Recent federal rules require registration of all clinical trials investigating a new therapy. These registrations are available to be viewed at ClinicalTrials.gov , a website maintained by the federal government. However, intepreting the information provided on ClinicalTrials.gov is not always straightforward. The tips below will help with understand particular data fields on the website.
Study Design: see
What is a "Phase" for details on these concepts
Allocation: Randomized or not
Placebo control: Use of placebo in any arms of the study
Endpoint classification: Is the goal of the study efficacy or safety?
Inteverntion model: Parallel assignment means all arms are open at the same time, instead of one at a time.
Masking: Also called blinding. Who knows about the arm to which a patient is randomized (if applicable)?
Primary endpoint: The single goal of the study, commonly one of the following:
Response rate: What percent of patients had a meaningful shrinkage of the tumor (RR)
Progression-free survival: The time that patients are alive without the cancer growing (PFS)
Time to progression: Variant of PFS measuring time until the cancer starts growing again (TTP)
Overall survival: The time that patients are alive, regardless of what may have caused the patients death (OS)
Enrollment: Number of patients to be treated, assuming that there is sufficient efficacy to fully enroll.
Arms: Patients treated in the same way are on the same study "arm". This section lists that number of arms and treatments proposed in each arm, also delineated in the full description.
Eligibility criteria: What type of patients are eligible to be enrolled. A few key items:
Measurable disease by RECIST (a way of measuring the amount of cancer from the CT scans) which typically requires one tumor at least 1 cm in size on CT scans.
Performance status reflects how sick the patient is from the cancer; more toxic regimens may have more
restrictive criteria for performance status in order to protect patients from therapies unlikely to benefit them.
Creatinine clearance: A measure of kidney function, derived from the creatinine blood level.
Time from last dose of chemotherapy (typically 3 or 4 weeks) to make sure the prior therapy is out of the body.
Histologically proven cancer means that some tissue has been demonstrated to have cancer by a pathologist.
Sponsor: This provides an estimate on who is the main propronent of this study or who came up with the idea. Some studies are the idea of pharmaceutical companies and are performed in collaboration of oncology facilities. Other studies are the idea of oncologists or researchers in academic institutions, and their institution will be listed as the sponsor. Neither academia nor industy has a monopoly on good ideas, so this may not be a critical factor in evaluating a clinical trial.
Funding Source: Simply put: who is paying for the study? Note, this can be different from the sponsor of the study.
Something else that needs explanation? Contact us by the link at the top right to request that it be added to the website.