Simulations Plus

Simulations Plus

Simulations Plus was incorporated in Lancaster, California, in 1996 and shifted the pharmaceutical industry's approach to drug testing with the 1998 launch of GastroPlus, a mechanistic simulation package that models absorption, pharmacokinetics, and pharmacodynamics. The firm expanded through a series of acquisitions: it absorbed Cognigen Corporation in 2014 to add population PK/PD expertise, acquired DILIsym Services in 2017 for drug-induced liver injury simulation, added the MonolixSuite through the 2020 purchase of Lixoft, and entered immunology and oncology via Immunetrics in 2023. The firm now operates six software platforms spanning the drug development continuum. GastroPlus performs physiologically based pharmacokinetic and biopharmaceutics modeling for multiple dosage routes. ADMET Predictor deploys machine learning for absorption, distribution, metabolism, excretion, and toxicity prediction, including AI-driven drug design. The DILIsym and Thales platforms handle quantitative systems toxicology and pharmacology, respectively, while Pro-ficiency, acquired in June 2024, adds a performance-management learning engine for clinical trial simulation training. The consulting division supports pharmaceutical, biotechnology, and regulatory agencies worldwide; the United States FDA has renewed its DILIsym software licenses for at least seven consecutive years. Simulations Plus employs a distributed scientific team and operates from its Lancaster headquarters, though it maintains no disclosed additional offices. The company's footprint is extended through partnerships with academic institutions such as the University of Bath, the University of Connecticut, and the University of Southern California to secure NIH and FDA grants for AI-driven drug discovery and mechanistic-model validation. Community engagement includes a $25,000 gift to Girls Who Code in 2022 and multiple grants to rare-disease and childhood-cancer organizations. In December 2025, the firm announced it was positioned to capitalize on the FDA's streamlined nonclinical safety guidance with advanced mechanistic and model-informed solutions. Simulations Plus is a publicly traded company listed on the Nasdaq under the symbol SLP, a structural reality that subjects it to quarterly earnings cycles and capital-market expectations — a posture distinct from a family office or a founder-owned bootstrapped scientific-tools company. Its model integrates software revenue, consulting services, and grant-funded research into a single entity, which means the same scientists building the FDA-used DILIsym platform also consult on regulatory submissions.