{"schema_version":"1.0","type":"article","title":"Tau Earned a Retest: Why Biogen Is Taking Diranersen Into Phase 3 After CELIA Missed Its Primary Endpoint","url":"https://drugnews.com.tw/articles/2026-08-03-diranersen-celia-tau-phase3-en.html","markdown_url":"https://drugnews.com.tw/articles/2026-08-03-diranersen-celia-tau-phase3-en.md","lang":"en","date":"2026-08-03","publish_at":"2026-08-03T08:01:00+08:00","updated_at":"2026-08-03","category":"商業分析系列","topic":"商業分析系列","tags":["Alzheimer's disease","tau","diranersen","BIIB080","IONIS-MAPTRx","Biogen","Ionis","antisense oligonucleotide","ASO","CDR-SB","clinical data","drug development"],"summary":"CELIA missed its prespecified dose-response primary endpoint, yet the lowest dose produced a 0.54-point CDR-SB difference, or 26% slowing, while CSF total tau and tau PET moved in the expected direction. That is enough to justify Phase 3 planning, but not enough to declare tau a validated second disease-modifying pathway.","key_points":[],"facts":[],"sections":["01 | Start With the Right Question: CELIA Tested Dose Response","02 | Where Did 26% Come From? Read the Point Difference First","03 | Why the Tau Debate Reopened: Three Evidence Layers Moved Together","04 | Reducing Tau Production Is Different From Clearing Existing Tau","05 | Safety Was Acceptable So Far, but ARIA Cannot Be Declared Impossible","06 | Do Not Rank CELIA's 26% Beside Leqembi and Kisunla","07 | Why Is Biogen Willing to Proceed?","08 | What Should Taiwan-Based Readers Watch?","09 | Conclusion: Tau Earned a Retest","References","Disclaimer"],"references":[{"title":"All references are first-party sources or official trial records. Information verified through July 19, 2026.","source":"","date":"","url":""},{"title":"AAIC 2026 official program, London, July 12–15, 2026:","source":"","date":"","url":"https://aaic.alz.org/program/schedule.asp"},{"title":"ClinicalTrials.gov, CELIA, NCT05399888:","source":"","date":"","url":"https://clinicaltrials.gov/study/NCT05399888"},{"title":"Biogen, complete CELIA Phase 2 data:","source":"","date":"","url":"https://investors.biogen.com/node/30826"},{"title":"Ionis, diranersen and CELIA announcement:","source":"","date":"","url":"https://ir.ionis.com/node/34616"},{"title":"Alzheimer's Association, 2026 drug-development pipeline overview:","source":"","date":"","url":"https://www.alz.org/news/2026/alzheimers-disease-drug-development-pipeline-is-growing"}],"images":[{"alt":"CELIA tested whether higher or more frequent dosing produced greater CDR-SB benefit","url":"https://drugnews.com.tw/assets/articles/diranersen-celia-tau-phase3-en/figure-01.png"},{"alt":"The lowest dose showed the largest CDR-SB difference, while the prespecified dose-response endpoint was missed","url":"https://drugnews.com.tw/assets/articles/diranersen-celia-tau-phase3-en/figure-02.png"},{"alt":"Mechanism, biomarkers and a selected clinical signal moved in the same direction but do not establish Phase 3 benefit","url":"https://drugnews.com.tw/assets/articles/diranersen-celia-tau-phase3-en/figure-03.png"},{"alt":"Five questions a confirmatory diranersen trial must answer","url":"https://drugnews.com.tw/assets/articles/diranersen-celia-tau-phase3-en/figure-04.png"}],"cover_image":"https://drugnews.com.tw/assets/articles/diranersen-celia-tau-phase3-en/cover.png","publisher":{"name":"Drugnews｜藥時事","url":"https://drugnews.com.tw/","profile":"https://drugnews.com.tw/brand-profile.json"},"citation":"Drugnews｜藥時事（2026-08-03）。Tau Earned a Retest: Why Biogen Is Taking Diranersen Into Phase 3 After CELIA Missed Its Primary Endpoint。https://drugnews.com.tw/articles/2026-08-03-diranersen-celia-tau-phase3-en.html","disclaimer":"This article is intended for industry research and knowledge sharing only. It does not constitute investment, medical, fundraising, or individual stock advice.","translations":{"zh-Hant":"2026-08-03-diranersen-celia-tau-phase3.html"},"relationship":"independent_editorial","disclosure_url":"https://drugnews.com.tw/policy/"}