DNLI sinks after BIIB122 failed a mid-stage Parkinson's study, prompting Denali and Biogen to halt development in idiopathic cases.

Biogen shares dropped approximately 6.4% in a single session after Phase 2 CELIA trial data for diranersen missed its primary endpoint -- wiping out billions in market value. NEW YORK, May 22, 2026 /PRNewswire/ -- Biogen Inc. (NASDAQ: BIIB) investors lost approximately 6.4% per share on May 14, 2026, when the company disclosed that its Phase 2 "CELIA" trial for diranersen (BIIB080) failed to meet its primary dose-response endpoint in early Alzheimer's disease.

U.S. Food & Drug Administration (FDA) events crystallize the risk/reward thesis for many biotechnology stocks, and Biogen Inc.'s NASDAQ: BIIB latest Alzheimer's update shows why that trade can turn quickly.

NEW YORK, May 21, 2026 /PRNewswire/ -- Pomerantz LLP is investigating claims on behalf of investors of Biogen Inc. ("Biogen" or the "Company") (NASDAQ: BIIB). Such investors are advised to contact Danielle Peyton at newaction@pomlaw.com or 646-581-9980, ext.

Biogen and Denali Therapeutics said on Thursday ​they will discontinue development of ‌their Parkinson's drug after it failed to meet the main goal ​in a mid-to-late stage ​study.

CAMBRIDGE, Mass. and SOUTH SAN FRANCISCO, Calif., May 21, 2026 (GLOBE NEWSWIRE) -- Biogen Inc. (Nasdaq: BIIB) and Denali Therapeutics Inc. (Nasdaq: DNLI) today announced topline results from the Phase 2b LUMA study evaluating BIIB122 (DNL151), an investigational small molecule inhibitor of LRRK2 (leucine-rich repeat kinase 2), in individuals with early-stage Parkinson's disease. Results from the study show that BIIB122 did not slow the progression of Parkinson's disease versus placebo, as measured by the primary endpoint of Time to Confirmed Worsening in the modified Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) Part II and III combined score. Secondary endpoints also did not show a benefit with BIIB122. Exploratory biomarker endpoints demonstrated >90% kinase inhibition of peripheral LRRK2 (phosphoserine 935) and, in a cerebrospinal fluid (CSF) sub-study, up to approximately 30% reduction observed in a biomarker of LRRK2 activity (phosphorylated Rab10). Expected levels of BIIB122 in the blood and CSF were sustained across the study. BIIB122 was generally well tolerated with an acceptable safety profile. Based on these results, Biogen and Denali will discontinue further development of BIIB122 in idiopathic Parkinson's disease. Denali will continue to independently conduct the Phase 2a BEACON study evaluating the small molecule inhibitor in carriers of a pathogenic LRRK2 variant.

Biogen stock fell approximately 6.4% in a single session after Phase 2 "CELIA" trial data for diranersen failed to meet its primary endpoint. NEW YORK, May 20, 2026 (GLOBE NEWSWIRE) -- Biogen Inc. (NASDAQ: BIIB) shares dropped approximately 6.4% on May 14, 2026, after the company released mixed Phase 2 "CELIA" topline data for its Alzheimer's candidate diranersen (BIIB080), with the trial failing to meet its primary dose-response endpoint.

NEW YORK--(BUSINESS WIRE)--Biogen Inc. (NASDAQ: BIIB) shareholders lost approximately 6.4% of their investment value on May 14, 2026, when the company disclosed that its Phase 2 "CELIA" trial for Alzheimer's candidate diranersen (BIIB080) failed to meet its primary dose-response endpoint. Investors who lost money on BIIB are encouraged to submit their information for a free evaluation. You may also contact Joseph E. Levi, Esq. via email at jlevi@levikorsinsky.com or by telephone at (212) 363-75.

New York, New York--(Newsfile Corp. - May 18, 2026) - Levi & Korsinsky notifies investors that it has commenced an investigation into Biogen Inc. ("Biogen Inc.") (NASDAQ:BIIB) concerning potential violations of the federal securities laws. The stock fell sharply on heavy volume following the May 14 topline data release.

Biogen Phase 2 CELIA trial data sent shares down 6.4% after it was revealed that topline data missed its primary endpoint. NEW YORK, May 18, 2026 /PRNewswire/ -- Biogen Inc. (NASDAQ: BIIB) shareholders lost 6.4% per share on May 14, 2026, when Phase 2 "CELIA" topline data for diranersen missed its primary dose-response endpoint.