Antibody Therapeutics最新文献

T-cell engagers (TCEs) represent an emerging class of immunotherapies that harness T cells' cytotoxic power to eliminate diseased cells-a transformative future therapeutic strategy. TCEs form immunological synapses to trigger potent immune responses, with proven efficacy in blood cancers; research expands their use to solid tumors via innovative molecular design and improved safety profiles. Beyond oncology, TCEs hold promise in autoimmune disorders by eliminating autoreactive cells, offering novel avenues for diseases like lupus. However, achieving optimal outcomes without disrupting immune homeostasis remains a challenge. Key obstacles-on-target off-tumor toxicity, cytokine release syndrome, tumor antigen loss, and T cell exhaustion-limit broader adoption. Current research addresses these via enhanced specificity, optimized design, improved druggability, and synergistic combinations. This review analyzes TCEs' mechanisms, challenges, innovations and applications, highlights our pipeline advances, and advocates sustained innovation to broaden TCE use across diseases.

The tumor-associated antigen mesothelin is highly expressed in many human cancers, while its expression in normal tissues is limited. Its interaction with the cancer antigen 125 promotes heterotypic cell adhesion and tumor metastasis. Mesothelin-targeted immunotherapies are being intensively investigated, which is aided by growing structural knowledge of the protein and its interactions with antibodies. Recent studies have produced a complete atomic model showing mesothelin as a compact, right-handed, conformationally flexible solenoid composed of nine layers of helices, with glycans attached at all three predicted N-glycosylation sites. Structural analyses reveal that most therapeutic antibodies target the rigid and immunogenic N-terminal domain, while a few bind to middle domain or C-terminal linear tail, revealing correlation between immunogenicity and structural stability. Crystallographic studies have also extended to the interactions between mesothelin and CA-125. These structural advances offer insights into the potential function of mesothelin and guidance for further development of therapeutic antibodies.

Background: Although CD19 and CD22 chimeric antigen receptor (CAR-T) cell therapies have demonstrated encouraging clinical responses in patients with B-cell lymphoma, over 50% of patients ultimately experience disease progression due to frequent antigen escape. The development of CD19/CD22 dual-target CAR-T cells holds promise for overcoming this limitation; however, their clinical application is currently challenging because of insufficient targeting of CD22.

Methods: In this study, we engineered CD19/CD22 BS Loop CAR-T cells with an enhanced targeting efficacy for CD22 and assessed their safety and effectiveness in patients with relapsed/refractory diffuse large B-cell lymphoma.

Results: Among the five patients who received CD19/CD22 bispecific Loop CAR-T-cell therapy (1.6 × 10⁶/kg) from December 2023 to May 2024, four patients (80%) achieved complete remission (CR), and one patient (20%) maintained a stable disease status 1 month after infusion. The expansion of the CD19/CD22 Beta-stranded (BS) Loop CAR-T cells was effective in vivo and detectable in the peripheral blood. All patients experienced only Grade 0-1 cytokine release syndrome without any observed neurotoxicity. With the follow-up extended to May 2025 (lasting for at least 1 year), three patients experienced disease progression and eventually died, while the remaining two patients remained in CR.

Conclusions: CD19/CD22 BS Loop CAR-T-cell therapy exhibits potent antilymphoma activity while addressing the challenges associated with designing CAR-T cells that are equally potent against two antigens. This treatment may represent a safe and effective unique immunotherapeutic strategy for lymphoma.

Objective: Antibodies against vascular cell adhesion molecule (VCAM)-1 represent an attractive strategy for atherosclerosis and cardiovascular disease management due to their ability to selectively block leukocyte-endothelial interactions involved in inflammatory cell recruitment. Herein, seven novel anti-VCAM-1 monoclonal antibodies (mAbs) generated from phage display biopanning were tested using a series of in vitro models of cell recruitment to determine their potential utility for treating atherosclerosis.

Methods and results: We assessed the inhibitory effects of the test antibodies on cell adhesion and transmigration using a series of in vitro assays that incorporated three-dimensional microfluidics and collagen hydrogel models. In summary, each of our mAb candidates were found to reduce RAW264.7 monocyte adhesion to activated SVEC4-10 endothelial monolayers under static conditions. Subsequently, the three most effective candidates from this assay-2E2, 3C12, and 3H4-were shown to inhibit monocyte adhesion to endothelial microvessels under flow conditions and monocyte transmigration into endothelialized gel matrices under static conditions.

Conclusion: These results indicate that our novel anti-VCAM-1 mAbs can effectively inhibit monocyte adhesion and transmigration in vitro, supporting the therapeutic rationale of VCAM-1 immunoblockade for the targeted treatment of atherosclerosis.

Background: Natural killer cell engager (NKCE) has gained attention recently. Conventional NKCEs exhibit mild anti-tumor efficacy despite acceptable safety profiles. Therefore, next-generation NKCE development is essential to enhance efficacy. IL-15, a key NK cell activator, is explored in NKCE design. However, wild-type IL-15 shows significant toxicity in clinical trials. In this study, we present the development of a novel tetravalent NKCE platform (IL15v-NKCE) by incorporating a potency-reduced IL-15 element (IL15v) into our proprietary anti-NKp46 based NKCEs.

Methods: The activity of the IL15v moiety was assessed by quantifying pSTAT5 induction in primary immune cells and evaluating STAT5 activation in an IL-15 reporter cell line. The in vitro activity of IL15v-NKCE was determined using co-culture assays with NK and tumor cells. The in vivo anti-tumor efficacy and safety profile of IL15v-NKCE were evaluated in tumor-bearing mouse models.

Results: In vitro, IL15v selectively activates NK cells without affecting T cells, enhances NKCE cytotoxicity, prevents NK apoptosis, and promotes NK proliferation. In vivo, IL15v-NKCE shows good tolerability and superior anti-tumor efficacy compared to conventional NKCE. All four components (anti-NKp46, Fc, IL15v, anti-tumor-associated antigen) of IL15v-NKCE are essential for maximal activity, and IL15v-NKCE is more potent than the conventional NKCE when combined with anti-PD-1 in preclinical models.

Conclusions: By integrating IL15v into our anti-NKp46 based NKCEs, IL15v-NKCE has exhibited enhanced anti-tumor efficacy while maintaining an acceptable safety profile, thereby positioning it as a promising next-generation therapeutic modality for NK cell-based therapy.

Background: Mesothelin (MSLN) is a surface antigen highly expressed in several solid tumors, including mesothelioma, ovarian, and pancreatic cancers. However, therapeutic efficacy of MSLN-targeted agents is often compromised by shed MSLN (SM), which acts as a soluble decoy and accumulates in tumor microenvironments, reducing antibody engagement at the tumor surface.

Methods: To overcome this barrier, we generated antibodies targeting the membrane-proximal, non-shed region of MSLN using a peptide encompassing major cleavage sites for rabbit immunization. From 200 B-cell clones, 14 antibodies specific to the juxtamembrane region of MSLN were identified. The lead candidate, RO4, underwent detailed characterization and humanization to improve clinical applicability.

Results: Humanized RO4 (hRO4) exhibited enhanced binding affinity to MSLN and specifically recognized tumor-associated, non-shed epitopes. Structural analysis confirmed precise epitope engagement near the cleavage site. hRO4 effectively inhibited mesothelin shedding in vitro and enabled potent tumor eradication when expressed in chimeric antigen receptor (CAR) T cells in NOD scid gamma mouse models.

Conclusions: Targeting a non-shed epitope of MSLN with hRO4 overcomes a critical limitation of conventional MSLN-directed therapies. By avoiding decoy interference and enhancing tumor-specific targeting, hRO4-based therapeutics offer promising clinical potential for improving outcomes in MSLN-positive cancers.

Background: Gastric cancer (GC) represents one of the most prevalent and lethal malignancies, however, current treatments have shown limited efficacy. Clinical investigations have revealed that Dickkopf-1 (DKK1)-high GC patients are associated with poor prognosis, and DKK1 expression is negatively correlated with overall survival, suggesting a means of pharmaceutical intervention by neutralizing DKK1 for GC patients.

Methods: To overcome antigen tolerance and stimulate antibody production, strategies were employed, including different adjuvants, antigen design, and various mouse strains. Finally, a novel antibody targeting DKK1 was screened out from ~100 000 candidates. GB22-45-2 underwent in vitro and in vivo evaluations, and was compared with clinical-stage anti-DKK1 benchmarks. A comprehensive assessment of drug developability was also performed.

Results: GB22-45 screened out from Murphy Roths Large (MRL/MpJ) mice immunized with Freund's adjuvant and full-length DKK1 conjugated with Keyhole Limpet Hemocyanin achieved the best affinity. C34V and M99V mutations were introduced to the final optimized humanized antibody, GB22-45-2, to prevent dimer formation and mitigate risks of methionine oxidation. In vitro, GB22-45-2 exhibited potent activities in restoring Wnt T-cell factor/lymphoid enhancer-binding factor signaling by reporter assay. Importantly, GB22-45-2 demonstrated a desirable specificity profile by baculovirus particle binding assay and cross-interaction chromatography assays. In vivo, GB22-45-2 showed a modest tumor growth inhibition (31.03%) that is significant (P = 0.0175), while DKN-01 did not reach significance, in the MKN-45-Balb/c-nude mouse model. Additionally, GB22-45-2 exhibited a satisfactory developability profile, including good thermal stability, low aggregation propensity, high structural integrity, and excellent stability under various stress conditions.

Conclusions: In summary, these preclinical results suggest that GB22-45-2 is a potential therapeutic candidate for GC, laying the foundation for its future drug development.

Background: As one of the most promising classes of next-generation antibody therapeutics, bispecific antibodies (bsAbs) have gained increasing attention owing to their unique dual-targeting mechanisms. However, current bsAb formats often face challenges such as low expression levels, poor homogeneity, and unstable therapeutic efficacy due to their complex structures. Therefore, it is urgent to overcome the current technical limitations and develop novel formats of bsAbs with more stable structures and improved expression efficiency.

Methods: Through rational design and phage display-based screening, we engineered a novel light-chain single-domain antibody (VHHL). Using modular assembly and replacement strategies, the VHHL was reconstituted into conventional immunoglobulin G (IgG)s and the resulting bsAbs were comprehensively characterized by size-exclusion high-performance liquid chromatography, biolayer interferometry binding assay, enzyme-linked immunosorbent assay, and flow cytometry.

Results: A light chain engineering strategy combining complementarity-determining region 3 (CDR3)-grafting with site-directed mutagenesis of CDR1/CDR2 was developed to generate VHHLs. Through phage screening, two mouse CD16-specific VHHL candidates with favorable binding affinities and biophysical properties were identified, and one of which was structurally resolved via X-ray crystallography (3.05 Å resolution). When incorporated into full-length IgGs, the resulting bsAbs retained high structural similarity to natural monoclonal antibodies and maintained dual antigen-binding capabilities through their respective light and heavy chains.

Conclusions: Consequently, this study presents a novel IgG-format bsAb platform enabled by the integration of a rationally designed antigen-binding VHHL, providing a streamlined and versatile strategy for the development of multifunctional antibodies.

Background: Prostate-specific membrane antigen (PSMA)-targeted therapies have revolutionized the management of patients with prostate cancer. However, not all patients benefit from such agents. Prostatic acid phosphatase (ACP3), a tyrosine phosphatase produced by prostate epithelial cells, has emerged as a promising alternative target for both early and advanced disease.

Methods: Here, we report on the generation and characterization of novel, fully human monoclonal antibodies targeting PSMA and ACP3. Antigen-specific clones were isolated from human antibody phage display libraries and characterized in vitro and in vivo.

Results: Selected clones bound with high specificity to the cognate target and demonstrated excellent tumor-targeting performance in biodistribution studies.

Conclusions: The lead candidates, termed H92A5 (anti-PSMA) and EKA4 (anti-ACP3), could serve as promising scaffolds for the development of next-generation tumor-targeted therapeutics for prostate cancer.

The integration of antibody-drug conjugates (ADCs) with immune checkpoint inhibitors (ICIs) represents a paradigm shift in oncology, combining targeted cytotoxicity and adaptive immune activation to overcome resistance in refractory tumors. This review explores their mechanistic synergy, focusing on dual functions in reprogramming the tumor immune microenvironment. ADCs mediate antibody-dependent cellular cytotoxicity (ADCC), engaging NK cells and macrophages to release tumor-associated antigens (TAAs) and damage-associated molecular patterns. Immunogenic cell death (ICD) amplifies adaptive immunity by releasing TAAs for T-cell priming, while PD-L1 upregulation creates a targetable niche for PD-1/PD-L1 inhibitors. This strategy sustains interferon-γ signaling and drives effector T-cell differentiation, but overlapping immunostimulatory signals raise risks of cytokine release syndrome and immune-related adverse events, requiring biomarker-guided risk stratification. We propose a multidimensional immune microenvironment reprogramming framework, integrating tumor-infiltrating lymphocyte phenotyping, serum biomarkers, and spatial transcriptomic mapping, to optimize ADC-ICI therapy and balance efficacy with immunopathology.