Combination of T cell-redirecting bispecific antibody ERY974 and chemotherapy reciprocally enhances efficacy against non-inflamed tumours

Targeting ErbB and tankyrase1/2 prevent the emergence of drug-tolerant persister cells in ALK-positive lung cancer

Targeting the drug tolerant persister (DTP) state in cancer cells should prevent further development of resistance mechanisms. This study explored combination therapies to inhibit alectinib-induced DTP cell formation from anaplastic lymphoma kinase-positive non-small cell lung cancer (ALK + NSCLC) patient-derived cells. After drug-screening 3114 compounds, pan-HER inhibitors (ErbB pathway) and tankyrase1/2 inhibitors (Wnt/β-catenin signaling) emerged as top candidates to inhibit alectinib-induced DTP cells growth. We confirmed knockdown of both TNKS1/2 in DTP cells recovered the sensitivity to alectinib. Further, our study suggested knockdown of TNKS1/2 increased stability of Axin1/2, which induced β-catenin degradation and decreased its nuclear translocation, thereby suppressing transcription of antiapoptotic and proliferation-related genes (survivin, c-MYC). Targeting both pathways with alectinib+pan-HER inhibitor and alectinib+TNKS1/2 inhibitor suppressed alectinib-induced DTP cells, and the triple combination almost completely prevented the appearance of DTP cells. In conclusion, combination with ALK-TKI, pan-HER and TNKS1/2 inhibitors has the potential to prevent the emergence of DTP in ALK + NSCLC.

Clinical Progresses and Challenges of Bispecific Antibodies for the Treatment of Solid Tumors

In recent years, bispecific antibodies (BsAbs) have emerged as a promising therapeutic strategy against tumors. BsAbs can recruit and activate immune cells, block multiple signaling pathways, and deliver therapeutic payloads directly to tumor sites. This review provides a comprehensive overview of the recent advances in the development and clinical application of BsAbs for the treatment of solid tumors. We discuss the different formats, the unique mechanisms of action, and the clinical outcomes of the most advanced BsAbs in solid tumor therapy. Several studies have also analyzed the clinical progress of bispecific antibodies. However, this review distinguishes itself by exploring the challenges associated with bispecific antibodies and proposing potential solutions. As the field progresses, BsAbs hold promise to redefine cancer treatment paradigms and offer new hope to patients with solid tumors.

T cell-redirecting antibody for treatment of solid tumors via targeting mesothelin

T cell engaging bispecific antibodies (TCBs) have recently become significant in cancer treatment. In this study we developed MSLN490, a novel TCB designed to target mesothelin (MSLN), a glycosylphosphatidylinositol (GPI)-linked glycoprotein highly expressed in various cancers, and evaluated its efficacy against solid tumors. CDR walking and phage display techniques were used to improve affinity of the parental antibody M912, resulting in a pool of antibodies with different affinities to MSLN. From this pool, various bispecific antibodies (BsAbs) were assembled. Notably, MSLN490 with its IgG-[L]-scFv structure displayed remarkable anti-tumor activity against MSLN-expressing tumors (EC50: 0.16 pM in HT-29-hMSLN cells). Furthermore, MSLN490 remained effective even in the presence of non-membrane-anchored MSLN (soluble MSLN). Moreover, the anti-tumor activity of MSLN490 was enhanced when combined with either Atezolizumab or TAA × CD28 BsAbs. Notably, a synergistic effect was observed between MSLN490 and paclitaxel, as paclitaxel disrupted the immunosuppressive microenvironment within solid tumors, enhancing immune cells infiltration and improved anti-tumor efficacy. Overall, MSLN490 exhibits robust anti-tumor activity, resilience to soluble MSLN interference, and enhanced anti-tumor effects when combined with other therapies, offering a promising future for the treatment of a variety of solid tumors. This study provides a strong foundation for further exploration of MSLN490's clinical potential.

Progresses of T-cell-engaging bispecific antibodies in treatment of solid tumors

T-cell-engaging bispecific antibody (TCB) therapies have emerged as a promising immunotherapeutic approach, effectively redirecting effector T cells to selectively eliminate tumor cells. The therapeutic potential of TCBs has been well recognized, particularly with the approval of multiple TCBs in recent years for the treatment of hematologic malignancies as well as some solid tumors. However, TCBs encounter multiple challenges in treating solid tumors, such as on-target off-tumor toxicity, cytokine release syndrome (CRS), and T cell dysfunction within the immunosuppressive tumor microenvironment, all of which may impact their therapeutic efficacy. In this review, we summarize clinical data on TCBs for solid tumor treatment, highlight the challenges faced, and discuss potential solutions based on emerging strategies from current clinical and preclinical research. These solutions include TCB structural optimization, target selection, and combination strategies. This comprehensive analysis aims to guide the development of TCBs from design to clinical application, addressing the evolving landscape of cancer immunotherapy.

Potent antitumor activity of a bispecific T-cell engager antibody targeting the intracellular antigen KRAS G12V

Kirsten Rat Sarcoma viral oncogene homolog (KRAS) is one of the most frequent oncogenes. However, there are limited treatment options due to its intracellular expression. To address this, we developed a novel bispecific T-cell engager (BiTE) antibody targeting HLA-A2/KRAS G12V complex and CD3 (HLA-G12V/CD3 BiTE). We examined its specific binding to tumor cells and T cells, as well as its anti-tumor effects in vivo. HLA-G12V/CD3 BiTE was expressed in Escherichia coli and its binding affinities to CD3 and HLA-A2/KRAS G12V were measured by flow cytometry, along with T-cell activation. In a xenograft pancreatic tumor model, the HLA-G12V/CD3 BiTE's anti-tumor effects were assessed through tumor growth, survival time, and safety. Our results demonstrated specific binding of HLA-G12V/CD3 BiTE to tumor cells with an HLA-A2/KRAS G12V mutation and T cells. The HLA-G12V/CD3 BiTE also activated T-cells in the presence of tumor cells in vitro. HLA-G12V/CD3 BiTE in vivo testing showed delayed tumor growth without severe toxicity to major organs and prolonged mouse survival. This study highlights the potential of constructing BiTEs recognizing an HLA-peptide complex and providing a novel therapy for cancer treatment targeting the intracellular tumor antigen.

Engineering CD3/CD137 Dual Specificity into a DLL3-Targeted T-Cell Engager Enhances T-Cell Infiltration and Efficacy against Small-Cell Lung Cancer

Small-cell lung cancer (SCLC) is an aggressive cancer for which immune checkpoint inhibitors (ICI) have had only limited success. Bispecific T-cell engagers are promising therapeutic alternatives for ICI-resistant tumors, but not all patients with SCLC are responsive. Herein, to integrate CD137 costimulatory function into a T-cell engager format and thereby augment therapeutic efficacy, we generated a CD3/CD137 dual-specific Fab and engineered a DLL3-targeted trispecific antibody (DLL3 trispecific). The CD3/CD137 dual-specific Fab was generated to competitively bind to CD3 and CD137 to prevent DLL3-independent cross-linking of CD3 and CD137, which could lead to systemic T-cell activation. We demonstrated that DLL3 trispecific induced better tumor growth control and a marked increase in the number of intratumoral T cells compared with a conventional DLL3-targeted bispecific T-cell engager. These findings suggest that DLL3 trispecific can exert potent efficacy by inducing concurrent CD137 costimulation and provide a promising therapeutic option for SCLC.

Stepping forward: T-cell redirecting bispecific antibodies in cancer therapy

T cell-redirecting bispecific antibodies are specifically designed to bind to tumor-associated antigens, thereby engaging with CD3 on the T cell receptor. This linkage between tumor cells and T cells actively triggers T cell activation and initiates targeted killing of the identified tumor cells. These antibodies have emerged as one of the most promising avenues within tumor immunotherapy. However, despite success in treating hematological malignancies, significant advancements in solid tumors have yet to be explored. In this review, we aim to address the critical challenges associated with T cell-redirecting bispecific antibodies and explore novel strategies to overcome these obstacles, with the ultimate goal of expanding the application of this therapy to include solid tumors.

Bispecific Nanobody-Aptamer Conjugates for Enhanced Cancer Therapy in Solid Tumors

Bispecific antibodies possess exceptional potential as therapeutic agents due to their capacity to bind to two different antigens simultaneously. However, challenges pertain to unsatisfactory stability, manufacturing complexity, and limited tumor penetration hinder their broad applicability. In this study, a versatile technology is presented for the rapid generation of bispecific nanobody-aptamer conjugates with efficient tumor penetration. The approach utilizes microbial transglutaminase (MTGase) and click chemistry to achieve site-specific conjugation of nanobodies and aptamers, which are termed nanotamers. The nanotamers recognize and bind to two types of molecular targets expressed on cancer cells. As a prototype, a bispecific nanotamer is developed that binds both clusters of differentiation 47 (CD47) and mesenchymal epithelial transition receptor (Met) expressed on the tumor cell membrane. This CD47-Met nanotamer demonstrates high affinity and specificity toward tumor cells expressing both targets, exhibits improved receptor functional inhibition through a strong steric hindrance effect. Moreover, its capacity for deep tumor penetration greatly enhances the impact of conventional chemotherapy on antitumor efficacy. The as-developed nanotamer synthesis approach shows promise to customize bispecific molecular probes targeting different cancer types and different therapeutic goals.

Development of pharmacological immunoregulatory anti-cancer therapeutics: current mechanistic studies and clinical opportunities

Immunotherapy represented by anti-PD-(L)1 and anti-CTLA-4 inhibitors has revolutionized cancer treatment, but challenges related to resistance and toxicity still remain. Due to the advancement of immuno-oncology, an increasing number of novel immunoregulatory targets and mechanisms are being revealed, with relevant therapies promising to improve clinical immunotherapy in the foreseeable future. Therefore, comprehending the larger picture is important. In this review, we analyze and summarize the current landscape of preclinical and translational mechanistic research, drug development, and clinical trials that brought about next-generation pharmacological immunoregulatory anti-cancer agents and drug candidates beyond classical immune checkpoint inhibitors. Along with further clarification of cancer immunobiology and advances in antibody engineering, agents targeting additional inhibitory immune checkpoints, including LAG-3, TIM-3, TIGIT, CD47, and B7 family members are becoming an important part of cancer immunotherapy research and discovery, as are structurally and functionally optimized novel anti-PD-(L)1 and anti-CTLA-4 agents and agonists of co-stimulatory molecules of T cells. Exemplified by bispecific T cell engagers, newly emerging bi-specific and multi-specific antibodies targeting immunoregulatory molecules can provide considerable clinical benefits. Next-generation agents also include immune epigenetic drugs and cytokine-based therapeutics. Cell therapies, cancer vaccines, and oncolytic viruses are not covered in this review. This comprehensive review might aid in further development and the fastest possible clinical adoption of effective immuno-oncology modalities for the benefit of patients.