Prothena Stock Price, News & Analysis

Prothena (NASDAQ:PRTA), a late-stage clinical biotechnology company specializing in protein dysregulation therapeutics, has announced its participation in the upcoming Cantor Fitzgerald Global Healthcare Conference. The company's senior management team will engage in a fireside chat on September 4, 2025, at 10:55 a.m. ET in New York.

Investors can access the presentation through a live webcast on the investor relations section of Prothena's website. The replay will remain available for 90 days following the presentation.

Prothena (NASDAQ:PRTA) has announced results from its Phase 1 ASCENT clinical program for PRX012, their anti-amyloid beta antibody for early symptomatic Alzheimer's disease. The study demonstrated that PRX012 achieved dose- and time-dependent reductions in amyloid plaque, with the 400mg dose showing mean reduction to 27.47 centiloids at month 12.

While PRX012 showed positive aspects including stable pharmacokinetics, low anti-drug antibodies, and low injection site reactions (4.1%), it demonstrated higher overall ARIA-E rates compared to FDA-approved anti-Aβ antibodies. Due to this non-competitive safety profile, Prothena plans to explore partnership opportunities to advance both PRX012 and its preclinical PRX012-TfR antibody variant.

Prothena (NASDAQ:PRTA) announced that Novo Nordisk will advance coramitug (formerly PRX004) into Phase 3 development for ATTR amyloidosis with cardiomyopathy (ATTR-CM) in 2025. Coramitug, a potential first-in-class amyloid depleter antibody, was initially developed by Prothena and acquired by Novo Nordisk in July 2021.

Under the agreement terms, Prothena is eligible to receive up to $1.2 billion in clinical development and sales milestones, including $100 million earned to date. The company will earn an additional milestone payment when prespecified enrollment criteria are met in the Phase 3 trial.

Prothena (NASDAQ:PRTA) reported Q2 2025 financial results and business updates. Key highlights include: Roche's advancement of prasinezumab into Phase 3 for early-stage Parkinson's disease by end-2025, with potential peak sales over $3 billion. The company reported a net loss of $125.8 million for Q2 2025, including $32.6 million in restructuring charges.

Financial position shows $372.3 million in cash as of June 30, 2025. The company plans to hold an EGM by year-end to propose a share capital reduction for potential share redemption. Notable pipeline developments include upcoming PRX012 Phase 1 data for Alzheimer's disease in August 2025 and potential milestone payments of up to $105 million in 2026 from partnerships with Novo Nordisk and Bristol Myers Squibb.

[ "Strong cash position of $372.3 million with no debt", "Potential milestone payments up to $105 million in 2026 from partnerships", "Prasinezumab advancing to Phase 3 with potential peak sales over $3 billion", "Multiple clinical trial catalysts expected in 2025-2026", "FDA Fast Track designation granted for PRX012 and PRX123 for Alzheimer's disease" ]

Prothena (NASDAQ:PRTA), a late-stage clinical biotechnology company focused on protein dysregulation therapeutics, has scheduled the release of its Q2 and H1 2025 financial results for Monday, August 4, 2025, following the U.S. market close. The company has indicated that it will maintain its standard practice of not holding a conference call to discuss the results.

Prothena Corporation (PRTA) announced a significant corporate restructuring, including a 63% workforce reduction to optimize operating costs. The restructuring follows several key milestones, including Roche's advancement of prasinezumab to Phase 3 for early-stage Parkinson's disease, upcoming PRX012 Phase 1 data for Alzheimer's, and various partnered programs with potential milestone payments. The company revised its 2025 financial guidance, projecting a net cash burn of $170-178 million and year-end cash position of approximately $298 million. The expected 2025 net loss is estimated at $240-248 million, including $36 million in non-cash share-based compensation and $45 million non-cash tax expense. The discontinuation of birtamimab development is expected to reduce annualized net cash burn by approximately $96 million.

Prothena (NASDAQ:PRTA) announced that its partner Roche will advance prasinezumab, a potential first-in-class anti-alpha-synuclein antibody, into Phase III development for early-stage Parkinson's disease. The decision follows data from the Phase IIb PADOVA study and open-label extensions from both PADOVA and Phase II PASADENA studies. While prasinezumab showed potential clinical efficacy in reducing motor progression at 104 weeks, it missed statistical significance in the primary endpoint. The drug demonstrated positive trends that appear sustained over longer treatment periods, and provided first biomarker evidence of impact on underlying disease biology. The ongoing PASADENA and PADOVA OLE studies are evaluating long-term safety and efficacy in over 750 early-stage Parkinson's patients.

Prothena (NASDAQ:PRTA) announced that its Phase 3 AFFIRM-AL clinical trial for birtamimab in AL amyloidosis patients failed to meet its primary endpoint of time to all-cause mortality (HR=0.915, p-value=0.7680). The trial also missed its secondary endpoints: 6-minute walk test distance and Short Form-36 Physical Component Score. As a result, Prothena will discontinue all birtamimab development, including the trial's open-label extension. While birtamimab demonstrated a consistent safety profile, the company plans substantial organizational downsizing and expense reductions, with detailed plans expected in June. Despite this setback, Prothena highlighted upcoming pipeline milestones, including Phase 1 ASCENT trial data for PRX012 in Alzheimer's disease (August), and partner updates from Roche (mid-2025), Novo Nordisk (2H25), and Bristol Myers Squibb (2026).

Prothena Corporation (PRTA) reported Q1 2025 financial results with a net loss of $60.2 million ($1.12 per share) and revenue of $2.8 million. The company ended Q1 with $418.8 million in cash and restricted cash. Key upcoming milestones include: 1. Topline results expected in Q2 2025 from Phase 3 AFFIRM-AL trial of birtamimab for AL amyloidosis 2. Multiple clinical readouts for PRX012 (Alzheimer's treatment) starting mid-2025 3. Phase 2b PADOVA trial results for prasinezumab in Parkinson's disease showed possible benefits 4. Phase 2 trial results for coramitug in ATTR-CM expected in 2H 2025 The company projects 2025 net cash use of $168-175 million in operating and investing activities, with an estimated year-end cash position of approximately $301 million.