{"entity":{"id":"prostate-stampede-arms","kind":"term","name":"STAMPEDE's arms, and what each one answered","aka":["STAMPEDE comparisons","STAMPEDE platform arms","what STAMPEDE showed"],"tldr":"One British trial, running since 2005, has asked nine separate questions about prostate cancer treatment by adding new arms as the answers came in. Four of them changed what men are offered, and five did not.","summary":"STAMPEDE is a multi-arm multi-stage platform: several experimental arms recruit at once against a shared control arm of androgen deprivation therapy, arms are added as new drugs appear, and arms are dropped at interim stages if they show no activity. Nearly 12,000 men joined at more than 100 hospitals in the United Kingdom and Switzerland. Because every arm shares one registration, NCT00268476, they are described here rather than as separate trial records.\n\nWhat each comparison asked and answered, with the publication it was read from.\n\nDocetaxel added to androgen deprivation, reported in the Lancet in 2016: improved overall survival, most clearly in metastatic disease. It replicated CHAARTED and made early chemotherapy a standard.\n\nZoledronic acid, reported alongside docetaxel in 2016: no survival benefit, alone or added to docetaxel. It is not given for that purpose now.\n\nCelecoxib, with and without zoledronic acid: the celecoxib arms were stopped in 2011 for lack of activity at the interim stage. This is what a platform is for; a standalone trial would have run to completion.\n\nAbiraterone with prednisolone added at the start of long-term androgen deprivation, reported in the New England Journal of Medicine in 2017 in 1,917 men: 184 deaths against 262, hazard ratio 0.63 (95 percent confidence interval 0.52 to 0.76, p<0.001), with a hazard ratio of 0.61 in metastatic and 0.75 in non-metastatic disease. Failure-free survival hazard ratio was 0.29 (0.25 to 0.34). Grade 3 to 5 adverse events occurred in 47 percent against 33 percent, with nine grade 5 events against three. Published within days of LATITUDE, it established abiraterone at first diagnosis of metastatic disease.\n\nRadiotherapy to the prostate in newly diagnosed metastatic disease, reported in the Lancet in 2018 in 2,061 men: failure-free survival improved (hazard ratio 0.76, 0.68 to 0.84, p<0.0001) but overall survival did not (0.92, 0.80 to 1.06, p=0.266). In the prespecified subgroup with low metastatic burden it did, and prostate radiotherapy for low-volume metastatic disease entered guidelines on that basis. Radiotherapy was well tolerated, with grade 3 to 4 events in 5 percent during and 4 percent after treatment.\n\nAbiraterone with enzalutamide against abiraterone alone in high-risk non-metastatic disease, reported in the Lancet in 2022 as a meta-analysis of two STAMPEDE comparisons in 1,974 men: combination therapy improved metastasis-free survival, hazard ratio 0.53 (0.44 to 0.64, p<0.0001), with 6-year metastasis-free survival 82 against 69 percent. Adding enzalutamide to abiraterone gave no further benefit (interaction hazard ratio 1.02, 0.70 to 1.50, p=0.91) and added toxicity. Two drugs are not better than one here.\n\nMetformin added to standard of care for metastatic hormone-sensitive disease, reported in Lancet Oncology in 2025 in 1,874 men: 473 deaths in the control group, median survival 61.8 months, against 453 deaths and 67.4 months with metformin, hazard ratio 0.91 (0.80 to 1.03, p=0.15). No significant survival benefit. Grade 3 or worse adverse events occurred in 52 against 57 percent, the extra being mostly gastrointestinal.\n\nTransdermal oestradiol, run jointly with the PATCH trial: oestrogen patches suppress testosterone as fast and as well as injections, with fewer hot flushes (35 against 86 percent), more gynaecomastia (86 against 38 percent), better bone density and no excess cardiovascular events (hazard ratio 1.11, 0.80 to 1.53). Oncological results are reported separately by cohort.\n\nThe design's weakness is honest and worth stating: the control arm changed as docetaxel and then abiraterone became standard, so later arms were compared against a moving baseline, and two of the practice-changing readings (prostate radiotherapy, enzalutamide) rest on subgroups. STAMPEDE2 opened in 2023 with stereotactic radiotherapy to metastases, lutetium PSMA radioligand therapy and niraparib with abiraterone.","status":"established","asOf":"2026-09-25","links":[{"label":"STAMPEDE abiraterone (New England Journal of Medicine 2017)","url":"https://doi.org/10.1056/NEJMoa1702900"},{"label":"STAMPEDE prostate radiotherapy (Lancet 2018)","url":"https://doi.org/10.1016/S0140-6736(18)32486-3"},{"label":"STAMPEDE abiraterone with or without enzalutamide in non-metastatic disease (Lancet 2022)","url":"https://doi.org/10.1016/S0140-6736(21)02437-5"},{"label":"STAMPEDE metformin (Lancet Oncology 2025)","url":"https://doi.org/10.1016/S1470-2045(25)00231-1"},{"label":"STAMPEDE trial website (MRC Clinical Trials Unit at UCL)","url":"https://www.stampedetrial.org"}],"tags":[],"related":[],"cancers":["prostate","prostate-mhspc","prostate-high-risk"],"sections":[],"technologies":["androgen-deprivation","cytotoxic-chemotherapy","imrt-igrt"],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":["adt","mcrpc-mhspc","arpi"],"trials":["stampede","chaarted","latitude","patch-transdermal-oestradiol","rtog-0521"],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"category":"Clinic basics"},"route":"/terms/prostate-stampede-arms/","neighbours":{"cancer":[{"id":"prostate-high-risk","kind":"cancer","name":"Localised prostate cancer, high and very high risk","route":"/cancers/prostate-high-risk/"},{"id":"prostate-mhspc","kind":"cancer","name":"Metastatic hormone-sensitive prostate cancer","route":"/cancers/prostate-mhspc/"},{"id":"prostate","kind":"cancer","name":"Prostate cancer","route":"/cancers/prostate/"}],"technology":[{"id":"androgen-deprivation","kind":"technology","name":"Androgen deprivation & AR pathway inhibitors","route":"/technologies/androgen-deprivation/"},{"id":"cytotoxic-chemotherapy","kind":"technology","name":"Cytotoxic chemotherapy","route":"/technologies/cytotoxic-chemotherapy/"},{"id":"imrt-igrt","kind":"technology","name":"IMRT / IGRT (modern external beam)","route":"/technologies/imrt-igrt/"}],"term":[{"id":"adt","kind":"term","name":"Androgen deprivation therapy (ADT)","route":"/terms/adt/"},{"id":"arpi","kind":"term","name":"Androgen receptor pathway inhibitor (ARPI)","route":"/terms/arpi/"},{"id":"mcrpc-mhspc","kind":"term","name":"mCRPC and mHSPC (castration-resistant vs hormone-sensitive prostate cancer)","route":"/terms/mcrpc-mhspc/"}],"trial":[{"id":"chaarted","kind":"trial","name":"CHAARTED (E3805)","route":"/trials/chaarted/"},{"id":"latitude","kind":"trial","name":"LATITUDE","route":"/trials/latitude/"},{"id":"rtog-0521","kind":"trial","name":"NRG Oncology RTOG 0521","route":"/trials/rtog-0521/"},{"id":"patch-transdermal-oestradiol","kind":"trial","name":"PATCH (Prostate Adenocarcinoma Transcutaneous Hormone)","route":"/trials/patch-transdermal-oestradiol/"},{"id":"stampede","kind":"trial","name":"STAMPEDE","route":"/trials/stampede/"}]}}