Meet the Experts

As Chief Medical Officer of Signant Health, Dawie’s deep expertise across multiple therapeutic areas, multinational development leadership, and experience in associated commercial growth supports the expanding impact of the Signant Science and Medical team. With over twenty years' experience combining medicine and business, Dawie oversees Signant's scientific and operational strategies.

Dr. Daniel has over 25 years of experience overseeing rater training and data quality management programs in various settings. He has supervised countless clinical trials for schizophrenia and bipolar disorder. In addition to his work with Signant, David serves as Clinical Professor of Psychiatry at George Washington University.

Dr. Sachs is the Therapeutic Area Leader in bipolar disease and mood disorders at Signant. He lends his extensive experience in rater training and the methodologies of mood and anxiety disorder research to support studies. 

Dr. Busner has over 35 years of experience as an academic psychiatric researcher and psychopharmacology principal investigator, and founded and directed two university psychiatric clinical trials units. Dr. Busner served continuously on University Institutional Review Boards for 20 years. At Signant she has scientific and clinical responsibility for studies in mood, anxiety, pediatrics, and rare/orphan diseases.

Dr. Fredane serves as the Therapeutic Area Leader for neurology, overseeing Signant’s eCOA, rater training, and quality assurance work. He has experience as a practicing neurologist, clinical assistant professor, and in the drug development for over 15 years.

Dr. Miller is a geriatric psychiatrist by training. He has over 25 years of experience in patient care, clinical research, teaching, and even served as a principal investigator for dementia studies. David currently serves as the Chair of the Alzheimer’s Association Research Roundtable.

Dr. Everhart is an innovator, educator, and leader in the pharmaceutical and biotechnology industries with over 25 years of experience in the practice of medicine and over 14 years of experience in clinical research.  Board-certified in Internal Medicine and a Fellow of the American College of Physicians, he is one of Signant Health’s experts in decentralized trials, rater training, blinded data analytics, and placebo response mitigation.

Dr. Elias Ketiar serves as the Clinical Vice President, Science & Medicine, at Signant Health. Dr. Ketiar draws on his wealth of more than 20 years of academic and clinical experience to advise on clinical trial design, execution, and governance.

Greta is a Senior Clinical Scientist, providing scientific expertise and guidance relating to the implementation of electronic clinical outcome assessments (eCOAs), with a special focus on eDiary design and accessibility of eCOA best practices. She completed her PhD in Physiological Sciences at Stellenbosch University, which focused on the bacterial and inflammatory involvement in colorectal carcinogenesis, and has 3+ years’ experience in the clinical research industry.

Dr. Petra Reksoprodjo, MD, is Director of Clinical Science, Data Analytics at Signant, where she leverages over 20 years of expertise in the clinical trials industry, with a particular focus on CNS and dermatology clinical trials. Holding a medical degree from Charles University in Prague, she oversees clinical project delivery and maintains quality assurance across a large portfolio. Petra collaborates closely with Signant’s data analytics team to prepare and deliver clinical data analyses for clients and is a frequent presenter at international investigator meetings. Based in Signant’s Prague office, she also contributes to internal training programs and fosters clinical excellence through mentoring and leadership.

Lauren has comprehensive cross-functional experience within the life sciences and information technology sectors. At Signant, she combines this experience to provide scientific consultation and support to clients on the implementation of eCOA to optimize patient care and outcomes in clinical trials. She has supported eCOA projects across multiple therapeutic areas, including dermatology and neurology, with a current focus on respiratory diseases.

Dr. Figueroa is a Clinical Scientist with the eCOA Science Team, where she leverages her extensive expertise in electronic Clinical Outcome Assessments (eCOA) across diverse therapeutic areas, including oncology, dermatology, and infectious diseases. With over a decade of translational research experience, Dr. Figueroa is dedicated to advancing the field of clinical trials and improving patient outcomes through innovative methodologies and strategic insights.

Juliet Brown, Clinical Director, Science & Medicine, is one of Signant Health’s Clinical Thought Leaders. Her specialties are evaluation and treatment in MDD, Bipolar Disorder, Anxiety Disorders, Psychotic Spectrum Disorders, and Substance Use Disorders, as well as Cognitive Behavioral Psychotherapy.

Marcela Roy, MA, ACC serves as Executive Director of Clinical Science & Medicine, bringing over 20 years of clinical and research expertise to her role. She provides strategic leadership across CNS and non-CNS therapeutic areas, with particular expertise in psychedelic research and central ratings data quality monitoring methodologies.

Sayaka Machizawa, Psy.D. is a neuropsychologist with 18 years of experience in neurodegenerative diseases. She serves as the Associate Director-APAC Lead supporting large-scale global clinical trials on various indications including but not limited to Alzheimer’s disease, Parkinson’s disease, schizophrenia, major depressive disorder, and rare diseases. She is fluent in Japanese and English and has delivered rater training at numerous Investigator Meetings.

Dr. Berman brings two decades of neuropsychology experience to Signant Health, including clinical science working differential diagnostic services and geriatrics. Specializing in psychiatric and neurological disorders like schizophrenia, bipolar disorder, and behavioral /neuropsychiatric symptoms in dementia, Rachel supports sponsors and CROs running trials in these and other CNS indications.

Margot is a Masters RN with extensive clinical background that include many areas in the medical field and child and adult Psychiatry. She spent years in the acute hospital setting working in a diverse group of settings. 

Christopher Murphy, PhD is Associate Director and Clinical Science Principal at Signant Health, with over 25 years of experience in academic and industry-supported CNS research and trials. Prior to Signant, he was on faculty of Weill Cornell Medical College and served as an Attending Psychologist at New York Presbyterian Hospital.

Maria Visser, PhD is a Clinical Scientist at Signant Health, specializing in Phase 3-4 dermatology clinical trials, with a focus on atopic dermatitis, pruritis, and vitiligo. With a Ph.D. in Physiological Sciences and a background in clinical research, Maria leverages their analytical and critical thinking skills to solve complex problems.

Marta Pereira studied at the University of Porto where she also graduated in Neuropsychology with a MSc degree. Later, she received her PhD degree in Neurosciences from the University of Sao Paulo. Prior to joining SH, Dr. Marta Pereira was part of the Nuffield Department of Clinical Neurosciences at the University of Oxford, where she worked with digital health tools / wearables in Parkinsonian syndromes.

Erica Appleman, Ph.D. is a licensed psychologist and Clinical Scientist at Signant Health. She completed her Ph.D. in Clinical Psychology at Boston University and a postdoctoral fellowship in Clinical Neuropsychology. Her clinical expertise includes neuropsychological assessment of adults presenting with a wide variety of neurological, neurodevelopmental, and neuropsychiatric conditions.