Science Translational Medicine: Low-dose radionuclide targeted therapy to make cold tumors warm and improve immunotherapy response

Cancer immunotherapy, represented by immune checkpoint inhibitors, has completely changed the current status of cancer treatment by strengthening the patient's immune system to fight cancer

Heat tumors: Many immune cells have gathered near the tumor tissues.

Cold tumor: In contrast to hot tumors, there are no or very few immune cells in the tumor tissue.

In the case of cold tumors, oncologists have developed External Radiation Therapy (EBRT)

For patients whose cancer has metastasized or spread to other parts of the body, EBRT usually cannot irradiate all tumor sites, because the distant tumor may be too small, too large, and diffuse, so that the patient cannot tolerate so much radiation

On July 14, 2021, a research team from the University of Pittsburgh School of Medicine and the University of Wisconsin-Madison published a research paper titled: Low-dose targeted radionuclide therapy renders immunologically cold tumors responsive to immune checkpoint blockade in Science Translational Medicine.

Unlike traditional beliefs, a large dose of radiation is needed to kill cancer cells

First, the research team used PET/CT 3, 24, and 48 hours after intravenous injection of 86Y-NM600 (a therapeutic TRT that can chelate radioactive metals and deliver them to tumors for diagnostic imaging or radiotherapy).

Next, the research team used a small dose of 90Y-NM600 combined with immune checkpoint therapy to evaluate the anti-tumor function

Although EBRT can safely deliver low-dose radiation to a large area or the whole body, it can lead to systemic lymphocyte failure and systemic immune suppression, thereby hindering the development of anti-tumor immunity

Since large animals are closer to the environment in which the combined method was used for clinical transformation in humans, the research team tested the feasibility and safety of 90Y-NM600 in the treatment of tumors in dogs with extensive metastatic osteosarcoma and metastatic melanoma

In summary, the research developed a method to safely deliver low-dose radiation to solid tumors and any potentially metastatic tumors using 90Y-NM600

Original source:

Ravi B.