Core Insights - Prothena presented clinical data updates for prasinezumab, targeting Parkinson's disease, and BMS-986446, aimed at Alzheimer's disease, at the AD/PD™ 2026 conference [1] Group 1: Clinical Data Updates - The updates on prasinezumab and BMS-986446 highlight Prothena's ongoing commitment to addressing neurodegenerative diseases [1] - The presentation at a prominent conference like AD/PD™ 2026 underscores the significance of these developments in the field of neurology [1]

Summary of Prothena's Conference Call Company Overview - Prothena is a biotechnology company focused on diseases characterized by dysfunctional proteins, established in 2012 as a spin-out from Elan Pharmaceuticals. The company has a diverse portfolio of partnered and unpartnered programs, including multiple phase 3 studies in collaboration with major pharmaceutical companies like Roche and Novo Nordisk [6][7][8]. Key Programs and Partnerships - **Parkinson's Disease**: Prothena has a partnership with Roche for a molecule targeting alpha-synuclein, which has advanced to phase 3 studies based on promising phase 2 data [7]. - **ATTR Cardiomyopathy**: A partnered program with Novo Nordisk is also in phase 3, focusing on a disease caused by transthyretin deposition in the heart [7]. - **Tau Protein Program**: In collaboration with Bristol Myers Squibb, Prothena is developing a molecule targeting the tau protein, which has received Fast Track designation from the FDA. The phase 2 study has been fully enrolled, with data expected in the first half of next year [8][9]. - **PRX-019**: Another program with Bristol Myers Squibb is completing phase 1 studies, with a decision on moving to phase 2 expected by year-end [9][10]. Financial Highlights - Prothena anticipates generating over $100 million in milestone payments from partner programs this year, including a recent $50 million milestone from Novo Nordisk [17][18]. - The company has announced a share repurchase program of up to $100 million for 2026, which is not included in the year-end guidance of $255 million [18][19]. - The total deal with Roche includes $755 million in milestones and royalties, with $135 million received to date [36]. Market Opportunities - The peak sales potential for the partnered programs is projected at over $3.5 billion, with significant milestone payments still to be received [36][68]. - The company is actively exploring business development opportunities to expand its proprietary pipeline and leverage its CYTOPE technology for previously undruggable targets [73][74]. CYTOPE Technology - CYTOPE technology aims to target previously undruggable proteins within cells, exemplified by the TDP-43 approach, which is significant in the context of ALS [14][79]. - The technology allows for specific targeting and clearance of cytosolic aggregates without disrupting normal protein functions, demonstrating potential in both CNS and peripheral applications [81][84]. Upcoming Data Releases - Roche is expected to present additional data on the prasinezumab program at the upcoming ADPD 2026 conference, including long-term extension data from previous trials [26][28]. - Prothena is looking forward to data releases from its partnered programs, particularly the phase 2 study with Bristol Myers Squibb and the phase 3 studies with Roche and Novo Nordisk [23][41]. Conclusion - Prothena is positioned as a science-focused, pipeline-rich company with significant partnerships and a robust portfolio. The company is strategically balancing capital allocation to maximize future opportunities while advancing its proprietary technologies [68][74].

Core Insights - Prothena Corporation reported a fourth-quarter 2025 adjusted loss per share of 45 cents, consistent with Zacks Consensus Estimate, compared to a loss of $1.08 per share in the same quarter last year [1] - Revenues for the quarter were $0.02 million, falling short of the Zacks Consensus Estimate of $3.0 million, and down from $2.1 million in the year-ago quarter [1] - The company experienced a significant decline in total revenues for 2025, reporting $9.7 million, a 93% decrease year over year [4] Financial Performance - Research and development expenses decreased by 71% year over year to $14.6 million, attributed to lower clinical trial, manufacturing, personnel, and consulting costs [3] - General and administrative expenses were reported at $12.6 million, down 25% year over year [3] - As of December 31, 2025, Prothena had $308.4 million in cash and equivalents, a decrease from $331.7 million as of September 30, 2025, with no debt [3] Future Guidance - For 2026, Prothena anticipates a net cash burn of $50 million to $55 million and projects year-end cash to be approximately $255 million [7] - The projected net loss for 2026 is estimated to be between $67 million and $72 million [7] - The company expects to earn up to $105 million in milestone payments related to clinical advancements in 2026 [6][7] Pipeline Developments - Prothena is collaborating with Roche on prasinezumab for Parkinson's disease, with peak sales potential exceeding $3.5 billion [8] - Novo Nordisk is evaluating Prothena's Coramitug for ATTR amyloidosis, with the study expected to complete by 2029 [9] - Prothena's pipeline includes several neurological programs in collaboration with Bristol Myers Squibb, including BMS-986446 for Alzheimer's disease, which has received Fast Track designation from the FDA [12][13]

Core Insights - Roche has advanced prasinezumab into the phase 3 PARAISO trial for early Parkinson's disease, aiming to enroll approximately 900 participants with primary completion expected in 2029 [2] - Prothena highlighted significant progress in its clinical pipeline during 2025, with two partner programs moving into phase 3 trials [3] - Prothena's cash burn guidance for 2026 has been sharply reduced, with an expected net cash use of $50–55 million and an anticipated year-end cash balance of approximately $255 million [6][18] Group 1: Clinical Trials and Pipeline Developments - Roche's prasinezumab showed a 40% relative reduction in progression on MDS-UPDRS part 3 versus placebo at 24 months in a subset of participants on stable levodopa, with a nominal p-value of 0.0177 [1] - Prothena's partner programs, including Roche's prasinezumab and Novo Nordisk's coramitug, have advanced to late-stage trials, with primary completions expected around 2029 [7] - The phase 2 trial of coramitug demonstrated a 48% reduction in NT-proBNP versus placebo, with a p-value of 0.0017 [8] Group 2: Financial Performance and Guidance - Prothena reported a net cash used in operations of $163.7 million for 2025, which was favorable compared to its guidance range of $170 million to $178 million [17] - The company ended 2025 with $308.4 million in cash and no debt, and it expects to maintain a cash balance of approximately $255 million by the end of 2026 [6][18] - Prothena's 2026 guidance excludes up to $105 million of potential clinical milestone payments related to coramitug and PRX019 [19] Group 3: Research and Development Focus - Prothena's CYTOPE platform is showing promising preclinical CNS activity, particularly in targeting intracellular disease pathways [5][14] - The company is advancing its anti-amyloid beta antibody program, with prior phase 1 results indicating significant amyloid reductions [16] - Prothena is also conducting a phase 1 trial for PRX019 under its agreement with Bristol Myers Squibb, with completion expected in 2026 [12]

Financial Data and Key Metrics Changes - In 2025, Prothena reported a net cash used in operating and investing activities of $163.7 million, which was favorable compared to the guidance range of $170 million to $178 million [37] - The net loss for 2025 was $244.1 million, aligning with the guidance range of $240 million to $248 million [37] - As of December 31, 2025, Prothena had $308.4 million in cash, cash equivalents, and restricted cash, exceeding the guidance of $298 million [38] Business Line Data and Key Metrics Changes - Prothena's clinical pipeline saw significant progress, with two partnered programs, prasinezumab and coramitug, advancing into phase 3 clinical trials [6][7] - The phase 2 clinical trial for BMS-986446 in early Alzheimer's disease was fully enrolled in 2025, with completion expected in the first half of 2027 [8] - The company introduced its CYTOPE technology, demonstrating potential for precise targeting of intracellular disease pathways [9][30] Market Data and Key Metrics Changes - The phase 3 PARAISO trial for prasinezumab is expected to enroll approximately 900 participants, with primary completion anticipated in 2029 [16] - The phase 3 CLEOPATTRA trial for coramitug is intended to enroll about 1,280 ATTR-CM patients, with primary completion also expected in 2029 [23] - Prothena's partnered clinical programs have the potential to deliver up to approximately $3 billion in future milestone payments [12] Company Strategy and Development Direction - Prothena aims to capture value from clinical partnerships, with potential clinical milestone payments of up to $105 million in 2026 [10][40] - The company plans to implement a share redemption program and invest in its preclinical portfolio to support ongoing partnering efforts [40] - Prothena is focused on advancing its knowledge of the preclinical portfolio to explore research collaborations and licensing agreements [11] Management's Comments on Operating Environment and Future Outlook - Management expressed confidence in the robust pipeline addressing significant unmet needs for millions of patients [40] - The company highlighted the importance of upcoming milestones and the potential for significant medical advances in areas with high unmet needs [45] - Prothena remains well-capitalized with a strong cash position, focusing on delivering long-term shareholder value [41] Other Important Information - Prothena's collaborations with Bristol Myers Squibb progressed, with BMS-986446 receiving Fast Track designation from the U.S. FDA for Alzheimer's treatment [8] - The company is engaged in research collaborations exploring multiple approaches for applying its CYTOPE technology [11] Q&A Session Summary Question: Key milestones for partnered program trials for PARAISO and CLEOPATTRA - Management outlined expectations for sharing more information on CYTOPE activities and data from the tau program with Bristol Myers Squibb in 2027, along with the phase 3 readouts expected in 2029 for coramitug and prasinezumab [42][44] Question: Keeping the amyloid beta story alive against competitors - Management discussed the advantages of the PRX012 transferrin-based approach, emphasizing its potential for improved amyloid removal and reduced ARIA rates compared to competitors [51][55] Question: Data sharing from the phase one study of PRX019 - Management confirmed that data from the PRX019 study will be shared with Bristol Myers Squibb, who holds global rights to the program [62][68] Question: Data necessary to secure a partnership for the CYTOPE platform - Management highlighted the importance of demonstrating robust CNS activity and specificity in targeting TDP-43 aggregates, which could facilitate partnerships [71][75]

Financial Data and Key Metrics Changes - In 2025, Prothena reported a net cash used in operating and investing activities of $163.7 million, which was favorable compared to the guidance range of $170 million to $178 million [37] - The net loss for 2025 was $244.1 million, aligning with the guidance range of $240 million to $248 million [37] - As of December 31, 2025, Prothena had $308.4 million in cash, cash equivalents, and restricted cash, exceeding the guidance of $298 million [38] - For 2026, the expected net cash used in operating and investing activities is projected to be between $50 million and $55 million, with an estimated net loss of $67 million to $72 million [38][39] Business Line Data and Key Metrics Changes - Prothena's clinical pipeline saw significant advancements, with two partnered programs, prasinezumab and coramitug, moving into phase III clinical trials [6][7] - The phase II TargetTau-1 clinical trial for BMS-986446 in early Alzheimer's disease was fully enrolled in 2025, with completion expected in the first half of 2027 [8] - The company introduced its CYTOPE technology, demonstrating potential for precise targeting of intracellular disease pathways [9][30] Market Data and Key Metrics Changes - The phase III PARAISO trial for prasinezumab is expected to enroll approximately 900 participants, with primary completion anticipated in 2029 [16] - The phase III CLEOPATRA trial for coramitug is set to enroll around 1,280 ATTR-CM patients, with primary completion also expected in 2029 [23] - Prothena's partnered clinical programs have the potential to deliver up to approximately $3 billion in future milestone payments, in addition to any royalties [12] Company Strategy and Development Direction - Prothena aims to capture value from clinical partnerships, with potential clinical milestone payments of up to $105 million in 2026 [10][41] - The company plans to implement a share redemption program and invest in its preclinical portfolio to support ongoing partnering efforts [10][41] - Prothena is focused on advancing its knowledge of the preclinical portfolio to explore research collaborations and licensing agreements [11] Management's Comments on Operating Environment and Future Outlook - Management expressed confidence in the robust pipeline addressing significant unmet needs for millions of patients [40] - The company highlighted the importance of upcoming milestones and the potential for significant medical advances in areas with high unmet needs [46] - Management emphasized the strategic importance of the share redemption program and the potential for clinical milestone payments from partners [47][48] Other Important Information - Prothena's cash position as of year-end 2025 was $308.4 million, allowing for prudent capital utilization to support future potential economics from partner programs [11] - The company is engaged in research collaborations exploring multiple approaches for applying its CYTOPE technology [10] Q&A Session Summary Question: Key milestones for partnered program trials for PARAISO and CLEOPATRA - Management outlined that significant activities are expected in 2026 and 2027, including data from the CYTOPE activities and the phase II tau program with Bristol Myers Squibb [44][46] Question: Keeping the amyloid beta story alive against competitors - Management discussed the advantages of the PRX-012 transferrin-based approach and the potential for improved profiles compared to existing therapies [51][55] Question: Data sharing from the phase I study of PRX-019 - Management indicated that data will be shared with Bristol Myers Squibb, who holds global rights to the program, and will decide on public dissemination [62][68] Question: Data necessary for securing a partnership for the CYTOPE platform - Management highlighted the importance of robust in-vivo data demonstrating the technology's ability to target intracellular disease pathways effectively [71][75]

Financial Data and Key Metrics Changes - In 2025, Prothena reported a net cash used in operating and investing activities of $163.7 million, which was favorable compared to the guidance range of $170 million to $178 million [35] - The net loss for 2025 was $244.1 million, aligning with the guidance range of $240 million to $248 million [35] - As of December 31, 2025, Prothena had $308.4 million in cash, cash equivalents, and restricted cash, exceeding the guidance of $298 million [36] Business Line Data and Key Metrics Changes - Prothena's clinical pipeline saw significant advancements, with two partnered programs, prasinezumab and coramitug, moving into phase 3 clinical trials [5] - The phase 3 PARAISO trial for prasinezumab will evaluate 900 participants with early Parkinson's disease, while the CLEOPATTRA trial for coramitug will enroll approximately 1,280 patients with ATTR-CM [5][17] - The company anticipates potential milestone payments of up to $105 million in 2026 from these partnered programs [9][38] Market Data and Key Metrics Changes - The global market for Parkinson's disease treatment is significant, with over 10 million patients and no approved disease-modifying therapies currently available [13] - The ATTR-CM market represents a multi-billion dollar opportunity, with coramitug expected to capture substantial future milestone payments [18] Company Strategy and Development Direction - Prothena aims to capture value from its clinical partnerships and has a strategic priority to implement a share redemption program in 2026 [9][39] - The company is focused on advancing its preclinical portfolio and exploring research collaborations, particularly around its CYTOPE technology [9][39] - Prothena's strategic priorities are supported by a robust cash position, allowing for prudent capital utilization [10] Management's Comments on Operating Environment and Future Outlook - Management expressed confidence in the company's execution and resilience in 2025, setting the stage for future growth [39] - The company is optimistic about the potential for significant medical advances in areas with high unmet needs, particularly in neurodegenerative diseases [42] - Management highlighted the importance of upcoming milestones and the potential for substantial clinical milestone payments in 2026 [46] Other Important Information - Prothena's collaborations with Bristol Myers Squibb progressed, with the phase 2 TargetTau-1 trial for BMS-986446 fully enrolled and expected to complete in the first half of 2027 [6] - The company introduced its CYTOPE technology, which aims to enable precise targeting of intracellular disease pathways [27] Q&A Session Summary Question: Key milestones for partnered program trials for PARAISO and CLEOPATTRA - Management outlined that significant activities are expected in 2026 and 2027, including updates on CYTOPE technology and data from the tau program with Bristol Myers Squibb [41][42] Question: Keeping the amyloid beta story alive versus competitors - Management discussed the advantages of the PRX012 transferrin-based approach, emphasizing its potential for robust amyloid removal and improved safety profile [50][52] Question: Data sharing from the phase one study of PRX019 - Management confirmed that data from the PRX019 study will be shared with Bristol Myers Squibb, who holds global rights to the program [61][66] Question: Data necessary for CYTOPE platform partnerships - Management highlighted the importance of demonstrating robust CNS activity and specificity in targeting TDP-43 aggregates to attract partnerships [69][73]

Core Viewpoint - Prothena Corporation (PRTA) has experienced a significant decline in share price, dropping 36.8% over the past year, primarily due to setbacks in its pipeline, particularly the failure of its candidate birtamimab in a late-stage study [1][6]. Financial Performance - The company has reported inconsistent earnings over the last four quarters, with losses widening due to increased research and development expenses and the impact of pipeline setbacks, including the discontinuation of birtamimab [2]. - Prothena's earnings have missed estimates in each of the last four quarters, with an average negative surprise of 26.72% [2]. Pipeline Setbacks - In May 2025, Prothena announced the discontinuation of birtamimab after the AFFIRM-AL study failed to meet its primary endpoint, removing a near-term value driver [3]. - The termination of birtamimab has significantly reduced near-term catalysts for the stock and shifted the company's strategic focus toward earlier-stage assets like PRX012, which are several years away from potential commercialization [4]. Workforce and Cost Management - In June, Prothena announced a 63% workforce reduction to streamline operating costs while ensuring continued support for its wholly owned programs and partnered program obligations [7]. Partnered Programs Progress - Prothena's pipeline progress is largely driven by partnered assets rather than wholly owned programs [8]. - Partner Novo Nordisk is evaluating coramitug in the phase III CLEOPATTRA program for ATTR cardiomyopathy, which could earn Prothena up to $1.23 billion in development and sales milestones [9]. - Roche has initiated the phase III PARAISO study on prasinezumab for early-stage Parkinson's disease, indicating ongoing commitment to this collaboration [10]. Collaboration Agreements - Prothena has a worldwide collaboration agreement with Roche, having received $135 million to date, with potential for up to $620 million in additional milestone payments and royalties on future sales [11]. - Bristol Myers Squibb is conducting a phase II study for its anti-tau antibody BMS-986446 in Alzheimer's disease, with primary completion expected in 2027 [12]. Ongoing Development - Prothena has initiated an early-stage first-in-human study on PRX019, with completion expected in 2026 [14].

Core Insights - Prothena Corporation (PRTA) reported a third-quarter 2025 adjusted loss per share of 67 cents, which was wider than the Zacks Consensus Estimate of a loss of 60 cents, compared to a loss of $1.10 per share in the same quarter last year [1][7] - Revenues for the quarter totaled $2.4 million, significantly missing the Zacks Consensus Estimate of $25 million, and up from $0.1 million in the year-ago quarter [1][7] Financial Performance - Research and development (R&D) expenses decreased by 42.9% year over year to $28.9 million, attributed to lower clinical trial, manufacturing, personnel, and consulting expenses [4] - General and administrative expenses were reported at $13.2 million, down 21% year over year [4] - As of September 30, 2025, Prothena had $331.7 million in cash, cash equivalents, and restricted cash, with no debt [4][7] Pipeline Developments - Prothena is collaborating with Roche to evaluate prasinezumab for the treatment of Parkinson's disease, with Roche set to initiate the late-stage PARAISO study by the end of 2025, expecting peak sales potential of over $3.5 billion [5] - Novo Nordisk has acquired Prothena's clinical-stage antibody, Coramitug, for treating ATTR amyloidosis with cardiomyopathy, and has initiated the late-stage CLEOPATTRA study [6] - Prothena is advancing an early-stage pipeline for neurological indications in collaboration with Bristol Myers Squibb (BMY), including BMS-986446, which has received Fast Track designation from the FDA for Alzheimer's disease [8][9] Future Expectations - Prothena anticipates earning a clinical milestone when enrollment criteria are met in the ongoing phase III study by Novo Nordisk [8] - The company expects a net cash burn from operating and investing activities in 2025 to be between $170 million and $178 million, with a projected year-end cash balance of approximately $298 million [12] - The projected net loss for 2025 is estimated to be in the range of $240 million to $248 million [12]

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]