It is impossible to imagine modern medicine without radiological methods of diagnostics and treatment of patients. Radiotherapy consists of a treatment of ionizing radiation and is most frequently used in oncology for treatment of malignant tumors. Radiotherapy, in conjunction with surgical and drug treatments such as chemotherapy, hormonal therapy, immunotherapy and target therapy, is one of the main treatment methods of malignant tumors.
The purpose of this method is in local, targeted implementation of ionizing radiation on the tumor, which allows to reach deep tissue tumors. During this process, healthy tissues near the deep tissue tumors are also affected however healthy cells regenerate after a certain amount of time, while cancer cells die. This is the principle and aim of radiotherapy.
There are three main types of radiotherapy:
- Contact therapy, during which the radiation source is in direct contact with the patients’ tissue (also known as brachytherapy);
- Remote therapy, when the source is at a certain distance from the patient;
- Radionuclear therapy, during which the radiopharmaceutical substance is injected into the patient’s blood.
Only radiopharmaceutical substances which can develop a strong link to the tumor are suitable for therapy. These substances are known as carriers with high affinity to the tumor, and can precisely direct radiation dosages at the tumor and its metastases, minimizing the effect on healthy tissues and organs. The main advantage of radionuclear therapy compared to other cancer treatment methods is that it can precisely affect the cancerous regions, which reduces the side effects.
To register a radiopharmaceutical substance, it is mandatory to conduct pre-clinical and clinical trials. Let’s take a look at their characteristics.
Pre-clinical and clinical trials of radiopharmaceutical substances are similar to trials of chemotherapy drugs:
- Since radiopharmaceutical substances are highly toxic, healthy volunteers do not participate in phase I trials. Patients with the corresponding illnesses participate instead.
- In trials of both radiopharmaceutical substances and other chemotherapy drugs placebo is usually not used since it would be unethical for the patients.
However, unlike other drugs, RPS are radioactive, which introduces certain specifics to their study and administration.
- RPS are direct radiation sources, which means that they affect their surroundings, the patient, medical personnel and those who produce them. Therefore, it is necessary to strictly follow the federal law “About radiation safety of the population”.
- Radioactivity negatively affects biological systems, so in medicine radionuclear substances with a short-half life are particularly valued, which reduces the time of the patient’s exposure to them.
The production of radiopharmaceutical substances must be efficient and be located in proximity to the medical center where they will be used to treat patients. It is important to precisely organize the logistics of RPS from the production location to the research center, bearing in mind that the activity of the drug is reduced by the minute. Often, the drug is logged not by weight but by level of its activity in megabecquerel (MBq).
Clinical trials of radiopharmaceutical substances are some of the most complicated types of studies, which is due to both the specifics of the illness, and the characteristics of RPS.
iPharma has successful experience in conducting clinical trials with RPS, obtaining all the necessary permits in compliance with the main sanitary requirements of assurance of radiation safety (MSRARS) and organizing the logistics. In order to successfully conduct RPS trials, it is crucial that the medical personnel, RPS developers and the clinical research organization (CRO) work in tandem.