Portfolio company case study: RayzeBio


City, State:

San Diego, California

Year Founded:




Deal Lead:

Irina Margine

Investment Date:


Series Invested:

Series D Preferred

Company overview

Rayzebio is a biotechnology company focused on developing targeted radiopharmaceutical drugs for solid tumors in cancers. The team prosecutes diverse sets of binders against clinically validated cancer targets through an iterative process involving in-vitro screening, X-ray crystallography, linker and radiolabeling optimization, and in-vivo screening with molecular imaging and biodistribution analysis.

Investment thesis

Our August 2022 investment in RayzeBio was centered on the strength of the clinical data for their lead asset (RZE-101). We believe the drug targets a well-defined market with remaining unmet need and that the company has emerged as one of the leaders in the space with their experienced team, strategy execution, manufacturing capabilities, and strong support from a high-quality shareholder base. 

The case study presented is for illustrative purposes only to show how Wellington engages with private company founders and management teams. The private biotech team makes investments in other companies with different characteristics and the full list can be found on here

Given Wellington's long track record within the healthcare space, and success working with innovative biotech companies, it's a no-brainer for any entrepreneur to want to have Wellington as an investor.

Dr. Ken Song, MD
President and CEO, Rayzebio

Dr. Ken Song is the CEO of Rayzebio, which is a portfolio company that Wellington has invested in. This statement about Wellington reflects a personal opinion that may not be shared by others. There has been no compensation provided for such statements.

We believe RayzeBio’s strong clinical data, experienced team, and robust manufacturing capabilities make them a leader in the radiopharmaceutical space addressing critical unmet needs for cancer patients.

Irina Margine, PhD
Wellington Sector Lead, Biotech Private Investments

Meet the late-stage biotechnology team

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Our Focus Areas

Venture capital

We look to partner with early-stage companies that can become leaders in large and growing markets.

From energy transformation to sustainable cities to next-generation agriculture, we support innovative companies helping to address the impacts of climate change.

We seek out companies at the nexus of scientific breakthroughs and medical needs with innovations that are improving the standard of care of medicine for patients.

To guide late-stage private companies through the finish line and beyond, we leverage our deep industry expertise, resources, and long-term relationships across public and private markets.

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We seamlessly combine our extensive private placement experience and deep expertise working with insurers — as one of the largest asset managers for insurance companies globally.