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Clinical Drug Trials - Why are they so important?


What is a clinical trial? 

"Behind most every treatment, medicine, therapy & medical device...are millions of people who have volunteered to take part in clinical trials." The Impact Clinical Trials Have on All of Us - CISCRP 

Clinical trials are research studies that rely on volunteers in order to answer questions about safety and efficacy of new drug (or device) treatments. There are several phases of clinical trials that must be completed before the drug can come to market, termed phases I-III. 

 

Phases of Clinical Trials 

 

Phase I trials focus on drug safety. These studies are typically small in number (20-100 participants), short in time, and enroll healthy volunteers. 

Phase II trials test drug efficacy: does the drug do what it is intended to do, e.g., prevent bleeding or lesion development? These studies are often longer in duration (months to years, depending on trial design) and may enroll several hundred volunteers who have cavernous angioma. The trial is seeking to determine whether a drug works on the condition, is safe, and what doses are most appropriate. 

Phase III trials are similar to Phase II in design, but typically follow a larger cohort of study participants for a longer duration of time. These trials determine whether the new drug is more effective and/or safer than the current standard of care. With positive Phase III results, the study investigator or pharmaceutical company running the trial will seek FDA approval for the drug. The FDA approval process typically requires 6 months to one year of time.

Phase IV trials are the largest and longest duration studies. These are post-marketing surveillance studies that follow patients who are being treated with the approved therapy. Phase IV studies aim to assess long term effectiveness, safety, side-effects and comparative effectiveness of the drug relative to other approved therapies. 

With at least a dozen therapeutic approaches under study (www.angioma.org/pipeline), the research is moving faster than ever. The atorvastatin trial for symptomatic hemorrhage is currently enrolling participants at the University of Chicago. 

Stay tuned for study announcements and don't forget to register for the patient registry (www.angioma.org/registry). 

 

Frequently Asked Questions

Several drugs under investigation are already approved for other uses, can I just go ahead and start taking them to treat my cavernous angiomas?

The development of medications to treat cavernous angiomas is the objective we have all been dreaming of - a non-invasive way of preventing hemorrhage and the development of new lesions. While it may be tempting to run to your doctor and get a prescription for any of the medications that will be tried, there are at least three reasons why this may not be a good idea:

  1. The medications under consideration have been tested only in mice and fish that have been genetically engineered to have the hereditary form of cavernous angioma. They have not been tested in humans with cavernous angiomas. This means that we do not know the proper dosing for humans, and it is also possible that they may not work or may indeed have a negative effect. To be as safe as possible, anyone taking a trial medication should be under the supervision of the researcher who is running the trial.
  2. If you take a medication before it is shown to be effective in humans for the treatment of cavernous angiomas, you will become ineligible for participation in drug studies, at least until you have been off the medication for a period of time. To prove that a medication works, we will need initially a small number of people to participate in pilot studies and then many people to participate in broader clinical trials. We need to help research move these possible treatments forward quickly and not muck up the studies with unsupervised use.
  3. A study may actually be trying to compare the effectiveness of a particular medication on a variety of disorders and cavernous angiomas may be an experimental control.  It may turn out that a medication works well for treating other vascular malformations but does not work for cavernous angiomas. Just because a medication is under study does not mean it is a good candidate for treating our specific lesions.

 

Who qualifies for trial participation? 

Qualification depends on what the drug does and how the trial is designed. For example, a drug designed to prevent hemorrhage will focus on cavernous angioma patients who have recently hemorrhaged, as this group is most likely to hemorrhage again. A drug that aims to shrink lesion size could include everyone with a lesion, while a drug that prevents new lesion formation would need to be tested on those with familial cavernous angioma and multiple lesions. Inclusion criteria may also include age restrictions, lab values, and current and recent medication use, for example. Each study will have a unique and well-defined set of inclusion and exclusion criteria. 

 

What is a phase I/II Study?

The atorvastatin trial for treatment of symptomatic hemorrhage is a phase I/II because it is assessing both safety and efficacy in one study. The safety part of the study is to determine whether the drug is safe for folks with cavernous angioma – it is previously known safe for treatment of high cholesterol.

Using the atorvastatin trial as an example, with positive results the study investigators will continue to phase III investigations and seek FDA approval, following the typical strategy diagrammed above.  

 

Why might different numbers of participants be required for different studies? 

Each trial will follow a unique protocol specific to the drug of interest, mechanism of action and intended effect on the treated individual. These factors influence the study design, duration and number of study participants. Study investigators use mathematical tools called power calculations to determine the number of participants and duration of a study. 

 

Why will some participants take a placebo?

Testing for efficacy (does the drug work to treat the condition?) requires a comparison of a treated group to a non-treated group. Commonly used study design is that of a randomized controlled trial (aka placebo-controlled trial). Following this study design, participants are randomly assigned to take either the study medication or a placebo. In a blinded study, the information is coded so that neither the participant nor the study doctor knows if the pill is the study drug or placebo. This information is only revealed at the end of the study during analysis.


For the most current information about studies that need participants, please visit this PAGE and consider joining the Cavernous Angioma Patient Registry: www.angioma.org/registry