R-flurbiprofen
Encyclopedia
Tarenflurbil, or R-flurbiprofen, is the single enantiomer
of the racemate NSAID flurbiprofen
. For several years, research and trials for the drug were conducted by Myriad Genetics
, to investigate its potential as a treatment for Alzheimer's disease
; that investigation concluded in June 2008 when the company announced it would discontinue development of the compound.
can potently inhibit COX, whereas the R-enantiomers exert almost no COX activity. R-Flurbiprofen is inefficiently converted into S-flurbiprofen, with 1.5% of the R-enantiomer undergoing bioinversion to the S-form. Although this compound lacks activity against COX, studies have shown that this drug is a potent reducer of levels of beta amyloid, the main constituent of amyloid
plaques in Alzheimer's disease
, and therefore there was interest in this drug as a therapeutic agent.
reported the results of its Phase II clinical trial of Flurizan; it was the largest ever Alzheimer's drug treatment trial using R-flurbiprofen. Patients were split into three treatment groups, receiving placebo, 400 or 800 mg R-flurbiprofen twice daily for a year. Result from this trial showed that the drug was well tolerated, and positive trends were observed with the 800 mg twice-daily dose in patients with mild Alzheimer's disease. A subgroup of patients that were diagnosed with mild disease, and had high plasma drug levels had significantly less decline in two primary behavioral outcomes (Activities of Daily Living scale (ADCS-ADL) and Global Function (CDR-SB)). Approximately 80 patients enrolled in the optional follow-on study showed continuing benefits with R-flurbiprofen, with increasing positive trends over this period for all primary outcomes after 24 months. On March 5, 2007 Myriad reported final results of the two-year trial, showing that 42% of those 80 patients showed improvement or no decline in one or more of the three primary endpoints of cognition, global function and activities of daily living, compared to a typical 10% of patients on placebo.
A Phase III clinical study evaluated 800 mg R-flurbiprofen twice-daily versus placebo for 18 months exclusively in 1800 patients with mild Alzheimer's disease. This second trial concluded in February 2008 with results reported in the summer. After Phase III testing, which included nearly 1,700 patients with mild Alzheimer’s disease treated for 18 months with either Flurizan or placebo, Myrial Genetics concluded that the drug did not improve thinking ability or the ability of patients to carry out daily activities significantly more than those patients with placebo. Peter Meldrum, the chief executive of Myriad, announced on June 30, 2008, that the company will no longer be developing Flurizan. Prior to this termination, Myriad had sold distribution rights in the European Union to Lundbeck
for an initial payment of $100 million, which Lundbeck has indicated it will now take as a write-down.
Enantiomer
In chemistry, an enantiomer is one of two stereoisomers that are mirror images of each other that are non-superposable , much as one's left and right hands are the same except for opposite orientation. It can be clearly understood if you try to place your hands one over the other without...
of the racemate NSAID flurbiprofen
Flurbiprofen
Flurbiprofen is a member of the phenylalkanoic acid derivative family of non-steroidal anti-inflammatory drugs used to treat the inflammation and pain of arthritis...
. For several years, research and trials for the drug were conducted by Myriad Genetics
Myriad Genetics
Myriad Genetics, Inc. is a molecular diagnostic company based in Salt Lake City, Utah. Myriad employs a number of proprietary technologies that permit doctors and patients to understand the genetic basis of human disease and the role that genes play in the onset, progression and treatment of disease...
, to investigate its potential as a treatment for Alzheimer's disease
Alzheimer's disease
Alzheimer's disease also known in medical literature as Alzheimer disease is the most common form of dementia. There is no cure for the disease, which worsens as it progresses, and eventually leads to death...
; that investigation concluded in June 2008 when the company announced it would discontinue development of the compound.
Mechanism of action
At proposed therapeutic concentrations, this molecule lacks anti-inflammatory activity, and does not inhibit either cyclooxygenase 1 (COX-1) or cyclooxygenase 2 (COX-2) enzymes. Only the S-enantiomers of arylpropionic acid NSAIDNon-steroidal anti-inflammatory drug
Nonsteroidal anti-inflammatory drugs, usually abbreviated to NSAIDs or NAIDs, but also referred to as nonsteroidal anti-inflammatory agents/analgesics or nonsteroidal Anti-inflammatory medicines , are drugs with analgesic and antipyretic effects and which have, in higher doses, anti-inflammatory...
can potently inhibit COX, whereas the R-enantiomers exert almost no COX activity. R-Flurbiprofen is inefficiently converted into S-flurbiprofen, with 1.5% of the R-enantiomer undergoing bioinversion to the S-form. Although this compound lacks activity against COX, studies have shown that this drug is a potent reducer of levels of beta amyloid, the main constituent of amyloid
Amyloid
Amyloids are insoluble fibrous protein aggregates sharing specific structural traits. Abnormal accumulation of amyloid in organs may lead to amyloidosis, and may play a role in various neurodegenerative diseases.-Definition:...
plaques in Alzheimer's disease
Alzheimer's disease
Alzheimer's disease also known in medical literature as Alzheimer disease is the most common form of dementia. There is no cure for the disease, which worsens as it progresses, and eventually leads to death...
, and therefore there was interest in this drug as a therapeutic agent.
Clinical trials
In 2005, Myriad GeneticsMyriad Genetics
Myriad Genetics, Inc. is a molecular diagnostic company based in Salt Lake City, Utah. Myriad employs a number of proprietary technologies that permit doctors and patients to understand the genetic basis of human disease and the role that genes play in the onset, progression and treatment of disease...
reported the results of its Phase II clinical trial of Flurizan; it was the largest ever Alzheimer's drug treatment trial using R-flurbiprofen. Patients were split into three treatment groups, receiving placebo, 400 or 800 mg R-flurbiprofen twice daily for a year. Result from this trial showed that the drug was well tolerated, and positive trends were observed with the 800 mg twice-daily dose in patients with mild Alzheimer's disease. A subgroup of patients that were diagnosed with mild disease, and had high plasma drug levels had significantly less decline in two primary behavioral outcomes (Activities of Daily Living scale (ADCS-ADL) and Global Function (CDR-SB)). Approximately 80 patients enrolled in the optional follow-on study showed continuing benefits with R-flurbiprofen, with increasing positive trends over this period for all primary outcomes after 24 months. On March 5, 2007 Myriad reported final results of the two-year trial, showing that 42% of those 80 patients showed improvement or no decline in one or more of the three primary endpoints of cognition, global function and activities of daily living, compared to a typical 10% of patients on placebo.
A Phase III clinical study evaluated 800 mg R-flurbiprofen twice-daily versus placebo for 18 months exclusively in 1800 patients with mild Alzheimer's disease. This second trial concluded in February 2008 with results reported in the summer. After Phase III testing, which included nearly 1,700 patients with mild Alzheimer’s disease treated for 18 months with either Flurizan or placebo, Myrial Genetics concluded that the drug did not improve thinking ability or the ability of patients to carry out daily activities significantly more than those patients with placebo. Peter Meldrum, the chief executive of Myriad, announced on June 30, 2008, that the company will no longer be developing Flurizan. Prior to this termination, Myriad had sold distribution rights in the European Union to Lundbeck
Lundbeck
H. Lundbeck A/S is a Danish international pharmaceutical company engaged in the research and development, production, marketing, and sale of drugs for the treatment of disorders in the central nervous system , including depression, schizophrenia, Alzheimer’s disease, Parkinson’s disease,...
for an initial payment of $100 million, which Lundbeck has indicated it will now take as a write-down.