Mechanism of action
Nalmefene is a modulator of the opioid system with pronounced affinity for the μ-, δ- and κ-receptors.
- Research in vitro showed that nalmefene is a selective opioid receptor ligand, exhibiting properties of an antagonist for the μ and δ receptors and a partial agonist for κ receptors.
- Research in vivo showed that nalmefene reduces the consumption of alcohol, apparently, modulating cortico-mesolimbic functions. Data obtained from preclinical studies, clinical studies and literature,Do not assume that nalmefene has the ability to cause addiction or abuse.
Clinical efficacy and safety
The effectiveness of nalmefene in reducing alcohol consumption in patients with alcohol dependence was evaluated in two studies. From the study excluded patients with alcohol delirium in history, hallucinations, convulsive seizures, serious mental disorders, patients with significant impairment of liver function. Also excluded were patients who, at the time of screening or randomization, showed significant physical symptoms of alcohol withdrawal. The majority of patients (80%) included in the study had a high or very high level of risk of developing harmful effects of alcohol use at the time of screening (DRL) (according to WHO definition, intake> 60 g of pure alcohol per day for men and> 40 g of pure alcohol per day for women), of whom 65% retained a high or very high risk until randomization.
Both studies were randomized, double-blind, placebo-controlled studies in parallel groups, and after 6 months of treatment, patients who received nalmefenewere re-randomized to receive either nalmefene, or a placebo for 1 month of so-called run-out period. The efficacy of nalmefene was also studied in a 1-year, randomized, double-blind, placebo-controlled study in parallel groups. In total, 1941 patients were treated in these studies, of which 1144 patients received nalmefene in a dose of 18 mg as needed.
During the first visit, the clinical status of the patient, the social situation and the nature of alcohol consumption were assessed (from the patient's words). At randomization, which was carried out after 1 to 2 weeks, the risk level of development of harmful consequences of alcohol consumption was reassessed and nalmefene therapy was administered in combination with psychosocial intervention (BRENDA), aimed at maintaining adherence to treatment and reducing alcohol consumption. Nalmefen was taken as necessary, which was an average of half the days of study.
The effectiveness of nalmefene was evaluated by two main criteria: the change in the number of days of heavy drunkenness (RTA) per month for the period between the baseline survey and the 6th month and the change in the daily dose of alcohol (SDA) for the period between the baseline survey and the 6th month.The accident was defined as the day that consumed ≥60 g of pure alcohol by men and ≥40 g by women.
In the period between the initial visit (screening) and randomization, a significant reduction in the number of road accidents and SDA caused by non-pharmacological effects was noted in some patients. In Studies 1 (n = 579) and 2 (n = 655) 18% and 33% of the total number of patients participating in the study, respectively, significantly reduced alcohol consumption between screening and randomization. As for patients with an initially high and very high risk of developing harmful effects of alcohol use, 35% of them improved because of non-pharmacological causes between screening and randomization. In these patients, by the time of randomization, the amount of alcohol consumed was so small that the possibilities for further improvement were very limited (the baseline was almost at a minimum level). Patients who maintained a high and very high risk of developing harmful effects of alcohol use between screening and randomization, retrospectively composed the target population.In this group, the effect of treatment was more significant than in the population as a whole.
The clinical efficacy of nalmefene and the reliability of the data were analyzed in patients with a high and very high risk of developing harmful effects of alcohol use in screening and randomisation. Initially, these patients had an average of 23 accidents per month (11% of patients - less than 14 accidents per month) with a daily intake of 106 grams of pure alcohol. In most patients, the level of alcohol dependence, as measured by the Alcohol Dependence Scale, was low (0-13 points in 55% of patients) or intermediate (14-21 points in 36% of patients).
Retrospective analysis of efficacy in patients with a high and very high risk of developing harmful effects of alcohol use at the time of randomization
In Study 1, the proportion of patients dropping out of the study was higher in the nalmefene group than in the placebo group (50% and 32%, respectively). The number of road accidents at the initial examination was 23 days per month as in the nalmefene group (n = 171), and in the placebo group (n = 167). Among patients who continued to participate in the study and who received performance data at 6 months, the number of road accidents was 9 days per month in the nalmefene group (n = 85) and 14 days per month in the placebo group (n = 114). At the initial examination, SDA was 102 g in the nalmefene group and 99 g in the placebo group. Among patients who continued to participate in the study and who received performance data at 6 months, the SDA was 40 g in the nalmefene group and 57 g in the placebo group.
In Study 2, the proportion of patients dropping out of the study was higher in the nalmefene group than in the placebo group (30% and 28%, respectively). At the initial examination, the number of road accidents was 23 days per month in the nalmefene group (n = 148) and 22 days per month in the placebo group (n = 155). Among patients who continued to participate in the study and who received performance data at 6 months, the number of road accidents was 10 days per month in the nalmefene group (n = 103) and 12 days per month in the placebo group (n = 111). At the initial examination, SDA was 1 13 g in the nalmefene group and 108 g in the placebo group. Among patients who continued to participate in the study and who received efficacy data at 6 months, the SDA was 44 g in the nalmefene group and 52 g in the placebo group.
An analysis of the generalized data on patients who participated in two studies responding to therapy is given in the table below.
A summary of the analysis of patients with a high and very high risk of developing harmful effects of alcohol use at the time of screening and randomization responding to therapy
Answera | Placebo | Nalmefen | The inequality coefficient (95% CI) | p-value |
SDA R70b | 19,9% | 25,4% | 1,44 (0,97; 2,13) | 0,067 |
0-4 Road accidentfrom | 16,8% | 22,3% | 1,54 (1,02; 2,35) | 0,040 |
a In the analysis, patients who left the study were classified as not responding to therapy.
b Reduction by ≥70% of the initial level of SOM by 6 months (28-day period)
from from 0 to 4 accidents per month to 6 months (28-day period)
For the nalmefene group, only limited efficacy data are available for the 1-month run-out period.
Annual research
The study included 665 patients. 52% of them had a high or very high risk of developing harmful effects of alcohol use at the time of screening; in turn, 52% of these patients (27% of the total population) retained a high or very high risk by the time of randomization. In this target population, among patients who stopped treatment prematurely, more patients were in the nalmefene group (45%) compared with patients who discontinued treatment in the placebo group (31%). At the initial examination, the number of road accidents was 19 days per month, both in the nalmefene group (n = 141), and in the placebo group (n = 42). Among patients who continued to participate in the study and who received performance data at 1 year, the number of road accidents was 5 days per month in the nalmefene group (n = 78) and 10 days per month in the placebo group (n = 29). At the initial examination, SDA was 100 g in the nalmefen group and 101 g in the placebo group. Among patients who continued to participate in the study and who received efficacy data at 1 year, SDA was 24 g in the nalmefen group and 47 g in the placebo group.