Edmonton, AB - Medical Researchers at the University of Alberta reported today evidence that the orphan generic drug Dichloroacetate (DCA) may hold promise as potential therapy for perhaps the deadliest of all human cancers: a form of brain cancer called glioblastoma. The report is published at the journal Science Translational Medicine, a journal of the American Association of the Advancement of Science; it appears today at the journal's web site http://www.sciencemag.org/

In 2007 the U of A team led by Dr Michelakis, published evidence that DCA reverses cancer growth in non-human models and test tubes. The team showed then that DCA achieves these antitumor effects by altering the metabolism of cancer. By altering the way cancer handles its nutrient fuels, specifically the sugars, DCA was able to take away cancer's most important strength, the resistance to death. Since then, several independent groups across the world have confirmed the Alberta team's findings. In December 2009, the editors of "Science" predicted that cancer metabolism is one of only 5 areas across all scientific disciplines, to "watch for major breakthroughs" in 2010.

The U of A team set out to show that the way that DCA works in actual patients is the same with the way it works in the lab. In addition, researchers wanted to show whether DCA is safe and possibly effective in very sick patients with brain cancer.

By extracting glioblastomas from 49 patients over a period of 2 years and studying them within minutes of removal in the operating room, the team showed that tumors respond to DCA by changing their metabolism. Then, the team treated 5 patients with advanced glioblastoma and secured tumor tissues before and after the DCA therapy. By comparing the two, the team showed that DCA works in these tumors exactly as was predicted by test tube experiments. This is very important because often the results in non-human models tested in the lab do not agree with the results in patients. In addition, the team showed that DCA has anti-cancer effects by altering the metabolism of glioblastoma cancer stem cells, the cells thought responsible for the recurrences of cancer.

In the 5 patients tested, the drug took 3 months to reach blood levels high enough to alter the tumor's metabolism. At those levels, there were no significant adverse effects. However, at some of the higher doses tested, DCA caused nerve malfunction, i.e. numbing of toes and fingers. Importantly, in some patients there was also evidence for clinical benefit, with the tumors either regressing in size or not growing further during the 18 month study.

No conclusions can be made on whether the drug is safe or effective in patients with this form of brain cancer, due to the limited number of patients tested by the study's leads Drs Michelakis and Petruk. Researchers emphasize that use of DCA by patients or physicians, supplied from for-profit sources or without close clinical observation by experienced medical teams in the setting of research trials, is not only inappropriate but may also be dangerous. The U of A results are encouraging and support the need for larger clinical trials with DCA. This work is also one of the first in humans to support the emerging idea that altering the metabolism of tumors is a new direction in the treatment of cancer, Michelakis and Petruk said.

The research team hopes to secure additional funding to continue the ongoing trials with DCA at the University of Alberta. Further studies would include more patients with brain cancer, and test the combination of DCA and standard chemotherapies, eventually including patients from other academic health sciences centres.

One of the intriguing features of this work was that it was funded largely by public donations, including philanthropic foundations and individuals. In addition, it received support by Alberta public institutions, both the University of Alberta and Alberta Health Sciences. The multidisciplinary team that performed this challenging translational research included members of the Departments of Medicine, Diagnostic Imaging and Biomedical Engineering, Oncology and Neurosurgery. Clinicians, scientists, nurses and graduate students worked together for 2 years and express their gratitude to the people of Alberta, philanthropists, the patients and their families.

http://www.dca.med.ualberta.ca/Home/Updates/2010-05-12_Update.cfm

Here is the abstract of Michelakis' paper:

Solid tumors, including the aggressive primary brain cancer glioblastoma multiforme, develop resistance to cell death, in part as a result of a switch from mitochondrial oxidative phosphorylation to cytoplasmic glycolysis. This metabolic remodeling is accompanied by mitochondrial hyperpolarization. We tested whether the small-molecule and orphan drug dichloroacetate (DCA) can reverse this cancer-specific metabolic and mitochondrial remodeling in glioblastoma. Freshly isolated glioblastomas from 49 patients showed mitochondrial hyperpolarization, which was rapidly reversed by DCA. In a separate experiment with five patients who had glioblastoma, we prospectively secured baseline and serial tumor tissue, developed patient-specific cell lines of glioblastoma and putative glioblastoma stem cells (CD133+, nestin+ cells), and treated each patient with oral DCA for up to 15 months. DCA depolarized mitochondria, increased mitochondrial reactive oxygen species, and induced apoptosis in GBM cells, as well as in putative GBM stem cells, both in vitro and in vivo. DCA therapy also inhibited the hypoxia-inducible factor–1α, promoted p53 activation, and suppressed angiogenesis both in vivo and in vitro. The dose-limiting toxicity was a dose-dependent, reversible peripheral neuropathy, and there was no hematologic, hepatic, renal, or cardiac toxicity. Indications of clinical efficacy were present at a dose that did not cause peripheral neuropathy and at serum concentrations of DCA sufficient to inhibit the target enzyme of DCA, pyruvate dehydrogenase kinase II, which was highly expressed in all glioblastomas. Metabolic modulation may be a viable therapeutic approach in the treatment of glioblastoma.

http://stm.sciencemag.org/content/2/31/31ra34.abstract