclinical Models. (2026 Apr 28). Business Wire. https://www.businesswire.com/news/home/20260428486531/en/Genexines-First-in-Class-SOX2-Degrader-GX-BP1-Demonstrates-Up-to-96-TGI-and-Eliminates-Tumor-Regrowth-in-Preclinical-Models
  2. Boumahdi S, de Sauvage FJ. (2020, Jan 19). The great escape: tumour cell plasticity in resistance to targeted therapy. Nature Reviews Drug Discovery. https://pubmed.ncbi.nlm.nih.gov/31601994
  3. Doudna JA. (2020 Jan 19). The promise and challenge of therapeutic genome editing. Nature. https://pmc.ncbi.nlm.nih.gov/articles/PMC8992613/
  4. Bondeson DP, Crews CM. (2017 Oct 12). Targeted protein degradation by small molecules. Annual Review of Pharmacology and Toxicology. https://pmc.ncbi.nlm.nih.gov/articles/PMC5586045/

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