Monday, April 26, 2010

Clinical trial - making sense of it

Hi everyone ,

I have started my new job in a busy tertiary hospital as clinical research fellow and I mostly deal with cancer clinical trial.Let me explain what is clinical trial .

Once the scientist come up with a new molecule which has effect on cancer in the test tubes (Cell culture ).This then goes to animal study .Most of the animal studies have human cancer transferred to an accessible site such as thigh .As the natural history of the cancer is to grow .The the new molecule is administered to the animal and the tumor is assessed for response .This not only gives us idea about efficacy also potential side effects .

Phase I Clinical trial - First in human trial
aim to find the right dose of the drug
secondary aim -efficacy and toxicity

started in a small group of patient at a low dose .This dose is double in subsequent groups ,till there is dose limiting side effects this is the maximum tolerable dose(MTL) .The cohort just below the MTL becomes the standard dose for next phase

For patient-- every one gets drug.No sugar pills
what if you start at low dose.Well if in the tumour starts to grow ,the dose is increased till you reach the standard dose .

Phase II - Pilot study for efficacy in a small group of patient
for patient -everyone gets the drug .No sugar pills(placebo)
Depending on the efficacy the drug advances to the next phase .

Phase III - Randomised clinical trial
The final stage before drug comes to market
Aim is to compare the experimental drug with standard treatment .
if there is no standard treatment ,then against placebo.

1- randomised - to avoid selecting particular group to certain arm of trial the patient are randomised .This is doen by computer.It could be 1:1 or 2:1 .Proportion of patient in each arm.

2- If the doctor ,and patient does not know what treatment he/she is on - its called Blinding,if not blinded its called open label

You can find all registered clinical trial world wide here

pooh thats a lot for a post .So let me know if it helped anyone .Please leave your comments or question

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