Can Cerebrolysin influence chronic deterioration of spatial learning and memory?

A 24-week, double-blind, placebo-controlled study of three dosages of Cerebrolysin in patients with mild to moderate Alzheimer's disease

Cerebrolysin (Cere) is a compound with neurotrophic activity shown to be effective in Alzheimer's disease in earlier trials. The efficacy and safety of three dosages of Cere were investigated in this randomized, double-blind, placebo-controlled, study. Two hundred and seventy-nine patients were enrolled (69 Cere 10 ml; 70 Cere 30 ml; 71 Cere 60 ml and 69 placebo). Patients received iv infusions of 10, 30, 60 ml Cere or placebo 5 days/week for the first 4 weeks and thereafter, two iv infusions per week for 8 weeks. Effects on cognition and clinical global impressions were evaluated 4, 12 and 24 weeks after the beginning of the infusions using the CIBIC+ and the modified Alzheimer's Disease Assessment Scale (ADAS)-cog. At week 24, significant improvement of cognitive performance on the ADAS-cog (P=0.038) and global function (CIBIC+; P>0.001) was observed for the 10 ml dose. The 30 and 60 ml doses showed significant improvement of the global outcome but failed to show significant improvement of cognition. The results are consistent with a reversed U-shaped dose-response relationship for Cere. The percentage of patients reporting adverse events was similar across all study groups. Cere treatment was well tolerated and led to significant, dose-dependent improvement of cognition and global clinical impression.

Sustained improvement of cognition and global function in patients with moderately severe Alzheimer's disease: a double-blind, placebo-controlled study with the neurotrophic agent Cerebrolysin

BACKGROUND

In a recent study, Cerebrolysin (Cere), a compound with neurotrophic activity, has been shown to be effective in the treatment of mild to moderate Alzheimer's disease (AD). A subgroup analysis of this double-blind, placebo-controlled study was performed to assess the effects of Cere in cases with more advanced forms of AD.

PATIENTS AND METHODS

Patients received infusions of 30 ml Cere or placebo five days/week for four weeks. This treatment was repeated after a two-months therapy-free interval. Effects on cognition, global function, behavioural symptoms and activities of daily living were evaluated 4, 12, 16, and 28 weeks after the beginning of the infusions. 109 patients with MMSE scores <20 were included in this analysis.

RESULTS

The responder rate of the Cere group was 65% on the CGI, compared to 24.5% in the placebo group (p < 0.004). In the ADAS-cog, a score difference of 4.1 points in favour of Cere was observed (p < 0.0001). Notably, improvements were largely maintained in the Cere group up to the week 28 visit.

CONCLUSION

The data clearly demonstrate the efficacy of Cere treatment in moderate to severe forms of AD with sustained treatment effects on cognition and global function even after discontinuation of treatment.

Improved global function and activities of daily living in patients with AD: a placebo-controlled clinical study with the neurotrophic agent Cerebrolysin

BACKGROUND

Cerebrolysin (Cere) is a peptidergic, neurotrophic drug which has been shown to improve cognitive performance and global function of Alzheimer's disease (AD) patients in earlier trials. In this study, we have attempted to replicate this findings with particular emphasis on functional improvement of the patients.

PATIENTS AND METHODS

Patients received infusions of 30 ml Cere or placebo five days/week for six consecutive weeks. Patients had to have a diagnosis of AD and a MMSE score of 14-25 inclusive. Effects on cognition, global function, and activities of daily living were evaluated 3, 6, and 18 weeks after the beginning of the infusions.

RESULTS

Significant improvement of cognitive function, clinical global impression and activities of daily living were seen after the end of the therapy. The effects were most pronounced in the DAD score, a measure for the capability to perform activities of daily living. Interestingly, and in line with the findings of earlier studies, the treatment effect of Cere was maintained after cessation of treatment up to the week 18 assessment.

CONCLUSION

The data confirm the findings of earlier trials and clearly demonstrates that Cere leads to functional improvement of patients with AD. The sustained treatment effect of Cere after withdrawal has been confirmed.

A brain derived peptide preparation reduces the translation dependent loss of a cytoskeletal protein in primary cultured chicken neurons

Neuronal cytoskeletal proteins like the microtubule associated protein 2 (MAP2) are objected to pathological proteolysis in case of Alzheimer's disease and brain ischemia. The neurotrophic peptidergic drug Cerebrolysin (EBEWE Arzneimittel, Austria, Europe) is produced by a standardized enzymatic break-down of lipid free porcine brain proteins. Cerebolysin protected MAP2 in primary neuronal cultures after a brief histotoxic hypoxia and in a rat model of acute brain ischemia. Furthermore the drug was shown to inhibit the proteases mu- and m-calpain dose dependently in several cell free protease activity assays. The question if the higher MAP2 levels are due to an alleviation of proteolysis, to a higher synthesis rate or both is addressed in the current investigation: Monitoring the MAP2 content of primary neuronal cell cultures over a period of eight days revealed MAP2 to reach a peak level on day six in vitro followed by a degradation phase. In other experiments the protein synthesis of Cerebrolysin treated and untreated cells was blocked with cycloheximide at that moment when all cells exhibited the same MAP2 content. After the following MAP2 degradation phase--i.e. after eight days in vitro--the MAP2 contents were determined by western blotting. Cerebrolysin treated cells contained more MAP2 than untreated controls proving that the drug protects MAP2 independently from de novo synthesis, although further work is in progress to investigate if the drug supplementary boosts this effect by increasing MAP2 synthesis.

Approach towards an integrative drug treatment of Alzheimer's disease

At present pharmacotherapy of Alzheimer's disease (AD) is limited to acetylcholinesterase inhibitors. These drugs produce small, but consistent improvements of memory and global function, some are also positively influencing activities of daily living. This therapeutic approach neglects the complexity of AD and the fact that most of the degenerating neurons are not cholinergic. Acetylcholinesterase inhibitors are symptomatic drugs, with no influence on disease progression. There is a need for disease modifying compounds, or preventive drugs. Data are indicating that vitamin E has some ability to influence the disease progression. The potency of non-steroidal anti-inflammatory drugs (NSAIDs) or estrogen as preventive agents has to be explored further in prospective clinical studies. The initial hope in the use of naturally occurring neurotrophic factors, like nerve growth factor, to rescue cholinergic neurons from degeneration and to restore cognitive function has been disappointed in first, small clinical studies. The peptidergic drug Cerebrolysin exhibiting neurotrophic stimulation, neuroimmunotrophic regulation and induction of BBB glucose transporter expression, might be able to address the pathological changes of AD at different levels simultaneously. In addition to an impressive preclinical database, results from 3 placebo-controlled, double-blind studies demonstrate significant improvements of cognitive performance, global function and activities of daily living in AD patients. In all studies persisting improvements, up to 6 months after drug withdrawal, indicate a powerful disease modifying activity.