Medical Director, Clinical Research Neuroscience Prothena Prothena’s success is driven by our people. We are dedicated to attracting individuals who share our vision to improve human health by putting patients first. But it’s not just about what we do at Prothena, it’s how we do it. That’s why we hire creative and courageous individuals who support one another and are not afraid to try new ideas. Our culture reflects our values which are brought to life every day by the following characteristics: SELFLESS - Patients come first and we’re in this together. Our environment is collaborative and we measure success through our collective accomplishments. COURAGEOUS - Transformational innovation leads to novel treatments. “Tried-and-true” won’t produce breakthroughs for patients – a pioneering spirit, willingness to accept certain risks and to try new approaches. Each Prothenian and functional team is expected to bring their heart, experience and trust on our journey. IMAGINATIVE - We value and encourage a creative approach across all aspects of our work. We challenge ourselves and each other to think beyond what is known and approach our work through a lens of continuous improvement. JOYFUL - Humor and heart allow us to tackle the seriousness of our work. Excellence and fun are not at odds – we love what we do and enjoy the journey. --- Position Overview: Reporting to the SVP Head of Clinical Development, you are responsible for implementing the development strategy, through design, execution, monitoring and interpretation of clinical study data in neurodegeneration. In this role you will interact with multiple functions and management within Prothena, and with key external stakeholders. Responsibilities: - Input into the development program strategy across Prothena’s neurodegeneration assets. - Overall responsibility for all aspects of end-to-end clinical trial including design, execution, interpretation and reporting of efficacy and safety across one or more clinical trials - Partner seamlessly with program management, biometrics, regulatory, clinical operations, development sciences, drug safety, and other functions to ensure successful development program delivery - Develop key design elements across clinical trial protocols - Responsible for high impact global decisions: monitoring and interpreting data from ongoing internal and external studies, assessing the medical and scientific implications and making recommendations that impact regional and global development such as “go/no go” decisions, modification of development plans or study designs that may have a significant impact on timelines or product labeling Requirements: Education and Experience: - D / Ph.D., M.D., (Neurology) or Ph.D. required, with clinical or research experience in neuroscience. - Ability to think critically and demonstrate troubleshooting and problem-solving skills. - Demonstrated leadership and team building skills as well as the ability to perform effectively in a multi-disciplinary environment. - Ability to lead directly and by influence, including strong interpersonal, problem solving, conflict resolution and analytical skills in a matrix environment. - Excellent communication skills (oral and written) and organizational skills. - Knowledge of Good Clinical Practices (GCP), FDA and EMEA/CHMP regulations and guidelines, and applicable international regulatory requirements Ability to effectively present ideas and document complex medical/clinical concepts in both written and oral communication - Demonstrated ability as a medical expert in a complex matrix environment - Provides leadership for the conduct of clinical studies. Competencies and Attributes: - Demonstrated leadership to drive results that are needed to achieve company objectives in accord with Prothena’s culture and values – courageous, imaginative, selfless, and joyful Compensation Overview: The anticipated annual salary range for this role at Director job level is $220,000 - $285,000. This is the lowest to highest salary we in good faith believe we would pay for this role at the time of this posting. We may ultimately pay more or less than the posted range, and the range may be modified in the future. The final salary offered to a successful candidate will be dependent on several factors that may include – but are not limited to – the final job level offered, the type and length of experience within the job and industry, relevant education, qualifications, skills, certifications, performance, and business or organizational needs. The hired applicant will be eligible to receive an annual bonus and an equity grant in the form of stock options. Health & Wellness Benefits, 401(k) and PTO Overview: - All Prothena employees (and their families) are covered by medical, dental, and vision insurance, with Prothena paying ~90% of plan premiums. - Prothena pays the full premium for basic life and disability insurance for all employees. - Prothena employees are also eligible to enroll in our Company’s 401(k) plan and are always 100% vested in their account balances. The 401(k) plan provides for a quarterly, non-discretionary, 3% company-paid contribution on eligible earnings, as well as an additional, annual discretionary Company match of up to 2% of eligible earnings. - New Prothena employees are also eligible for 17 days of paid vacation accrued over the course of the first year of employment, paid sick time in accordance with state law, and company-paid holidays – which includes a Company-wide shutdown at the winter holidays. --- More information about Prothena can be found at the Company’s website: www.prothena.com.

Medical Director, Vaccine Development Prothena Prothena’s success is driven by our people. We are dedicated to attracting individuals who share our vision to improve human health by putting patients first. But it’s not just about what we do at Prothena, it’s how we do it. That’s why we hire creative and courageous individuals who support one another and are not afraid to try new ideas. Our culture reflects our values which are brought to life every day by the following characteristics: SELFLESS - Patients come first and we’re in this together. Our environment is collaborative and we measure success through our collective accomplishments. COURAGEOUS - Transformational innovation leads to novel treatments. “Tried-and-true” won’t produce breakthroughs for patients – a pioneering spirit, willingness to accept certain risks and to try new approaches. Each Prothenian and functional team is expected to bring their heart, experience and trust on our journey. IMAGINATIVE - We value and encourage a creative approach across all aspects of our work. We challenge ourselves and each other to think beyond what is known and approach our work through a lens of continuous improvement. JOYFUL - Humor and heart allow us to tackle the seriousness of our work. Excellence and fun are not at odds – we love what we do and enjoy the journey. --- Position Overview: Serves as the lead for Vaccine development strategy and execution of clinical trials. This role will be responsible for designing and executing clinical studies, helping to build the clinical development plan and execute the plan for new vaccine assets. Provides input on local risk management activities and medical oversight of all clinical trial related activities, adhering to GCP/GMP standards & quality. Connect with both internal and external scientific leaders and key stakeholders. Function as key leader on all vaccine-related business development Responsibilities: - Execute, the design and conduct of Prothena’s vaccine assets, responsible for the design and medical monitoring (MD) of clinical studies. Create, develop, and implement a successful strategy for our vaccine portfolio that will bring forth programs to successful approval and registration. - Ensure that clinical programs and clinical studies are designed and monitored optimally. Ensure that clinical documents (Protocols, CSRs, Background Documents) are of the highest quality. Implement clinical R&D policies, SOPs, and related directives - As the primary expert for assigned studies, be the first point of contact internally and externally for questions regarding the study (e.g., eligibility, enrollment; safety and patient management). Monitor study progress to ensure proper study conduct and adherence to the protocol, lead data review, evaluation, and analyses with support from the cross functional team. Take a key role in the authoring of critical study documents (e.g., CSR, IB, protocol synopsis). - Contribute to the analysis and interpretation of data generated internally or externally and present study updates, interim results, and final headline data to senior management as required - Contribute to the cross functional development of clinical development plans (CDPs) that integrate pre-clinical, early clinical findings and data sciences approaches - working to ensure cross-functional alignment on an ongoing basis throughout the phases of clinical development. - Identify and engage with external Key Opinion Leaders to address scientific and medical questions relevant to the program. Requirements: Education and Experience: - MD, MD / Ph.D. or Ph.D. - 4+ years’ industry clinical development experience, preferably in vaccine development including 3+ years’ experience leading cross-functional development teams and management experience - Demonstrated excellence and experience in late-stage clinical development for vaccines, including the design, execution, and reporting of pivotal trials and NDA/BLA/MAA filing experience - Experience in leading medical and scientific aspects of clinical studies on cross functions teams - Ability to critically review, analyze and interpret key aspects of clinical study conduct, including research design, methods, outcome measures, is required. - Phase 1 clinical study experience desirable - Effective communication skills to enable engaging and influencing diverse stake holders - Ability to navigate complexity and make risk-based decisions - Self-starter who can independently lead assigned projects - Demonstrated ability to engage and influence diverse stakeholders from a variety of professional backgrounds Competencies and Attributes: - Demonstrated leadership to drive results that are needed to achieve company objectives in accord with Prothena’s culture and values – courageous, imaginative, selfless, and joyful Compensation Overview: The anticipated annual salary range for this role at Director job level is $220,000 - $285,000. This is the lowest to highest salary we in good faith believe we would pay for this role at the time of this posting. We may ultimately pay more or less than the posted range, and the range may be modified in the future. The final salary offered to a successful candidate will be dependent on several factors that may include – but are not limited to – the final job level offered, the type and length of experience within the job and industry, relevant education, qualifications, skills, certifications, performance, and business or organizational needs. The hired applicant will be eligible to receive an annual bonus and an equity grant in the form of stock options. Health & Wellness Benefits, 401(k) and PTO Overview: - All Prothena employees (and their families) are covered by medical, dental, and vision insurance, with Prothena paying ~90% of plan premiums. - Prothena pays the full premium for basic life and disability insurance for all employees. - Prothena employees are also eligible to enroll in our Company’s 401(k) plan and are always 100% vested in their account balances. The 401(k) plan provides for a quarterly, non-discretionary, 3% company-paid contribution on eligible earnings, as well as an additional, annual discretionary Company match of up to 2% of eligible earnings. - New Prothena employees are also eligible for 17 days of paid vacation accrued over the course of the first year of employment, paid sick time in accordance with state law, and company-paid holidays – which includes a Company-wide shutdown at the winter holidays. --- More information about Prothena can be found at the Company’s website: www.prothena.com.

(Sr.) Medical Science Liaison Prothena Prothena’s success is driven by our people. We are dedicated to attracting individuals who share our vision to improve human health by putting patients first. But it’s not just about what we do at Prothena, it’s how we do it. That’s why we hire creative and courageous individuals who support one another and are not afraid to try new ideas. Our culture reflects our values which are brought to life every day by the following characteristics: SELFLESS - Patients come first and we’re in this together. Our environment is collaborative and we measure success through our collective accomplishments. COURAGEOUS - Transformational innovation leads to novel treatments. “Tried-and-true” won’t produce breakthroughs for patients – a pioneering spirit, willingness to accept certain risks and to try new approaches. Each Prothenian and functional team is expected to bring their heart, experience and trust on our journey. IMAGINATIVE - We value and encourage a creative approach across all aspects of our work. We challenge ourselves and each other to think beyond what is known and approach our work through a lens of continuous improvement. JOYFUL - Humor and heart allow us to tackle the seriousness of our work. Excellence and fun are not at odds – we love what we do and enjoy the journey. --- Position Overview: The (Sr) MSL will be a field-based representative of the medical affairs organization at Prothena based in France. The MSL/Sr. MSL will serve to develop and maintain working relationships with external collaborators and key opinion leaders within disease areas relevant to the company. The (Sr) MSL will be Prothena’s scientific regional expert. Responsibilities: - Develop and maintain relationships with key opinion leaders, other external experts, and principal investigators - Identify key national and regional thought leaders and any other external expert of interest (i.e., patient advocacy groups, digital opinion leaders, new investigators, etc.) - Support clinical trial related activities, related to patient identification, recruitment and investigator education - Help coordinate medical education to external stakeholders (patient advocacy groups, investigators, and other experts within Company’s disease areas) - Participate in the collection and exchange of scientific/technical information important to Prothena development efforts - Ensure all materials and activities reflect the highest standard of quality (i.e., material accurately referenced, correctly interpreted, and communicated appropriately) - Identify, coordinate, evaluate, and monitor investigator-sponsored trials intended to support the clinical and scientific strategy of Prothena products - Help develop and manage timelines and publication plans of investigator-sponsored studies - Represent Prothena at major meetings and conferences relevant to research and development efforts - Maintain clinical and technical expertise in the therapeutic area through review of the scientific literature and attendance at key scientific meetings - Assist in the development of, and participate in, regional advisory boards and medical education programs - Coordinate with Prothena HEOR team on country-specific payer-related needs and education - Collaborate with and support in-office staff, e.g., publications, resource development, training, internal events, etc. - Other duties as assigned Requirements: Education and Experience: - Advanced scientific or clinical degree (Ph.D., PharmD, or MD required) with a minimum of 3-5 years of experience in industry (i.e., biotech, pharmaceutical., medical device company, Contract Research Organization) - 1-3+ years of experience as an MSL required - Neuroscience and/or Oncology preferred (Amyloidosis, Multiple Myeloma) - Must be natively fluent in French and bi-lingual in English Competencies and Attributes: - Demonstrated leadership to drive results that are needed to achieve the company objectives in accord with Prothena’s culture and values - courageous, imaginative, selfless, and joyful - Ability to manage timelines and multiple priorities under time constraints - Experience with clinical research, publication activities, congress, conference, and academy presentations - Aptitude to develop technical expertise in new therapeutic areas - Strong analytical and problem-solving skills - Ability to work effectively in a cross-functional environment - Ability to cultivate and maintain relationships with thought leaders and to establish trust through the consistent demonstration of scientific expertise and satisfactory follow-through to requests from thought-leaders - Strong leadership skills and the ability to compile and disseminate information to others in a cohesive fashion to ensure a clear understanding of project status and direction - Excellent communicator, skilled at diplomacy, and capable of effectively combining science and relationship building - Field-based position – approximately 70% travel required --- More information about Prothena can be found at the Company’s website: www.prothena.com.

(Sr.) Medical Science Liaison - Northeast Prothena Prothena’s success is driven by our people. We are dedicated to attracting individuals who share our vision to improve human health by putting patients first. But it’s not just about what we do at Prothena, it’s how we do it. That’s why we hire creative and courageous individuals who support one another and are not afraid to try new ideas. Our culture reflects our values which are brought to life every day by the following characteristics: SELFLESS - Patients come first and we’re in this together. Our environment is collaborative and we measure success through our collective accomplishments. COURAGEOUS - Transformational innovation leads to novel treatments. “Tried-and-true” won’t produce breakthroughs for patients – a pioneering spirit, willingness to accept certain risks and to try new approaches. Each Prothenian and functional team is expected to bring their heart, experience and trust on our journey. IMAGINATIVE - We value and encourage a creative approach across all aspects of our work. We challenge ourselves and each other to think beyond what is known and approach our work through a lens of continuous improvement. JOYFUL - Humor and heart allow us to tackle the seriousness of our work. Excellence and fun are not at odds – we love what we do and enjoy the journey. --- Position Overview: The (Sr.) MSL will be a field-based representative of the medical affairs organization at Prothena, who will serve to develop and maintain working relationships with external collaborators and key opinion leaders within disease areas relevant to the company. The (Sr.) MSL will be Prothena’s scientific regional expert. Responsibilities: - Develop and maintain relationships with key opinion leaders, other external experts, and principal investigators - Identify key national and regional thought leaders and any other external expert of interest (i.e. patient advocacy groups, digital opinion leaders, new investigators, etc.) - Support clinical trial related activities, related to patient identification, recruitment and investigator education - Help coordinate medical education to external stakeholders (patient advocacy groups, investigators and other experts within Company’s disease areas) - Participate in the collection and exchange of scientific/technical information important to Prothena development efforts - Ensure all materials and activities reflect the highest standard of quality (i.e., material accurately referenced, correctly interpreted and communicated appropriately) - Identify, coordinate, evaluate and monitor investigator-sponsored trials intended to support the clinical and scientific strategy of Prothena products - Help develop and manage timeline publication plans of investigator-sponsored studies - Represent Prothena at major meetings and conferences relevant to research and development efforts - Maintain clinical and technical expertise in the therapeutic area through review of the scientific literature and attendance at key scientific meetings - Assist in the development of, and participate in, regional advisory boards and medical education programs - Collaborate with and support in-office staff, e.g., publications, resource development, training, internal events, etc. - Other duties as assigned Requirements: Education and Experience: - Accredited science doctorate required (eg PharmD, DSc, MD, DNP, PhD) with a minimum of 3-5 years of experience in industry (i.e., biotech/pharmaceutical/medical device company, Contract Research Organization) - Minimum 2+ years’ experience as an MSL required - Rare Disease and hematology experience preferred - Neuroscience experience a plus Competencies and Attributes: - Demonstrated leadership to drive results that are needed to achieve company objectives in accord with Prothena’s culture and values – courageous, imaginative, selfless, and joyful - Ability to manage timelines, multiple priorities under time constraints - Experience with clinical research, publication activities, congress/conference/academy presentations - Aptitude to develop technical expertise in new therapeutic areas - Strong analytical and problem-solving skills - Ability to work effectively in a cross-functional environment - Ability to cultivate and maintain relationships with thought leaders and to establish trust through the consistent demonstration of scientific expertise and satisfactory follow-through to requests from thought-leaders. - Strong leadership skills and the ability to compile and disseminate information to others in a cohesive fashion to assure a clear understanding of project status and direction. - Excellent communicator, skilled at diplomacy, and capable of effectively combining science and relationship building - Field-based position – approximately 70% travel required Compensation Overview: The anticipated annual salary range for this role is $165,000 to $215,000. This is the lowest to highest salary we in good faith believe we would pay for this role at the time of this posting. We may ultimately pay more or less than the posted range, and the range may be modified in the future. The final salary offered to a successful candidate will be dependent on several factors that may include – but are not limited to – the final job level offered, the type and length of experience within the job and industry, relevant education, qualifications, skills, certifications, performance, and business or organizational needs. The hired applicant will be eligible to receive an annual bonus and an equity grant in the form of stock options. Health & Wellness Benefits, 401(k) and PTO Overview: - All Prothena employees (and their families) are covered by medical, dental, and vision insurance, with Prothena paying ~90% of plan premiums. - Prothena pays the full premium for basic life and disability insurance for all employees. - Prothena employees are also eligible to enroll in our Company’s 401(k) plan and are always 100% vested in their account balances. The 401(k) plan provides for a quarterly, non-discretionary, 3% company-paid contribution on eligible earnings, as well as an additional, annual discretionary Company match of up to 2% of eligible earnings. - New Prothena employees are also eligible for 17 days of paid vacation accrued over the course of the first year of employment, paid sick time in accordance with state law, and company-paid holidays – which includes a Company-wide shutdown at the winter holidays. --- More information about Prothena can be found at the Company’s website: www.prothena.com.

(Sr.) Medical Science Liaison - Southeast Prothena Prothena’s success is driven by our people. We are dedicated to attracting individuals who share our vision to improve human health by putting patients first. But it’s not just about what we do at Prothena, it’s how we do it. That’s why we hire creative and courageous individuals who support one another and are not afraid to try new ideas. Our culture reflects our values which are brought to life every day by the following characteristics: SELFLESS - Patients come first and we’re in this together. Our environment is collaborative and we measure success through our collective accomplishments. COURAGEOUS - Transformational innovation leads to novel treatments. “Tried-and-true” won’t produce breakthroughs for patients – a pioneering spirit, willingness to accept certain risks and to try new approaches. Each Prothenian and functional team is expected to bring their heart, experience and trust on our journey. IMAGINATIVE - We value and encourage a creative approach across all aspects of our work. We challenge ourselves and each other to think beyond what is known and approach our work through a lens of continuous improvement. JOYFUL - Humor and heart allow us to tackle the seriousness of our work. Excellence and fun are not at odds – we love what we do and enjoy the journey. --- Position Overview: The (Sr.) MSL will be a field-based representative of the medical affairs organization at Prothena, who will serve to develop and maintain working relationships with external collaborators and key opinion leaders within disease areas relevant to the company. The (Sr.) MSL will be Prothena’s scientific regional expert. Responsibilities: - Develop and maintain relationships with key opinion leaders, other external experts, and principal investigators - Identify key national and regional thought leaders and any other external expert of interest (i.e. patient advocacy groups, digital opinion leaders, new investigators, etc.) - Support clinical trial related activities, related to patient identification, recruitment and investigator education - Help coordinate medical education to external stakeholders (patient advocacy groups, investigators and other experts within Company’s disease areas) - Participate in the collection and exchange of scientific/technical information important to Prothena development efforts - Ensure all materials and activities reflect the highest standard of quality (i.e., material accurately referenced, correctly interpreted and communicated appropriately) - Identify, coordinate, evaluate and monitor investigator-sponsored trials intended to support the clinical and scientific strategy of Prothena products - Help develop and manage timeline publication plans of investigator-sponsored studies - Represent Prothena at major meetings and conferences relevant to research and development efforts - Maintain clinical and technical expertise in the therapeutic area through review of the scientific literature and attendance at key scientific meetings - Assist in the development of, and participate in, regional advisory boards and medical education programs - Collaborate with and support in-office staff, e.g., publications, resource development, training, internal events, etc. - Other duties as assigned Requirements: Education and Experience: - Accredited science doctorate required (eg PharmD, DSc, MD, DNP, PhD) with a minimum of 3-5 years of experience in industry (i.e., biotech/pharmaceutical/medical device company, Contract Research Organization) - Minimum 2+ years’ experience as an MSL required - Rare Disease and hematology experience preferred - Neuroscience experience a plus Competencies and Attributes: - Demonstrated leadership to drive results that are needed to achieve company objectives in accord with Prothena’s culture and values – courageous, imaginative, selfless, and joyful - Ability to manage timelines, multiple priorities under time constraints - Experience with clinical research, publication activities, congress/conference/academy presentations - Aptitude to develop technical expertise in new therapeutic areas - Strong analytical and problem-solving skills - Ability to work effectively in a cross-functional environment - Ability to cultivate and maintain relationships with thought leaders and to establish trust through the consistent demonstration of scientific expertise and satisfactory follow-through to requests from thought-leaders. - Strong leadership skills and the ability to compile and disseminate information to others in a cohesive fashion to assure a clear understanding of project status and direction. - Excellent communicator, skilled at diplomacy, and capable of effectively combining science and relationship building - Field-based position – approximately 70% travel required Compensation Overview: The anticipated annual salary range for this role is $165,000 to $215,000. This is the lowest to highest salary we in good faith believe we would pay for this role at the time of this posting. We may ultimately pay more or less than the posted range, and the range may be modified in the future. The final salary offered to a successful candidate will be dependent on several factors that may include – but are not limited to – the final job level offered, the type and length of experience within the job and industry, relevant education, qualifications, skills, certifications, performance, and business or organizational needs. The hired applicant will be eligible to receive an annual bonus and an equity grant in the form of stock options. Health & Wellness Benefits, 401(k) and PTO Overview: - All Prothena employees (and their families) are covered by medical, dental, and vision insurance, with Prothena paying ~90% of plan premiums. - Prothena pays the full premium for basic life and disability insurance for all employees. - Prothena employees are also eligible to enroll in our Company’s 401(k) plan and are always 100% vested in their account balances. The 401(k) plan provides for a quarterly, non-discretionary, 3% company-paid contribution on eligible earnings, as well as an additional, annual discretionary Company match of up to 2% of eligible earnings. - New Prothena employees are also eligible for 17 days of paid vacation accrued over the course of the first year of employment, paid sick time in accordance with state law, and company-paid holidays – which includes a Company-wide shutdown at the winter holidays. --- More information about Prothena can be found at the Company’s website: www.prothena.com.