Results from New Drug Studies Reported at International Conference on Alzheimer's Disease
Last month I provided a preview of what were predicted to be some of the “Hot Topics” to be presented at ICAD – The International Conference on Alzheimer’s Disease. ICAD, attended by more than 5,000 participants from 60 countries, is by far the largest conference on AD and the premier forum for presenting the results of important research into diagnosis, treatment, and prevention of Alzheimer’s disease. Among the results reported at the meeting were:
- Bapineuzumab – “The Alzheimer’s Disease Vaccine” - The most anticipated presentation at ICAD was the results of the phase II trial of Bapineuzumab. More than 2,000 scientists, practitioners, and financial analysts, packed an enormous lecture hall and many others were directed to satellite rooms with video feeds to learn he results of a study that suggested that bapinuezumab was beneficial to some patients participating in the trial, and for those patients the data also suggested that the progression of the disease was significantly slowed. The data also showed a manageable side effect profile. Comment: The results of phase II studies must always be treated with caution. They are primarily intended to evaluate the safety of a drug and to use the data on both safety and effectiveness to design a much larger phase III trial (now enrolling patients), that will ultimately determine just how effective the drug might be and whether it will be FDA approved for use.
- Tarenflurbil (Flurizan, Myriad Genetics) – The results of this clinical trial were presented at the same session. Despite a good safety profile, there was no cognitive or functional benefit realized by patients taking Flurizan. Comment: Following the largest and longest study of AD to date, Flurizan has now been withdrawn from development. Had this been a positive trial, the FDA may have considered approving Flurizan as the first drug to slow progression of AD.
- MTC (brand name, RemberTM, TauRX Therapeutics) is hypothesized to block the toxic effects of tangles (as opposed to amyloid plaques as in the case of Bapineuzumab and Tarenflurbil) and in doing so to alter disease progression. The results of this phase II study claimed to significantly slow disease progression. Comment: although provocative and worthy of further study, many expressed skepticism about the large effects reported (the title of the paper stated that “remberTM arrests disease progression”) and that the data were reported by the Chairman of the company, rather than an independent investigator. To date, no firm plans for subsequent clinical trials have been announced.
- PBT2 (Prana Biotechnlogy) is another compound that is hypothesized to reduce amyloid in the brain. It does so by preventing the interaction of amyloid with brain copper and zinc. The small (78 participants) phase II study found a reduction of amyloid in the spinal fluid of treated patients. It also found preliminary evidence of some cognitive benefit. Comment: Although preliminary, the results of this trial suggest that this drug will move into larger scale trials.
- PRX3140 (EPIX Pharmaceuticals) – This drug is hypothesized to both improve the symptoms of AD and to slow disease progression by affecting amyloid. Results reported results from a small phase II study that showed that the drug was well tolerated and suggested substantial cognitive benefit in just two weeks. Comment: These interesting early results are now being tested in two larger studies that are currently enrolling patients. (EPIX website).