Cloverleaf Bio Raises $33 Million Seed Financing to Advance Novel RNA-Based Cancer Therapeutics
- Oversubscribed round led by 4BIO Capital includes strategic investment from AbbVie Ventures, Lilly, and Boehringer Ingelheim Venture Fund, reflecting depth of industry interest in this novel RNA therapeutics platform
- Financing will support proof of concept in hepatocellular carcinoma and advancement of follow-on programs including colorectal cancer
- Cloverleaf’s tRNA therapeutic platform, has demonstrated significantly greater potency and selectivity for cancer cells over healthy tissue in preclinical studies
NEW HAVEN, CT – 08 September 2026 – Cloverleaf Bio (“Cloverleaf”), an RNA therapeutics company developing a novel class of engineered transfer RNA (tRNA) based payloads for cancer, today announced the closing of a $33 million seed financing round. The upsized and oversubscribed round was led by 4BIO Capital and includes meaningful participation from strategic investors AbbVie Ventures, Eli Lilly and Company, and Boehringer Ingelheim Venture Fund, alongside Draper Associates, Mission BioCapital, and American Cancer Society BrightEdge.
The simultaneous participation of three major pharmaceutical venture arms at pre-clinical stage reflects strong industry interest in both the scientific platform and the founding team. The proceeds of the fundraise will be used to advance Cloverleaf’s two lead programs: an inhibitory tRNA asset targeting hepatocellular carcinoma through early clinical testing and an antibody-tRNA conjugate (ATC) asset targeting colorectal cancer through preclinical development.
Cloverleaf's platform is built around selective and durable inhibition of multiple RNA-modifying enzymes, a class of proteins that cancer cells become abnormally dependent on as they proliferate.
Austin Draycott, PhD, CEO and Co-Founder of Cloverleaf Bio, said “We are excited to secure this financing to advance a new generation of cancer therapeutics. We're grateful to 4BIO Capital for leading this round, and to attract major strategic investors, including AbbVie Ventures, Lilly, and Boehringer Ingelheim Venture Fund at this stage reflects the level of scientific interest in this approach. We look forward to delivering the data that will test that conviction. We would also like to acknowledge the early support Cloverleaf received from the National Cancer Institute Small Business Innovation Research / Small Business Technology Transfer program. Federally funded research was foundational to getting this platform off the ground, and we're proud to build on that public investment as we move toward the clinic.”
Dima Kuzmin, Co-founder and Managing Partner at lead investor 4BIO Capital said: “Cloverleaf reflects the core thesis of 4BIO: backing transformative frontier science that has the potential to become an entirely new class of cancer therapeutics with applicability to every major cancer of unmet need. The team at Cloverleaf have built a highly promising platform from a first-principles insight into a mechanism that the field has largely taken for granted for sixty years. The preclinical data on potency and selectivity is compelling, and the strategic interest from three major pharma venture arms at seed reflects how seriously the broader industry is taking this approach. We are proud to lead this round and look forward to supporting the team as they advance toward the clinic.”
Christina Vorvis, Ph.D., Director at AbbVie Ventures, said: “Cloverleaf’s platform reflects the kind of bold and novel scientific approaches we seek to advance. Our support of Cloverleaf, from its beginnings as a Yale spinout through its current efforts to develop next-generation RNA therapeutics, reflects how AbbVie Ventures works with emerging companies. Beyond investing capital, we engage as dedicated collaborators early on, bringing scientific and operational expertise to help turn promising science into potential new therapies.”
Matthias Samwer, Director, at Boehringer Ingelheim Venture Fund, said: “Cloverleaf combines deep expertise in RNA biology with a highly innovative approach to tackling cancer. We believe its engineered tRNA platform has the potential to create an important new class of cancer medicines, and we are excited to support the company as it advances toward the clinic.”
Differentiated Preclinical Profile
In preclinical studies, Cloverleaf’s lead compound, CLB-001, demonstrated significantly greater potency and selectivity for cancerous cells over healthy cells. The compound retains activity in cancer cell lines resistant to both frontline chemotherapy and current-generation ADC payloads, a meaningful finding given that treatment resistance is a major clinical challenge in colorectal cancer. CLB-001 also outperformed frontline standard of care in both hepatocellular carcinoma and lung adenocarcinoma models at substantially lower doses. Tolerability studies in animals showed no increases in markers of liver damage and no signs of systemic toxicity across the dose range tested.
This project has been funded in whole or in part with Federal funds from the National Cancer Institute, National Institutes of Health, Department of Health and Human Services, under Project No 1R44CA295426
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About Cloverleaf Bio
Cloverleaf Bio is an RNA therapeutics company developing engineered tRNA-based therapeutics for cancer. Cloverleaf Bio’s tunable platform has the potential to be applied across multiple cancer indications and, in the longer term, across non-oncology disease areas including neurodegenerative and fibrotic diseases. The company is headquartered in New Haven, Connecticut, and is a spinout from Yale University.
Cloverleaf Bio's early research was supported in part by funding from the National Cancer Institute, whose support for foundational science was instrumental to the company's formation.
Cloverleaf Bio was founded by Austin Draycott, PhD (CEO), Cole Lewis, PhD (CSO), and Wendy Gilbert, PhD (SAB Chair), all with directly relevant expertise in RNA biology and therapeutic development.
The company’s Scientific Advisory Board and advisory network include Albert Lai, PhD ((Senior Venture Partner at AbbVie Ventures), Luisa Escobar-Hoyos, PhD (Associate Professor of Therapeutic Radiology at Yale), Wendy Gilbert, PhD (Maxine F. Singer '57 PhD Professor of Molecular Biophysics and Biochemistry at Yale) and Michael McCaman, PhD (former CMC head at Intellia, with more than 30 years of experience in process scale-up).
Media and Investor Enquiries
ICR Healthcare
Amber Fennell, Chris Welsh
cloverleaf@icrhealthcare.com
Company Contact
Austin Draycott, CEO
contact@cloverleafbio.com

