🧬 Crossover Investing, Gene Therapy & LP Trust | Stephanie Sirota Rerelease (3/3)
July 16, 2026
In this episode of The Biotech Startups Podcast, host Jon Chee continues his conversation with Stephanie Sirota, Partner and Head of Strategic Partnerships at RTW Investments, as she traces RTW’s evolution from a lean public-equity fund into a major life sciences platform spanning crossover investing, company creation, and global commercialization. Stephanie explains how RTW built the modern crossover ecosystem, why they chose to found Rocket Pharma instead of a fleet of gene therapy startups, and how a disciplined, science-first research process underpins the firm’s long-term, concentrated investing strategy and deep alignment with LPs and portfolio founders.
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"Drug development is not a linear process."
In this episode of The Biotech Startups Podcast, host Jon Chee continues his conversation with Stephanie Sirota, Partner and Head of Strategic Partnerships at RTW Investments, as she traces RTW’s evolution from a lean public-equity fund into a major life sciences platform spanning crossover investing, company creation, and global commercialization. Stephanie explains how RTW built the modern crossover ecosystem, why they chose to found Rocket Pharma instead of a fleet of gene therapy startups, and how a disciplined, science-first research process underpins the firm’s long-term, concentrated investing strategy and deep alignment with LPs and portfolio founders.
Key Topics Covered:
- Building the biotech crossover investing ecosystem: RTW’s early role in late-stage private rounds.
- Gene therapy deep dives & Rocket Pharma: Why RTW built one platform company instead of many.
- Thesis-driven company creation in China: Licensing Western assets to tackle cardiovascular & ophthalmology.
- Conviction, position sizing & non-linear drug development: How RTW underwrites multiple inflection points.
- Educating LPs & tracking a 60% batting average: Process, data libraries & domain expertise.
- Navigating cycles with transparency & trust: Berkshire-style moments, metabolic disease opportunities & backing science through downturns.
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Find our guest, Stephanie Sirota at these links:
LinkedIn: https://www.linkedin.com/in/stephsirota/
Website: https://www.rtwfunds.com/
Find our host, Jon Chee, at these links:
LinkedIn: https://www.linkedin.com/in/jonchee/
Learn more about Excedr:
LinkedIn: https://www.linkedin.com/company/excedr/
Website: https://www.excedr.com
Intro & Outro Songs Created by OkKyojin, Owned by Excedr:
Website: https://flow.page/kyojin
Resources & Articles:
Jesse Gelsinger case & early gene therapy: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2907126/
AveXis (Zolgensma) gene therapy overview: https://www.novartis.com/news/media-releases/novartis-agrees-acquire-avexis-inc-expand-leadership-gene-therapy
Rocket Pharmaceuticals pipeline overview: https://www.rocketpharma.com/pipeline/
GLP-1 receptor agonists in metabolic disease: https://www.nejm.org/doi/full/10.1056/NEJMra1907937
Metabolic disease & obesity drug landscape: https://www.nature.com/articles/s41574-021-00556-9
Biotech market benchmark XBI profile: https://www.ssga.com/us/en/institutional/etfs/spdr-sp-sbx-biotech-etf-xbi
IMG Academy tennis training program: https://www.imgacademy.com/sport-camps/tennis
Companies, Universities, & People Mentioned:
RTW Investments: https://www.rtwfunds.com/
AveXis: https://www.novartis.com/our-products/avexis
Novartis: https://www.novartis.com
Rocket Pharmaceuticals: https://www.rocketpharma.com/
Ji Xing Pharmaceuticals: https://www.jxpharma.com/
IMG Academy: https://www.imgacademy.com/
Lehman Brothers (archived): https://www.lehman.com
Valhalla Capital Management: https://www.valhallacap.com/
Berkshire Hathaway: https://www.berkshirehathaway.com/
Excedr: https://www.excedr.com/
University of Pennsylvania: https://www.upenn.edu/
Timestamps:
00:00 Intro
01:45 RTW’s crossover strategy & gene therapy
09:37 Building Rocket Pharma as a platform company
11:43 Creating Ji Xing to unlock China’s market
14:15 RTW’s thesis-building & conviction process
18:04 Educating LPs & proving a repeatable edge
20:12 Market cycles, batting averages & investor trust
24:26 RTW’s outlook on biotech & metabolic disease
26:11 Long-term horizons, generalists & first-principles thinking
28:34 Being first-dollar capital & partner through downturns
29:44 Career shout-outs & mentors who shaped Steph
29:48 Outro
The Biotech Startups Podcast gives you a front-row seat to the business and science of building a biotech. Hosted by Jon Chee, CEO of Excedr, the show features honest conversations with founders, execs, and investors about their work, their companies, and how they got there. From scientific breakthroughs to startup lessons, each episode explores what it really takes to grow a life science company—from pre-seed to IPO.