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Prothena Announces that Novo Nordisk Will Advance Coramitug (formerly PRX004) into Phase 3 Development for ATTR Amyloidosis with Cardiomyopathy Coramitug is a potential first-in-class amyloid depleter antib

Key Takeaway: Prothena Corporation announced that Novo Nordisk will advance coramitug into Phase 3 development for ATTR amyloidosis with cardiomyopathy. This is a significant milestone, as coramitug is a potential first-in-class amyloid depleter antibody. The advancement is expected to address the unmet needs of patients who suffer from this disease. Prothena stands to earn up to $1.2 billion from the agreement, reflecting strong collaboration opportunities with Novo Nordisk.
Price reaction · baseline $7.03 (2025-08-05 close) · hit after-hours · clean, no other PRTA news in the window
day 0 close · peak
+12.7%
day 1
+9.8%
day 3
+9.1%

Market Sentiment Analysis

POSITIVE FACTORS

  • Coramitug advances into Phase 3, indicating strong development progress.
  • Potential to address significant unmet needs in ATTR amyloidosis patients.
  • Up to $1.2 billion available to Prothena upon achieving milestone payments.

BiopharmaWatch Analysis

From our catalyst data and publicly available data · not financial advice
Best trade, last catalyst
+34%
120-day peak, hindsight
Typical move
8.1%
average across 2 past catalysts
Cash runway
~34 mo
Minimal dilution risk
Lead asset
PRX003
Phase 1 · Psoriasis

Full Press Release Details

Prothena Announces that Novo Nordisk Will Advance Coramitug (formerly PRX004) into Phase 3 Development for ATTR Amyloidosis with Cardiomyopathy
DUBLIN, Ireland, August 6, 2025 Prothena Corporation plc (NASDAQ:PRTA), announced that Novo Nordisk
communicated during their second quarter 2025 earnings call on August 6, 2025 that they expect to advance coramitug, a potential first-in-class amyloid depleter
antibody, into a Phase 3 program for ATTR amyloidosis with cardiomyopathy (ATTR-CM) in 2025. Coramitug was initially developed by Prothena and was acquired by Novo Nordisk in July 2021.
We are excited by Novo Nordisk s decision to advance coramitug into Phase 3 development. There remains a significant unmet need in patients with
ATTR amyloidosis with cardiomyopathy, who are at high risk for early mortality and significant morbidity due to amyloid deposition in vital organs, said Gene Kinney, Ph.D., President and Chief Executive Officer, Prothena.
Under the terms of the agreement, Prothena is eligible to receive up to $1.2 billion dollars upon achievement of clinical development and sales
milestones, including the $100 million earned to date. Prothena is eligible to earn a clinical milestone payment when prespecified enrollment criteria are met in the Phase 3 clinical trial. Novo Nordisk gained full worldwide rights to the
intellectual property and related rights of the ATTR amyloidosis business and pipeline it acquired from Prothena in July 2021.
About Coramitug (formerly PRX004)
Coramitug (formerly PRX004) is an investigational antibody designed to deplete amyloid associated with disease pathology in hereditary and wild type ATTR
amyloidosis, without affecting the native, normal tetrameric form of the protein1-3. Coramitug s proposed mechanism of action is to deplete both the
deposited amyloid to improve organ function and circulating non-native TTR to prevent further organ deposition1-3.
In preclinical studies, coramitug or its murine form demonstrated ability to inhibit amyloid fibril formation, bind soluble aggregate forms of non-native TTR and promote clearance of insoluble amyloid fibrils
through antibody-mediated phagocytosis1,2. In a Phase 1 clinical study, coramitug was well tolerated in patients with ATTRv amyloidosis and demonstrated potential clinical activity on Global
Longitudinal Strain (GLS) and Neuropathy Impairment Score (NIS)3. This differentiated depleter mechanism of action could be developed as a monotherapy approach to ATTR amyloidosis and might also
complement existing therapeutic approaches which either stabilize or reduce production of the native TTR tetramer3.
Prothena Corporation plc is a late-stage
clinical biotechnology company with expertise in protein dysregulation and a pipeline of investigational therapeutics with the potential to change the course of devastating neurodegenerative and rare peripheral amyloid diseases. Fueled by its deep
scientific expertise built over decades of research, Prothena is advancing a pipeline of therapeutic candidates for a number of indications and novel targets for which its ability to integrate scientific insights around neurological dysfunction and
the biology of misfolded proteins can be leveraged. Prothena s pipeline includes both wholly-owned and partnered programs being developed for the potential treatment of diseases including ATTR amyloidosis with cardiomyopathy, Alzheimer s
disease, Parkinson s disease and a number of other neurodegenerative diseases. For more information, please visit the Company s website at www.prothena.com and follow the Company on X (formerly Twitter) @ProthenaCorp.
Forward-Looking Statements
This press release contains
forward-looking statements. These statements relate to, among other things, the treatment potential, design, and proposed mechanism of action coramitug; plans for ongoing and future clinical trials of coramitug; and amounts we might receive under
our agreement with Novo Nordisk. These statements are based on estimates, projections and assumptions that may prove not to be accurate, and actual results could differ materially from those anticipated due to known and unknown risks, uncertainties
and other factors, including but not limited to those described in the Risk Factors sections of our Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission (SEC) on
August 4, 2025, and discussions of potential risks, uncertainties, and other important factors in our subsequent filings with the SEC. We undertake no obligation to update publicly any forward-looking statements contained in this press release
as a result of new information, future events, or changes in our expectations.
1 Preclinical studies of PRX004 (coramitug) data on file
2 Higaki JN et al. Amyloid, 2016
3 Suhr OB et al., Amyloid, 2025

Frequently Asked Questions

What is Coramitug and its proposed use?

Coramitug is an investigational antibody aimed at depleting amyloid in ATTR amyloidosis.

When will Coramitug enter Phase 3 development?

Coramitug is expected to advance into Phase 3 development in 2025.

What milestone payments can Prothena receive?

Prothena could earn up to $1.2 billion in milestone payments from the agreement.

What was Coramitug's previous name?

Coramitug was formerly known as PRX004 before its rebranding.

How was Coramitug tolerated in clinical studies?

In Phase 1 studies, Coramitug was well tolerated by patients with ATTRv amyloidosis.

Last updated: Aug 6, 2025