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Profiling Sensitivity to Targeted Therapies in EGFR-Mutant NSCLC Patient-Derived Organoids
Published on: November 22, 2021
Bispecific T-cell Engager (CD3 × EGFR)-Based Triplet Therapy Unlocks CD40/CD40L Crosstalk to Revert Immunosuppression
Haoyue Guo1, Yuanyuan Wang1, Meng Diao1
1Department of Medical Oncology, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, People's Republic of China; Department of Medical Oncology, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, People's Republic of China.
Introduction:
Acquired resistance to third-generation EGFR-tyrosine kinase inhibitors (EGFR-TKIs) is a major challenge in NSCLC, with approximately 50% of cases lacking precise resistance mechanisms. This study investigates the immunosuppressive tumor microenvironment (TME) driving resistance and develops a novel triple-combination therapy to restore T-cell antitumor activity.
Methods:
Single-cell RNA sequencing and multicolor fluorescence staining were performed on NSCLC patient samples to analyze TME changes post-EGFR-TKI resistance. A triple therapy combining BC3448 (EGFR and CD3 bispecific T-cell engager), tucidinostat (histone deacetylase inhibitor), and WBP3425 (4-1BB agonist) was tested using in vitro co-culture assays, syngeneic cell-derived xenograft models in humanized NOG-EXL mice, and multi-omics analyses.
Results:
Single-cell RNA sequencing revealed reduced T-cell infiltration or activation and increased immunosuppressive myeloid cells in resistant NSCLC. BC3448 monotherapy activated T cells and induced tumor cell apoptosis in vitro but was limited in vivo because of myeloid-driven immunosuppression. The triple therapy significantly enhanced tumor regression in osimertinib-resistant models (tumor growth inhibition >70%, p < 0.001), promoted CD8+ effector T-cell differentiation, and suppressed Tregs and M2 macrophages. CD40-CD40L axis activation between T cells and monocyte-derived macrophages was critical for TME remodeling, with spatial profiling revealing increased CD40L+ T-cell and CD40+ macrophage proximity, correlating with higher IFN-γ and reduced angiogenesis. A durable response to BC3448 monotherapy was observed in an immunotherapy-resistant patient with NSCLC (>2 y of stable disease), presenting a translational potential of this approach.
Conclusions:
This study establishes a novel triple therapy that overcomes the limitations of bispecific T-cell engagers in cold and immunosuppressive TMEs and provides an immunomodulatory approach to addressing third-generation EGFR-TKI resistance.
Insights
A new triple therapy combining BC3448, Tucidinostat, and WBP3425 effectively overcomes resistance to EGFR-TKIs in non-small cell lung cancer (NSCLC). This approach restores T-cell activity within the tumor microenvironment, significantly improving treatment outcomes.
Area of Science:
- Oncology
- Immunology
- Cancer Therapy
Background:
- Acquired resistance to third-generation EGFR-TKIs presents a significant challenge in non-small cell lung cancer (NSCLC).
- Approximately 50% of NSCLC cases exhibit resistance mechanisms that are not fully understood, highlighting a critical unmet need.
- The tumor microenvironment (TME) plays a crucial role in mediating resistance to targeted therapies.
Purpose of the Study:
- To investigate the role of the immunosuppressive TME in acquired resistance to EGFR-TKIs in NSCLC.
- To develop and evaluate a novel triple-combination therapy to restore T-cell anti-tumor activity and overcome resistance.
- To elucidate the mechanisms underlying the efficacy of the triple therapy in remodeling the TME.
Main Methods:
- Single-cell RNA sequencing (scRNA-seq) and multicolor fluorescence staining were employed to analyze TME alterations in resistant NSCLC patient samples.
- A triple therapy comprising BC3448 (EGFR/CD3 BiTE), Tucidinostat (HDAC inhibitor), and WBP3425 (4-1BB agonist) was evaluated.
- In vitro co-culture assays, syngeneic cell-derived xenograft (CDX) models in humanized mice, and multi-omics analyses were utilized to assess therapeutic efficacy and mechanisms.
Main Results:
- scRNA-seq identified reduced T-cell infiltration and activation, alongside increased immunosuppressive myeloid cells, in resistant NSCLC.
- While BC3448 monotherapy showed in vitro efficacy, in vivo treatment was limited by myeloid-driven immunosuppression.
- The triple therapy demonstrated significant tumor regression (>70% inhibition) in osimertinib-resistant models, enhanced CD8+ effector T-cell differentiation, and suppressed regulatory T cells (Tregs) and M2 macrophages.
- CD40/CD40L axis activation between T cells and macrophages was critical for TME remodeling, evidenced by increased proximity of CD40L+ T cells and CD40+ macrophages, correlating with higher IFN-γ and reduced angiogenesis.
- A durable response was observed in an immunotherapy-resistant NSCLC patient treated with BC3448 monotherapy, suggesting translational potential.
Conclusions:
- The novel triple therapy effectively overcomes limitations of BiTEs in cold and immunosuppressive TMEs.
- This immunomodulatory approach offers a promising strategy for addressing third-generation EGFR-TKI resistance in NSCLC.
- The findings provide a foundation for developing new therapeutic strategies targeting the TME in resistant lung cancers.
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