Don't get Fazed by Phases

Don't get Fazed by Phases

With the information from the current American Society of Hematology (ASH) 2013 beginning to flood out, we'll be reading of findings in different trial phases.

Your decision on whether to join a treatment trial may well be influenced by the phase of the trial, so it is well worth understanding what is covered in each phase.

From the Wikipedia references:

Clinical Trial

Phases of clinical research

"Clinical trials involving new drugs are commonly classified into four phases. Each phase of the drug approval process is treated as a separate clinical trial. The drug-development process will normally proceed through all four phases over many years. If the drug successfully passes through Phases 0, 1, 2, and 3, it will usually be approved by the national regulatory authority for use in the general population.

Phase 0: Pharmacodynamics and Pharmacokinetics

Phase 1: Screening for safety

Phase 2: Establishing the efficacy of the drug, usually against a placebo

Phase 3: Final confirmation of safety and efficacy

Phase 4: Sentry studies during sales

Each phase has a different purpose and helps scientists answer a different question:

Phase 0 trials are the first-in-human trials. Single subtherapeutic doses of the study drug are given to a small number of subjects (10 to 15) to gather preliminary data on the agent's pharmacodynamics (what the drug does to the body) and pharmacokinetics (what the body does to the drugs).[19]

In Phase 1 trials, researchers test an experimental drug or treatment in a small group of people (20–80) for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.

In Phase 2 trials, the experimental treatment is given to a larger group of people (100–300) to see if it is effective and to further evaluate its safety.

In Phase 3 trials, the treatment is given to large groups of people (1,000–3,000) to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow it to be used safely.

In Phase 4 trials, postmarketing studies delineate additional information, including the treatment's risks, benefits, and optimal use.

Before pharmaceutical companies start clinical trials on a drug, they conduct extensive preclinical studies."

We owe so much to those who have entered clinical trials. They've ventured into unknown territory so that we know how effective different treatments are and what the likely side effects will be. When you read the side effects listed on the information leaflets that comes in each medicine packet, just remember that a person suffered one or more of those side effects and it was most likely documented during a clinical trial.


8 Replies

  • Great overview Neil, thanks.

    One comment, phase III clinical trials in CLL are usually well under 1000 participants, because we are an orphaned, rare and neglected disease...

    A huge CLL trial worldwide might set a goal at 500 or 600 patients... the largest trial I can recall was the German CLL8 FC/FCR and it had 816 patients... but it took forever to accrue.


  • The phase 3 RESONATE2 trial that I am taking part in is recruiting 272 (approximately) from up to 85 centres around the world.

  • Makes you appreciate the effort into coordinating all those sites to ensure a consistent approach and then collating all the information from so many centres. With an average of around 3 patients per site, for the trial you are in, I'd assume that some sites have only 1 or 2 patients enrolled. It's no wonder that trial results don't always get published or can take so long.

  • Yes, my consultant tells me that they have just recruited their 5th patient so it's on a 'first come first served' basis. Bournemouth have been told that they are the top recruiter so far. We have a very strict protocol to follow in order to ensure a consistent approach across the centres. Given that the study opened in the first quarter of this year and only for 272 patients around the world, I'm rather surprised that it is still open to recruitment.

  • Is the clinical trial system broken anyway..

    There is some criticism of the whole process.

    See :-


  • Conflicts of interest in the medical world.

    As detailed by The Pew Charitable Trust.

    Out of concern that certain industry relationships can threaten the integrity of academic medical centers and bias physicians’ therapeutic choices and clinical practices, a number of medical schools have adopted conflict-of-interest policies for their faculty and medical centers that ban many industry inducements to influence students, trainees, and faculty.

    In addition, pressure from the U.S. Office of the Inspector General, congressional hearings, and lawsuits alleging deceptive marketing practices led the Pharmaceutical Research and Manufacturers of America to recommend that member companies cease providing non-educational gifts and certain types of free meals to physicians.

    See more at :-

    From personal knowledge I know the sometimes extreme measures adopted by drug companies to induce doctors to prescribe the newest and latest ( expensive ) drug.


  • No mention of all the branded trinkets you typically see on your doctor's desk like the diary, calendar, pens, notepaper, post-it notes etc. They wouldn't have any influence when your doctor goes to fill out a prescription for you.

    The funniest trinket I've ever seen hands down (pun intended) was a Viagra branded wall clock at my local hospital. The battery was nearly flat and I'm sure we've all seen how this can make the minute hand gets stuck at around the 40 minute mark and make a little jump every minute. Well that's what this clock was doing.

  • Additional news on the above subject.

    See BBC news at :-


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