An Explanation of the DCA Clinical Trials
The news stories I first heard said that placebos were to be used in the trials. That is an error. There are no placebos being used.
------------- the following is from an email we received January 15, 2008, by an anonymous scholar and scientist:
A description of the trial is here:
The study has two arms of twenty-five patients, involving recurrent glioblastoma patients (those who have received previous treatment, but whose tumors have grown back) and newly diagnosed patients (those who have not received any previous treatment). Both arms will receive DCA. There are no control arms, i.e. nobody will receive a placebo. The trial is "open label", meaning everyone knows what agent they are receiving.
Clinical trials of this type (called phase II) often do not contain control groups, and are usually compared to "historical controls" (for example, control groups from previous phase III studies). A phase III trial is performed after a positive result from a phase II trial, and includes many more patients, as well as a randomized control group, and may be "blinded" if feasible, ie. the doctors and patients may not know whether they are administering/receiving the drug or a placebo. Phase III trials are much more expensive than phase II trials.
Here is an example of a recent (successful) phase II trial for the same cancer, recurrent glioblastoma multiforme.
For a disease like recurrent glioblastoma multiforme, or other cancers for which no effective treatment is available, a strong positive result from a phase II clinical trial may be sufficient for many oncologists to consider prescribing DCA "off label", particularly if their patients request it and the reported side-effects are minimal.
Furthermore, there are some instances where treatments have received FDA approval without a phase III trial through a process called “accelerated approval”. Accelerated approval is “intended to make promising products for life threatening diseases available on the market on the basis of preliminary evidence prior to formal demonstration of patient benefit”. More details on this process are available here: http://www.accessdata.fda.gov/scripts/cder/onctools/Accel.cfm. Additionally, if there is currently no available treatment and the condition is sufficiently rare, a drug may be granted "orphan drug status" in which the formal criteria for FDA approval are also less rigorous. Potential treatments for recurrent glioblastoma have previously received this designation, for example TM601: http://www.pr-inside.com/transmolecular-receives-orphan-drug-designation-r374039.htm. There is more on orphan drug status here: http://www.fda.gov/orphan/designat/prevalence.html. Interestingly, another criterion for orphan drug status that may be particularly pertinent to DCA is if “there is no reasonable expectation that costs of research and development of the drug…can be recovered by sales of the drug in the United States”.
Because the University of Alberta trial is open-label and not blinded, data will be continually compiled. The outcomes that will be assessed by the researchers are response of tumor size on CT or MRI scans, progression-free survival time, and overall survival. Median survival for glioblastoma patients with current treatment is about 14 months (i.e. half of patients are dead by 14 months, half live longer than 14 months), so unless DCA makes things worse, it will take 14 months to gather this type of survival data (after the last patients have been recruited). However, the data on the effect of DCA on tumor size and progression-free survival will be collected more rapidly. The median progression-free survival rate for glioblastoma is only about 5-6 months: this means that with current treatment, half of tumors will appreciably increase in size after six months. It will require even less time to gather information on the 25 recurrent glioblastoma cases, for which historical median survival is only twelve weeks. Interim reports on the progress of the trial may be published or provided at research conferences, such as the ASCO annual conference in May 30-June 3. It is also common for researchers to publish interim reports on phase II clinical trials. For example, here is an interim report on the clinical trial mentioned above, published about six months before the final study:
Abstracts for this year's ASCO conference (i.e. summaries of what researchers will present) have not yet been published: