The radioisotope copper-67 has long been recognised as having ideal properties for the treatment of disease, in particular cancer. It is a short-range beta emitter with a half-life of 2.6 days and has ideal chemical characteristics to be used as a payload in targeted radioisotope therapy, where the radioisotope is delivered to tumor using a targeting agent such as a monoclonal antibody ort peptide. Such treatments are effective and have far fewer side effects than conventional therapies. In addition, recent published studies have demonstrated the potential of copper radioisotopes to be used directly to treat tumors due to a natural affinity as a result of abnormal copper metabolism in cancer.
How is copper-67 better than other radioisotopes for treating disease?
In order to treat disease effectively a radioisotope must have very specific characteristics in terms of half-life, radiation emissions and chemistry. In nuclear medicine circles copper-67 has been recoginized for decades as having perfect properties but until now has been very difficult to make.
Cancer is the leading cause of death in the developed world and incidence is increasing due to life expectancy and lifestyle changes. Current treatments are invasive and have serious side effects and associated toxicities. Radioimmunotherapy is a novel way to target cancer by using engineered compounds such as antibodies or peptides which bind to receptors sites on tumor cells. By the addition of a radioactive payload such as copper-67 it is possible to develop effective single-shot treatments which can be administered in an out-patient environment and have minimal side-effects.
Why is targeted radioisotope therapy not more common?
Immunotherapy agents are the most successful new class of pharmaceuticals in recent years and represent 6 of the top 10 best selling prescrition drugs worldwide in 2013. These include Rituxan, Avastin, Herceptin, Humira and Remicade. Improved disease response by the addition of a radioisotope payload (radioimmunotherapy) has been demonstrated many times in clinical trials but commercialization has been limited at least in part by the infererior characteristics of available radioisotopes.
After many years of dedicated research with our partners at the Argonne National Laboratory we are finally ready to commercialize a novel production process for copper-67 which uses a compact electron accelerator and enriched zinc-68 target to produce high purity, high specific activity copper-67 in a commercially sustainable and affordable way for the first time.
What forms of cancer respond to therapy with copper-67?
Radioimmunotherapy has generally been focussed, to date, on blood cancers such a Non-Hodgkin Lymphoma (the seventh most common cancer with around 70,000 new cases annually in North America). However there are clinical trials in colon and bladder cancer, and recent animal studies have demonstrated direct action of copper radioisotopes in the treatment of melanoma and glioblastoma (brain cancer).
Is copper-67 similar to copper-64?
Copper-64 is a short-liver positron emitter increasingly used for detailed imaging and diagnostic procedures using the technique of Positron Emission Tomography (PET). It is made on a cyclotron accelerator. Our radioisotope copper-67 has characteristics that make is suited to disease therapy, particularly the treatment of cancer. However, there is significant interest among researchers in the use of radioisotopes of the same element which facilitate the integration of diagnostics and therapy - so called 'theranostics'. In this case detailed imaging with copper-64 attached to a suitable vector, such as a monoclonal antibody or peptide, could assess the suitability of a patient for radioimmunotherapy, and where effective tumor targeting was demonstrated this could be followed by a higher therapy dose of copper-67 attached to the same vector.
Can copper-67 be imaged?
A further advantage of copper-67 is that it also emits low energy gamma rays very similar in characteristic to the most common imaging radioisotope technetium-99m. This allows its location in the body to be easily imaged and quantified using common SPECT imaging equipment readily available in hospitals.
Iotron Medical, a division of Iotron Industries - providing innovative solutions using electron beam technology for more than 25 years
If you have any queries or wish to contact us: