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Prothena Corporation plc researches potential treatments for Parkinson’s disease, Alzheimer’s disease and other diseases linked to abnormal proteins. It has no approved drugs and has not sold products. Its revenue comes mainly from pharmaceutical partnerships, with Bristol Myers Squibb supplying nearly all reported revenue through Prothena’s work on the PRX019 clinical trial.
Partners pay for drug rights and development work, with further payments tied to agreed development, approval or sales milestones. Bristol Myers Squibb licenses PRX019 and BMS-986446, while Roche licenses prasinezumab for Parkinson’s disease. These agreements also provide for royalties if the drugs reach the market. Novo Nordisk bought Prothena’s ATTR amyloidosis business, including coramitug, and owes additional payments if specified milestones are achieved.
All active clinical programs are partnered, although Prothena itself develops PRX019 within its Bristol Myers Squibb partnership. It also retains early-stage research programs. Further income depends on partners advancing the drugs and meeting payment conditions; sales-based income requires regulatory approval and commercial sales. No candidate can be sold for an indication before regulators accept evidence of its safety and effectiveness.
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Prothena’s results depend on partners advancing clinical programs and triggering payments, including Roche’s development of prasinezumab—a major dependency missing from this list.
Prothena depends on drugmaker Bristol Myers Squibb for fees and development revenue from licensing BMS-986446 and PRX019, with further milestone payments and sales royalties possible. Watch PRX019 development: BMS collaboration revenue fell from $135.1 million in 2024 to $9.6 million in 2025, when it reflected partial performance of Prothena’s Phase 1 trial obligation.
Prothena’s further payments from Novo Nordisk depend on development and sales milestones after the drugmaker bought its ATTR amyloidosis business. Watch coramitug’s progress under Novo Nordisk: the purchase agreement provides up to $1.23 billion in upfront and milestone payments combined, not guaranteed remaining revenue.
Denali Therapeutics competes with Prothena in developing treatments intended to slow Parkinson’s and Alzheimer’s disease rather than just treat symptoms. Watch its Alzheimer’s programs targeting amyloid beta and tau, particularly whether treatments delivered into the brain improve plaque clearance and achieve broad brain distribution.
Voyager Therapeutics’ anti-tau antibody for Alzheimer’s disease competes with the antibody program Prothena licensed to Bristol Myers Squibb. Progress in that anti-tau program is the relevant comparison for Prothena, rather than Voyager’s broader gene-therapy platform.
ProMIS Neurosciences overlaps with Prothena in discovering antibodies against misfolded amyloid beta, alpha-synuclein, tau and TDP-43 for neurodegenerative diseases. Watch whether ProMIS’ antibodies selectively target toxic protein forms without interfering with healthy proteins—the distinction its discovery platform is designed to achieve.
AC Immune competes with Prothena in developing immune treatments against abnormal proteins involved in neurodegenerative disease, and both use pharmaceutical partnerships to generate revenue. Its SupraAntigen approach aims to make patients produce their own antibodies against misfolded proteins, offering a different treatment approach to watch.
Alector competes with Prothena in Alzheimer’s and Parkinson’s drug development, with research overlapping in amyloid beta, tau and alpha-synuclein. Watch its brain-penetrant anti-amyloid beta antibody and tau- and alpha-synuclein-targeting research, which remain preclinical or research programs rather than established treatments.
Alnylam’s ATTR amyloidosis medicines compete in the disease market that matters to Prothena’s potential coramitug payments from Novo Nordisk. Watch AMVUTTRA and ONPATTRO, for which Alnylam holds worldwide development and commercialization rights, alongside coramitug’s development and sales milestones.
Biogen already markets Leqembi with Eisai to the Alzheimer’s patients Prothena’s development programs aim to treat. Leqembi’s commercial progress is therefore a concrete comparison for the market Prothena hopes to enter.
Acumen Pharmaceuticals’ sabirnetug competes with Prothena’s amyloid-beta research in seeking to treat Alzheimer’s by targeting harmful amyloid forms. Watch sabirnetug’s safety and efficacy results; Acumen had no approved products or product-sales revenue through 2025, so this is a development comparison, not an established sales benchmark.
Eli Lilly’s approved Alzheimer’s antibody Kisunla sets efficacy, safety and commercial benchmarks for Prothena’s Alzheimer’s programs. Watch Kisunla’s treatment results and sales progress to judge what Prothena’s developing therapies will need to match or improve on.
Alnylam Pharmaceuticals, Inc. earningsALNY
Alnylam’s report will show how its ATTR amyloidosis medicines are selling, a market comparison for Novo Nordisk’s coramitug and potential milestone payments to Prothena.
Look for sales progress in AMVUTTRA and ONPATTRO. Stronger sales would show that existing medicines are building a commercial foothold in the disease market, raising the bar coramitug must clear to generate sales milestones for Prothena; weaker sales would mean those products have not demonstrated the same demand, not that coramitug will succeed.
Bristol-Myers Squibb Co. earningsBMY
If Bristol Myers Squibb reports on its partnered programs, its results can show whether development of Prothena’s PRX019 and BMS-986446 is moving forward.
Look for Bristol Myers Squibb’s updates on trial progress or investment in PRX019 and BMS-986446; a single quarter’s collaboration revenue can fluctuate and does not by itself establish program progress. Continued development would mean ongoing partner support, with potential future milestones or royalties for Prothena; stalled work or reduced investment would make that funding and research support less certain.
Eli Lilly & Co. earningsLLY
Eli Lilly’s report will show uptake of its Alzheimer’s drug Kisunla, a commercial benchmark for Prothena’s investigational Alzheimer’s therapies.
Watch Kisunla’s treatment uptake and sales progress. Rising uptake would show patients and the healthcare market adopting an approved therapy, giving Prothena’s candidates a clearer efficacy, safety, and commercial bar to meet; limited uptake would show weaker traction for Kisunla, not prove Prothena’s drugs will succeed.
Novo-Nordisk A/S earningsNVO
If Novo Nordisk reports continued progress on coramitug, its report will show whether Prothena’s former ATTR program still has a path to potential milestone payments.
Look for Novo Nordisk’s updates on coramitug’s clinical development and any achieved milestones. Continued progress and a met milestone could bring Prothena a payment; delays or a halt would weaken that potential funding source. The transaction’s up-to-$1.23 billion figure included upfront and milestone payments, not guaranteed future revenue.
Prothena Corporation plc earningsThis company
Prothena’s report will show whether spending on its clinical programs and research remains within its funding plan.
Read cash on hand alongside net cash used in operating and investing activities, against Prothena’s outlook for about $50 million to $55 million of full-year 2026 net cash use. Cash use near that range with a balance that still supports its plan would indicate that research and trials remain funded for now; materially higher use or a faster-dwindling balance would point to a greater need for new capital to keep them going.
Voyager Therapeutics, Inc. earningsVYGR
If Voyager Therapeutics updates its Alzheimer’s anti-tau antibody, its report will offer a same-target comparison for Prothena’s BMS-986446, licensed to Bristol Myers Squibb.
Look for clinical progress or data on Voyager’s anti-tau antibody. Progress would show another company advancing a therapy against the same protein target, making the comparison more direct for BMS-986446; a setback would show difficulty for Voyager’s program, not establish the prospects of BMS-986446.
