Latrepirdine

Latrepirdine

Systematic (IUPAC) name
2,3,4,5-tetrahydro-2,8-dimethyl-5-(2-(6-methyl-3-pyridyl)ethyl)-1H-pyrido(4,3-b)indole
Clinical data
Pregnancy cat.	?
Legal status	℞ Prescription only
Routes	Oral
Identifiers
CAS number	3613-73-8
ATC code	None
PubChem	CID 197033
ChemSpider	170644
UNII	OD9237K1Z6 Y
Chemical data
Formula	C21H25N3
Mol. mass	319.443 g/mol

Latrepirdine (INN, also known as dimebolin and sold as Dimebon), is an antihistamine drug which has been used clinically in Russia since 1983.^[1]

Research is continuing in both Russia and western nations into potential applications as a neuroprotective drug to combat Alzheimer's disease and, possibly, as a nootropic as well.^[2] However, a Phase III clinical trial for Alzheimer's disease (AD) treatment failed to show any benefit. Three other AD trials continue.^[3] Dimebon failed in the phase III trial for Huntington disease.^[4]

Uses

Latrepirdine is an orally-active small molecule compound that has been shown to inhibit brain cell death in preclinical studies of Alzheimer's disease and Huntington's disease, making it a potential treatment for these and other neurodegenerative diseases. Research suggests that it may also have cognition-enhancing effects in healthy individuals, in the absence of neurodegenerative disease pathology.^[5]

Alzheimer's disease: failed clinical trial

Latrepirdine attracted renewed interest in 2009 after being shown in small preclinical trials to have positive effects on persons suffering from Alzheimer’s disease. Animal studies showing potential beneficial effects on Alzheimer's disease models were shown in Russian research in 2000.^[6] Preliminary results from human trials have also been promising. In an initial six-month phase II trial, results have shown that at 12 months there was significant improvement over placebo.^[7] Latrepirdine showed promising results in a Phase III equivalent double blind trial in Russia with mild–moderate stage patients.^[8][9] In April 2009, Pfizer and Medivation initiate a phase III trial (CONCERT study) aiming for FDA approval.^[10] In March 2010, Pfizer announced that this clinical trial failed to show any benefit for the treatment of Alzheimer's disease patients.^[3]

Numerous phase III trials for AD were recruiting in 2009.^{[11][12][13][14]}

In July 2009 Pfizer and Medivation announced that latrepirdine will be the proposed international nonproprietary name for latrepirdine for the treatment of Alzheimer's.^[15]

In March 2010 the results of a clinical trial phase III were released. It was announced that the investigational Alzheimer's disease drug dimebon failed in the pivotal CONNECTION trial of patients with mild-to-moderate disease.^[16]

Huntington's disease

In April 2011 latrepirdine failed in a Phase 3 clinical trial of patients affected with Huntington’s disease.^[4] The trial was sponsored by Medivation Inc. and Pfizer.

Pharmacology

Latrepirdine appears to operate through multiple mechanisms of action, both blocking the action of neurotoxic beta-amyloid proteins and inhibiting L-type calcium channels,^[17] modulating the action of AMPA and NMDA glutamate receptors,^[18] and may exert a neuroprotective effect by blocking a novel target that involves mitochondrial pores,^[19] which are believed to play a role in the cell death that is associated with neurodegenerative diseases and the aging process.^[20] It also blocks a number of other receptors including α-adrenergic, 5-HT_2C, 5-HT_5A, and 5-HT₆.^[21] It is of significance to note that latrepirdine lacks any anticholinergic effects.^[22]

See also

For Alzheimers disease :

• Donepezil
• Galantamine
• Memantine
• Rivastigmine also for Parkinsons

References

1. ^ Matveeva IA (July-August 1983). "Action of dimebon on histamine receptors" (in Russian). Farmakologiia i Toksikologiia 46 (4): 27–29. PMID 6225678. 
2. ^ Shevtsova EF, Kireeva EG, Bachurin SO (2005). "Mitochondria as the target for neuroprotectors" (in Russian). Vestnik Rossiiskoi Akademii Meditsinskikh Nauk (9): 13–17. PMID 16250325. 
3. ^ ^{a b} Novel Alzheimer's Drug Flops, MedPage Today, March 03, 2010
4. ^ ^{a b} http://www.genengnews.com/gen-news-highlights/phase-iii-failure-leads-medivation-and-pfizer-to-ditch-dimebon-for-huntington-disease/81244981/
5. ^ Bachurin S, Bukatina E, Lermontova N, Tkachenko S, Afanasiev A, Grigoriev V, Grigorieva I, Ivanov Y, Sablin S, Zefirov N (June 2001). "Antihistamine agent Dimebon as a novel neuroprotector and a cognition enhancer". Annals of the New York Academy of Sciences 939: 425–435. doi:10.1111/j.1749-6632.2001.tb03654.x. PMID 11462798. 
6. ^ Lermontova NN, Lukoyanov NV, Serkova TP, Lukoyanova EA, Bachurin SO (June 2000). "Dimebon improves learning in animals with experimental Alzheimer's disease". Bulletin of Experimental Biology and Medicine 129 (6): 544–546. doi:10.1007/BF02434871. PMID 11022244. 
7. ^ Pollack, Andrew (2007-06-11). "Antihistamine Shows Promise in Treating Alzheimer’s". New York Times. http://www.nytimes.com/2007/06/11/business/11drug.html?ei=5090&en=6dd260f0ecf61466&ex=1339214400&partner=rssuserland&emc=rss&pagewanted=print. Retrieved 2010-05-01. 
8. ^ Phend Crystal, Jasmer Robert (2008-07-17). "Old Antihistamine Pops Up as Potential Alzheimer's Therapy". Medpage Today. http://www.medpagetoday.com/Geriatrics/AlzheimersDisease/tb/10174. 
9. ^ Doody Rachelle S et al (2008-07-19). "Effect of dimebon on cognition, activities of daily living, behaviour, and global function in patients with mild-to-moderate Alzheimer's disease: A randomised, double-blind, placebo-controlled study". Lancet 372 (9634): 207–215. doi:10.1016/S0140-6736(08)61074-0. PMID 18640457. 
10. ^ http://www.reuters.com/article/pressRelease/idUS117499+15-Apr-2009+PRN20090415 "Pfizer and Medivation Initiate Phase 3 Trial of Dimebon Added to Donepezil in Patients with Alzheimer's Disease" Apr 2009
11. ^ http://clinicaltrials.gov/ct2/show/NCT00838110 "A Phase 3 Study To Evaluate The Safety And Tolerability Of Dimebon Patients With Mild To Moderate Alzheimer's Disease"
12. ^ http://clinicaltrials.gov/ct2/show/NCT00912288 "A Phase 3 Efficacy Study Of Dimebon In Patients With Moderate To Severe Alzheimer's Disease"
13. ^ http://clinicaltrials.gov/ct2/show/NCT00939783 "An Extension To The B1451027 Protocol To Evaluate The Long Term Safety And Tolerability Of Dimebon In Patients With Alzheimer's Disease"
14. ^ http://clinicaltrials.gov/ct2/show/NCT00954590 "A Safety and Efficacy Study Evaluating Dimebon (Latrepirdine) in Patients With Moderate to Severe Alzheimer's Disease (CONTACT)"
15. ^ "Pfizer And Medivation Initiate Phase 3 Trial Of Dimebon In Patients With Huntington Disease" (Press release). Pfizer Inc.. 2009-07-30. http://newsblaze.com/story/2009073005345800002.bw/topstory.html. Retrieved July 31, 2009. 
16. ^ Dimebon Disappoints in Phase 3 Trial
17. ^ Lermontova NN, Redkozubov AE, Shevtsova EF, Serkova TP, Kireeva EG, Bachurin SO (November 2001). "Dimebon and tacrine inhibit neurotoxic action of beta-amyloid in culture and block L-type Ca(2+) channels". Bulletin of Experimental Biology and Medicine 132 (5): 1079–1083. doi:10.1023/A:1017972709652. PMID 11865327. 
18. ^ Grigorev VV, Dranyi OA, Bachurin SO (November 2003). "Comparative study of action mechanisms of dimebon and memantine on AMPA- and NMDA-subtypes glutamate receptors in rat cerebral neurons". Bull Exp Biol Med 136 (5): 474–477. doi:10.1023/B:BEBM.0000017097.75818.14. PMID 14968164. 
19. ^ Bachurin SO, Shevtsova EP, Kireeva EG, Oxenkrug GF, Sablin SO (May 2003). "Mitochondria as a target for neurotoxins and neuroprotective agents". Annals of the New York Academy of Sciences 993: 334–44; discussion 345–9. doi:10.1111/j.1749-6632.2003.tb07541.x. PMID 12853325. http://www3.interscience.wiley.com/resolve/openurl?genre=article&sid=nlm:pubmed&issn=0077-8923&date=2003&volume=993&spage=334. 
20. ^ "Medivation's Dimebon(TM) Maintains Statistically Significant Benefit on All Five Efficacy Endpoints in Alzheimer's Disease Trial After One Year of Therapy" (Press release). 2007-06-11. http://www.prnewswire.com/cgi-bin/stories.pl?ACCT=104&STORY=/www/story/06-11-2007/0004605280&EDATE=. 
21. ^ Wu J, Li Q, Bezprozvanny I (2008). "Evaluation of Dimebon in cellular model of Huntington's disease". Molecular Neurodegeneration 3: 15. doi:10.1186/1750-1326-3-15. PMC 2577671. PMID 18939977. http://www.molecularneurodegeneration.com/content/3//15. 
22. ^ Gankina EM, Porodenko NV, Kondratenko TI, Severin ES, Kaminka ME, Mashkovskiĭ MD (1993). "[The effect of antihistaminic preparations on the binding of labelled mepyramine, ketanserin and quinuclidinyl benzilate in the rat brain]" (in Russian). Eksperimental'naia I Klinicheskaia Farmakologiia 56 (1): 22–4. PMID 8100727.