antibody-drug conjugate

Overview

Antibody-drug conjugates (ADCs) are a class of targeted cancer therapeutics that combine the antigen-binding specificity of monoclonal antibodies with the cytotoxic potency of small-molecule payloads, typically linked via a chemical linker. By directing cytotoxic agents — such as camptothecin derivatives or tubulin inhibitors — to tumour-associated antigens expressed on cancer cell surfaces, ADCs aim to selectively kill malignant cells while minimizing systemic toxicity compared to conventional chemotherapy. The canonical ADC architecture consists of three components: a tumour-associated antigen-specific antibody, a cleavable or non-cleavable linker, and a cytotoxic payload that disrupts key cellular mechanisms such as mitosis and DNA replication. Upon antigen binding and internalization, the linker is cleaved in the lysosomal compartment, releasing the active drug intracellularly. This "Trojan horse" mechanism enables delivery of highly potent agents — often too toxic for systemic administration alone — at therapeutically relevant concentrations within the tumour microenvironment.

Over the past decade, ADCs have transitioned from a niche concept to a central pillar of oncology drug development. As of the mid-2020s, twelve ADCs have received FDA approval spanning hematologic malignancies and solid tumours, including breast cancer, urothelial carcinoma, cervical cancer, and non-small cell lung cancer (NSCLC). Their clinical success has prompted broad investigation into next-generation designs featuring novel payloads, site-specific conjugation chemistries, optimized drug-to-antibody ratios (DARs), and combination strategies alongside bispecific T-cell engagers, checkpoint inhibitors, PARP inhibitors, and Cdk4/6 inhibitors.

Focus of Latest Publications

Recent literature reflects a rapidly maturing ADC field advancing simultaneously on mechanistic, clinical, and computational fronts.

Clinical approvals and expanding indications. A 2026 review in Physiological Reviews (PMID 41855081) provides a comprehensive state-of-the-art synthesis of ADCs that have reached clinical approval, characterizing them as a leading area of targeted cancer therapeutics that converge antibody specificity with payload potency against mechanisms including mitosis and cell survival. Across oncology indications, ADCs are now routinely considered alongside other modern therapeutic classes. In hormone receptor-positive, HER2-negative advanced breast cancer, a 2026 review in The Oncologist (PMID 42266036) positions ADCs alongside PI3K/AKT inhibitors, oral selective estrogen receptor degraders (SERDs), proteolysis-targeting chimeras (PROTACs), and PARP inhibitors as newer agents reshaping first- and second-line treatment sequencing. In relapsed/refractory multiple myeloma, ADCs together with monoclonal antibodies have become backbone therapies, as reviewed in Expert Opinion on Biological Therapy (PMID 41842719). In metastatic castration-resistant prostate cancer, a 2026 review in the International Journal of Oncology (PMID 41992975) highlights ADCs alongside bispecific T-cell engagers and immune checkpoint inhibitors as strategies moving beyond androgen receptor pathway inhibition, with glutamate carboxypeptidase II (PSMA) remaining a key imaging and therapeutic target in this disease.

NSCLC and resistance to EGFR tyrosine kinase inhibitors. A focused 2026 review in the Journal of Controlled Release (PMID 41730505) examines the emerging role of ADCs in EGFR-mutant NSCLC following acquired resistance to third-generation EGFR tyrosine kinase inhibitors. Multiple ADCs have been evaluated in this setting, with trophoblast cell-surface antigen 2 (TROP2; tumor associated calcium signal transducer 2) — directed ADCs recently receiving approval from both the National Medical Products Administration and the FDA for use after EGFR-TKI resistance. A separate phase I dose-expansion study published in the Journal of Clinical Oncology (PMID 42008777) evaluated sigvotatug vedotin (SV), a novel integrin beta-6 (IB6)-directed ADC, in advanced NSCLC, reporting acceptable safety and encouraging antitumour activity, illustrating continued investigation of novel antigen targets in thoracic oncology.

Novel targets and oncofusion-driven cancers. Research published in Cancer Discovery (PMID 41973074) demonstrates ADC engineering targeting IL1RAP with different cytotoxic payloads to address primary and metastatic disease in multiple oncofusion-driven cancers. This work illustrates how ADC technology can be tailored to address rare oncogenic drivers where standard therapies are limited.

Resistance mechanisms in breast cancer. A 2026 article in Advanced Science (PMID 41874465) reviews biological mechanisms of ADC resistance in breast cancer, framing ADCs as having "revolutionized" the treatment landscape by combining monoclonal antibody precision with cytotoxic potency. The study discusses both intrinsic and acquired resistance, encompassing antigen loss, altered internalization, lysosomal dysfunction, and payload efflux — topics increasingly relevant as ADCs move into earlier lines of therapy.

Clinical pharmacology and immunogenicity. A 2026 analysis in the Journal of Clinical Pharmacology (PMID 41906492) synthesizes clinical pharmacology learnings from all FDA-approved ADCs, noting that immunogenicity assessments at approved doses indicated a low incidence of anti-drug antibodies (ADAs). Relatedly, a study in the Journal of Pharmaceutical Sciences (PMID 42036038) addresses the broader challenge of clinical immunogenicity for biologics, noting that anti-drug antibodies continue to occur in clinical settings, compromising both safety and efficacy. These pharmacological considerations are important for optimizing ADC dosing regimens and patient selection.

Pharmacokinetics and computational optimization. A 2026 study in mAbs (PMID 41996252) addresses a recognized bottleneck in ADC development: the largely empirical and resource-intensive nature of pharmacokinetic (PK) optimization. The authors apply multi-modal feature learning to prioritize ADCs with favorable half-life profiles in mice, demonstrating that favorable PK properties — enabling higher systemic exposure — are associated with improved clinical efficacy. This work positions artificial intelligence and machine learning as practical tools for de-risking ADC development prior to costly in vivo experiments.

Key Publications

• Jun A Case Study on the Impact of Thermal Hydrolysis and Lactone Ring Opening of Linker-Payload on Drug-to-Antibody Ratio Determination in a Topoisomerase I Inhibitor-Based ADC. (Bioconjugate chemistry, 2026, PMID 42237689): "Accurate determination of the drug-antibody ratio (DAR) of an antibody-drug conjugate (ADC) requires multiple orthogonal analytical methods to ensure appropriate control of this critical quality attribute (CQA)."
• Jun Navigating first- and second-line treatment options in HR+HER2-negative advanced breast cancer. (The oncologist, 2026, PMID 42266036): "Newer therapeutic classes include PI3K/AKT inhibitors, oral selective estrogen receptor degraders (SERDs), proteolysis-targeting chimeras (PROTACs), poly ADP ribose polymerase (PARP) inhibitors, and antibody-drug conjugates (ADCs)."
• Jun First step towards predicting clinical immunogenicity of biologics using in vitro based readouts as animal trial alternatives. (Journal of pharmaceutical sciences, 2026, PMID 42036038): "However, anti-drug antibodies continue to occur in the clinic, compromising safety and efficacy and contributing to discontinuation of otherwise effective drugs."
• Apr First-in-Human, Phase I Study of Sigvotatug Vedotin, an Integrin Beta-6-Directed Antibody-Drug Conjugate: Results From Dose Expansion in Advanced Non-Small Cell Lung Cancer. (Journal of clinical oncology : official journal of the American Society of Clinical Oncology, 2026, PMID 42008777): "Sigvotatug vedotin (SV), a novel IB6-directed antibody-drug conjugate, demonstrated acceptable safety and encouraging antitumor activity in dose escalation."
• Apr Multi-modal feature learning to prioritize ADCs with favorable half-life in mice. (mAbs, 2026, PMID 41996252): "Favorable pharmacokinetic (PK) properties of antibody-drug conjugates (ADCs) enable higher systemic exposure and are associated with improved clinical efficacy, yet ADC PK optimization remains largely empirical and resource-intensive."
• Apr Novel therapeutic strategies for metastatic castration‑resistant prostate cancer: Beyond androgen receptor pathway inhibition (Review). (International journal of oncology, 2026, PMID 41992975): "These include bispecific T‑cell engagers, antibody‑drug conjugates and immune checkpoint inhibitors."
• Apr IL1RAP antibody-drug conjugates potently target primary and metastatic disease in multiple oncofusion-driven cancers. (Cancer discovery, 2026, PMID 41973074): "We therefore engineered antibody-drug conjugates (ADCs) with different cytotoxic payloads to target IL1RAP."
• Apr A review of the clinical efficacy of monoclonal antibody (mAb)-based therapies for relapsed/refractory multiple myeloma (RRMM). (Expert opinion on biological therapy, 2026, PMID 41842719): "Monoclonal antibodies (mAbs) and antibody-drug conjugates (ADCs) are among the backbones of treatment for relapsed/refractory multiple myeloma (RRMM)."
• Apr The emerging role of antibody-drug conjugates in EGFR-mutant non-small cell lung cancer with acquired resistance to third-generation EGFR tyrosine kinase inhibitors. (Journal of controlled release : official journal of the Controlled Release Society, 2026, PMID 41730505): "In recent years, multiple antibody-drug conjugates (ADCs) have been developed and evaluated in this setting, with trophoblast cell-surface antigen 2 ADCs recently receiving approval from the National Medical Products Administration and the Food and Drug Administration for use after EGFR-TKI resistance."
• Apr Understanding and Overcoming Antibody-Drug Conjugate Resistance: Biological Mechanisms and Emerging Analytical Frameworks in Breast Cancer. (Advanced science (Weinheim, Baden-Wurttemberg, Germany), 2026, PMID 41874465): "Antibody-drug conjugates (ADCs) have revolutionized the treatment landscape of breast cancer by combining the precision of monoclonal antibodies with the potency of cytotoxic agents."