David Biggerstaff, MHA
President
David Biggerstaff began his career at Riley Children’s Health on Monday, Feb. 3, 2025. He brings a wealth of experience and a strong record of accomplishments in healthcare leadership to the IU Health team. He is a seasoned executive with extensive experience in both adult and pediatric academic medical centers, as well as community-based programs and facilities. His leadership emphasizes fostering a culture of excellence, enhancing research and clinical programs and implementing performance management systems to improve quality, service, employee engagement and philanthropy outcomes.
Since 2022, he served as chief operating officer at Intermountain Health’s Saint Joseph Hospital in Denver, where he oversaw all service lines and clinical operations, including real estate and facility planning, physician contracting and strategic relationships. Before that, he was enterprise executive vice president and chief operating officer at Children’s Colorado for six years where his responsibilities included all aspects of nursing, clinical support and operations across four hospital campuses, including patient care services, ambulatory operations, facilities planning, professional and support services as well as performance improvement and accreditation.
Biggerstaff also served as president and chief operating officer at Children’s Medical Center of Dallas for nine years in a number of leadership roles. He was awarded “Top C-Suite Executive” by the Denver Business Journal for leadership accomplishments throughout the COVID-19 pandemic.
He holds a master’s degree in healthcare administration from Trinity University in San Antonio, Texas, and completed an administrative residency at INTEGRIS Health in Oklahoma City. He has a bachelor’s degree in business administration with an emphasis in accounting from Oklahoma State University.
Mara Nitu, MD
Chief Medical Officer
Mara Nitu, chief medical officer, oversees clinical hospital operations and physician and APPs integration and creates an exceptional practice environment to ensure optimal patient outcomes.
Nitu joined the Department of Pediatrics at Riley Children’s Health in 2001. She previously served as Pediatric Lifeline’s medical director, PICU’s medical director and the Division of Pediatric Care’s division chief. She was vice chair of Clinical Affairs for the Department of Pediatrics and ACMO at Riley Children’s, engaging in clinical operations, statewide expansion, mentorship and professional development. Since 2018, she has led clinical effectiveness work and engaged Riley’s medical director team to eliminate waste and increase value.
A Carol Davila University of Medicine and Pharmacy graduate, she completed her residency at State University of New York at Stony Brook and fellowship at the University of Cincinnati. She is currently a professor of Clinical Pediatrics at Indiana University School of Medicine.
Megan Isley, DNP, MBA, RN, NEA-BC, NPD-BC
Vice President & Chief Nursing Officer
Dr. Megan Isley, vice president and chief nursing officer for Riley Children’s Health, oversees the nursing staff and respiratory therapists. In addition, she coordinates and manages nursing operations to support clinical care objectives and outcomes. Fostering a relationship-driven, values-based culture with an engaged workforce, she provides world-class care for patients.
Isley has more than a decade of clinical pediatrics and management experience. Accomplishments include opening the Riley Maternity Tower, expanding the behavioral health inpatient services and accrediting the new graduate nursing transition to practice program. Before Riley Children’s, she was assistant vice president of patient services at Cincinnati Children’s Hospital Medical Center. She also served in leadership roles at Nationwide Children’s Hospital and Duke University Medical Center.
Isley has been appointed a member of the Board of Commissioners for the National League for Nursing (NLN) Commission for Nursing Education Accreditation (CNEA).
She received her doctor of nursing practice and master’s degree in nursing from Duke University and her master’s in business administration and bachelor’s degree in nursing from West Liberty University.
Frank Runion
Chief Financial Officer
As chief financial officer for Riley Children’s Health, Frank Runion directs the financial operations and strategic financial planning for Riley Children’s and its pediatric service line. He oversees the budget, financial analysis and planning, capital management and workforce contract management.
Runion has been with Indiana University Health for over 20 years. Prior, he worked at St. Vincent Health and Wishard Health Services (now Eskenazi Health). He has over 30 years of healthcare and financial experience.
With a bachelor’s degree in accounting from Anderson University, he is a certified public accountant and a member of the Children’s Hospital Association, CFO Forum. Runion also serves on the Board of the Indiana Burn Camp and is the treasurer of his church.
Tyler Leishman, MHA
Interim Chief Operating Officer
Tyler Leishman joined Riley Children’s Health in February, 2022 as vice president and chief strategy officer. He transitioned to the role of interim chief operating officer in 2023.
Recently, Leishman was the vice president of Strategic Provider Integration and executive director of the Pediatric Care Network at Children’s Hospital Colorado. Previously, he held leadership positions at the University of Colorado School of Medicine and the University of Minnesota Medical Center. Leishman has over ten years of leadership experience in academic medical centers in strategy and planning, business development, physician alignment, clinical integration, value-based care and reimbursement reform.
He earned his master’s degree in healthcare administration from the University of Minnesota and his bachelor’s degree in health management services from Weber State University.
Leishman is passionate about defining and driving value in children’s health. Having a child with complex medical needs, he is acutely aware of the importance of making pediatric care accessible to every child in Indiana.
D. Wade Clapp, MD
Department of Pediatrics Chairman
D. Wade Clapp, MD, was named chairman of the Department of Pediatrics at Indiana University School of Medicine in 2009. He leads 420 faculty members, over 250 residents, and subspecialty fellows in five categorical and integrated residency programs and 19 fellowship programs.
Dr. Clapp is a neonatologist and scientist doing clinical work at Riley Children’s Health’s neonatal intensive care units, focusing on research in childhood cancer. He is the Richard L. Schreiner Distinguished Professor of Pediatrics and a professor of microbiology and immunology and biochemistry and molecular biology at Indiana University, joining the faculty in 1991. Also, a researcher at the Herman B Wells Center for Pediatric Research, his internationally acclaimed work has had numerous breakthrough clinical trials.
Earning a bachelor’s degree from Hanover College and a medical degree from Indiana University School of Medicine in 1982, he completed his residency at Riley Hospital for Children and fellowships at Case Western Reserve University. He was previously the founding director of the Medical Scientist Training program and the director of Eskenazi Health NICU. Dr. Clapp is a member of the National Academy of Medicine.
Mark Cain, MD, FAAP
Surgeon-in-Chief
Dr. Cain returns to Riley Children’s as Surgeon-in-Chief. He is also a Professor of Urology at the Indiana University School of Medicine.
Dr. Cain graduated from medical school at Oregon Health Sciences University in 1987. He completed his residency in Urology at Albany Medical Center, followed by a two-year fellowship in Pediatric Urology at the Mayo Clinic.
He was a faculty member at Georgetown University for two years, then spent the next 23 years at Riley Hospital for Children and the Indiana University Department of Urology. He served as the Robert Garrett Professor of Urology and Chief of Pediatric Urology until moving to Seattle where he was Associate Surgeon in Chief, Director of Regional Surgical Services, and Director of Surgical Ambulatory Care for Seattle Children’s Hospital from 2019-2023.
His primary clinical interests are surgical reconstruction of congenital anomalies of the genitalia, complex lower urinary tract reconstruction, management of prenatal urologic abnormalities, and surgical management of urinary tract obstruction. Dr. Cain has published nearly 300 articles and book chapters and lectured internationally regarding various topics in pediatric urology, but with a focus on both long-term and patient-centered outcomes of urologic reconstruction.
Dr. Cain is a trustee on the American Board of Urology and serves as the liaison for the examination committee and chair for pediatric urology specialization, and is president elect for the ABU in 2025. He is a past chair for the Section on Urology of the American Academy of Pediatrics, and the Society for Fetal Urology.
Dr. Cain is a native of the Pacific Northwest, growing up in Willamette Valley’s Sherwood, Oregon. He is married to Charla Cain, has three married adult children and two grandchildren.