Saisei Ventures

What Saisei Ventures does

Saisei Ventures is a venture capital firm founded around 2020 that builds and invests in early-stage biotechnology companies, with a stated focus on bridging Japan's academic and life sciences research base to global capital, business partners, and pharmaceutical markets. The firm is organized as Saisei Ventures LLC, domiciled in the State of New York with a principal office in Cambridge, Massachusetts, and a second office in Tokyo. It employs 10-12 people across functions including Managing Partner, Partners, Venture Partners, Senior Associates, Associates, Entrepreneur-in-Residence, and Board Managers, led by Managing Partner Jonathan Yeh alongside Partners Hikaru Saito and Dr. Sven Kili.

The firm's investment thesis targets early-stage biotech companies (proof-of-concept through early clinical) working on advanced therapeutic platforms — specifically cell immunotherapies, pluripotent cell replacement therapies, and in vivo/ex vivo gene therapy approaches — applied to life-threatening or debilitating diseases. Its current portfolio of six companies (Craif, CureApp, Kenai Therapeutics, Notch Therapeutics, Tune Therapeutics, and United Immunity) spans epigenetic editing, iPSC-derived cell therapies, macrophage/dendritic cell nanoparticle oncology, and digital therapeutics. Beyond capital, Saisei offers two structured programs: the Executive Fellows Program (launched April 2025), which pairs global biotech leaders with Japanese executives, and the Bridge-to-Biotech Venture Creation Initiative (announced February 2026), which supports Japanese biotech founders in accessing international capital and partnerships.

Saisei's revenue model is that of a traditional venture capital firm: management fees on committed fund capital and carried interest on successful exits, with investment terms negotiated bilaterally with portfolio companies and LPs. The firm does not publicly disclose AUM, fund size, revenue, or specific investment terms. Its go-to-market is relationship-driven and event-driven — leveraging partnerships with Kyushu University (designated Life Sciences Partner VC, January 2026), Japan's Ministry of Health, Labor and Welfare (selected for the Drug Discovery Ecosystem Development Support Project, August 2025), and Japan Agency for Medical Research and Development (AMED) to source deals and access co-funding — alongside content marketing, industry symposiums, and a LinkedIn/newsletter presence.

Name

Saisei Ventures

Legal name

Saisei Ventures LLC

Website

https://saiseiventures.com

Company type

Private

Founded year

2020

Operating status

Operating

Headcount range

1–10 employees

Short description

Saisei Ventures is a venture capital firm that creates and invests in early-stage Japanese biotechnology companies, bridging Japan's academic research base to global capital and pharmaceutical partners. It targets advanced therapeutic platforms including cell immunotherapies, gene therapies, and regenerative medicine, supported by fellowship and founder-development programs.

Ownership category

akta.pro rank

Product category

Venture Capital / Biotech Investment

NAICS

Other Investment Pools and Funds (5259), All Other Financial Investment Activities (52399)

SIC

Investment Advice (6282), Finance Services (6199)

akta.pro primary industry

Early-Stage Venture Capital (Series A/B) (FSANAAAB)

akta.pro secondary industry

Venture Growth / Recurring Revenue Credit Funds (FSANAIAG)

Keywords

• Venture capital
• Biotech investment
• Life sciences funding
• Venture creation
• Engineered biology

Headquarters

HQ city

Cambridge

HQ country

United States

HQ region

North America

Offices2 records

Markets served

GTM type

B2B

Offering type

Services

Cost components

Personnel, Operations, Marketing or Sales, Others

Revenue model

1. Venture Capital Investment Returns: Saisei Ventures generates returns through equity investments in early-stage biotechnology companies, taking ownership stakes in portfolio companies and realizing returns through exits, IPOs, or secondary sales.

Go-to-market motion2 records

Distribution channels1 record

Marketing channels4 records

Core offering

Saisei Ventures is a venture capital firm that creates and invests in early-stage biotechnology companies, taking equity stakes in ventures that leverage engineered biology. The firm bridges Japan's pioneering academic research with global capital and business expertise, providing hands-on technical, operational, and financial support to portfolio companies in cell immunotherapies, pluripotent cell replacement therapies, in vivo/ex vivo gene therapy, and other advanced therapeutic platforms.

Product overview

Saisei Ventures is a venture capital firm focused on growing and harnessing the Japanese biotech ecosystem. Rather than a unified software product, the firm offers venture creation services, investment in portfolio biotech companies (CureApp, Craif, Kenai Therapeutics, Notch Therapeutics, Tune Therapeutics, United Immunity), and programs including the Bridge-to-Biotech initiative and Executive Fellows Program. The firm combines Western expertise with Japanese innovation to build globally competitive biotechnology companies, supporting advanced therapeutic platforms such as cell immunotherapies, pluripotent cell replacement therapies, and in vivo/ex vivo gene therapy approaches.

Differentiator

Problem solved

Functional benefit

Products and services

• Saisei Ventures Venture Creation Venture capital investment and company creation service that identifies scientific advancements and pairs them with global business and development experience to build biotech ventures in cell immunotherapies, pluripotent cell replacement therapies, in vivo/ex vivo gene therapy, and advanced therapeutic platforms. Targeted at Japanese biotech founders and scientists.
• Bridge-to-Biotech Venture Creation Initiative Program designed to support Japanese biotech founders and entrepreneurs by bridging the gap between Japan's pioneering research and international capital investment. Provides venture creation resources and ecosystem building for early-stage biotech founders in Japan.
• Executive Fellows Program Structured mentorship program that pairs CEOs of Japanese biotech startups with seasoned global leaders to compress learning curves and accelerate growth through decades of experience in company formation, clinical development, business development, fundraising, and regulatory strategy. Aimed at Japanese biotech startup executives.

Named customers6 records

Segments3 records

Ideal customer profiles2 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Partnerships

Three partnerships are on record, tiered core.

• Kyushu UniversitycoreStrategic or Co-development Partner · 26 January 2026Saisei Ventures announced collaboration with Kyushu University to advance life science ventures and cultivate talent in Western Japan. The firm was designated as a Kyushu University Life Sciences Partner VC to support the creation and growth of Kyushu University-born biotech ventures.
• Ministry of Health, Labor and Welfare (Japan)coreStrategic or Co-development Partner · 1 August 2025Saisei Ventures was selected as a partner for the Ministry of Health, Labor and Welfare's Drug Discovery Ecosystem Development Support Project (創薬エコシステム発展支援事業), aiming to accelerate the creation of globally competitive drug discovery startups originating from Japan.
• Japan Agency for Medical Research and Development (AMED)coreStrategic or Co-development Partner · 1 January 2024AMED supports biotech startups through programs like the Pharmaceutical Startup Ecosystem Strengthening Program, covering up to two-thirds of project costs with maximum awards of ¥10 billion (~$70 million) per project. Saisei portfolio companies Optieum Biotechnologies (JPY 5 billion/~ $39 million award) and United Immunity have received AMED funding.

Scale indicators3 records

Recent moves6 records

Expansion highlights6 records

Direct peers

• ARCH Venture Partners: One of the largest US early-stage biotech venture capital firms, founded by biotech industry veterans. Closely comparable to Saisei as an early-stage, science-led biotech investor that builds companies around breakthrough academic science - though ARCH operates at significantly larger scale.
• Flagship Pioneering: Biotech venture creation firm that originates and builds platform companies from emerging scientific concepts. Directly comparable to Saisei's venture creation thesis of pairing breakthrough Japanese science with operational support to build globally competitive biotech companies.
• Atlas Venture: Early-stage biotech venture capital firm focused on building companies around transformative science. Comparable to Saisei in stage focus (seed/Series A), modality focus (advanced therapeutics), and hands-on company-building approach.
• OrbiMed: Healthcare-dedicated investment firm covering venture, growth, and credit across therapeutics, medtech, and diagnostics. Comparable in life-sciences focus and in investing across capital stages of biotech companies like those in Saisei's portfolio.
• RA Capital Management: Biotech-focused crossover fund investing across private and public healthcare companies. Comparable in modality alignment with Saisei's gene therapy, cell therapy, and advanced therapeutic focus and in active engagement with portfolio company strategy.

Broad incumbents

• Bessemer Venture Partners: Large multi-stage venture firm with a significant healthcare and biotech practice. Overlaps with Saisei in biotech investing but operates much more broadly across stages, sectors, and geographies.

Regional players

• Beyond Next Ventures: Japan-based early-stage venture capital firm investing in deep tech and life sciences. Closest direct comparable within Japan as a science-led, early-stage life-sciences VC - though with broader sector scope and without Saisei's explicit Japan-to-global bridge positioning.
• Fast Track Initiative: Tokyo-based venture capital firm focused on early-stage Japanese technology and biotech ventures with international expansion support. Comparable to Saisei in Japan-based early-stage biotech investing and bridging Japanese founders to global markets.
• ANRI: Japan-focused early-stage venture capital firm. Comparable as a Japanese VC serving early-stage companies, though ANRI's sector focus skews more toward software/internet than biotech-heavy thesis.
• UTEC (University of Tokyo Edge Capital): Japan-based venture capital firm originating from University of Tokyo, investing in deep tech and life sciences startups from Japanese academia. Comparable to Saisei in academic-sourced Japanese biotech investing and bridging university IP toward commercialization.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat5 records

Key risks6 records

Key highlights7 records

Customer concentration

• LinkedInlinkedin.com/company/saisei-ventures

Revenue estimate

Valuation estimate

Number of profiles

Profiles11 records

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments8 records

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Saisei Ventures