In the past few decades, research efforts have focused on transitioning cancer treatments from a systemic approach to being able to specifically target cancer cells while minimizing the side effects for the patient. Here we will present the use of actinium, a relatively short-lived radioisotope, coupled to antibodies specific against synovial sarcoma. A promising new concept that combines the specificity of antibodies with the potency of radiotherapy.
Early therapy against cancer focused on killing cells with high proliferation rates. As such, normal cells in the human body that rapidly divide are also affected and often results in harsh off-target effects for the patient. In addition, chemotherapy with these early drugs may promote the selection of chemoresistant cells and enhance the difficulty of clearing the disease. With all its problems, systemic forms of chemotherapy are still in widespread use in the clinic as it remains one of the most effective methods of treatment. (1)
Radiotherapy is an additional form of treatment that avoids the systemic drawbacks of chemotherapy. This form of treatment is highly effective as it can be used to treat solid tumors without the downside of selecting for chemoresistant cells. However, the drawback is that it is not able to eliminate the metastatic or circulating cells. (2)
In the past 20 years, a variety of antibodies targeting different cancer surface markers with highly specific antibodies have emerged. In the article by Sudo et al., a well-characterized antibody targeting fzd10 was coupled with an atom of radioactive actinium. (3) Actinium-225 decay results in the release of 4, short-distance and high-energy alpha particles at the site of decay. Fzd10 has previously been shown to be a surface marker for synovial sarcoma. The researchers demonstrated that they were able to achieve 80% survival of mice compared to 0% survival in untreated mice. Furthermore, treatment using actinium conjugated antibodies were able to completely clear 60% of mice of all detectable cancer cells.
Specific targeting of cancer cells with antibodies for therapeutic or diagnostic purposes often requires de novo generation of antibodies. Here at MediMabs, we offer a large variety of services from de novo antibody generation to recombinant expression to help your research team in their project. Focus on your target, we will build the antibody to get you there.