Prothena Corporation plc has announced a significant corporate reorganization, which includes a reduction of approximately 63% of its workforce. This move is aimed at substantially reducing operating costs to focus on remaining wholly-owned programs, obligations to partnered programs, and anticipated business development activities. The workforce reduction is expected to be completed by the end of the fourth quarter of 2025. The decision follows the company's May 2025 announcement to discontinue the development of birtamimab. Affected employees, both in the U.S. and internationally, will receive severance payments and benefits as per the company's amended severance plan. Notably, the employment of Carol D. Karp, Chief Regulatory Officer, and David A. Ford, Chief People Officer, will end on August 1, 2025, which will also result in specific compensation arrangements. The company estimates recognizing around $16 to $20 million in severance-related expenses. Further details will be disclosed in upcoming quarterly and annual reports.