{"entity":{"id":"prosper","kind":"trial","name":"PROSPER","aka":[],"tldr":"PROSPER showed that enzalutamide delayed the appearance of metastases by about two years, and later helped men live longer, when given at the point where prostate cancer is rising on hormone therapy but has not yet spread on scans.","summary":"PROSPER randomised 1401 men with castration-resistant prostate cancer, no metastases on conventional imaging and a PSA doubling time of ten months or less two to one to enzalutamide or placebo alongside androgen deprivation. The primary endpoint was metastasis-free survival.\n\nEnzalutamide lengthened metastasis-free survival substantially and delayed the time to PSA progression and to further antineoplastic therapy; with longer follow-up overall survival was also improved. Fatigue, hypertension and falls were the main added toxicities. It was approved for this indication in July 2018 and, with SPARTAN (apalutamide) and ARAMIS (darolutamide), defined androgen receptor pathway inhibition as the standard for high-risk non-metastatic castration-resistant disease, a group that PSMA PET imaging has since shrunk.","status":"positive","asOf":"2026-09-17","links":[{"label":"ClinicalTrials.gov NCT02003924","url":"https://clinicaltrials.gov/study/NCT02003924"},{"label":"NICE TA580: enzalutamide for hormone-relapsed non-metastatic prostate cancer, not recommended","url":"https://www.nice.org.uk/guidance/ta580"}],"tags":["subtype-trials"],"related":[],"cancers":["prostate-nmcrpc","prostate"],"sections":[],"technologies":["androgen-deprivation"],"targets":[],"drugs":["enzalutamide"],"companies":["pfizer","astellas"],"institutions":[],"pathways":[],"terms":["prostate-uk-drug-approvals","metastasis-free-survival"],"trials":["nct01946204","aramis"],"people":["maha-hussain"],"bottlenecks":[],"keyPapers":["paper-prosper-nejm-2018"],"journals":[],"dependsOn":[],"notes":["In England NICE TA580 does not recommend enzalutamide for high-risk hormone-relapsed non-metastatic prostate cancer. The committee accepted that adding enzalutamide extends the time until the cancer starts spreading but found no evidence that it increases how long people live, and judged the cost-effectiveness estimates uncertain because survival on enzalutamide could not be estimated accurately and because the costs and benefits of subsequent treatments in the economic analysis did not reflect NHS practice. Apalutamide (TA740) and darolutamide (TA660) are recommended in the same population."],"nct":"NCT02003924","phase":"3","setting":"Non-metastatic castration-resistant prostate cancer with a PSA doubling time of ten months or less: enzalutamide against placebo, both with continued androgen deprivation","sponsor":"Pfizer (Medivation) and Astellas","result":"Enzalutamide lengthened metastasis-free survival and, with longer follow-up, overall survival compared with placebo; approved in July 2018.","started":"2013-10-31","startedType":"actual","yearReported":2018,"enrolled":1401,"enrolledBasis":"registry","outcomes":[{"endpoint":"Metastasis-free survival","primary":true,"unit":"months","arms":[{"name":"Enzalutamide","n":933,"value":36.6},{"name":"Placebo","n":468,"value":14.7}],"hr":0.29,"ci":[0.24,0.35],"p":"<0.001","source":"https://doi.org/10.1056/NEJMoa1800536"},{"endpoint":"Time to PSA progression","unit":"months","arms":[{"name":"Enzalutamide","n":933,"value":37.2},{"name":"Placebo","n":468,"value":3.9}],"hr":0.07,"p":"<0.001","source":"https://doi.org/10.1056/NEJMoa1800536"},{"endpoint":"Time to first subsequent antineoplastic therapy","unit":"months","arms":[{"name":"Enzalutamide","n":933,"value":39.6},{"name":"Placebo","n":468,"value":17.7}],"hr":0.21,"p":"<0.001","source":"https://doi.org/10.1056/NEJMoa1800536"},{"endpoint":"Grade 3 or higher adverse events","unit":"%","arms":[{"name":"Enzalutamide","value":31},{"name":"Placebo","value":23}],"source":"https://doi.org/10.1056/NEJMoa1800536"}]},"route":"/trials/prosper/","neighbours":{"cancer":[{"id":"prostate-nmcrpc","kind":"cancer","name":"Non-metastatic castration-resistant prostate cancer","route":"/cancers/prostate-nmcrpc/"},{"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/"}],"drug":[{"id":"enzalutamide","kind":"drug","name":"Enzalutamide","route":"/drugs/enzalutamide/"}],"company":[{"id":"astellas","kind":"company","name":"Astellas","route":"/companies/astellas/"},{"id":"pfizer","kind":"company","name":"Pfizer (incl. Seagen)","route":"/companies/pfizer/"}],"term":[{"id":"metastasis-free-survival","kind":"term","name":"Metastasis-free survival (MFS)","route":"/terms/metastasis-free-survival/"},{"id":"prostate-uk-drug-approvals","kind":"term","name":"Prostate cancer drugs in England: what NICE recommends, and what it refuses","route":"/terms/prostate-uk-drug-approvals/"}],"trial":[{"id":"nct01946204","kind":"trial","name":"A Study of Apalutamide (ARN-509) in Men With Non-Metastatic Castration-Resistant Prostate Cancer","route":"/trials/nct01946204/"},{"id":"aramis","kind":"trial","name":"ARAMIS","route":"/trials/aramis/"}],"person":[{"id":"maha-hussain","kind":"person","name":"Maha Hussain","route":"/people/maha-hussain/"}],"paper":[{"id":"paper-prosper-nejm-2018","kind":"paper","name":"PROSPER: enzalutamide in men with non-metastatic castration-resistant prostate cancer","route":"/key-papers/paper-prosper-nejm-2018/"}]}}