BIO
Aaron Sosa, M.D.
Vice President, Technical, Regulatory Consulting
Explore end-to-end solutions throughout development — from portfolio optimization and regulatory strategy, to Phase I-IV clinical trials, market access planning, and more.
Our team optimizes your portfolio utilizing integrated expert clinical, regulatory, and market access strategies, enabling earlier and more informed risk-reward decisions.
Our multi-disciplinary early phase approach accelerates the path to proof of concept by integrating diverse expertise to optimize study design, generate robust clinical evidence, and reduce gaps between development phases.
We deliver whole-study solutions with integrated strategies that ensure safety, data integrity, and regulatory compliance. We design patient-informed protocols that remove participation barriers, accelerate enrollment, and increase the likelihood of successful drug launches.
Our team of former regulators and HTA professionals provide tailored regulatory, compliance, and market access strategies across specialized therapeutic areas, creating customized pathways to maximize global market reach throughout your product's lifecycle.
We enhance your product's value story through post-approval studies and holistic lifecycle management services that satisfy regulators and payers while building stakeholder trust and maximizing your drug's market impact throughout its entire lifecycle.
ParexelAI leverages our full suite of AI capabilities to deliver with greater speed, quality, and efficiency.

ParexelAI
ParexelAI is a proprietary AI-enabled clinical development suite that accelerates patient outcomes by combining Parexel's operational expertise with cutting-edge AI technology.
Utilize our expertise across therapeutic areas, combining innovative trial designs, leading clinical and regulatory expertise, global reach, and a passion for changing patient lives.
Our team delivers high-quality clinical trials through forward-thinking medical expertise across multiple indications by combining strategic insight with operational excellence to support programs of all sizes.
Our infectious disease and vaccines cro services help treat and prevent life-threatening illnesses. Learn how our team of experts can aid in any complex trial.
Discover our inflammation and immunology CRO services. We bring agile support and a unique MOA-driven model to inflammation and immunology.
Parexel is a leading Oncology CRO with more than 80 ex-agency regulators and nearly 2,500 sites globally. Learn more about our oncology indications.
As a leading neuroscience CRO, we leverage global site relationships, specialized resources, and indication-specific expertise to accelerate breakthroughs in neurological and psychiatric treatments for patients worldwide.
As a top hematology CRO, our integrated teams use advanced analytics and real-world evidence to optimize hematology trial outcomes, ensuring faster, more effective drug development.
Rethinking strategies for rescue treatment in wet AMD and retinal vascular disease clinical trials
Learn more
Our experts help you stay at the forefront of the industry — and ahead of change.

Clinical Trialblazers
Step into the world of biotech leaders and hear the untold stories behind their journeys to bring breakthrough innovations to life.
Honest conversations with the experts shaping what's next
Thinking about joining a clinical trial? Learn the drug development process, what it’s like to participate, how to find a trial, and answers to frequently asked questions.
Clinical trials provide patients with access to innovative investigational treatments that advance medical research. Participation requires careful consideration that weighs both the benefits and risks.

Patient Stories
Clinical study participation represents a deeply personal decision with potentially far-reaching impact, as evidenced by these inspiring individual stories that highlight both the life-changing potential for participants and the broader advancement of healthcare for all.
We are one of the largest CROs in the world, speeding life-changing medicine to market by engaging patients With Heart™. Learn about who we are, what we do, and what we believe.
With decades of biopharmaceutical leadership experience and a deep dedication to patients, our executive team drives us forward in delivering better trials, faster.
Find key information on our policies, strategies, pay data, and more.
Explore end-to-end solutions throughout development — from portfolio optimization and regulatory strategy, to Phase I-IV clinical trials, market access planning, and more.
Our team optimizes your portfolio utilizing integrated expert clinical, regulatory, and market access strategies, enabling earlier and more informed risk-reward decisions.
Our multi-disciplinary early phase approach accelerates the path to proof of concept by integrating diverse expertise to optimize study design, generate robust clinical evidence, and reduce gaps between development phases.
We deliver whole-study solutions with integrated strategies that ensure safety, data integrity, and regulatory compliance. We design patient-informed protocols that remove participation barriers, accelerate enrollment, and increase the likelihood of successful drug launches.
Our team of former regulators and HTA professionals provide tailored regulatory, compliance, and market access strategies across specialized therapeutic areas, creating customized pathways to maximize global market reach throughout your product's lifecycle.
We enhance your product's value story through post-approval studies and holistic lifecycle management services that satisfy regulators and payers while building stakeholder trust and maximizing your drug's market impact throughout its entire lifecycle.
ParexelAI leverages our full suite of AI capabilities to deliver with greater speed, quality, and efficiency.

ParexelAI
ParexelAI is a proprietary AI-enabled clinical development suite that accelerates patient outcomes by combining Parexel's operational expertise with cutting-edge AI technology.
Utilize our expertise across therapeutic areas, combining innovative trial designs, leading clinical and regulatory expertise, global reach, and a passion for changing patient lives.
Our team delivers high-quality clinical trials through forward-thinking medical expertise across multiple indications by combining strategic insight with operational excellence to support programs of all sizes.
Our infectious disease and vaccines cro services help treat and prevent life-threatening illnesses. Learn how our team of experts can aid in any complex trial.
Discover our inflammation and immunology CRO services. We bring agile support and a unique MOA-driven model to inflammation and immunology.
Parexel is a leading Oncology CRO with more than 80 ex-agency regulators and nearly 2,500 sites globally. Learn more about our oncology indications.
As a leading neuroscience CRO, we leverage global site relationships, specialized resources, and indication-specific expertise to accelerate breakthroughs in neurological and psychiatric treatments for patients worldwide.
As a top hematology CRO, our integrated teams use advanced analytics and real-world evidence to optimize hematology trial outcomes, ensuring faster, more effective drug development.
Rethinking strategies for rescue treatment in wet AMD and retinal vascular disease clinical trials
Learn more
Our experts help you stay at the forefront of the industry — and ahead of change.

Clinical Trialblazers
Step into the world of biotech leaders and hear the untold stories behind their journeys to bring breakthrough innovations to life.
Honest conversations with the experts shaping what's next
Thinking about joining a clinical trial? Learn the drug development process, what it’s like to participate, how to find a trial, and answers to frequently asked questions.
Clinical trials provide patients with access to innovative investigational treatments that advance medical research. Participation requires careful consideration that weighs both the benefits and risks.

Patient Stories
Clinical study participation represents a deeply personal decision with potentially far-reaching impact, as evidenced by these inspiring individual stories that highlight both the life-changing potential for participants and the broader advancement of healthcare for all.
We are one of the largest CROs in the world, speeding life-changing medicine to market by engaging patients With Heart™. Learn about who we are, what we do, and what we believe.
With decades of biopharmaceutical leadership experience and a deep dedication to patients, our executive team drives us forward in delivering better trials, faster.
Find key information on our policies, strategies, pay data, and more.
Dr. Aaron Sosa is a highly skilled Medical Oncologist and experienced EU regulator, with a unique combination of clinical expertise and in-depth knowledge of medicinal product regulation. Over the course of a multifaceted career, he has bridged the gap between patient care and regulatory science, driving the approval and clinical development of cancer therapies across Europe. His expertise empowers him to optimize clinical development strategies, ensure regulatory compliance, and facilitate market access for innovative medicinal products.
Work Experience
Dr. Sosa's career began as an Oncologist specializing in thoracic malignancies, providing him with deep insights into cancer care and research. He transitioned to the regulatory field, working at the Danish Medicines Agency and representing Denmark at EMA's Scientific Advice Working Party, where he provided expert guidance on clinical development of new cancer therapies. As Denmark's alternate CHMP member, he oversaw the agency's Oncology and Hematology product portfolio and participated in regulatory decisions at EMA. Dr. Sosa's unique blend of clinical and regulatory expertise has positioned him as a key contributor to EU policies and regulatory guidelines, shaping the future of cancer treatment.
Education
Dr. Sosa's medical education and training span multiple prestigious institutions across Guatemala, Spain, and the United States, including specialties in Medical Oncology and Internal Medicine. His career progression includes roles as Chief Resident at Hospital Clinic de Barcelona and Hospital Roosevelt, as well as clinical experience at institutions like the University of Chicago Medical Center and Children's Hospital Boston.
Blog
Data without borders: Assessing China-only evidence for EMA approval – insights from ex-EMA and seasoned subject matter experts
Blog
FDA novel oncology drug approvals in 2025: Trends and strategic insights for developers
Blog
EMA’s evolving stance on external controls: Key takeaways and preparation strategies for sponsors
Blog
Tightening rules, global trials: Sponsors’ concerns at ESMO 2025
Video
Oncology experts roundtable: Practical insights on FDA draft guidance discussing OS data in cancer trials
Blog
Accelerated approval: Navigating FDA’s recent guidance and confirmatory trial considerations
Blog
Data without borders: Assessing China-only evidence for EMA approval – insights from ex-EMA and seasoned subject matter experts
Blog
FDA novel oncology drug approvals in 2025: Trends and strategic insights for developers
Blog
EMA’s evolving stance on external controls: Key takeaways and preparation strategies for sponsors
Blog
Tightening rules, global trials: Sponsors’ concerns at ESMO 2025
Video
Oncology experts roundtable: Practical insights on FDA draft guidance discussing OS data in cancer trials
Blog
Accelerated approval: Navigating FDA’s recent guidance and confirmatory trial considerations
Learn More