Clinical trial (medical term)

Clinical trials

According to the definition of clinical trials in the "Code of Quality Management of Drug Clinical Trials" promulgated by the State Food and Drug Administration, clinical trials refer to any clinical trials in humans (patients or health volunteers). Person) conduct systematic studies of drugs to confirm or reveal the effects, adverse reactions, and/or absorption, distribution, metabolism and excretion of the test drugs, with the purpose of determining the efficacy and safety of the test drugs. In foreign countries, people who participate in clinical trials are called volunteers, and in China, they are generally called "subjects." Volunteers include healthy people and patients, depending on what kind of test they are participating in. The trials we usually have the most contact with are still carried out by patients. The purpose is to investigate whether the new drug is effective and whether there are side effects. To put it in a more straightforward way, before a new drug is officially launched, the doctor allows the patient to take ( Use) This new drug, of course, must be approved by the patient. After a certain course of treatment, look at the efficacy and side effects of this drug. The most important point of a clinical trial is that it must meet our ethical requirements, that is, the person participating in the trial must respect his (her) personality. Participating in the trial must conform to the interests of the participant. Under this premise, the trial can be done. . Moreover, during the trial period, the participant can not continue the trial without any reason, and everyone including the doctor has no right to interfere with his (or her) choice. In short, well-designed and operated clinical trials are the fastest and safest way to improve human health and find new therapeutic drugs and methods.

Contents

Phase I clinical trials

Including preliminary clinical pharmacology, human safety evaluation trials and pharmacokinetic trials, for the formulation of dosing regimens Provide a basis. Including: tolerance test: preliminary understanding of the safety of the test drug to the human body, and observation of the human body's tolerance and adverse reactions to the test drug. Pharmacokinetic test: To understand the human body's disposal of the test drug, that is, the absorption, distribution, metabolism, and elimination of the test drug.

① Approval for clinical trials of drugs must be obtained from the State Food and Drug Administration (CFDA) before the start of the trial.

②Clinical research plan design, record form preparation, SOP preparation.

③The ethics committee reviewed and approved the phase I clinical research protocol, informed consent form, case report form and other relevant trial documents.

④Researcher training, preparation of phase I ward

⑤ Voluntary subjects are selected through physical examination, and then further comprehensive examination, and qualified candidates are selected.

⑥ Before the start of the trial, an informed consent form was signed for eligible subjects.

⑦Single-dose tolerance test

⑧Multi-dose tolerance test

⑨Data entry and statistical analysis

Phase II clinical trial

Preliminary evaluation stage of therapeutic effect. Its purpose is to preliminarily evaluate the therapeutic effect and safety of the drug on patients with target indications, and also to provide a basis for the design of phase III clinical trials and the determination of the dosage regimen. The research design at this stage can adopt various forms according to specific research purposes, including randomized blinded controlled clinical trials. In Phase II trials, a control group must be set up for blinded randomized controlled trials, and double-blind randomized parallel controlled trials (Double-Blind, Randomized, Parallel Controlled ClinicalTrial) are often used. The sponsor of the double-blind trial needs to provide the test drug and the control drug with the same appearance, color and fragrance, and only indicate the A drug and the B drug. The tester and the subject do not know which drug A or B is the test drug. If it is difficult to prepare the two drugs A and B without distinction, the Double-Blind, Double Dummy Technique can be used, that is, a placebo (C) consistent with drug A is prepared at the same time, and a placebo consistent with drug B is prepared at the same time. The two groups of patients were randomly divided into two groups of placebo (D), and two drugs were taken, one group took A+D, and the other group took B+C. There was no difference in appearance, color, and fragrance of the drugs between the two groups.

Phase III clinical trial

Confirmation stage of therapeutic effect. Its purpose is to further verify the therapeutic effect and safety of the drug on patients with target indications, evaluate the relationship between benefits and risks, and ultimately provide a sufficient basis for the review of drug registration applications. The test should generally be a randomized blinded controlled trial with sufficient sample size.

The design requirements of controlled trials in phase III clinical trials are in principle the same as phase II blinded randomized controlled trials, but phase III clinical controlled trials can be blinded or unblinded for randomized controlled open trials ( Randomized Controlled Open Labeled Clinical Trial). Certain drug categories, such as cardiovascular disease drugs, often have both short-term test purposes, such as observing the effects on blood pressure and blood lipids during a certain test period, and long-term test purposes, such as comparing the mortality of diseases or the incidence of serious complications after long-term treatment. Then, the phase III clinical trial is not only an expansion of the number of cases in the phase II trial, but also a detailed design according to the purpose and requirements of the long-term trial, and careful arrangements can be made to obtain scientific conclusions.

Phase IV clinical trial

Phase IV clinical trial is the application research phase conducted by the applicant after the new drug is marketed. Its purpose is to investigate the efficacy and adverse reactions of drugs under widely used conditions, to evaluate the relationship between benefits and risks used in general or special populations, and to improve dosages.

Technical features of Phase IV clinical trials:

① Phase IV clinical trials are open after market trials, and do not require a control group, but it does not exclude certain indications or Some subjects conduct small randomized controlled trials.

② The number of phase IV clinical trials is in accordance with SFDA regulations, requiring >2000 cases.

③ Although the phase IV clinical trial is an open trial, the selection criteria, exclusion criteria, withdrawal criteria, efficacy evaluation criteria, adverse reaction evaluation criteria, and various observation indicators for determining efficacy and adverse reactions are all relevant. Please refer to the design requirements of Phase II clinical trials.

EAP clinical trials (expanded access program)

EAP clinical trials refer to pharmaceutical companies in order to allow patients with serious diseases who are not suitable to participate in controlled trials, under certain conditions, It is a type of clinical trial that is able to get the treatment of a new drug that is in the clinical trial stage.

Most of the new drug clinical trials adopt a controlled design to evaluate the safety and effectiveness of the new drug. The data from these clinical trials can usually be used to determine whether the drug is safe and effective, and as the basic basis for drug marketing applications. But sometimes, patients are not eligible to participate in these controlled trials due to their own health, age, and other factors, or cannot be selected for other reasons (for example, the patient's residence is too far away from the clinical research center).

These patients with severe diseases may benefit from the treatment of the new drug, but cannot participate in clinical trials of the drug. In order to benefit such patients, the US National Food and Drug Administration (FDA) allows manufacturers of such drugs to provide those patients with the opportunity to obtain new drug treatments under specific conditions, which is called "expanded pathways."

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