RayzeBio is focused on improving outcomes for people with cancer by harnessing the power of targeted radioisotopes. As the emerging leader in radiopharmaceuticals, RayzeBio is developing an innovative robust pipeline against validated oncology drug targets to deliver radioisotopes that emit alpha particles such as Actinium-225.

Defeating cancer with
radiopharmaceutical medicines


Target selection

Validated solid tumor targets

Numerous tumor targets have been
clinically validated but have yet to be
pursued as radiopharmaceuticals. A
systematic evaluation was
conducted by RayzeBio to identify
biologically-relevant, tumor-specific
targets suitable for targeted
radiotherapy. These targets have
high expression on solid tumors with
little to no expression on normal

Binders to target

Macrocyclic peptide-mimetics

Several criteria are critical when
considering delivery of a radioactive
isotope. Macrocycle
peptide-mimetics provide exquisite
affinity and specificity to tumor
targets akin to the specificity of
antibodies while also being small
and agile, allowing deep tumor
penetration with tunable drug-like
properties that can be quickly and
efficiently synthesized.

Radioisotope choice

Actinium-225 (alpha isotope)

Actinium-225 is an alpha emitting
radioactive particle that has high
energy density acting at distances of
just a few cell widths. At these short
distances, radiation can be
restricted to the cancer cells of
interest with minimal risk to nearby
normal healthy tissue. RayzeBio has
established key partnerships to
secure sufficient supply of
Despite therapeutic advances made in the last decade, there remains a high unmet need for new cancer treatments. Radiation therapy is a proven approach to treating many cancers and is typically administered by an external beam of high energy rays. In contrast, radiopharmaceuticals deliver radioisotopes to tumors via the bloodstream. 
Radiopharmaceuticals have the unique advantage of being both diagnostic and therapeutic. The same drug conjugate could be used for both diagnostic imaging and therapeutic use by switching out the radioisotope. Direct visualization of drug conjugate uptake by tumors with imaging allows for proper patient selection to receive the therapeutic radioisotope (e.g. Actinium-225).



Ken Song, MD

President and CEO

Eric Bischoff

SVP Development & Operations

Derek Cole, PhD

SVP Chemistry, Head of Discovery

Gary Li, PhD

SVP Biology & Translational Medicine

Kathie Huynh

VP, Finance

Nicholas Smith, PhD

SVP, Chemistry Innovation

Board of Directors

Jerel Davis, PhD

Board Member

Aaron Kantoff

Board Member

Bong Koh, MD​

Board Member

Yi Larson

Board Member

Aaron Royston, MD

Board Member

Ken Song, MD

Board Member

Mike Dybbs, PhD

Board Observer



August 4, 2020

PeptiDream Announces Strategic Partnership with RayzeBio for the Discovery and Development of Peptide-Radiotherapeutics

KANAGAWA, JAPAN – PeptiDream Inc., a public Kanagawa-based biopharmaceutical company (“PeptiDream”)(Tokyo:4587) today announced that it has entered into a strategic partnership with San Diego, California, US – based RayzeBio Inc., (“RayzeBio”) for the discovery and development of peptide-radioisotope (RI) conjugates for use as therapeutics (“Peptide Radiotherapeutics”).


RayzeBio is a dynamic work environment that looks for passionate truth-seeking
individuals who want to make a material impact in improving outcomes for people
with cancer. We value our employees and strive for a collegial, inclusive and honest
team culture. We offer full benefits as well as stock options to all employees.

Contact us

RayzeBio, Inc.
9880 Campus Point Dr
Suite 410
San Diego, CA 92121

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