{"entity":{"id":"idea-adc-for-mesothelioma","kind":"idea","name":"Antibody-drug conjugates for mesothelioma: why they have failed so far and how they could work","aka":[],"tldr":"Nearly every mesothelioma carries the surface protein mesothelin, yet the one antibody-drug conjugate tried in a randomised trial did no better than chemotherapy. The idea is to fix the three reasons it failed rather than abandon the approach.","summary":"Mesothelioma looks ideal for antibody-drug conjugates: mesothelin is on almost every tumour cell and rare elsewhere. Anetumab ravtansine, a mesothelin antibody carrying the tubulin poison DM4, proved otherwise in 248 patients, matching vinorelbine's 4.5-month progression-free survival and no more. Three explanations have evidence behind them. Mesothelioma sheds soluble mesothelin into the blood, which binds the antibody before it reaches the tumour. Expression is patchy and the tumour grows as thin sheets with dense stroma, so few cells take up enough payload. And a tubulin payload adds little to a slow-cycling tumour that already resists chemotherapy. The idea proposes conjugates built for these facts: antibodies that bind membrane mesothelin epitopes not present on the shed form, topoisomerase I payloads with a bystander effect that kill neighbouring cells that took up no drug (the DXd and SN-38 class that transformed breast and lung cancer ADCs), regional intrapleural delivery to bypass shed antigen in blood, and combination with PD-1 blockade to turn payload-induced cell death into an immune response, which the National Cancer Institute is already testing with anetumab ravtansine and pembrolizumab. Other targets present on mesothelioma, such as folate receptor alpha, on which the conjugate Rina-S is being tested across solid tumours, and B7-H3, widen the options beyond mesothelin.","asOf":"2026-09-07","links":[{"label":"Kindler et al., anetumab ravtansine versus vinorelbine (Lancet Oncology 2022)","url":"https://doi.org/10.1016/S1470-2045(22)00061-4"},{"label":"Pembrolizumab with or without anetumab ravtansine, NCT03126630","url":"https://clinicaltrials.gov/study/NCT03126630"},{"label":"Rinatabart sesutecan in advanced solid tumours, NCT05579366","url":"https://clinicaltrials.gov/study/NCT05579366"}],"tags":[],"related":[],"cancers":["mesothelioma"],"sections":[],"technologies":["adc","checkpoint-inhibitor"],"targets":["mesothelin"],"drugs":["anetumab-ravtansine","trastuzumab-deruxtecan"],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":["anetumab-vs-vinorelbine-mpm","nci-anetumab-pembrolizumab-mpm"],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"notes":[],"hypothesis":"A mesothelin- or FRα-directed conjugate with a bystander-capable topoisomerase I payload, given with PD-1 blockade, will produce a response rate above 30 percent and median progression-free survival beyond 8 months in second-line pleural mesothelioma, roughly double what vinorelbine or anetumab ravtansine achieved.","rationale":"Mesothelin expression is near universal in epithelioid mesothelioma; TOP1-payload ADCs with bystander killing succeeded where tubulin-payload ADCs failed in HER2-low breast cancer and in lung cancer; shed antigen and heterogeneity are documented and addressable; the pleural space is accessible for regional dosing.","test":"Expansion cohorts for mesothelioma in ongoing trials of TOP1-payload conjugates against mesothelin and folate receptor alpha, measuring soluble mesothelin as a stratification factor; then a randomised second-line trial against vinorelbine or gemcitabine with progression-free survival as the primary endpoint.","maturity":"early-clinical","actor":"industry","cost":"large","horizonYears":6},"route":"/ideas/idea-adc-for-mesothelioma/","neighbours":{"cancer":[{"id":"mesothelioma","kind":"cancer","name":"Mesothelioma","route":"/cancers/mesothelioma/"}],"technology":[{"id":"adc","kind":"technology","name":"Antibody-drug conjugate (ADC)","route":"/technologies/adc/"},{"id":"checkpoint-inhibitor","kind":"technology","name":"Immune checkpoint inhibitors","route":"/technologies/checkpoint-inhibitor/"}],"target":[{"id":"mesothelin","kind":"target","name":"Mesothelin","route":"/targets/mesothelin/"}],"drug":[{"id":"anetumab-ravtansine","kind":"drug","name":"Anetumab ravtansine","route":"/drugs/anetumab-ravtansine/"},{"id":"trastuzumab-deruxtecan","kind":"drug","name":"Trastuzumab deruxtecan","route":"/drugs/trastuzumab-deruxtecan/"}],"trial":[{"id":"anetumab-vs-vinorelbine-mpm","kind":"trial","name":"Anetumab ravtansine versus vinorelbine in relapsed mesothelin-positive pleural mesothelioma","route":"/trials/anetumab-vs-vinorelbine-mpm/"},{"id":"nci-anetumab-pembrolizumab-mpm","kind":"trial","name":"Pembrolizumab with or without anetumab ravtansine in mesothelin-positive pleural mesothelioma (NCI)","route":"/trials/nci-anetumab-pembrolizumab-mpm/"}]}}