Roche Stock Slides After Failed Blood Cancer Trial With AbbVie, But Parkinson’s Therapy Progress Boosts Retail Mood

Shares of Roche drew increased retail attention Monday after the Swiss drugmaker said it would move its investigational Parkinson’s disease treatment prasinezumab into Phase 3 trials. 

The company cited encouraging efficacy trends and sustained safety data from the Phase IIb Padova study and open-label extensions.

Roche’s prasinezumab is a potential first-in-class anti-alpha-synuclein antibody designed to slow disease progression by targeting a key pathological protein. 

The Phase IIb Padova trial, which enrolled 586 early-stage Parkinson’s patients on stable symptomatic therapy, showed a positive trend toward delayed motor progression. 

A pre-specified analysis in patients on levodopa showed nominal statistical significance.

Padova also offered first-time biomarker evidence that prasinezumab may impact Parkinson’s disease biology. 

The open-label extension follow-up data showed sustained motor benefits over two years with a 30%-40% relative slowdown in progression versus placebo.

Prasinezumab, co-developed by Prothena in 2013, has been administered to more than 900 patients, while over 500 patients received it for a duration between 1.5 years and 5 years.

On the other hand, Genentech, a Roche unit, and AbbVie (ABBV) said the Phase 3 Verona trial of Venclexta plus azacitidine in higher-risk myelodysplastic syndromes — a group of cancers in which the bone marrow fails to produce enough healthy blood cells — failed to meet its primary survival endpoint.

However, the result does not affect Venclexta’s approved uses or Roche’s ongoing programs.

Roche is also under some pressure after discontinuing both commercial and clinical use of Elevidys — developed by Sarepta Therapeutics — following two cases of fatal acute liver failure.

On Stocktwits, retail sentiment for Roche was ‘bullish’ amid ‘extremely high’ message volume late Monday.

Roche’s stock has risen 14.9% so far in 2025.

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