Patent Application: US-201414307139-A

Abstract:
a method for improving cognition comprising administering to a patient - 7 - chloro - n - benzothiophene - 2 - carboxamide or a pharmaceutically acceptable salt thereof and an acetylcholinesterase inhibitor is described together with related compositions .

Description:
the safety and efficacy of ( r )- 7 - chloro - n -( quinuclidin - 3 - yl ) benzo [ b ] thiophene - 2 - carboxamide hcl salt was assessed in a phase 1b study of 48 mild to moderate ad patients 60 - 80 years of age , on stable donepezil ( 5 or 10 mg / day ) or rivastigmine ( 6 - 12 mg / day administered as a twice daily dose , i . e ., 3 or 6 mg per dose ). patients were dosed with placebo or two different doses of ( r )- 7 - chloro - n -( quinuclidin - 3 - yl ) benzo [ b ] thiophene - 2 - carboxamide ( 0 . 3 or 1 . 0 mg / d ) for 28 days . safety was evaluated by adverse events , ecg , and clinical laboratory measures . cognitive effects were measured by cogstate computerized cognitive testing and a subset of ntb scales ( category fluency , trails a and b ). the results of this analysis are shown in fig1 . ( r )- 7 - chloro - n -( quinuclidin - 3 - yl ) benzo [ b ] thiophene - 2 - carboxamide appeared to be safe and well tolerated with no significant adverse events reported more frequently in treated versus placebo patients ; there were no saes reported . subjects exposed to ( r )- 7 - chloro - n -( quinuclidin - 3 - yl ) benzo [ b ] thiophene - 2 - carboxamide in addition to donepezil or rivastigmine showed an increase in cognitive function , primarily in the domains of non - verbal learning , memory , and executive function . the study described below examined the effect of subthreshold doses of the α7 nicotinic receptor agonist ( r )- 7 - chloro - n -( quinuclidin - 3 - yl ) benzo [ b ] thiophene - 2 - carboxamide and the ache inhibitor donepezil on short - term memory deficits , induced by the muscarinic antagonist scopolamine in the object recognition task in 5 - months - old male wistar rats . the object recognition task allows the assessment of consolidation of ( object ) information into memory ( ennaceur and delacour , 1988 ; prickaerts et al ., 1997 ). in this task a rat is given two trials . in the first trial the rat is put into an arena in which two identical objects are placed . usually , a rate will inspect the two objects for a certain amount of time . after a certain delay , the rat is given a second trial . in this trial the rat is again placed in the same arena but one of the objects has been replaced by a novel object . similar to the first trial the rat again explores the two objects . the amount of time exploring each object is recorded in order to determine whether the rat spent a different amount of time exploring the two objects . on basis of this scoring the memory performance can be determined . several studies have shown that wistar rats show a good object memory performance when a one - hour delay is interposed between the first and second trial . however , when a twenty - four hour delay is used the rats do not discriminate between the novel and the familiar object in the second trial , indicating that the rats do not remember the familiar object ( i . e . the object presented in both the first trial and the second trial ). using a six - hour delay , the discrimination performance is between the performance of the one hour and twenty - four hour delay , suggesting a delay - dependent forgetting in this task . a previous study found that 0 . 3 mg / kg ( r )- 7 - chloro - n -( quinuclidin - 3 - yl ) benzo [ b ] thiophene - 2 - carboxamide ( p . o .) completely attenuated the object memory deficit induced by the muscarinic antagonist scopolamine ( 0 . 1 mg / kg , i . p . ), whereas a dose of 0 . 03 mg / kg had no effect . it was also been found that a dose of 0 . 3 mg / kg donepezil ( p . o .) attenuated the scopolamine - induced object memory deficit , while 0 . 1 mg / kg donepezil had no effect . in a preliminary study , it was surprisingly found that combined administration of this subthreshold dose of donepezil with a subthreshold dose of ( r )- 7 - chloro - n -( quinuclidin - 3 - yl ) benzo [ b ] thiophene - 2 - carboxamide , which neither had an effect on performance when given alone at the subthreshold doses , enhanced memory performance in rats with an object memory deficit induced by scopolamine . this suggests additive synergistic effects between both compounds on cognitive impairment . in the present study , 30 minutes before the learning trial , rats received an injection with the muscarinic receptor antagonist scopolamine ( 0 . 1 mg / kg , administered i . p .). after treatment with scopolamine , rats will show no memory of the objects one hour after the learning trial . it was investigated whether a combination of subthreshold doses of ( r )- 7 - chloro - n -( quinuclidin - 3 - yl ) benzo [ b ] thiophene - 2 - carboxamide ( 0 . 03 mg / kg , administered p . o .) and donepezil ( 0 . 1 mg / kg administered p . o .) could attenuate the scopolamine - induced object memory deficit . all drugs were given 30 minutes before the first trial . all experimental procedures were approved by the local ethical committee of the maastricht university for animal experiments and met governmental guidelines . twenty - four 5 - month - old male wistar rats ( harlan , the netherlands ) were used ( average body weights : 465 g ). of these twenty - four animals , only twenty - three animals were included in the final analysis , this was due to the continuous escaping of one the rats . the animals were individually housed in standard type 3 makrolon cages on sawdust bedding in an air - conditioned room ( about 20 ° c .). they were kept under a 12 / 12 - hour light / dark cycle ( lights on from 19 . 00 to 7 . 00 h ) and had free access to food and water . rats were housed in the same room as where the animals were tested . a radio , which was playing softly , provided background noise in the room . all testing was done between 9 . 00 and maximally 18 . 00 h . based on an earlier dose - response study of scopolamine , it was decided that a 0 . 1 mg / kg dose is the most effective dose to induce memory deficits . scopolamine hydrobromide was prepared daily and dissolved in saline . scopolamine was administered i . p . ( injection volume 1 ml / kg ) 30 min before trial 1 . evp - 6124 was dissolved in h 2 o . the solution was prepared daily and tested at a dose of 0 . 03 mg / kg p . o . ( injection volume 2 ml / kg ). administration was always 30 min before trial 1 immediately after scopolamine . donepezil was dissolved in saline . the solution was prepared daily and tested at a dose of 0 . 1 mg / kg p . o . ( injection volume 2 ml / kg ). administration was always 30 min before trial 1 immediately after ( r )- 7 - chloro - n -( quinuclidin - 3 - yl ) benzo [ b ] thiophene - 2 - carboxamide . the vehicle and scopolamine conditions were tested first . subsequently donepezil , ( r )- 7 - chloro - n -( quinuclidin - 3 - yl ) benzo [ b ] thiophene - 2 - carboxamide and the combination of both were tested ( n = 8 per condition per day of testing ). all rats were treated once with each dose condition . but one rat was excluded from the study due to continuous jumping out of the apparatus , thus n = 23 . the experimentator was unaware of the condition / drugs being tested . the object recognition test was performed as described elsewhere ( ennaceur and delacour , 1988 ). the apparatus consisted of a circular arena , 83 cm in diameter . half of the 40 cm high wall was made of gray polyvinyl chloride , the other half of transparent polyvinyl chloride . the light intensity was equal in the different parts of the apparatus . two objects were placed in a symmetrical position about 10 cm away from the gray wall . each object was available in triplicate . the objects were : 1 ) a cone consisting of a gray polyvinyl chloride base ( maximal diameter 18 cm ) with a collar on top made of brass ( total height 16 cm ), 2 ) a standard 1 l brown transparent glass bottle ( diameter 10 cm , height 22 cm ) filled with water , 3 ) a massive metal cube ( 10 . 0 × 5 . 0 × 7 . 5 cm ) with two holes ( diameter 1 . 9 cm ), and 4 ) a massive aluminum cube with a tapering top ( 13 . 0 × 8 . 0 × 8 . 0 cm ). a rat could not displace the objects . fluorescent red tubes and a light bulb provided a constant illumination of about 20 lux on the floor of the apparatus . a testing session comprised two trials . the duration of each trial was 3 min . during the first trial ( t1 ) the apparatus contained two identical objects ( samples ). a rat was always placed in the apparatus facing the wall at the middle of the front ( transparent ) segment . after the first exploration period the rat was put back in its home cage . subsequently , after a predetermined delay interval , the rat was put back in the apparatus for the second trial ( t2 ), but now with two dissimilar objects , a familiar one ( the sample ) and a new one . the times spent in exploring each object during t1 and t2 were recorded manually with a personal computer . exploration was defined as follows : directing the nose to the object at a distance of no more than 2 cm and / or touching the object with the nose . sitting on the object was not considered as exploratory behavior . in order to avoid the presence of olfactory trails the objects were always thoroughly cleaned . all combinations and locations of objects were used in a balanced manner to reduce potential biases due to preferences for particular locations or objects . several studies have shown that wistar rats show a good object memory performance when a one - hour delay interposed between the first trial and the second trial . however , when a twenty - four hour delay is used the rats do not discriminate the novel and the familiar in the second trial , indicating that the rats do not remember the object that was presented in the first trial . using a six hour delay , the discrimination performance is between the performance of the one hour and twenty - four hour delay , suggesting a delay - dependent forgetting in this task . in this study a 1 h interval is used . in the two weeks , the animals were handled daily and adapted to the procedure in two days , i . e ., they were allowed to explore the apparatus ( without any objects ) twice for 3 min each day . then the rats were adapted to the testing and i . p . and p . o . injections by a saline injection ( 1 . 0 ml / kg and 2 . 0 ml / kg respectively ) 30 min before the first trial until they showed a stable discrimination performance , i . e . a good discrimination at 1 - h interval and no discrimination at 24 - h interval . next , the control sessions ( vehicle and scopolamine were tested ). subsequently , testing of the drugs ( r )- 7 - chloro - n -( quinuclidin - 3 - yl ) benzo [ b ] thiophene - 2 - carboxamide ( 0 . 03 mg / kg ) and donepezil ( 0 . 1 mg / kg ) began . compounds / vehicle were always tested on monday , wednesday and friday ( or tuesday and thursday ) in order to have a sufficient wash - out period between compound sessions . the basic measures were the times spent by rats in exploring an object during t1 and t2 . the time spent in exploring the two identical samples will be represented by ‘ a1 ’ and ‘ a2 ’. the time spent in t2 in exploring the sample and new object will be represented by ‘ a ’ and ‘ b ’, respectively . the following variables were calculated : e1 = a1 + a2 , e2 = a + b , and d2 =( b − a )/ e2 ( see table 1 ). e1 and e2 are measures of the total exploration time of both objects during t1 and t2 respectively . d2 is a relative measure of discrimination corrected for exploration activity ( e2 ). thus , there should be no differences in d2 indices between experiments with similar treatments at similar intervals . there were five conditions in this experiment and each rat was subjected to each condition : one - sample t - statistics were performed in order to assess per treatment condition whether d2 differed from zero . however , comparison of the value of d2 with the value zero with no variance may not be the most suitable way for analyzing recognition ( increased chance of making a type i error ). effects were therefore also assessed by a within subjects ( repeated measures ) anova . in case of a significant difference between conditions , post hoc analyses with bonferroni corrections were performed . e1 is the measure of the time spent in exploring both identical objects ( a1 and a2 ) in the first trial , and e2 is the measure of the time spent in exploring both the familiar ( a ) and new object ( b ) in the second trial ; d2 corresponds to the ability to discriminate between the old and new object during the second trial and is corrected for exploration time during that trial . the results of the evp - 6124 and donepezil treatment , 30 min before t1 , are summarized in table 2 . there were no differences found between treatment conditions in the level of exploration in t1 ( e1 : f ( 4 , 88 )= 1 . 138 , n . s .). in t2 , there were also no differences between treatment conditions in the level of exploration in t2 ( e2 : f ( 4 , 88 )= 0 . 888 , n . s .). scopolamine ( i . p . ), evp - 6124 ( p . o .) and donepezil ( p . o .) administration was 30 min before t1 . the delay interval between the first and second trial was one hour . the d2 measures different from zero are depicted with asteriks ( one - sample t - tests , ***: p & lt ; 0 . 001 ). n = 23 per experimental condition . one sample t - tests showed that the d2 value of the combined and vehicle condition differed from zero ( see table 2b ). this in contrast to the separately administered scopolamine , ( r )- 7 - chloro - n -( quinuclidin - 3 - yl ) benzo [ b ] thiophene - 2 - carboxamide and donepezil conditions , which showed no difference . the effects of ( r )- 7 - chloro - n -( quinuclidin - 3 - yl ) benzo [ b ] thiophene - 2 - carboxamide and donepezil treatment on the relative discrimination index d2 are graphically presented in fig1 . when comparing between groups , differences were found for the d2 index ( f ( 4 , 88 )= 8 . 181 , p & lt ; 0 . 001 ). the d2 was higher in the combined and vehicle condition than in the scopolamine , ( r )- 7 - chloro - n -( quinuclidin - 3 - yl ) benzo [ b ] thiophene - 2 - carboxamide and donepezil conditions ( bonferrone t - tests ; see fig2 ). for the evaluation of the cognition enhancing effects of combined subthreshold doses of the drugs ( r )- 7 - chloro - n -( quinuclidin - 3 - yl ) benzo [ b ] thiophene - 2 - carboxamide ( given p . o .) and donepezil ( p . o .) after scopolamine administration ( i . p . ), a 1 h delay interval was used . it was found that in the control vehicle condition the rats remembered the familiar object after such an interval . this is in contrast to the scopolamine ( 0 . 1 mg / kg ) condition in which no more memory of the familiar object was found . in the present study the dose of scopolamine used for drug testing had no effect on exploratory activity of the animals . neither ( r )- 7 - chloro - n -( quinuclidin - 3 - yl ) benzo [ b ] thiophene - 2 - carboxamide nor donepezil changed exploratory behavior . the relative discrimination index d2 corrects for alterations in exploratory activity ( though these were not observed in the present study ). further it is a reliable measure since the within analysis , i . e . comparison with zero , is able to detect subtle effects on object recognition . the d2 of the donepezil condition as well as that of the ( r )- 7 - 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