• Prothena to receive $80 million from Bristol Myers Squibb for exclusive global license to PRX019, a potential treatment of neurodegenerative diseases with an undisclosed target
• Prothena will initiate a Phase 1 clinical trial for PRX019 in 2024

DUBLIN / May 28, 2024 / Business Wire / Prothena Corporation plc (NASDAQ:PRTA), a late-stage clinical biotechnology company with a robust pipeline of investigational therapeutics built on protein dysregulation expertise, today announced that Bristol Myers Squibb obtained the exclusive global license for PRX019 and will pay Prothena $80 million.

The U.S. Food and Drug Administration (FDA) cleared the investigational new drug (IND) application for PRX019, a potential treatment of neurodegenerative diseases with an undisclosed target, in December 2023. Prothena plans to initiate the Phase 1 clinical trial for PRX019 by year-end 2024.

“Our collaboration agreement with Bristol Myers Squibb has now generated two clinical development programs, supporting both organizations’ commitments to advancing potential therapeutics to help treat neurodegenerative diseases. We are proud of this partnership and are excited that Bristol Myers Squibb has exercised their option for the exclusive global license for PRX019. With the IND in effect and our agreement with Bristol Myers Squibb in place, we’re well-positioned to initiate the Phase 1 clinical trial by year-end 2024,” said Gene Kinney, PhD, President and Chief Executive Officer at Prothena. “At Prothena, we are continuing to leverage strategic partnerships to further advance our broad portfolio of product candidates to treat diseases caused by protein dysregulation. We believe that our portfolio has the potential to help the millions of patients suffering from these devastating diseases.”

“Our expanding research and development efforts in neuroscience demonstrate our commitment to tackling some of the most pressing areas of unmet medical need. Through our partnership with Prothena, we have identified and advanced PRX019 as a potential disease-modifying treatment option for patients suffering from neurodegenerative diseases,” said Richard Hargreaves, Senior Vice President and Head of Bristol Myers Squibb’s Neuroscience Thematic Research Center. “PRX019 adds to our growing neuroscience pipeline, and we look forward to continuing its development as we strive to make a meaningful improvement on patients’ lives.”

As part of the PRX019 global license with Bristol Myers Squibb, Prothena will be eligible to receive additional development, regulatory, and sales milestone payments of up to $617.5 million. Prothena also will be eligible to receive tiered royalties on net sales.

About Prothena

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 AL amyloidosis, ATTR amyloidosis, 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 Twitter @ProthenaCorp.

Forward-Looking Statements

This press release contains forward-looking statements. These statements relate to, among other things, the treatment potential of PRX019; the timing for advancement of our PRX019 program, including initiation of a Phase 1 study by year-end 2024; and amounts we might receive under our collaboration with BMS. 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 May 8, 2024, 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.