TCR-mimic antibody-drug conjugates targeting intracellular tumor-specific mutant antigen KRAS G12V mutation

Limited clinical application of antibody-drug conjugates(ADCs)targeting tumor associated antigens(TAAs)is usually caused by on-target off-tumor side effect.Tumor-specific mutant antigens(TSMAs)only expressed in tumor cells which are ideal targets for ADCs.In addition,intracellular somatic mutant proteins can be presented on the cell surface by human leukocyte antigen class I(HLA I)molecules forming tumor-specific peptide/HLA I complexes.KRAS G12 V mutation frequently occurred in varied cancer and was verified as a promising target for cancer therapy.In this study,we generated two TCR-mimic antibodydrug conjugates(TCRm-ADCs),2E8-MMAE and 2 A5-MMAE,targeting KRAS G12 V/HLAA*0201 complex,which mediated specific antitumor activity in vitro and in vivo without obvious toxicity.Our findings are the first time validate the strategy of TCRm-ADCs targeting intracellular TSMAs,which improves the safety of antibody-based drugs and provides novel strategy for precision medicine in cancer therapy.

The ABC of ADCs (Antibody-Drug Conjugates): A Comprehensive Review of Technical, Regulatory, and Clinical Challenges

Over the past several decades, there has been a significant surge in the development of Antibody-Drug Conjugates (ADCs). Designing an ideal ADC presents a multifaceted challenge, requiring the precise orchestration of various elements such as antigens, antibodies, linkers, and payloads. While ADCs aim to target tumor cells specifically, several antigens can also be found in regular tissues, potentially compromising the specificity of ADCs in therapeutic applications. The complexity extends to antibody selection, necessitating effective targeting of the desired antigen and ensuring compatibility with linkers for effective payload delivery. Additionally, the linker and payload combination are critical for the ADC’s therapeutic efficiency, balancing stability in circulation and timely payload release upon target binding. ADC doses must be safe for normal tissues while ensuring the released payloads are effective. The success of ADCs is attributed to their unmatched efficacy compared to traditional chemotherapy agents. The current research article aims to provide a technical review of Antibody-Drug Conjugates (ADCs) for cancer therapies. A brief discussion on the basics of ADCs, regulatory approach, overview, and technical complexities for quantification is presented. This review also summarizes recently approved ADCs and introduces the concepts of antibodies, linkers, and payloads. The article also outlines cancer-specific ADCs currently in late-stage clinical trials for cancer treatment.

Current LC-MS-based strategies for characterization and quantification of antibody-drug conjugates

The past few years have witnessed enormous progresses in the development of antibody-drug conjugates(ADCs).Consequently,comprehensive analysis of ADCs in biological systems is critical in supporting discovery,development and evaluation of these agents.Liquid chromatography-mass spectrometry(LC-MS)has eme rged as a promising and versatile tool for ADC analysis across a wide range of scenarios,owing to its multiplexing ability,rapid method development,as well as the capability of analyzing a variety of targets ranging from small-molecule payloads to the intact protein with a high,molecular resolution.However,despite this tremendous potential,challenges persist due to the high complexity in both the ADC molecules and the related biological systems.This review summarizes the up-to-date LC-MS-based strategies in ADC analysis and discusses the challenges and opportunities in this rapidly-evolving field.

Antibody-Drug Conjugates (ADCs): Navigating Four Pillars of Safety, Development, Supply Chain and Manufacturing Excellence

Antibody-drug conjugates (ADCs) are pioneering biologics that merge antibodies’ specificity with small molecules’ potency. With a handful of FDA-approved ADCs in the market and many under development, ADCs are poised to revolutionize therapeutics. This paper examines the complexities of ADC production, emphasizing the importance of process characterization and the pivotal role of supply chain characteristics, safety requirements, and Contract Manufacturing Organizations (CMOs) with proficiency. The swift transition of antibody-drug conjugate (ADC) programs from early to advanced clinical stages underscores the urgency for quick and efficient commercial launch preparation. This article delves into strategies to hasten commercial readiness, supply chain strategy, the significance of partnering with adept contract development and manufacturing organizations (CDMOs), and the challenges of ADC production.

Antibody-drug conjugates： recent advances in conjugation and linker chemistries

The antibody-drug conjugate （ADC）, a humanized or human monoclonal antibody conjugated with highly cytotoxic small molecules （payloads） through chemical linkers, is a novel therapeutic format and has great potential to make a paradigm shift in cancer chemother- apy. This new antibody-based molecular platform enables selective delivery of a potent cytotoxic payload to target cancer cells, resulting in improved efficacy, reduced systemic toxicity, and preferable pharmacokinetics （PK）I pharmacodynamics （PD） and biodistribution compared to traditional chemotherapy. Boosted by the successes of FDA-approved Adcetris~ and Kadcyla~, this drug class has been rapidly growing along with about 60 ADCs cur- rently in clinical trials. In this article, we briefly review molecular aspects of each component （the antibody, payload, and linker） of ADCs, and then mainly discuss traditional and new technologies of the conjugation and linker chemistries for successful construction of clini- cally effective ADCs. Current efforts in the conjugation and linker chemistries will provide greater insights into molecular design and strategies for clinically effective ADCs from medicinal chemistry and pharmacology standpoints. The development of site-specific conjuga- tion methodologies for constructing homogeneous ADCs is an especially promising path to improving ADC design, which will open the way for novel cancer therapeutics.

A mild phenoxysilyl linker for self-immolative release of antibody-drug conjugates

Self-immolative linkers have been widely used to construct prodrugs to improve their efficacy and safety.In this study,we report the use of phenoxysilyl linker as a self-immolative unit to prepare antibody-drug conjugates(ADCs).Phenoxysily based ADC Ate-PPS-CA4 was prepared and its release was systematically investigated by mass spectrometry.Biological evaluation showed that Ate-PPS-CA4 displayed the ability to target delivery and self-immolative release the active payload CA4 on PD-L1 positive cells MDA-MB-231.As the same with its payload CA4,it could arrest the cell cycle to the G2/M phase and induced changes in cell morphology at the dose of its IC_(50).The development of this linker with novel drug release mechanisms will expand the methodology to construct ADCs,especially for non-internalizing ADCs by extracellular cleavage.

Antibody-drug conjugates:Recent advances in linker chemistry

Antibody-drug conjugates(ADCs)are gradually revolutionizing clinical cancer therapy.The antibody-drug conjugate linker molecule determines both the efficacy and the adverse effects,and so has a major influence on the fate of ADCs.An ideal linker should be stable in the circulatory system and release the cytotoxic payload specifically in the tumor.However,existing linkers often release payloads nonspecifically and inevitably lead to off-target toxicity.This defect is becoming an increasingly important factor that restricts the development of ADCs.The pursuit of ADCs with optimal therapeutic windows has resulted in remarkable progress in the discovery and development of novel linkers.The present review summarizes the advance of the chemical trigger,linker-antibody attachment and linker-payload attachment over the last 5 years,and describes the ADMET properties of ADCs.This work also helps clarify future developmental directions for the linkers.

Resistance to antibody-drug conjugates in breast cancer:mechanisms and solutions

Antibody-drug conjugates(ADCs)are a rapidly developing therapeutic approach in cancer treatment that has shown remarkable activity in breast cancer.Currently,there are two ADCs approved for the treatment of human epidermal growth factor receptor 2-positive breast cancer,one for triple-negative breast cancer,and multiple investigational ADCs in clinical trials.However,drug resistance has been noticed in clinical use,especially in trastuzumab emtansine.Here,the mechanisms of ADC resistance are summarized into four categories:antibodymediated resistance,impaired drug trafficking,disrupted lysosomal function,and payload-related resistance.To overcome or prevent resistance to ADCs,innovative development strategies and combination therapy options are being investigated.Analyzing predictive biomarkers for optimal therapy selection may also help to prevent drug resistance.

Antibody-drug conjugates in HER2-positive breast cancer

Antibody-drug conjugates(ADCs)combine the high specificity of monoclonal antibodies with the high anti-tumor activity of small molecular cytotoxic payloads.The anti-tumor activity of ADCs is mainly achieved by the direct blocking of the receptor by monoclonal antibodies,direct action and bystander effect of cytotoxic drugs,and antibody-dependent cell-mediated cytotoxicity and complement-dependent cytotoxicity.ADCs have been used in adjuvant therapy and rescue treatment of human epidermal receptor 2(HER2)-positive breast cancer,greatly improving the prognosis of breast cancer patients.Several ongoing clinical trials of ADC for breast cancer and other solid tumors proved the potential of ADCs will provide more promising treatment options for patients with malignant tumors.This review introduces the mechanism and latest clinical progress of ADC drugs approved for HER2-positive breast cancer to guide clinical practice and conduct research.

Advances in preclinical evaluation of experimental antibody-drug conjugates

The ability to chemically modify monoclonal antibodies with the attachment of specific functional groups has opened up an enormous range of possibilities for the targeted treatment and diagnosis of cancer in the clinic.As the number of such antibody-based drug candidates has increased,so too has the need for more stringent and robust preclinical evaluation of their in vivo performance to maximize the likelihood that time,research effort,and money are only spent developing the most effective and promising candidate molecules for translation to the clinic.Concurrent with the development of antibody-drug conjugate(ADC)technology,several recent advances in preclinical research stand to greatly increase the experimental rigor by which promising candidate molecules can be evaluated.These include advances in preclinical tumor modeling with the development of patient-derived tumor organoid models that far better recapitulate many aspects of the human disease than conventional subcutaneous xenograft models.Such models are amenable to genetic manipulation,which will greatly improve our understanding of the relationship between ADC and antigen and stringently evaluate mechanisms of therapeutic response.Finally,tumor development is often not visible in these in vivo models.We discuss how the application of several preclinical molecular imaging techniques will greatly enhance the quality of experimental data,enabling quantitative pre-and post-treatment tumor measurements or the precise assessment of ADCs as effective diagnostics.In our opinion,when taken together,these advances in preclinical cancer research will greatly improve the identification of effective candidate ADC molecules with the best chance of clinical translation and cancer patient benefit.

Antibody-drug conjugates:Recent advances in payloads

Antibody-drug conjugates(ADCs),which combine the advantages of monoclonal antibodies with precise targeting and payloads with efficient killing,show great clinical therapeutic value.The ADCs’payloads play a key role in determining the efficacy of ADC drugs and thus have attracted great attention in the field.An ideal ADC payload should possess sufficient toxicity,low immunogenicity,high stability,and modifiable functional groups.Common ADC payloads include tubulin inhibitors and DNA damaging agents,with tubulin inhibitors accounting for more than half of the ADC drugs in clinical development.However,due to clinical limitations of traditional ADC payloads,such as inadequate efficacy and the development of acquired drug resistance,novel highly efficient payloads with diverse targets and reduced side effects are being developed.This perspective summarizes the recent research advances of traditional and novel ADC payloads with main focuses on the structure-activity relationship studies,co-crystal structures,and designing strategies,and further discusses the future research directions of ADC payloads.This review also aims to provide valuable references and future directions for the development of novel ADC payloads that will have high efficacy,low toxicity,adequate stability,and abilities to overcome drug resistance.

Design of pH-responsive antimicrobial peptide melittin analog-camptothecin conjugates for tumor therapy

Melittin,a classical antimicrobial peptide,is a highly potent antitumor agent.However,its significant toxicity seriously hampers its application in tumor therapy.In this study,we developed novel melittin analogs with pH-responsive,cell-penetrating and membranelytic activities by replacing arginine and lysine with histidine.After conjugation with camptothecin(CPT),CPT-AAM-1 and CPT-AAM-2 were capable of killing tumor cells by releasing CPT at low concentrations and disrupting cell membranes at high concentrations under acidic conditions.Notably,we found that the C-terminus of the melittin analogs was more suitable for drug conjugation than the N-terminus.CPT-AAM-1 significantly suppressed melanoma growth in vivo with relatively low toxicity.Collectively,the present study demonstrates that the development of antitumor drugs based on pH-responsive antimicrobial peptide-drug conjugates is a promising strategy.

Antibody-platinum(IV)prodrugs conjugates for targeted treatment of cutaneous squamous cell carcinoma

Antibody-drug conjugates(ADCs)are a new type of targeting antibodies that conjugate with highly toxic anticancer drugs via chemical linkers to exert high specificity and efficient killing of tumor cells,thereby attracting considerable attention in precise oncology therapy.Cetuximab(Cet)is a typical antibody that offers the benefits of good targeting and safety for individuals with advanced and inoperable cutaneous squamous cell carcinoma(cSCC);however,its anti-tumor activity is limited to a single use.Cisplatin(CisPt)shows good curative effects;however,its adverse effects and non-tumor-targeting ability are major drawbacks.In this study,we designed and developed a new ADC based on a new cytotoxic platinum(IV)prodrug(C8Pt(IV))and Cet.The so-called antibody-platinum(IV)prodrugs conjugates,named Cet-C8Pt(IV),showed excellent tumor targeting in cSCC.Specifically,it accurately delivered C8Pt(IV)into tumor cells to exert the combined anti-tumor effect of Cet and CisPt.Herein,metabolomic analysis showed that Cet-C8Pt(IV)promoted cellular apoptosis and increased DNA damage in cSCC cells by affecting the vitamin B6 metabolic pathway in tumor cells,thereby further enhancing the tumor-killing ability and providing a new strategy for clinical cancer treatment using antibody-platinum(IV)prodrugs conjugates.

HER3-targeted therapeutic antibodies and antibody-drug conjugates in non-small cell lung cancer refractory to EGFR-tyrosine kinase inhibitors

Human epidermal growth factor receptor 3(HER3)is a unique member of the human epidermal growth factor receptor(HER/EGFR)family,since it has negligible kinase activity.Therefore,HER3 must interact with a kinase-proficient receptor to form a heterodimer,leading to the activation of signaling cascades.Overexpression of HER3 is observed in various human cancers,including non-small cell lung cancer(NSCLC),and correlates with poor clinical outcomes in patients.Studies on the underlying mechanism demonstrate that HER3-initiated signaling promotes tumor metastasis and causes treatment failure in human cancers.Upregulation of HER3 is frequently observed in EGFR-mutant NSCLC treated with EGFR-tyrosine kinase inhibitors(TKIs).Increased expression of HER3 triggers the so-called EGFR-independent mechanism via interactions with other receptors to activate“by-pass signaling pathways”,thereby resulting in resistance to EGFR-TKIs.To date,no HER3-targeted therapy has been approved for cancer treatment.In both preclinical and clinical studies,targeting HER3 with a blocking an-tibody(Ab)is the only strategy being examined.Recent evaluations of an anti-HER3 Ab-drug conjugate(ADC)show promising results in patients with EGFR-TKI-resistant NSCLC.Herein,we summarize our understanding of the unique biology of HER3 in NSCLC refractory to EGFR-TKIs,with a focus on its dimerization partners and subsequent activation of signaling pathways.We also discuss the latest development of the therapeutic Abs and ADCs targeting HER3 to abrogate EGFR-TKI resistance in NSCLC.

Bioinspired Passive Tactile Sensors Enabled by Reversible Polarization of Conjugated Polymers

Tactile perception plays a vital role for the human body and is also highly desired for smart prosthesis and advanced robots.Compared to active sensing devices,passive piezoelectric and triboelectric tactile sensors consume less power,but lack the capability to resolve static stimuli.Here,we address this issue by utilizing the unique polarization chemistry of conjugated polymers for the first time and propose a new type of bioinspired,passive,and bio-friendly tactile sensors for resolving both static and dynamic stimuli.Specifically,to emulate the polarization process of natural sensory cells,conjugated polymers(including poly(3,4-ethylenedioxythiophen e):poly(styrenesulfonate),polyaniline,or polypyrrole)are controllably polarized into two opposite states to create artificial potential differences.The controllable and reversible polarization process of the conjugated polymers is fully in situ characterized.Then,a micro-structured ionic electrolyte is employed to imitate the natural ion channels and to encode external touch stimulations into the variation in potential difference outputs.Compared with the currently existing tactile sensing devices,the developed tactile sensors feature distinct characteristics including fully organic composition,high sensitivity(up to 773 mV N^(−1)),ultralow power consumption(nW),as well as superior bio-friendliness.As demonstrations,both single point tactile perception(surface texture perception and material property perception)and two-dimensional tactile recognitions(shape or profile perception)with high accuracy are successfully realized using self-defined machine learning algorithms.This tactile sensing concept innovation based on the polarization chemistry of conjugated polymers opens up a new path to create robotic tactile sensors and prosthetic electronic skins.

Effect of Liposome Double-Coated with Chitosan and Chitosan-EDTA Conjugates on Oral Absorption of Insulin

Aim To evaluate the gastrointestinal uptake of the insulin liposomes double-coated with chitosan （Ch） and chitosan-EDTA conjugates （CEC）, and verify their efficiencies. Methods Insulin-liposomes were prepared by reversed-phase evaporation. The hypoglycemic effects of the insulin liposomes coated with Ch or/and CEC were investigated using the glucose oxidase method after oral administration in diabetic rats, normal rats, and beagle dogs. Serum insulin concentrations in beagle dogs were determined by radioimmunoassay and were assessed by Pkanalyst computer program. Results The animals fed the insulin liposomes coated with Ch or/and CEC were able to regulate better the glucose load than the animals receiving PBS or uncoated insulin liposome, and the regulative effects of the insulin liposomes double-coated with Ch and CEC were better than those of the insulin liposomes coated with Ch or CEC alone. After oral administration of the insulin-liposomes double-coated with Ch and CEC to animals, a significant （P 〈 0. 05 ） blood glucose reduction was observed. Their relative pharmacological bioavailability was higher than 9 % in comparison with subcutaneous injection of insulin. In addition, in comparison with subcutaneous injection of insulin, the relative bioavailability was 12. 67 % calculated by area under the curve of serum insulin concentration versus time profile after oral administration of the insulin-liposomes double-coated with Ch and CEC to beagle dogs. Conclusion The insulin-liposomes double-coated with Ch and CEC were conducive to improving oral bioavailability of insulin.

CT- B Conjugates顺行示踪显色α-晶状体蛋白对损伤后视神经纤维保护作用的实验研究

目的观察α-晶状体蛋白对损伤后视神经纤维的保护作用。方法将成年Long evens大鼠26只,其中10只用于提取α-晶状体蛋白,另外16只分成4组,分别为正常对照组和伤后2,4,6周组,每组4只。损伤神经后分别右眼经玻璃体腔注射浓度为1×10-5g/L的α-晶体蛋白5μl,左眼牛血清白蛋白5μl,分别于伤后2,4,6周进行视神经取材。取材前48h,在每只眼玻璃体腔中注射CT-B(霍乱毒素B亚单位)Conjugates2.5μl,取材固定脱水并行冰冻切片后进行激光共聚焦照相(488nm波长光)观察。结果CTB Conjugates标记的夹伤视神经中可见线状条索神经纤维染色,并呈现一定扭曲,夹杂点状或者小团块状染色。α-晶状体蛋白组的荧光强度显著高于牛血清白蛋白组。结论CTB Conjugates顺染视神经示踪技术是观察和研究损伤后视神经病理变化的有效和简便的方法,α-晶状体蛋白对损伤后的视神经纤维具有保护作用。

Characterization and in vitro release studies of oral microbeads containing thiolated pectin–doxorubicin conjugates for colorectal cancer treatment

Novel oral microbeads were developed based on a biopolymer–drug conjugate of doxorubicin(DOX) conjugated with thiolated pectin via reducible disulfide bonds. The microbeads were fabricated by ionotropic gelation with cations such as Al3+, Ca2+ and Zn2+. The results showed that using zinc acetate can produce the strongest microbeads with spherical shape.However, the microbeads prepared from thiolated pectin–DOX conjugate were very soft and irregular in shape. To produce more spherical microbeads with suitable strength, the native pectin was then added to the formulations. The particle size of the microbeads ranged from 0.87 to 1.14 mm. The morphology of the microbeads was characterized by optical and scanning electron microscopy. DOX was still in crystalline form when used in preparing the microbeads, as confirmed by powder X-ray diffractometry. Drug release profiles showed that the microbeads containing thiolated pectin–DOX conjugate exhibited reduction-responsive character;in reducing environments, the thiolated pectin–DOX conjugate could uncouple resulting from a cleavage of the disulfide linkers and consequently release the DOX. The best-fit release kinetics of the microbeads containing thiolated pectin–DOX conjugate, in the medium without reducing agent, fit the Korsmeyer–Peppas model while those in the medium with reducing agent fit a zero-order release model. These results suggested that the microbeads containing thiolated pectin–DOX conjugate may be a promising platform for cancer-targeted delivery of DOX, exploiting the reducing environment typically found in tumors.

Characterization of Hapten-Protein Conjugates for Immunoassay of Polycyclic Aromatic Hydrocarbons(PAHs)

Preparation and characterization of the hapten-protein conjugates are fundamental to developing environmental immunoassays. As a hapten, 1-pyrenebutyric acid（PBA） was conjugated to the carrier protein of bovine serum albumin（BSA） or ovalbumin（OVA） by active ester method. Infrared spectra（IR） showed that PBA-BSA and PBA-OVA conjugates were successfully prepared. The number of the haptens conjugated to the carrier protein was determined by ultraviolet spectra（UV） and matrix-assisted laser desorption ionization time-of-flight mass spectrometry（MALDI-TOF-MS）. The calculated average binding ratios of PBA/BSA and PBA/OVA were 18：1 and 10：1 by UV, and 31：1 and 22：1 by MALDI-TOF-MS, respectively. Although there was a discrepancy between the results determined by the two methods, both of them were useful for the characterization of the hapten-protein conjugates. The antibody was produced against the antigen of PBA-BSA, and the affinity was tested by the double agar diffusion method The conjugates and the antibody could be used for developing a sensitive and selective immunoassay of polycyclic aromatic hydrocarbons（PAHs）.

Synthesis and characterization of HPMA copolymer-5-FU conjugates

N-（2-Hydroxypropyl） methacrylamide copolymer-5-fluorouracil （PHPMA-FU） conjugates were synthesized by a novel and simplified synthetic route, and characterized by UV, FTIR and HPLC analyses. The conjugated content of 5-fluorouracil （5-FU） was 3.41 ± 0.07 wt%. The stabilities of PHPMA-FU conjugates under different conditions were studied. The results showed that HPMA copolymer was a potential carrier for tumor-targeting delivery of 5-FU.