IsoBio

IsoBio, Inc. is a U.S.-based biotechnology company founded in 2025 that develops radiotherapeutic products for cancer treatment. The firm was co-founded by Dr. Bruce Turner, a biotech executive and radiation oncologist who serves as the CEO and President. Dr. Turner previously co-led a merger of companies that formed Immunome, a targeted oncology biotech, and also co-founded Xanadu Bio, a nanoparticle company focused on immunology, oncology, and vaccines.

The company's core focus is on creating a pipeline of monoclonal antibody-based radioisotope therapeutics, which they term antibody-isotope conjugates (AICs). This technology combines monoclonal antibodies with highly active radioisotopes to precisely target both well-understood and new tumor antigens. The goal is to deliver potent anti-tumor activity while minimizing side effects and off-target toxicity. IsoBio is developing therapies using isotopes such as Lutetium-177, Actinium-225, and Terbium-161, attached to antibodies via proprietary linker and conjugation technology.

In July 2025, IsoBio secured $5 million in a Series Seed financing round from ASP Isotopes Inc. (ASPI). This strategic partnership is designed to overcome historical supply chain challenges in the radiotherapeutics field by leveraging ASPI's technology and manufacturing capabilities, including those of its subsidiary, PET Labs. The collaboration aims to accelerate the development of novel radiotherapeutics by ensuring a stable supply of isotopes. IsoBio operates as a privately held, venture capital-backed startup and has established offices in Seattle, Washington, and Gladwyne, Pennsylvania.

Keywords: radiotherapeutics, antibody-isotope conjugates, oncology, biotechnology, cancer treatment, monoclonal antibodies, nuclear medicine, Lutetium-177, Actinium-225, targeted therapy