Jonathan Leff
Executive Partner at Sofinnova Investments
Menlo Park, California
Jonathan Leff, Executive Partner at Sofinnova Investments is an active investor based in Menlo Park, California. This profile covers what Jonathan Leff backs, at which stage, and how founders can reach out in 2026.
- Investor type
- VCPEInvestment PartnerHedge FundInvestor
- Stages
- SeedSeries B
- Invests in
- Healthcare & BiotechBiotech & PharmaMedTech & Medical Devices
- Location
- Menlo Park, California
- Typical check
- $1.6M
- Past investments
- 71
Notable investments
ENYO PharmaY-mAbs TherapeuticsNuCana
HistogenicsAmplyx Pharmaceuticals
Sorbent Therapeutics
Visen Pharmaceuticals
VersartisAuris Medical
Aerovate Therapeutics
Medeor Therapeutics
GuavusHow to reach Jonathan Leff
Angels and operators like Jonathan Leff reply to specific, personalized notes that show real traction, not mass blasts. Build a verified list, write a note that fits their thesis, and track replies, all on Round Funded.
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About this profile
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Cite this page
Round Funded. "Jonathan Leff." Round Funded investor database, updated September 9, 2026.
Stable URL, it will not change: https://www.roundfunded.com/en/investor/jonathan-leff
Frequently Asked Questions
What does Jonathan Leff invest in?
Jonathan Leff invests in Healthcare & Biotech, Biotech & Pharma and MedTech & Medical Devices, typically at Seed and Series B. Match your sector and stage, then reach out with a personalized pitch.
What stage does Jonathan Leff invest at?
Jonathan Leff typically invests at Seed and Series B. Lead with traction that fits the stage when you reach out.
What is Jonathan Leff's typical check size?
Jonathan Leff typically writes checks around $1.6M. Use it as a signal for whether your raise fits their stage.
How do founders reach investors like this?
Round Funded lists active investors with verified, professional contact details for signed-up founders. Filter by sector, stage and location, then send a personalized pitch from your own inbox.
What is Round Funded?
Round Funded is an investor database and outreach platform for startup founders. It lists 60,000+ active investors with verified contacts, filtered to recent investment activity, and lets founders send personalized pitches from their own Gmail, track replies, and share a free Data Room. Round+ starts at $99 per month with a 3-day trial.