{"entity":{"id":"single-arm","kind":"term","name":"Single-arm trial","aka":["single-arm","single arm","single-arm trial","single-arm phase 2","single-arm study","uncontrolled","non-randomised","nonrandomized","non-randomized","one-arm","open-label single-arm","basket cohort","expansion cohort","phase 2 cohort","expansion cohorts","single-arm studies","single-arm trials"],"tldr":"A trial where everyone gets the new drug and there is no comparison group; success is judged by the share of tumours that shrink and for how long. Fast and small, it underpinned accelerated approvals for larotrectinib, sotorasib, tarlatamab and most CAR-T products, but it cannot show that patients live longer.","summary":"Single-arm phase 2 trials with objective response rate and duration of response as endpoints supported accelerated approvals for a series of targeted drugs in rare or heavily pretreated populations (larotrectinib, sotorasib, tarlatamab, most CAR-T products) where randomisation was impractical or considered unethical. Their weaknesses are patient selection, lack of a comparator for time-to-event endpoints, and susceptibility to response-evaluable population definitions; the FDA increasingly asks for a randomised confirmatory trial to be under way at approval and has issued guidance on when single-arm data suffice. External or synthetic control arms are attempts to add a comparator after the fact.","asOf":"2026-09-09","wikipedia":"https://en.wikipedia.org/wiki/Single-arm_study_design","links":[{"label":"FDA guidance: clinical trial considerations to support accelerated approval of oncology therapeutics","url":"https://www.fda.gov/regulatory-information/search-fda-guidance-documents/clinical-trial-considerations-support-accelerated-approval-oncology-therapeutics"}],"tags":[],"related":["orr","duration-of-response-term","external-control-arm","accelerated-approval","basket-umbrella-platform","basket-trial","trial-failure-modes","clinical-equipoise","surrogate-validation"],"cancers":[],"sections":["drug-discovery"],"technologies":[],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":["navigate","l-mind","roar-atc","arrow-thyroid","nmtrc003","pathfinder-2"],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"category":"Trials"},"route":"/terms/single-arm/","neighbours":{"term":[{"id":"accelerated-approval","kind":"term","name":"Accelerated approval","route":"/terms/accelerated-approval/"},{"id":"amnog","kind":"term","name":"AMNOG (Germany, 2011)","route":"/terms/amnog/"},{"id":"basket-trial","kind":"term","name":"Basket trial","route":"/terms/basket-trial/"},{"id":"basket-umbrella-platform","kind":"term","name":"Basket, umbrella, and platform trials","route":"/terms/basket-umbrella-platform/"},{"id":"double-blind","kind":"term","name":"Blinding (double-blind, open-label, placebo-controlled)","route":"/terms/double-blind/"},{"id":"china-drug-administration-law","kind":"term","name":"China Drug Administration Law (2019) and expedited pathways","route":"/terms/china-drug-administration-law/"},{"id":"clinical-equipoise","kind":"term","name":"Clinical equipoise","route":"/terms/clinical-equipoise/"},{"id":"duration-of-response-term","kind":"term","name":"Duration of response (DoR) and disease control rate (DCR)","route":"/terms/duration-of-response-term/"},{"id":"external-control-arm","kind":"term","name":"External and synthetic control arms","route":"/terms/external-control-arm/"},{"id":"orr","kind":"term","name":"Objective response rate (ORR)","route":"/terms/orr/"},{"id":"trial-phases","kind":"term","name":"Phase 1, 2 and 3 trials","route":"/terms/trial-phases/"},{"id":"pivotal-trial","kind":"term","name":"Pivotal (registrational) trial","route":"/terms/pivotal-trial/"},{"id":"surrogate-validation","kind":"term","name":"Surrogate endpoint validation: which stand-ins have earned trust","route":"/terms/surrogate-validation/"},{"id":"umbrella-trial","kind":"term","name":"Umbrella trial","route":"/terms/umbrella-trial/"},{"id":"trial-failure-modes","kind":"term","name":"Why trials fail: underpowered, wrong endpoint, control arm drift, subgroup fishing, crossover","route":"/terms/trial-failure-modes/"}],"section":[{"id":"drug-discovery","kind":"section","name":"Drug Discovery Platforms","route":"/fronts/drug-discovery/"}],"trial":[{"id":"arrow-thyroid","kind":"trial","name":"ARROW (thyroid cohorts)","route":"/trials/arrow-thyroid/"},{"id":"nct05318469","kind":"trial","name":"Ivermectin with balstilimab or pembrolizumab in metastatic triple-negative breast cancer (Cedars-Sinai phase 1/2)","route":"/trials/nct05318469/"},{"id":"l-mind","kind":"trial","name":"L-MIND","route":"/trials/l-mind/"},{"id":"navigate","kind":"trial","name":"NAVIGATE","route":"/trials/navigate/"},{"id":"nmtrc003","kind":"trial","name":"NMTRC003/003B (DFMO maintenance)","route":"/trials/nmtrc003/"},{"id":"pathfinder-2","kind":"trial","name":"PATHFINDER 2","route":"/trials/pathfinder-2/"},{"id":"nct06658353","kind":"trial","name":"Phase III Clinical Study of VC004 in Patients With Localized Advanced/ Metastatic Solid Tumors","route":"/trials/nct06658353/"},{"id":"roar-atc","kind":"trial","name":"ROAR (anaplastic thyroid cancer cohort)","route":"/trials/roar-atc/"}],"drug":[{"id":"ivermectin","kind":"drug","name":"Ivermectin","route":"/drugs/ivermectin/"}],"paper":[{"id":"paper-mansoori-mebendazole-gi-cancer-phase-2a-sci-rep-2021","kind":"paper","name":"A phase 2a clinical study on the safety and efficacy of individualized dosed mebendazole in patients with advanced gastrointestinal cancer","route":"/key-papers/paper-mansoori-mebendazole-gi-cancer-phase-2a-sci-rep-2021/"}]}}