Note 1. Description of Business

Nature of Operations

VivoSim Labs, Inc., formerly known as Organovo Holdings, Inc. ("VivoSim" and the “Company”), is a pharmaceutical and biotechnology services company that is focused on providing testing of drugs and drug candidates in three-dimensional (“3D”) human tissue models of liver and intestine. The Company offers partners liver and intestinal toxicology insights using its new approach methodologies ("NAM") models. The Company anticipates accelerated adoption of human tissue models following the U.S. Food and Drug Administration (“FDA") announcement on April 10, 2025 to refine animal testing requirements in favor of these non-animal NAM methods. The Company will also offer bespoke services in the areas of investigational toxicology, mechanism of drug action elucidation, and other applications of these complex human tissue models.

Prior to March 2025, the Company was a clinical stage biotechnology company that was focused on developing FXR314 in inflammatory bowel disease ("IBD"), including ulcerative colitis ("UC"), based on demonstration of clinical promise in 3D human tissues as well as strong preclinical data. The Company's clinical focus was in advancing FXR314 in IBD, including UC and Crohn’s disease ("CD"). The Company planned to start a Phase 2a clinical trial in UC in the calendar year 2025 and was also exploring the potential for combination therapies using FXR314 and approved mechanisms in preclinical animal studies and the Company's IBD disease models.

In March 2025, the Company sold its FXR program for $10.0 million, with $9.0 million paid at closing and $1.0 million held in escrow for a period of 15 months, with future milestones of up to $50.0 million in the aggregate to be paid if the asset, FXR314, hits key development, regulatory and commercial milestones. In July 2026, the Company received a milestone payment in the amount of $5.0 million upon the achievement of a certain development milestone related to FXR314. Additionally, in July 2026, the $1.0 million held in escrow was released to the Company.

Effective April 24, 2025, the Company changed its corporate name to VivoSim Labs, Inc. by filing a Certificate of Amendment to its Amended and Restated Certificate of Incorporation with the Secretary of State of the State of Delaware. The Company changed its name to reflect its new business model, which includes the use of other longstanding assets of the Company, intestinal and liver tox models and expertise, and its IP portfolio for 3D bioprinting.

The Company is now offering liver toxicology predictive screening and research services as well as working on predicting and studying the intestinal side effect profiles of drugs that are therapeutic candidates of pharmaceutical and biotech companies at all stages of drug development. The Company plans to not only market this directly to pharmaceutical and biotech companies, but also partner with specific contract research organizations to complement its offering and to quickly grow its portfolio of clients. The Company's services offer the potential benefit of reducing the significant risk and cost of bringing therapeutics to market through the regulatory process. It is estimated that less than 10% of drug candidates entering clinical trials are approved, with a portion of the failures due to unexpected liver toxicity or intestinal intolerability. In addition, even approved drugs are occasionally withdrawn after liver toxicity is determined to be caused by the drug in a phenomenon called drug induced liver injury. The Company presented findings at the May 2025 Digestive Disease Week scientific conference showing that the liver toxicology platform had a best-in-class predictive power. VivoSim's liver predictive power was shown to be 87.5% for a set of challenging liver toxicity cases – inclusive of classic cases of “liver tox misses” drugs with unforeseen liver toxicity found in clinical trials or drugs that were withdrawn from the market after liver toxicity issues emerged later. The platform identified correctly that 87.5% of the known liver-toxic drugs could be seen as liver toxic using NAMkind™ liver. This is known as the sensitivity of the platform, which at 87.5% is the world’s best. Importantly, the specificity was 100%, meaning that none of the compounds tested that are not liver toxic were incorrectly identified as having liver toxicity issues by the platform.

The Company uses its proprietary technologies to build functional 3D human tissues that mimic key aspects of native human tissue composition, architecture, function, and disease. The Company believes these attributes can enable critical complex, multicellular disease models that can be used to study and develop clinically effective drugs across multiple therapeutic areas.

The Company has also used these human disease models to identify new molecular targets responsible for driving IBD and to explore the mechanism of action of known drugs including JAK inhibitors and related molecules. A portion of its internal research continues to focus on early stage internal drug discovery programs, validating targets, and testing potentially licensable or transactable external drug compounds to identify drug candidates for partnering and/or internal clinical development.

Except where specifically noted or the context otherwise requires, references to “VivoSim” and “the Company” in these notes to the unaudited condensed consolidated financial statements refers to VivoSim Labs, Inc. and its wholly owned subsidiaries, Organovo, Inc., and VivoSim, Inc.