Mantis Bio (formerly Louiza Labs) builds physics-based, high-fidelity synthetic human patients that let medical device, AI, and sports-medicine teams test on virtual anatomy instead of animals, cadavers, and scarce clinical data. The wedge is a proprietary physics engine that produces behaving, instrumented organ-level digital twins: a beating heart took roughly one week to program on top of a year of underlying research, and each new organ takes about a week thereafter (2025-08-28 note). The company sells these as datasets and per-seat model licenses. The insight is that the largest medical players still validate on pig hearts, so a scalable synthetic alternative can compress FDA timelines and remove the ethical and cost friction of physical testing.
Validation is real and commercial: as of the 2025-10-23 note the company had signed a $900K, two-year Cleveland Cavaliers contract for Eastern Conference exclusivity, was cashflow positive, and was taking in-person meetings with the Knicks and Nets, with a Johnson & Johnson $500K shoulder-model discussion in the pipeline (2025-08-28 note). StoryHouse committed $500K from Fund II on the same terms as lead Decibel Ventures: a $5M priced Series Seed at a $15M pre / $20M post valuation, buying 344,210 shares at a $1.4526 Series Seed price (Deal Terms; investment dated 2025-11-24). Georgia notably lowered the round valuation from the earlier $28M-post Decibel SAFE to a $20M-post priced round to reward Decibel for navigating her co-founder separation (2025-10-23 note).
Interpretation: the healthcare-specific digital-twin segment is small today but among the fastest-growing slices of a very large digital-twin market, driven by AI-training data scarcity, regulatory pressure to reduce animal testing, and the FDA's own validation of simulated anatomy (Dassault's Living Heart). Mantis is early in a market where the medical-device design-and-testing sub-segment is projected to grow fastest, so timing favors a synthetic-data-native entrant.
| Player | Positioning | Funding / Stage | Edge vs. them |
|---|---|---|---|
| Mantis Bio | Physics-engine multi-organ digital twins; LLM-routed synthetic biomedical datasets; sports-medicine wedge into devices & pharma | Seed, $20M post; $7.2M raised | — |
| Unlearn.AI | AI digital twins for synthetic control arms in clinical trials | Series C, $50M (Altimeter) | Mantis targets device / pre-clinical validation, not just trial control arms |
| Dassault Systèmes | FDA-validated Living Heart Project; simulation incumbent | Public | Startup speed and per-organ generation vs. legacy CAD-style modeling |
| Tempus / Insilico | Data-driven patient twins (oncology) and AI drug discovery | Public / late-stage | Mantis is physics-first synthetic anatomy vs. genomics / data-mining approaches |
Moat: a physics engine that generates behaving, instrumented organ twins in roughly a week each, plus retained model IP and patents (2025-07-17 note), creates a compounding data-and-simulation asset that is hard to replicate without the founder's underlying research.
Most probable exit is strategic acquisition by a medical-device or life-sciences-software incumbent (Johnson & Johnson, Medtronic, and Stryker were cited as roadmap targets in the 2025-08-28 note; Dassault Systèmes and Tempus are natural simulation / data acquirers). Recent comparable financing signal: Unlearn.AI's $50M Series C for synthetic-trial digital twins Web shows deep-pocketed appetite in the category. At a $20M-post entry, a mid-nine-figure medtech outcome would return the position several-fold, though the outcome distribution is wide given the company's stage.
Catch-up call confirming the new entity, final round terms, and a clear path to close. The Cavaliers contract is signed, the company is cashflow positive, and StoryHouse is invited in on the same priced-round terms as Decibel.
Next steps: pursue close; Georgia is connecting us with Fenwick for final documents.
Summary: Company continuing to do well. Cavs contract signed for $900K over two years. In NY for Nets and Knicks meetings. Decided to do a priced round and lower the valuation since Decibel was so helpful with the separation, and will include us on those same terms. Separation agreement is finalized; Larissa doesn't own any portion of the company now, which is why Georgia left instead of the other way around. We should close quickly.
Separation: everything is finalized; the reason Georgia left instead of Larissa was so Larissa couldn't own any of the new company, Mantis. Decibel helped navigate everything.
New round: Decibel asked for higher ownership because of their heavy involvement with the CEO leaving, and Georgia obliged. $20M cap priced round, $5M size: Decibel $4M, YC $500K, StoryHouse $500K. She has interest for another $2M she plans to do on a Seed+SAFE at an increased cap (Magic Johnson / Cavs family office).
Business: Cavs contract now signed, $900K over two years. Currently in NY for in-person meetings with the Knicks and Nets; ran a court-side pilot with the Knicks who seemed interested. Company is now cashflow positive and planning to start making hires. She is connecting us with the Fenwick team for the final docs.
Miles & Georgia call: a full IP carve-out from the ex-co-founder is complete, Georgia enters the next YC batch as a solo founder, and she is preparing a Decibel-led priced round while finalizing the Cavs contract and expanding the team.
Summary: Georgia finalized a full IP carve-out from her former co-founder, retaining all investors and YC founder status, and will enter YC as a solo founder. She is preparing a Decibel-led priced round while finalizing a $1M, two-year Cavs contract and expanding her team. Miles will introduce her to Fast Break AI once the Cavs contract and insurance are complete.
Company split resolution: full IP carve-out with ex-co-founder Larissa, who kept her original YC investment and 3 angel investors plus YC founder status and the company name. All investors recommended she leave. Georgia entering the YC batch as a solo founder; money being wired soon; all investors transferred over.
Funding status: Decibel wants to lead the priced round, waiting for the YC term-sheet signature to set MFN; no official timeline. Dan Gilbert (Cavs owner) potentially investing $2M; GM Koby suggested holding allocation, no direct follow-up from Dan yet.
Cavs contract: $1M over 2 years for Eastern Conference exclusivity; essentially a blank contract to fill in product specifications; already used by the Cavs with good results; working toward full system integration; platform currently complex and needs simplification for handoff.
Team expansion: hired 3 total (1 FT, 2 contractors pending); planning to use the StoryHouse hiring pipeline. Strategic: a Fast Break AI introduction (they serve the 17 largest sports leagues and are finishing a Series A) was offered, delayed until the Cavs contract is executed and insurance secured.
Georgia called with an update: the Larissa situation is not as smooth as Decibel had suggested. She still wants StoryHouse in on the same terms but advises against signing documents until the exit is fully resolved.
Next steps: pause investment for now and resume once the Larissa situation is resolved.
Summary: it does not sound like the situation with Larissa is going as smoothly as Jon / Decibel made it seem. Nothing to do right now, but we should not move forward until it is clear the situation is handled and not a risk.
Raw notes: Georgia called to give an update. She is still excited to work with us and will let us invest on the same terms as Decibel, but is busy dealing with the Larissa situation. Larissa has threatened to sue and is lawyering up, and pulled money out of the Decibel accounts. Jon and Decibel are advising Georgia and YC has gotten involved: YC is banning Larissa and kicking her off Bookface. The issue will likely not settle for at least another week. She recommends not signing any investment documents until Larissa is officially gone.
Two reference calls with Jon Sakoda of Decibel Ventures (lead investor) on 2025-09-22, both referencing founder Georgia Witchel. Sakoda, a former 12-year NEA partner and early backer of Cloudflare, Elastic, and MongoDB, called Louiza / Mantis an exploratory bet outside Decibel's core AI / data / cyber wheelhouse, made on the strength of Georgia's exceptional technical ability. He characterized the Larissa separation as nearly resolved at that time (Larissa to ~5% equity and a $100–150K payout), recommended a priced round with proper governance over continued SAFEs, and confirmed the Cavs / Dan Gilbert family-office interest as strong commercial validation. StoryHouse's takeaway: fewer concerns on the co-founder dynamic and positive team references, but reservations on price (Meeting Notes rec8PFZHkFvv9MO3e, reczod1jbYIqVJ1rv).