Show Notes
Part 2 of 4 of our series with Caitlyn Krebs, co-founder and CEO of Nalu Bio.
In this episode of The Biotech Startups Podcast, Caitlyn Krebs, co-founder and CEO of Nalu Bio, traces her path from building the Bay Area's biotech ecosystem to operating at the cutting edge of science and business. She shares how launching BayBioNEST taught her what it really takes—beyond great science—to build durable companies, before diving into her time at Entelos, where she helped pioneer virtual patients and digital twins nearly twenty years before AI became a buzzword, and unpacks what BD actually means in biotech, from navigating black-box skepticism to running "bake-off" pilots that let the data speak for itself. The conversation then shifts to Tethys Bioscience, where Caitlyn helped bring a prediabetes diagnostic to market—winning over physicians, employers, and major payers like Aetna, United, and Cigna—only to watch a single Medicare/CMS misstep shutter a well-funded company, and what every founder can learn from that hard-won experience.
Key topics covered:
- Building BayBioNEST: Launching a scrappy pre-accelerator to give academic scientists the business skills they never learned at the bench.
- Pioneering virtual patients: Building biological models and digital twins decades before AI hype to reshape drug development.
- What BD really is in biotech: Structuring deals, overcoming skepticism, and using “bake-off” pilots so the science sells itself.
- Selling prediabetes diagnostics: Winning physicians and employers over to a predictive test for an under-recognized disease.
- The power and peril of reimbursement: How one Medicare/CMS call can wipe out strong data, major payers, and massive funding.
Resources & Articles
- What Is Business Development in Biotech & Pharma? https://chivanta.com/what-is-business-development-biotech-pharma/
- What Is Quantitative Systems Pharmacology (QSP) Modeling? https://www.news-medical.net/life-sciences/What-is-Quantitative-Systems-Pharmacology-(QSP)-Modeling.aspx
- How CMS/Medicare Reimbursement Works for Diagnostic Lab Tests https://www.fiercebiotech.com/medical-devices/diagnostics-companies-strike-back-at-cms-lab-test-rule
- Top Biotech Accelerators and Incubators in 2026 https://www.peony.ink/blog/top-10-biotech-startup-accelerators
- Quantitative Systems Pharmacology (QSP) Modeling – University of Florida Course Overview https://onlinepc.pharmacy.ufl.edu/programs/courses/quantitative-systems-pharmacology-qsp-modeling/
- US Medicare Sets Reimbursement Price for PromarkerD — A Case Study in Diagnostic Reimbursement https://biotechdispatch.com.au/news/us-medicare-sets-reimbursement-price-for-promarkerd-paving-way-for-major-commercial-rollout
Organizations & People
- Entelos: https://mtec-sc.org/life-sciences/entelos
- Pfizer: https://www.pfizer.com
- Aetna: https://www.aetna.com
- UnitedHealthcare: https://www.uhc.com
- Cigna: https://www.cigna.com
- George Rathmann: https://en.wikipedia.org/wiki/George_Rathmann




