Pamedic Spotlight｜Radionuclide Drug Conjugates (RDC): a New Era in Targeted Tumour Therapy

In recent years, Radionuclide-adionuclide Drug Conjugates (RDC) have emerged in the field of oncology therapy and are seen as a great innovation in targeted tumour therapy. This class of drugs combine the properties of radionuclides with the precision of targeted drugs, bringing new possibilities for tumour therapy. Although ADC drugs are currently more mature, the gradual increase in the number of FDA-approved RDC drugs in recent years demonstrates the great potential of the RDC track.

01Structural Features of RDC

RDC drugs are structurally similar to ADC drugs - ADCs consist of three modules: antibody, linker and small molecule drug, whereas RDCs are mainly composed of an antibody or small molecule (Ligand), a linker, a chelator and a radioisotope. The major difference between the two is the drug load, as RDC uses radionuclides while ADC uses small molecules.

Targeting Ligand has a precise targeting effect and guides the radionuclide to the tumour cell.

Linker connects the targeting ligand to the load and maintains structural stability.

Chelator is used to bind the radionuclide to the ligand, commonly used chelators include DOTA, DTPA, etc.

Radionuclide (Radioisotope) as the drug load, can be selected from its various types to achieve different therapeutic effects. The commonly used radionuclides are 177Lu and 225Ac, etc.

02Advantages and Applications of RDC

Precision and Safety: RDC drugs deliver radionuclides directly to tumour cells through precise targeting, which greatly reduces damage to normal tissues and thus improves the safety of the treatment.The difference between RDC drugs and other coupled drugs is that the load is a radionuclide rather than a toxic molecule, so there is no need for the linker to be broken during the onset of the drug's effect, which further strengthens the stability and safety of the drug in the body. This further enhances the stability and safety of the drug in the body.

Whole-body Imaging: With RDC, a single injection and a whole-body imaging scan can provide a complete picture of the location and sensitivity of the tumour lesion, avoiding problems that can be associated with traditional biopsy sampling, for example, missed diagnose.

Diversified Treatment Options: Appropriate radionuclide and ligand combinations can be selected to achieve individualized treatment plans according to different tumour types and conditions.

Diagnostic and Therapeutic Effects: RDC drugs are able to give signals within a very short half-life, achieving rapid diagnosis and therapeutic effects, and improving the quality and chances of survival of patients.

In terms of clinical application, a series of breakthroughs have been made in RDC drugs have made, for example, iodine [131I] Tositumomab and  Ibritumomab have been approved for marketing, and R&D projects for specific targets, such as prostate-specific membrane antigen (PSMA), are steadily progressing.

However, the development of RDC drugs in China is still in its infancy due to the high technical barriers of RDC drugs, as well as the supply of nuclide raw materials, distribution timeframe and other factors. In the future, with the promotion of policies and the gradual improvement of the supply of nuclide raw materials, the domestic RDC drug market will continue to expand.

As an innovative company focusing on the research and supply of radionuclides, Pamedic Holdings has always been committed to promoting the innovation and development of Radionuclide Drug Conjugates (RDC) in the field of oncology treatment. We are well aware of the potential and prospects of RDC drugs, and will continue to increase our investment and research and development efforts in this field, and continuously improve our product line to provide safer and more effective treatment solutions for cancer patients.