Core Insights - Prothena Corporation's shares have decreased by 40% year-to-date, contrasting with a 6.6% gain in the industry, primarily due to pipeline setbacks [1][8] - The company is working to advance other pipeline projects after halting the development of birtamimab, but challenges persist [1] Pipeline Updates - Prothena provided an update on PRX012, a candidate for early symptomatic Alzheimer's disease, showing promising results in a phase I program [3][4] - PRX012 demonstrated a mean reduction in amyloid PET to 27.47 centiloids at the 400 mg dose level after 12 months, which is favorable compared to FDA-approved anti-Aβ antibodies [4] - However, PRX012 exhibited higher overall ARIA-E rates, raising concerns about its suitability for the studied patient population [5] - The company plans to seek partnerships to advance PRX012 and its preclinical PRX012-TfR antibody, which may reduce ARIA risks and enhance amyloid clearance [6][8] Recent Developments - Novo Nordisk will advance coramitug, an amyloid depleter antibody, into a phase III program for ATTR amyloidosis with cardiomyopathy in 2025, which Prothena initially developed [9] - Prothena is eligible for up to $1.2 billion in milestone payments from Novo Nordisk, having already earned $100 million [10] Setbacks and Workforce Changes - The discontinuation of birtamimab's development was announced in May 2025 after it failed to meet primary endpoints in a late-stage study [11] - Following this, Prothena implemented a 63% workforce reduction to streamline costs and support ongoing programs [12] Partnered Programs - Roche is advancing prasinezumab into phase III development for early-stage Parkinson's disease, with initiation expected by the end of 2025 [13][14] - Prothena will receive double-digit teen royalties on net sales of prasinezumab [14] - Bristol Myers is conducting phase II and phase I trials for potential Alzheimer's treatments, with Prothena collaborating on several early-stage programs [15][16] Overall Outlook - Despite progress in partnered programs, setbacks in wholly owned programs present significant challenges for Prothena [17]

Core Viewpoint - Prothena's recent earnings report indicates significant losses and revenue misses, but the company is focusing on key pipeline developments that could drive future growth [2][12]. Financial Performance - Prothena reported a second-quarter adjusted loss per share of $1.86, which was wider than the Zacks Consensus Estimate of a loss of $1.11 [2]. - Revenues for the quarter totaled $4.4 million, missing the Zacks Consensus Estimate of $21 million, compared to $132 million in the previous year [2]. - Research and development expenses decreased by 29.5% year-over-year to $40.5 million, attributed to lower clinical trial and manufacturing costs [3]. - General and administrative expenses were slightly reduced to $15.9 million from $16.1 million in the prior year [3]. - As of June 30, 2025, Prothena had $372.3 million in cash and equivalents, with no debt [3]. Pipeline Developments - Prothena is collaborating with Roche on prasinezumab for Parkinson's disease, with phase III development expected to start by the end of 2025 [4]. - The company is evaluating PRX012 for Alzheimer's disease, which has received Fast Track designation from the FDA, with initial data from phase I trials expected soon [5]. - Prothena is advancing several early-stage programs in collaboration with Bristol Myers, including BMS-986446 for Alzheimer's disease [6]. - PRX019, a potential treatment for neurodegenerative diseases, is undergoing a phase I clinical trial, expected to complete in 2026 [8]. - The dual Aβ-Tau vaccine, PRX123, has also received Fast Track designation and is being advanced through efficient funding structures [9][10]. Guidance and Estimates - Prothena expects a net cash burn of $170 to $178 million for 2025, with a projected year-end cash balance of approximately $298 million [12]. - The company anticipates a net loss in the range of $240 to $248 million for 2025 [12]. - Since the earnings release, consensus estimates have shifted upward by 29.35% [13]. Market Position - Prothena holds a Zacks Rank of 3 (Hold), indicating an expectation of in-line returns in the coming months [15]. - The company has an average Growth Score of C, a Momentum Score of A, but a low value score of F, placing it in the bottom 20% for value investors [14].

Pipeline and Milestones - Prothena has multiple clinical programs ongoing, including one partnered Phase 3 program, two partnered Phase 2 programs, one partnered Phase 1 program, and one wholly-owned Phase 1 program[13] - Prothena is eligible to receive up to $1.23 billion in total consideration from Novo Nordisk for coramitug and the broader ATTR amyloidosis program[13, 16] - Prothena anticipates up to $105 million in clinical milestones in 2026, including completion of Phase 3 development for prasinezumab and initial data from the Phase 1 ASCENT trial for PRX012[18] Partnerships and Financials - Prothena's partnerships are expected to generate meaningful value, with up to $755 million in total milestones and royalties for prasinezumab, up to $1.23 billion for coramitug, and up to $1.55 billion across two clinical-stage programs (BMS-986446 and PRX019)[20] - Bristol Myers Squibb (BMS) owns approximately 2.2% of Prothena's outstanding shares as of March 3, 2025[21] Alzheimer's Disease Programs - PRX012, Prothena's anti-Aβ candidate, has approximately 10X greater binding potency to fibrillar Aβ vs aducanumab and approximately 20X greater binding potency against protofibrils vs lecanemab[24] - BMS-986446 (formerly PRX005), an anti-tau candidate, has the potential to reduce pathogenic tau spread in Alzheimer's disease[27] - PRX123, a dual Aβ/tau vaccine candidate, is designed for both treatment and prevention of Alzheimer's disease, and its IND has been cleared[27] Parkinson's Disease Program - Roche will initiate Phase 3 development for prasinezumab in early-stage Parkinson's disease[15, 111] - The Parkinson's disease affects >10 million people worldwide and represents an overall economic burden of $52 billion in the US[5] ATTR Amyloidosis Program - Coramitug (formerly PRX004) is in Phase 2 development for ATTR amyloidosis with cardiomyopathy (ATTR-CM)[15, 142] - An estimated 450,000 patients worldwide have wtATTR or ATTRv[8]