{"entity":{"id":"trop2-adc-roadmap","kind":"roadmap","name":"TROP2 ADC roadmap: sacituzumab govitecan → Dato-DXd → sac-TMT → bispecifics and PET","aka":[],"tldr":"One target, three approved-or-nearly-approved drugs, and a fourth wave. How TROP2 went from an obscure trophoblast antigen to the centre of breast and lung cancer treatment.","summary":"TROP2 is not a driver but an address, so this roadmap follows what is delivered to it. It starts with target discovery on trophoblasts and Immunomedics humanising the RS7 antibody, moves to sacituzumab govitecan proving the target in ASCENT, then to datopotamab deruxtecan and the first-line phase 3 trials ASCENT-03, ASCENT-04 and TROPION-Breast02. Sacituzumab tirumotecan and the Merck TroFuse programme form a third wave, while selection, sequencing and cross-resistance among TOP1 payloads remain unsolved, with TROP2 PET and ctDNA biomarkers entering trials. The speculative end is bispecific and next-payload TROP2 ADCs in early-stage disease. The route links TNBC, HR-positive breast cancer, NSCLC and urothelial cancer, the TROP2 target and the incentive-misalignment bottleneck.","asOf":"2026-09-04","links":[{"label":"ASCENT: sacituzumab govitecan doubles survival in heavily pretreated metastatic triple-negative breast cancer (New England Journal of Medicine 2021)","url":"https://doi.org/10.1056/NEJMoa2028485"}],"tags":[],"related":[],"cancers":["tnbc","breast-hr-positive","nsclc","urothelial"],"sections":["adcs"],"technologies":[],"targets":["trop2"],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"steps":[{"era":"1981-2015","title":"Target discovery and antibody development","description":"TROP2 identified on trophoblasts (1981); overexpression across epithelial cancers established in the 2000s. Immunomedics humanises the RS7 antibody and conjugates SN-38 (IMMU-132) with a moderately stable, hydrolysable linker designed to release payload in the tumour microenvironment.","refs":["trop2"],"status":"historic"},{"era":"2020-2021","title":"Sacituzumab govitecan proves the target","description":"ASCENT: OS 12.1 vs 6.7 months in pretreated metastatic TNBC; accelerated then full approval. Gilead acquires Immunomedics for $21B. Benefit irrespective of TROP2 IHC, so no companion diagnostic is required.","refs":["ascent","sacituzumab-govitecan","gilead"],"status":"historic"},{"era":"2023-2025","title":"Second entrant: datopotamab deruxtecan","description":"Datopotamab deruxtecan carries the DXd payload at DAR 4 on a different anti-TROP2 antibody. TROPION-Breast01 (HR+, PFS only) and TROPION-Lung01 (mixed) produce narrow approvals (HR+ breast 2025; EGFR-mutant NSCLC 2025). Stomatitis and ocular toxicity define its profile versus sacituzumab's neutropenia and diarrhoea. Sacituzumab expands to HR+ (TROPiCS-02) but loses its urothelial indication.","refs":["datopotamab-deruxtecan","tropion-breast01","tropion-lung01"],"status":"current"},{"era":"2025-2026","title":"First line: three positive phase 3 trials","description":"ASCENT-03 (sacituzumab, PD-1-ineligible), ASCENT-04 (sacituzumab + pembrolizumab, PD-L1+), and TROPION-Breast02 (Dato-DXd, PD-1-ineligible, first OS benefit) all read out positive, with FDA approvals in Q2 2026. TROP2 ADCs displace chemotherapy in first-line metastatic TNBC. TROPION-Breast05 (Dato-DXd + durvalumab) is pending.","refs":["ascent-03","ascent-04","tropion-breast02","tropion-breast05"],"status":"current"},{"era":"2024-2027","title":"Third entrant: sacituzumab tirumotecan and the Merck programme","description":"Kelun's sac-TMT, with a belotecan-derived payload and a more stable linker, is approved in China (2024) and licensed to Merck, which is running >10 phase 3 TroFuse trials across TNBC, HR+ breast, NSCLC, endometrial, and cervical cancer, often with pembrolizumab. FDA priority voucher July 2026; US approval expected to follow positive first-line TNBC data.","refs":["sacituzumab-tirumotecan","kelun-biotech","merck"],"status":"emerging"},{"era":"2026-2029","title":"Unsolved: selection, sequencing, resistance","description":"IHC does not predict benefit. Cross-resistance among TOP1 payloads limits sequencing (T-DXd → sacituzumab or vice versa). TROP2 PET tracers (89Zr-antibody, 68Ga/18F-nanobody) enter phase 1 to map antigen, guide choice, and monitor loss. ctDNA and SLFN11/TOP1 biomarkers for payload resistance are under study.","refs":["trop2-pet","adc-sequencing","adc-after-adc-caution","trop2-pet-to-adc"],"status":"emerging"},{"era":"2027+","title":"Next generation: bispecific and next-payload TROP2 ADCs","description":"Nectin-4×TROP2 bispecific ADCs (AK146D1, AVZO-103), TROP2 ADCs with non-TOP1 or dual payloads, TROP2-directed radioconjugates, and TROP2 CAR-T. The class moves into early-stage disease (neoadjuvant/post-neoadjuvant TNBC) and into lung, gastric, and endometrial cancer. A TROP2 PET-guided, payload-switching treatment algorithm is the field's implicit goal.","refs":["ak146d1","bispecific-adc","dual-payload-adc","radioimmunotherapy","idea-trop2-pet-selection"],"status":"speculative"}],"watch":[]},"route":"/roadmaps/trop2-adc-roadmap/","neighbours":{"cancer":[{"id":"urothelial","kind":"cancer","name":"Bladder & urothelial cancer","route":"/cancers/urothelial/"},{"id":"breast-hr-positive","kind":"cancer","name":"HR-positive / HER2-negative breast cancer","route":"/cancers/breast-hr-positive/"},{"id":"nsclc","kind":"cancer","name":"Non-small-cell lung cancer","route":"/cancers/nsclc/"},{"id":"tnbc","kind":"cancer","name":"Triple-negative breast cancer (TNBC)","route":"/cancers/tnbc/"}],"section":[{"id":"adcs","kind":"section","name":"Antibody-Drug Conjugates","route":"/fronts/adcs/"}],"target":[{"id":"trop2","kind":"target","name":"TROP2","route":"/targets/trop2/"}],"trial":[{"id":"ascent","kind":"trial","name":"ASCENT","route":"/trials/ascent/"},{"id":"ascent-03","kind":"trial","name":"ASCENT-03","route":"/trials/ascent-03/"},{"id":"ascent-04","kind":"trial","name":"ASCENT-04 / KEYNOTE-D19","route":"/trials/ascent-04/"},{"id":"tropion-breast01","kind":"trial","name":"TROPION-Breast01","route":"/trials/tropion-breast01/"},{"id":"tropion-breast02","kind":"trial","name":"TROPION-Breast02","route":"/trials/tropion-breast02/"},{"id":"tropion-breast05","kind":"trial","name":"TROPION-Breast05","route":"/trials/tropion-breast05/"},{"id":"tropion-lung01","kind":"trial","name":"TROPION-Lung01","route":"/trials/tropion-lung01/"}],"drug":[{"id":"ak146d1","kind":"drug","name":"AK146D1","route":"/drugs/ak146d1/"},{"id":"datopotamab-deruxtecan","kind":"drug","name":"Datopotamab deruxtecan","route":"/drugs/datopotamab-deruxtecan/"},{"id":"sacituzumab-govitecan","kind":"drug","name":"Sacituzumab govitecan","route":"/drugs/sacituzumab-govitecan/"},{"id":"sacituzumab-tirumotecan","kind":"drug","name":"Sacituzumab tirumotecan","route":"/drugs/sacituzumab-tirumotecan/"}],"company":[{"id":"gilead","kind":"company","name":"Gilead Sciences (incl. Kite)","route":"/companies/gilead/"},{"id":"merck","kind":"company","name":"Merck & Co. (MSD)","route":"/companies/merck/"},{"id":"kelun-biotech","kind":"company","name":"Sichuan Kelun-Biotech","route":"/companies/kelun-biotech/"}],"technology":[{"id":"bispecific-adc","kind":"technology","name":"Bispecific ADC","route":"/technologies/bispecific-adc/"},{"id":"dual-payload-adc","kind":"technology","name":"Dual-payload ADC","route":"/technologies/dual-payload-adc/"},{"id":"radioimmunotherapy","kind":"technology","name":"Radio-antibody & radio-ADC","route":"/technologies/radioimmunotherapy/"},{"id":"trop2-pet","kind":"technology","name":"TROP2 PET","route":"/technologies/trop2-pet/"}],"term":[{"id":"adc-sequencing","kind":"term","name":"ADC sequencing","route":"/terms/adc-sequencing/"}],"pairing":[{"id":"adc-after-adc-caution","kind":"pairing","name":"Caution: TOP1 ADC immediately after TOP1 ADC","route":"/pairings/adc-after-adc-caution/"},{"id":"trop2-pet-to-adc","kind":"pairing","name":"TROP2 PET → TROP2 ADC selection","route":"/pairings/trop2-pet-to-adc/"}],"idea":[{"id":"idea-tnbc-adc-sequencing-trial","kind":"idea","name":"A randomised trial of antibody-drug conjugate sequence in metastatic triple-negative breast cancer","route":"/ideas/idea-tnbc-adc-sequencing-trial/"},{"id":"idea-trop2-pet-selection","kind":"idea","name":"TROP2 PET to choose and sequence TROP2 ADCs","route":"/ideas/idea-trop2-pet-selection/"}],"paper":[{"id":"paper-tropion-breast02-ann-oncol-2026","kind":"paper","name":"Datopotamab deruxtecan in patients with untreated, advanced triple-negative breast cancer (TROPION-Breast02): a randomised, open-label, international, phase III trial","route":"/key-papers/paper-tropion-breast02-ann-oncol-2026/"}],"roadmap":[{"id":"tnbc-roadmap","kind":"roadmap","name":"Triple-negative breast cancer roadmap: from a remainder defined by three negative tests to immunotherapy, antibody-drug conjugates and the residual disease problem","route":"/roadmaps/tnbc-roadmap/"}],"bottleneck":[{"id":"b-incentive-misalignment","kind":"bottleneck","name":"Incentives reward me-too drugs and marginal gains","route":"/bottlenecks/b-incentive-misalignment/"}]}}