Meet our Leaders

Our Leadership Team includes physicians, professionals, students, patient volunteers, and physician-entrepreneurs with a tremendous amount of disease-specific knowledge, organizational management skills, and start-up experience.

David Fajgenbaum, MD, MBA, MSc, FCPP
Co-Founder & President

Dr. David Fajgenbaum, MD, MBA, MSc, FCPP, is the co-founder and President of the Castleman Disease Collaborative Network (CDCN), Founding Director of the Center for Cytokine Storm Treatment & Laboratory (CSTL), Associate Director of Patient Impact for the Penn Orphan Disease Center, and Associate Professor of Medicine in Translational Medicine & Human Genetics at the University of Pennsylvania. Dr. Fajgenbaum is also the national bestselling author of Chasing My Cure: A Doctor’s Race to Turn Hope Into Action and a patient battling idiopathic multicentric Castleman disease (iMCD). He became ill during his third year of medical school in 2010, had his last rites read, and had four deadly iMCD relapses. In 2012, Dr. Fajgenbaum co-founded the CDCN, through which he has spearheaded the “Collaborative Network Approach.” (more)

Katherine Haeusel, MA, MS
Executive Director

Katherine was appointed Executive Director for the Castleman Disease Collaborative Network in February 2025. In this role, she enjoys applying her passion and knowledge to strategic leadership, partnership building, and the oversight of all operational, programmatic, and fundraising efforts to advance innovative solutions for Castleman disease.

Katherine lost her father to Castleman disease in 1997 but found the CDCN in 2019 through David Fajgenbaum’s book, Chasing My Cure. An avid CDCN supporter, has also been a member of the CDCN Board of Directors since 2022. (more)

Frits van Rhee MD, PhD
Co-Founder & Co-Chair of Scientific Advisory Board

Frits van Rhee, MD, PhD, co-founded the Castleman Disease Collaborative Network. He is a Professor of Medicine and Director of Developmental and Translational Medicine at the UAMS Myeloma Institute. He earned his medical degree from Erasmus University, Rotterdam, Netherlands and his PhD at the Imperial College of Science, Medicine and Technology, University of London. Dr. van Rhee trained in Internal Medicine and Hematology in the UK, and in Bone Marrow Transplantation at John Radcliffe University Hospital in Oxford and the Royal Postgraduate Medical School in London. He holds the Charles and Clydene Scharlau Chair for Hematological Malignancies. (more)

Madison Ahearn, MHA
Director of Programming and Operations

Madison Ahearn is the Director of Programming and Operations at the CDCN. Madison serves the Castleman disease community of patients, loved ones, physicians, and researchers. Prior to this role, Madison was with Penn Medicine Academy, where she developed strategic planning, change management and leadership skills. Madison also worked as a Research Assistant at Temple University’s Pathology and Laboratory Medicine lab, where she studied the impact of traumatic brain injuries on the blood brain barrier and how multiple repeated TBIs increased the likelihood of developing substance abuse disorders. She is passionate about medical science and engaging with the patient community to help guide them through their battle with Castleman disease.

Madison has a BS in Neuroscience and a Master of Health Administration from Temple University. She also received a Certificate in Healthcare Innovation Management.

Scott Ashley, PhD
Scientific Director

Scott Ashley, PhD, became the Scientific Director of the Castleman Disease Collaborative Network (CDCN) in 2025, bringing scientific and leadership expertise to drive advancements in research and treatment. In this role, he leverages his expertise in science and leadership to accelerate discovery and therapeutic development through close collaboration with partners and the broader Castleman disease community.

Since 2017, Scott has focused on therapeutic development for rare diseases, beginning with his postdoctoral fellowship. Most recently, he led preclinical development for an idiopathic pulmonary disease at Spark Therapeutics while providing scientific guidance and collaboration across multiple research programs.

Scott earned his PhD in molecular biology from the University of Pennsylvania in 2017, where his research at the Gene Therapy Program (GTP) explored how germline mutations influence antigen presentation and the adaptive immune response to gene therapy. He continued his work at GTP, focusing on preclinical development of multiple rare monogenic disorders.

In 2021, Scott completed a postdoctoral fellowship at the Children’s Hospital of Philadelphia in John Wolfe’s lab, where he conducted protein engineering studies to advance therapeutic development for alpha mannosidosis.

Emily Melberger, MA
Program Coordinator

Emily Melberger  is the Program Coordinator at the CDCN. She has over six years of experience in education, community-building, and supporting diverse populations. Throughout her career as an educator in Newark, NJ, and Milwaukee, WI, Emily has focused on creating inclusive, student-centered environments that engage students, families, and communities. In addition to her work in education, Emily has coordinated programs for refugee populations in Camden, NJ, and Heidelberg, Germany, which enhanced her ability to foster meaningful community connections and provide personalized support to individuals.

Emily is passionate about leveraging her expertise in communication, program development, and empathy to make a lasting impact on the lives of those affected by Castleman disease. Emily holds a Master of Arts in Education from Alverno College and a Bachelor of Arts in International Studies from The College of New Jersey.

Amber Vas, BA
Program Manager

Amber Vas is the Program Manager for the Center for Cytokine Storm Treatment & Laboratory (CSTL) at the Perelman School of Medicine. She oversees the day-to-day operations and the administrative functions of the CSTL’s various projects and events. Prior to her work with the CSTL, Amber was the Executive Coordinator for the Department of Biostatistics, Epidemiology, and Informatics and the Center for Health Behavior Research. Amber earned her BA in Psychology from the University of Richmond.

Martin Lukac, MD, PhD, MPH
European Communications and ACCELERATE Registry Lead

Martin Lukac is board certified in Clinical Pharmacology with more than 20 years of experience in clinical development. Martin is passionate about clinical research, which was the reason to study this specialization at the University of London where he received a Postgraduate Diploma in Clinical Trials. He is currently based in Prague where he works as a Medical Director at PAREXEL. In cooperation with Dr. Fajgenbaum on the ACCELERATE global patient registry, Martin decided to join the CDCN as a volunteer to help spread awareness about Castleman Disease in Europe.

Sheila Pierson, MS
Senior Research Advisor

Sheila Pierson, MS is a Senior Research Advisor for the Castleman Disease Collaborative Network (CDCN). Since 2016, she has been a pivotal figure in the Castleman disease field and has published extensively on disease subgroups and treatment patterns that inform clinical practice. Previously, Sheila served as the Director of Clinical Research for the Center for Cytokine Storm Treatment & Laboratory (CSTL) at the University of Pennsylvania, where she made significant contributions to Castleman research through her oversight of the ACCELERATE Registry and her biostatistical analyses of large-scale proteomics datasets. She holds an MS in nutrition from Columbia University and an MS in biostatistics from the University ofPennsylvania, and she is currently pursuing her medical degree at the Lewis Katz School of Medicine at Temple University. Sheila’s multifaceted expertise and commitment to advancing Castleman disease research are shaping the future of treatment options for this vulnerable community.

Colin Smith, PhD
Senior Collaborative Research Advisor

Colin received his BA from Macalester College and his PhD from the University of Pennsylvania, both in Neuroscience. During the day, Colin is a Strategic Science and Academic Innovation Manager at EMD Serono, a global specialty pharmaceutical company with a focus on oncology, immuno-oncology, and immunology. He previously served as a Licensing Manager at Partners Healthcare Innovation. Prior to joining Partners, he was a Senior Associate in the Business Development office at The Wistar Institute where he was introduced to the work of the CDCN. He’s passionate about basic research and translating exciting research findings into the clinic.

Caitlin Fajgenbaum
Co-Chair Quest for a Cure

Caitlin Fajgenbaum is a Strategic Communications Advisor for the CDCN. Caitlin is passionate about fighting back against Castleman disease and wants to help others to fight back too. Caitlin’s nonprofit work dates back to when she organized the inaugural National Conference on College Student Grief and started a chapter of Students of AMF, a grief support network, while she was a sophomore at Meredith College. Under her leadership, the organization participated in community service projects throughout the Raleigh-area and developed a deep, meaningful support group. Caitlin graduated from Meredith College, where she received a BS in Fashion Merchandising & Design.

Mileva Repasky, MS
Co-Chair Quest for a Cure

Mileva Repasky is the  mother to one of our youngest Castleman Disease patients, Katie. She is passionate about connecting patients and loved ones, fundraising, patient advocacy, and raising awareness. She will continue to advance the CDCN’s mission by collaborating with the patient and loved one community, physicians, researchers, and our partners, to advance our life saving mission. She is particularly interested in finding new and innovative ways to raise awareness of this disease.

Mileva graduated with a BS in Psychology and completed her Masters in Clinical Psychology in 2016. Mileva began as a volunteer with the CDCN in 2014.