Radioimmunotherapy of solid cancers: A review

Area of Science:

• Oncology
• Nuclear Medicine
• Immunotherapy

Background:

• Radioimmunotherapy (RIT) leverages radioactivity to eliminate cancer cells distant from targeted cells, making it suitable for heterogeneous tumors.
• While RIT has shown significant success in non-Hodgkin's lymphoma, its efficacy in bulky solid tumors like adenocarcinomas is more limited due to insufficient radiation doses.

Purpose of the Study:

• To review the current status and challenges of radioimmunotherapy (RIT) in cancer treatment.
• To discuss strategies for improving RIT efficacy and overcoming limitations such as myelotoxicity and the Human Anti-Mouse Antibody (HAMA) response.

Main Methods:

• Review of existing clinical trials and research on systemic and regional RIT applications.
• Analysis of radionuclide selection (beta, alpha, Auger emitters) and delivery methods (e.g., intraperitoneal administration).
• Exploration of techniques to mitigate RIT-associated toxicities and immune responses.

Main Results:

• RIT has demonstrated substantial complete response rates in non-Hodgkin's lymphoma.
• Modest results are reported for bulky solid tumors, with dose escalation limited by myelotoxicity.
• Intraperitoneal RIT has shown promise for colorectal and ovarian carcinomas, including pseudomyxoma.

Conclusions:

• Strategies like anti-antibody enhancement, multi-step approaches, bispecific monoclonal antibodies, and immunoadsorption can reduce myelotoxicity.
• Careful radionuclide selection is crucial for optimizing RIT efficacy.
• Despite challenges like tumor penetration and HAMA response, ongoing developments position RIT as a significant future cancer management modality.