|Chemical and physical data|
|Molar mass||319.443 g/mol|
Research was conducted in both Russia and western nations into potential applications as a neuroprotective drug to treat Alzheimer's disease and, possibly, as a nootropic, as well. After a major phase III clinical trial for Alzheimer's disease (AD) treatment failed to show any benefit, three other AD trials continued. Major industry-based development in this indication essentially stopped after another Phase III trial suffered the same fate in 2012. Dimebon failed in the phase III trial for Huntington disease.
Latrepirdine is an orally active, small molecule compound that has been shown to inhibit brain cell death in animal models of Alzheimer's disease and Huntington's disease. Research suggests it may also have cognition-enhancing effects in healthy individuals, in the absence of neurodegenerative disease pathology. However, because of negative results in human clinical trials, the drug remains unlicensed for any neurodegenerative condition.
Alzheimer's disease: failed in Phase III clinical trials
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. Preliminary results from human trials have also been promising. In an initial six-month phase II trial, results have shown significant improvement over placebo at 12 months. Latrepirdine showed promising results in a phase III-equivalent, double-blind trial in Russia with mild–moderate stage patients. In April 2009, Pfizer and Medivation initiated a phase III trial (CONCERT study) aiming for FDA approval. In March 2010, Pfizer announced that this clinical trial failed to show any benefit for the treatment of Alzheimer's disease patients.
In March 2010, the results of a clinical trial phase III were released; the investigational Alzheimer's disease drug dimebon failed in the pivotal CONNECTION trial of patients with mild-to-moderate disease.
With CONCERT, the remaining Pfizer and Medivation Phase III trial for latrepirdine in Alzheimer's disease failed in 2012, effectively ending the development in this indication.
A Cochrane meta-analysis of the three pivotal phase III efficacy trials found no significant effect of latrepirdine on cognition and function in mild-to-moderate Alzheimer's patients, though there appears to be a modest benefit for overall behavior disturbances.
Latrepirdine appears to operate through multiple mechanisms of action, both blocking the action of neurotoxic beta-amyloid proteins and inhibiting L-type calcium channels, modulating the action of AMPA and NMDA glutamate receptors, and may exert a neuroprotective effect by blocking a novel target that involves mitochondrial pores, which are believed to play a role in the cell death that is associated with neurodegenerative diseases and the aging process. It also blocks a number of other receptors, including α-adrenergic, 5-HT2C, 5-HT5A, and 5-HT6. It is of significance to note latrepirdine lacks any anticholinergic effects.
- Matveeva IA (July–August 1983). "Action of dimebon on histamine receptors". Farmakologiia i Toksikologiia (in Russian). 46 (4): 27–29. PMID 6225678.
- Shevtsova EF, Kireeva EG, Bachurin SO (2005). "Mitochondria as the target for neuroprotectors". Vestnik Rossiiskoi Akademii Meditsinskikh Nauk (in Russian) (9): 13–17. PMID 16250325.
- Novel Alzheimer's Drug Flops, MedPage Today, March 03, 2010
- Sweetlove M: Phase III CONCERT Trial of Latrepirdine. Negative results. Pharm Med 2012;26(2):113-115
- 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. PMID 11462798. doi:10.1111/j.1749-6632.2001.tb03654.x.
- 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. PMID 11022244. doi:10.1007/BF02434871.
- Pollack, Andrew (2007-06-11). "Antihistamine Shows Promise in Treating Alzheimer's". New York Times. Retrieved 2010-05-01.
- Phend Crystal; Jasmer Robert (2008-07-17). "Old Antihistamine Pops Up as Potential Alzheimer's Therapy". Medpage Today.
- 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. PMID 18640457. doi:10.1016/S0140-6736(08)61074-0.
- 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
- 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"
- http://clinicaltrials.gov/ct2/show/NCT00912288 "A Phase 3 Efficacy Study Of Dimebon In Patients With Moderate To Severe Alzheimer's Disease"
- 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"
- http://clinicaltrials.gov/ct2/show/NCT00954590 "A Safety and Efficacy Study Evaluating Dimebon (Latrepirdine) in Patients With Moderate to Severe Alzheimer's Disease (CONTACT)"
- "Pfizer And Medivation Initiate Phase 3 Trial Of Dimebon In Patients With Huntington Disease" (Press release). Pfizer Inc. 2009-07-30. Retrieved July 31, 2009.
- Dimebon Disappoints in Phase 3 Trial
- Chau, Sarah A; Herrmann, Nathan; Ruthirakuhan, Myuri T; Chen, Jinghan J; Lanctôt, Krista L (2015). "Latrepirdine for Alzheimer's disease". Cochrane Database Syst Rev. (4): CD009524. PMID 25897825. doi:10.1002/14651858.CD009524.pub2.
- 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. PMID 11865327. doi:10.1023/A:1017972709652.
- 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. PMID 14968164. doi:10.1023/B:BEBM.0000017097.75818.14.
- 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. PMID 12853325. doi:10.1111/j.1749-6632.2003.tb07541.x.
- "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.
- Wu J, Li Q, Bezprozvanny I (2008). "Evaluation of Dimebon in cellular model of Huntington's disease". Molecular Neurodegeneration. 3: 15. PMC . PMID 18939977. doi:10.1186/1750-1326-3-15.
- 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]". Eksperimental'naia I Klinicheskaia Farmakologiia (in Russian). 56 (1): 22–4. PMID 8100727.