clinical trial

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 [tri´al, trīl]
a test or experiment.
clinical trial an experiment performed on human beings in order to evaluate the comparative efficacy of two or more therapies. See also single blind, double blind, and triple blind.

clinical trial

a controlled experiment involving a defined set of human subjects, having a clinical event as an outcome measure, and intended to yield scientifically valid information about the efficacy or safety of a drug, vaccine, diagnostic test, surgical procedure, or other form of medical intervention.

Four phases of clinical trial are distinguished. Phase I trials usually involve fewer than 100 healthy volunteers who are exposed to a new drug or procedure. Such studies seek to establish optimal dosage and route of administration and to detect adverse reactions. Phase II trials generally involve 200-500 volunteers randomly assigned to control and study groups. These are pilot efficacy studies, with emphasis on immunogenicity in the case of vaccines, and on relative efficacy and safety in the case of drugs, procedures, and devices. Phase III trials, often multicenter, involve thousands of volunteers, randomly assigned to control and study groups. The aim is to generate statistically relevant data. Phase IV trials are conducted after a national drug registration authority (in the U.S., the Food and Drug Administration) has approved an agent for distribution or sale. They may explore specific pharmacologic effects, adverse reactions, or long-term effects.

clinical trial

A research study using consenting human subjects that tests the effectiveness and safety of a treatment, a diagnostic tool, or a prophylactic intervention.

clinical trial

A research study involving human subjects designed to answer specific questions about the safety and efficacy of a biomedical intervention (drug, treatment, device), or new ways of using a known drug, treatment or device.

clinical trial

Clinical medical trial, clinical research trial Research A controlled study involving human subjects, designed to evaluate prospectively the safety and effectiveness of new drugs or devices or behavioral interventions. See Drug discovery, IND, Phase I, II, and III studies.

clin·i·cal trial

(klini-kăl trīăl)
A controlled experiment involving a defined set of human subjects, having a clinical event as an outcome measure, and intended to yield scientifically valid information about the efficacy or safety of a drug, vaccine, diagnostic test, surgical procedure, or other form of medical intervention.

clinical trial

a scientifically controlled study under specific conditions, to test, for example, the effectiveness of a drug/ treatment.

Clinical trial

All new drugs undergo clinical trials before approval. Clinical trials are carefully conducted tests in which effectiveness and side effects are studied, with the placebo effect eliminated.

trial, randomized controlled (RCT) 

An experimental design used for testing the effectiveness of a new medication or a new therapeutic procedure. Individuals are assigned randomly to a treatment group (experimental therapy) and a control group (placebo or standard therapy) and the outcomes are compared. The trial is strengthened by 'blinding' or masking (single-blind, double-blind or triple-blind study) and cross-over design. RCT is the most accepted scientific method of determining the benefit of a drug or a therapeutic procedure. It represents the best evidence available, which is integrated into the final decision about the management of a condition by healthcare practitioners in what is called evidence-based healthcare. Syn. randomized clinical trial. See sampling; significance; study.

clinical trial,

n a trial based upon the scientific method in which a control group and a test group are compared over time in order to study a single, differing factor.
References in periodicals archive ?
We are making plans to initiate a Phase III trial in adults in the first half of calendar 2007, and to conduct a small pharmacokinetic study in children to enable us to choose doses for a Phase II / III pediatric study to start later in 2007.
The authors further investigated the relationship between Targretin-induced hypertriglyceridemia and survival, which was reported initially in the SPIRIT Phase III trials in patients with previously untreated NSCLC.
Long-term catalysts include: 1) the initiation of Phase III trial for NX-1207; and 2) the approval and timing for launch of AlzheimAlert test kits in the U.
GlaxoSmithKline also announced today the details of the Phase III trial.
Top line results of the Phase II trial in ITP -- which had a similar design as the Phase III trial, but tested various dosing levels -- were reported in December 2005, in conjunction with the 47th Annual Meeting of the American Society of Hematology in Atlanta.
XIFAXAN (rifaximin), dosed 400 mg three times daily, is being investigated in a vancomycin comparator, 300-subject Phase III trial to evaluate the efficacy and safety of XIFAXAN for the treatment of CDAD.
Completing enrollment in the first of two Phase III trials is a major milestone toward the commercialization of this important product," said Dr.
However, three Phase III trials undertaken by GSK failed and development was stopped.
A pivotal Phase III trial in HIV-positive patients with OPC is expected to initiate in the US in 2006, under an IND recently allowed by the US Food and Drug Administration (FDA).
Commencement of a Phase III Trial with Extina: The Phase III trial has been initiated with Extina(R), an investigational new drug formulation of 2% ketoconazole using the Company's VersaFoam(R) delivery system for the treatment of seborrheic dermatitis.
PARIS -- BioAlliance Pharma Announces FDA Allowance of IND for US Pivotal Phase III Trial of Miconazole Lauriad(R) for Treatment of Oropharyngeal Candidiasis.
As part of the IND filing, BioAlliance will also submit the results of two completed Phase III trials conducted in the EU, one in head & neck cancer patients following radiotherapy and the other in HIV-positive patients.