The senior leadership team at Simulations Plus, Inc. includes:

Shawn O’Connor – Mr. Shawn O’Connor is Chief Executive Officer at Simulations Plus, Inc. He recently served as president, chief executive officer and a director of Entelos, a provider of unique quantitative systems pharmacology software and services to the pharmaceutical drug development market. Prior to Entelos, O’Connor served as chairman, president, and chief executive officer of Pharsight Corporation, a developer and marketer of software products and services that help pharmaceutical and biotechnology companies improve their decision-making in drug development and commercialization.



John R. Kneisel – Mr. John Kneisel is Chief Financial Officer of Simulations Plus, Inc. and joined the Company in November 2013. He worked as the Western Regional Controller of Group 1 Automotive Inc. from August 2004 through October 2009. At that time he started a consulting business providing outsourced financial management services (CFO and Controller) to small to medium sized companies. In October 2010 he became the CFO of Dreamhammer, Inc. where he worked until August 2012. His career spans 30 plus years of financial management and accounting related services.

Simulations Plus


John A. DiBella, M.S. – Mr. John A. DiBella is President, Lancaster Division of Simulations Plus, Inc.. He joined the company in 2003, spending time working on the development of GastroPlus and DDDPlus software and consulting projects. Now, he leads the Simulations Plus, Lancaster division while continuing to travel the world hosting training seminars.


Sandra Suarez-Sharp

Sandra Suarez-Sharp, Ph.D – Dr. Sandra Suarez-Sharp is Vice President, Regulatory Affairs at Simulations Plus, Inc.. She received her Ph.D. from the University of Florida and spent two years as a postdoctoral fellow at the University of North Carolina (Chapel Hill) before joining the U.S. FDA in 1999. At that time she was actively involved in the development of several internal procedures for FDA reviewers and guidance documents for industry, and she is recognized as one of the preeminent thought leaders for Physiologically Based Biopharmaceutics Modeling (PBBM). She co-chaired various workshops including, Current State and Future Expectations of Translational Modeling Strategies to Support Drug Product Development, Manufacturing Changes and Controls REdI and CERSI Workshop and In Vitro Dissolution Profiles Similarity Assessment in Support of Drug Product Quality CERSI Workshop and Dissolution and Translational Modeling Strategies Enabling Patient-Centric Product Development.



Viera Lukacova, Ph.D. – Viera Lukacova is Director of Simulation Sciences at Simulations Plus, Inc. She’s been with the company for ~ 15 years working on the of GastroPlus®, DDDPlus™, and MembranePlus™ software packages as well as contributing to modeling studies helping companies with their drug development programs in different stages of drug development process and interactions with regulatory agencies.



Michael B. Bolger, Ph.D. – Dr. Michael B. Bolger is Chief Scientist at Simulations Plus, Inc. He joined the company in 1996 and programmed the first version of GastroPlus in 1997. He works with our team of scientists and programmers on the continued development of modeling & simulation software programs. In addition to his role at Simulations Plus, he is currently Adjunct Full Professor of Pharmacology and Pharmaceutical Sciences at USC. In 1996, he was elected to the rank of AAAS Fellow by the American Association for the Advancement of Science.



Robert D. Clark, Ph.D. – Dr. Robert D. Clark is Sr. Research Fellow at Simulations Plus, Inc.. He joined the company in 2010, working with the scientists on the development of ADMET Predictor and MedChem Studio. Prior to joining the company, he worked at Monsanto Co. on agrochemical screening, physiology, and SAR-guided synthesis and at Tripos, Inc. Having risen to the post of VP of Science and Research, Bob left Tripos, Inc. to found Biochemical Infometrics, an independent research and consulting company specializing in drug design. He continues to serve as an adjunct professor at Indiana University.




Thaddeus Grasela, PharmD, Ph.D. – Dr. Ted Grasela is Executive Vice President, of Cognigen, a Simulations Plus company. Ted joined Simulations Plus in the fall of 2014 as part of our acquisition of Cognigen. Ted has extensive experience in modeling and simulation, clinical pharmacology, and outcomes research. Ted has built Cognigen into a profitable industry leader in the high-quality analysis of clinical trial data, serving customers ranging from top-5 pharmaceutical companies to numerous mid- and smaller-size organizations.



Jill Fiedler-Kelly, M.S., FISoP– Ms. Jill Fiedler-Kelly is President, Cognigen, a Simulations Plus company.  A co-founder of Cognigen, Ms. Fiedler-Kelly has over 20 years experience in the design and implementation of pharmacometrics M&S approaches in drug development programs and in PK/PD model development. She is Adjunct Associate Professor of Pharmaceutical Sciences at the University at Buffalo and has co-authored Introduction to Population PK/PD Analysis with Nonlinear Mixed Effects Models with Joel Owen of Union University. In 2016, Ms. Fiedler-Kelly was named Fellow of the International Society of Pharmacometrics.


DILIsym Services

Brett Howell, Ph.D.-Dr. Brett Howell is President of DILIsym Services, Inc., a company developing and using DILIsym software to improve the development of safer drug therapies. He is also an associate director of the DILI-sim Initiative since its inception in 2011. In addition to overseeing DILIsym Services operations, Dr. Howell also helps guide the architecture and use of the DILIsym modeling software.


Scott Siler

Scott Siler, Ph.D. – DrScott Q Siler, Ph.D. is the Chief Scientific Officer of DILIsym Services, Inc., a company developing and using DILIsym software to improve the development of safer drug therapies. He is also an associate director of the DILI-sim Initiative since its inception in 2011. He helps oversee the development of the DILIsym software and is also a project manager for DILIsym services projects contracted by pharmaceutical companies. In addition to his duties in helping manage and advance the business of DILIsym Services, Dr. Siler continues to be a scientific contributor to DILIsym services projects and development. Dr. Siler is leading the company’s efforts in the development and use of NAFLDsym software, computational model of nonalcoholic fatty liver disease (NAFLD) that can be used to predict efficacy for treatment modalities developed for treating NAFLD.



Jérôme Kalifa

Jérôme Kalifa, Ph.D. – Dr. Jérôme Kalifa is an applied mathematician and high tech entrepreneur. Jérôme Kalifa joined the Monolix project in 2010 to create a company based on the breakthrough technologies created at Inria, and co-founded Lixoft with several key members of the Monolix team. Prior to Lixoft, Jérôme Kalifa co-founded Let It Wave (Paris, France and Palo Alto, USA) in 2001, a startup dedicated to digital image processing spun off from the Center for Applied Mathematics at Ecole Polytechnique (Paris, France). Jérôme was a key contributor to Let It Wave’s technologies, and developed Let It Wave’s business in several industrial markets and overseas, while managing its most complex product development programs. Let It Wave had grown to 40 employees when it was acquired by Zoran Semiconductors in 2008, after raising venture capital in early 2006. Jérôme Kalifa has a Ph.D in applied mathematics from Ecole Polytechnique, Paris, France in 1999, and did a post-doc at Columbia University (New York, USA) on biomedical image processing, from 1999 to 2001. He is the author of numerous research papers, patents, and software applications, in the areas of digital signal, image & video processing, seismic data processing, wavelet analysis, inverse problems and non-parametric statistical estimation.


Jonathan Chauvin

Jonathan Chauvin, Ph.D. – Dr. Jonathan Chauvin is an applied mathematician and joined Lixoft in 2015 as COO for operational management and products managements. Prior to Lixoft, Jonathan Chauvin held positions as a research engineer, project manager and product manager at IFP Energies nouvelles. The applications and products were in the field of mobility (thermal, hybrid and electric vehicles ) and energy (as part of onshore wind and marine systems). During this period, he filed more than thirty patents and directed twenty publications in refereed committees newspaper articles and fifty conference papers in these areas. Jonathan Chauvin graduated as a civil engineer at MINES ParisTech in 2003 and obtained his PhD in Mathematics Applied MINES ParisTech in 2006. He received the award for “Best thesis ParisTech” in 2007.