Antibody-drug conjugate (ADC), a novel class of antineoplastic agents, combines tumor-specific targeting with potent cytotoxic activity. In recent years, ADC has achieved notable advances in the treatment of non-small cell lung cancer (NSCLC), particularly within therapeutic sequencing after failure of first-line therapy or the emergence of resistance. This paper will systematically review the efficacy and safety evidence of representative ADC in NSCLC, and further to discuss progress and challenges in ADC structural optimization, toxicity management, biomarker identification, and combination strategies, aiming to provide a comprehensive theoretical foundation and practical reference for clinical practice and future research.
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Humans ; Carcinoma, Non-Small-Cell Lung/drug therapy* ; Immunoconjugates/chemistry* ; Lung Neoplasms/drug therapy* ; Drug Resistance, Neoplasm/drug effects* ; Antineoplastic Agents/chemistry*

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 chemotherapy. 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)/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 currently 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 clinically 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 conjugation methodologies for constructing homogeneous ADCs is an especially promising path to improving ADC design, which will open the way for novel cancer therapeutics.
Amino Acids ; metabolism ; Animals ; Antibodies, Monoclonal ; chemistry ; metabolism ; Antigens ; metabolism ; Genetic Engineering ; Humans ; Immunoconjugates ; chemistry ; metabolism

Antibody drug conjugates (ADCs) are an emerging class of targeted therapeutics with the potential to improve therapeutic index over the traditional chemotherapy. However, it is difficult to control the site and stoichiometry of conjugation in mAb, typically resulting in heterogeneous mixtures of ADCs that are difficult to optimize. New methods for site-specific drug attachment allow development of more homogeneous conjugates and control of the site of drug attachment. In this article, the new literature on development of ADCs and site-specific ADCs is reviewed. In addition, we summarized the various strategies in production of site-specific ADCs.
Antibodies, Monoclonal ; chemistry ; Antibody Specificity ; Binding Sites, Antibody ; Immunoconjugates ; chemistry

This paper reports the determination of the drug antibody ratio in an antibody-drug conjugate with two methods, i.e. LC-MS and UV/VIS, and to provide a reliable method to scientifically evaluate and effectively control the drug antibody ratio. Deglycosylated sample was analyzed with C4 column followed by MS, and the number of conjugated drugs in the antibody was determined by the molecular weight increase due to the addition of different number of drugs to the antibody, and then drug antibody ratio was calculated by weighted average of different number of drugs conjugated to the antibody. Optical density at 252 and 280 nm was measured with UV/VIS, and due to the difference of extinction coefficients between the antibody and the drug, the drug antibody ratio was calculated from linear equation with two unknowns. The drug antibody ratio was 3.21 and 3.25 respectively measured by the two methods, and the results were similar with the two methods. Our study indicated that both methods, LC-MS and UV/VIS, could be applied to the analysis of drug antibody ratio of the antibody drug conjugate.
Antibodies ; analysis ; chemistry ; Gas Chromatography-Mass Spectrometry ; methods ; Glycosylation ; Immunoconjugates ; analysis ; chemistry ; Maleimides ; analysis ; chemistry ; Molecular Weight ; Pharmaceutical Preparations ; analysis ; chemistry ; Spectrophotometry, Ultraviolet ; methods

Chemotherapy remains one of the major tools, along with surgery, radiotherapy, and more recently targeted therapy, in the war against cancer. There have appeared a plethora of highly potent cytotoxic drugs but the poor discriminability between cancerous and healthy cells of these agents limits their broader application in clinical settings. Therapeutic antibodies have emerged as an important class of biological anticancer agents, thanks to their ability in specific binding to tumor-associated antigens. While this important class of biologics can be used as single agents for the treatment of cancer through antibody-dependent cell cytotoxicity (ADCC), their therapeutical efficacy is often limited. Antitumor antibody drug conjugates (ADCs) combine the target-specificity of monoclonal antibody (mAb) and the highly active cell-killing drugs, taking advantages of the best characteristics out of both components. Thus, insufficiency of most naked mAbs in cancer therapy has been circumvented by arming the immunoglobulin with cytotoxic drugs. Here mAbs are used as vehicles to transport potent payloads to tumor cells. ADCs contain three main components: antibody, linker and cytotoxics (also frequently referred as payload). Antibodies can recognize and specifically bind to the tumor-specific antigens, leading to an antibody-assisted internalization, and payload release. While ADC has demonstrated tremendous success, a number of practical challenges limit the broader applications of this new class of anticancer therapy, including inefficient cellular uptake, low cytotoxicity, and off-target effects. This review article aims to cover recent advances in optimizing linkers with increased stability in circulation while allowing efficient payload release within tumor cells. We also attempt to provide some practical strategies in resolving the current challenges in this attractive research area, particularly to those new to the field.
Aminobenzoates ; pharmacology ; therapeutic use ; Animals ; Antibodies, Monoclonal ; pharmacology ; therapeutic use ; Antineoplastic Agents ; pharmacology ; therapeutic use ; Cell Survival ; drug effects ; Cytotoxins ; pharmacology ; therapeutic use ; Drug Design ; Humans ; Immunoconjugates ; chemistry ; pharmacology ; therapeutic use ; Maytansine ; pharmacology ; therapeutic use ; Neoplasms ; drug therapy ; pathology ; Oligopeptides ; pharmacology ; therapeutic use

Monoclonal antibody-targeted therapy has been a hot spot in current clinical cancer treatment. As current antibody drugs have large molecule sizes leading to poor tissue penetration, and high dosage in clinical application leading to high cost, to overcome the problems, the development of new antibody drugs with miniaturization and high potency has become a new trend. In recent years, the conjugates of monoclonal antibodies and cytotoxins, called antibody-drug conjugates (ADCs), have entered the arsenal of anti-cancer drugs, becoming a new format of antibody drugs and attracting extensive attentions. The ADC molecule usually consists of antibody, linker and effector molecule. According to different effector molecules, ADCs can be divided into three categories as chemo-conjugates, immunotoxins and radio-conjugates. When ADC molecules are internalized into cancer cells, cytotoxins will be released by chemical, enzyme degradation or by action of lysosomal proteases, then kill targeted cells by inhibiting protein synthesis, depolymerizing microtubules or breaking double-strand DNA. Recently, two ADC drugs have been approved by the US FDA and more ADC drug candidates are in clinical phase II or III trials which show significantly clinical effects and attracting much attention and competition of pharmaceutical enterprises. In this review, antibody conjugates in the past and present will be summarized and the future development trends and challenges of this type of antibody drugs will be discussed.
Antigens, CD ; metabolism ; Hematologic Neoplasms ; metabolism ; therapy ; Humans ; Immunoconjugates ; chemistry ; therapeutic use ; Immunotherapy ; methods ; Immunotoxins ; chemistry ; therapeutic use ; Radioimmunotherapy ; methods

OBJECTIVETo observe the effect of the immunonanoparticles loaded with adriamycin in reversing multidrug resistance (MDR) in liver cancer in a nude mouse model and explore the possible mechanisms.

METHODSThe cytotoxicity of adriamycin, adriamycin-loaded nanoparticles, and adriamycin-loaded immunonanoparticles was assessed in a nude mouse model bearing implant tumors of adriamycin-resistant hepatoma cell line SMMC-7721/ADM. The concentration of adriamycin in the tumor tissue was determined.

RESULTSAdriamycin-loaded immunonanoparticles showed significantly stronger cytotoxicity against the implant tumors of SMMC-7721/ADM than adriamycin-loaded nanoparticles and adriamycin. Administration of adriamycin-loaded immunonanoparticles resulted in significantly higher drug concentrations in the tumor tissue than adriamycin-loaded nanoparticles and adriamycin.

CONCLUSIONAdriamycin-loaded immunonanoparticles may reverse the MDR of liver cancers in vivo probably resulting from the close binding of the particles with the tumor cells to produce a high local concentration of adriamycin in the tumors.

Animals ; Cell Line, Tumor ; Doxorubicin ; chemistry ; metabolism ; pharmacology ; therapeutic use ; Drug Resistance, Multiple ; drug effects ; Drug Resistance, Neoplasm ; drug effects ; Female ; Humans ; Immunoconjugates ; chemistry ; Liver Neoplasms ; drug therapy ; metabolism ; pathology ; Mice ; Mice, Nude ; Nanoparticles ; chemistry

Recently the use of peptides in bee venom (PBV) for cancer therapy has attracted considerable attention. In this study, the sterically stabilized liposomal PBV (PBV-SL) was prepared using soybean phosphatidylcholine, cholesterol, and cholesterol-PEG-COOH. The humanized antihepatoma disulfide-stabilized Fv (hdscFv25) was coupled to sterically stabilized liposomes using the N-hydroxysuccinimide ester method. The hdscFv25-immunoliposomes (SIL[hdscFv25]) were immunoreactive as determined by ELISA assay. SIL[hdscFv25] showed higher tumor cells selectivity. PBV-SIL[hdscFv25] can kill SMMC-7721 cells in vitro with higher efficiency than non-targeted liposomes. Whereas cytotoxicties were compared for Hela cells, no significant differences was observed between PBV-SIL[hdscFv25] and PBV-SL. Sterically stabilized immunoliposomal peptides in bee venom could be one drug targeting delivery system.
Antineoplastic Agents ; administration & dosage ; pharmacology ; Bee Venoms ; chemistry ; Carcinoma, Hepatocellular ; pathology ; Cell Line, Tumor ; Cell Survival ; drug effects ; Cholesterol ; chemistry ; Drug Delivery Systems ; HeLa Cells ; Humans ; Immunoconjugates ; chemistry ; pharmacology ; Liposomes ; chemistry ; Liver Neoplasms ; pathology ; Melitten ; administration & dosage ; isolation & purification ; pharmacology ; Peptides ; administration & dosage ; isolation & purification ; pharmacology ; Recombinant Proteins ; administration & dosage ; pharmacology

OBJECTIVETo explore the methods for labeling CDTPA-coupled CD45 monoclonal antibody (mAb) with yttrium-90 ((90)Y) for potential acute myeloid therapy.

METHODSCD45 mAb was labeled with (90)Y by CDTPA and the labeling rate, radiochemical purity, final specific activity, and immunological activity of the mAb were detected.

RESULTSWith the optimal molar ratio of CDTPA/Ab at 20:1, the labeling rate was 95%, radiochemical purity 99.8%, and final specific activity 1.9 mCi/mg. This conjugate was stable in vitro with comparable immunological activity in comparison with unlabeled CD45 mAb.

CONCLUSION(90)Y-CDTPA-CD45 mAb possesses good properties as an ideal targetting therapeutic agent for acute leukemia.

Anhydrides ; chemistry ; Antibodies, Monoclonal ; chemistry ; immunology ; Humans ; Immunoconjugates ; chemistry ; immunology ; Isotope Labeling ; methods ; Leukocyte Common Antigens ; immunology ; Pentetic Acid ; chemistry ; Radiopharmaceuticals ; chemical synthesis ; chemistry ; immunology ; Yttrium Radioisotopes ; chemistry

AIMTo study the antitumor effect of an immunoconjugate composed of pingyangmycin (PYM) and anti-type IV collagenase monoclonal antibody (mAb) 3G11.

METHODS3G11-PLG-PYM immunoconjugate was prepared by linking 2-iminothiolane (2-IT) modified mAb to PYM via N-succinimidyl-3-(2-pyridyldithiol) -propionate (SPDP) derived poly-alpha-L-glutamic acid (PLG) backbone as the intermediate drug carrier. Characterization of the conjugate was performed by SDS-PAGE and spectrophotometry. Immunoreactivity of the conjugate against type IV collagenase was determined by ELISA. The cytotoxicity of the conjugate to hepatoma 22 (H22) and KB cells was examined by MTT assay. Antitumor effect of the conjugate in vivo was evaluated in mice bearing subcutaneously implanted H22 tumor, the candidate drugs were administered intravenously by "q2d x 6" regimen.

RESULTSThe molecular weight of the conjugate was approximately 170 kD. The molecular ratio of 3G11-PLG-PYM was 1 : 2. 4 : 10. The conjugate retained part of the immunoreactivity of mAb 3G11 against the antigen. The cytotoxicity of the conjugate to H22 and KB cells was moderate comparing with free PYM. In vivo however, free PYM inhibited the growth of H22 by 60.6% on day 22 at the dose of 10 mg x kg(-1), while the equivalent dose of 3G11-PLG-PYM conjugate reached 90.8%. The median survival time of the mice treated with the conjugate was prolonged by 71.7% as compared with that of the untreated group, whereas that of free PYM prolonged only 10.9%. 3G11-PLG-PYM conjugate was notably more effective than free PYM in tumor suppression and life span prolongation.

CONCLUSION3G11-PLG-PYM displayed more marked antitumor efficacy than free PYM in vivo and might be a novel candidate for cancer treatment.

Animals ; Antibiotics, Antineoplastic ; pharmacology ; Antibodies, Monoclonal ; Bleomycin ; analogs & derivatives ; pharmacology ; Carcinoma, Squamous Cell ; pathology ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Collagen Type IV ; immunology ; Female ; Humans ; Immunoconjugates ; chemistry ; pharmacology ; Liver Neoplasms, Experimental ; pathology ; Mice ; Molecular Weight ; Mouth Neoplasms ; pathology ; Neoplasm Transplantation