2 - methylene - 19 - nor - 20 ( s )- 1α , 25 - dihydroxyvitamin d 3 ( referred to herein as 2md ) was synthesized and tested . structurally , this 19 - nor analog is characterized by the general formula i previously illustrated herein . the preparation of 2 - methylene - 19 - nor - 20 ( s )- 1α , 25 - dihydroxyvitamin d 3 having the basic structure i can be accomplished by a common general method , i . e . the condensation of a bicyclic windaus - grundmann type ketone ii with the allylic phosphine oxide iii to the corresponding 2 - methylene - 19 - nor - vitamin d analog iv followed by deprotection at c - 1 and c - 3 in the latter compound : in the structures ii , iii , and iv groups y 1 and y 2 are hydroxy - protecting groups , it being also understood that any functionalities that might be sensitive , or that interfere with the condensation reaction , be suitably protected as is well - known in the art . the process shown above represents an application of the convergent synthesis concept , which has been applied effectively for the preparation of vitamin d compounds ( e . g . lythgoe et al ., j . chem . soc . perkin trans . i , 590 ( 1978 ); lythgoe , chem . soc . rev . 9 , 449 ( 1983 ); toh et al ., j . org . chem . 48 , 1414 ( 1983 ); baggiolini et al ., j . org . chem . 51 , 3098 ( 1986 ); sardina et al ., j . org . chem . 51 , 1264 ( 1986 ); j . org . chem . 51 , 1269 ( 1986 ); deluca et al ., u . s . pat . no . 5 , 086 , 191 ; deluca et al ., u . s . pat . no . 5 , 536 , 713 ). hydrindanones of the general structure ii are known , or can be prepared by known methods . for the preparation of the required phosphine oxides of general structure iii , a new synthetic route has been developed starting from a methyl quinicate derivative which is easily obtained from commercial ( 1r , 3r , 4s , 5r )-(−)- quinic acid as described by perlman et al ., tetrahedron lett . 32 , 7663 ( 1991 ) and deluca et al ., u . s . pat . no . 5 , 086 , 191 . the overall process of the synthesis of compound i is illustrated and described more completely in u . s . pat . no . 5 , 843 , 928 issued dec . 1 , 1998 and entitled “ 2 - alkylidene - 19 - nor - vitamin d compounds ” the specification of which is specifically incorporated herein by reference . biological activity of 2 - methylene - 20 ( s )- 19 - nor - 1 , 25 -( oh ) 2 d 3 ( fig1 - 8 ) the introduction of a methylene group to the 2 - position of the 20 ( s ) isomer of 19 - nor - 1 , 25 -( oh ) 2 d 3 had little or no effect on binding to the porcine intestinal vitamin d receptor . this compound bound equally well to the full length recombinant rat receptor as compared to the standard 1 , 25 -( oh ) 2 d 3 ( fig1 ). similar results were found when the native receptor from porcine intestine was studied . it might be expected from these results that this compound would have equivalent biological activity . surprisingly , however , the 2 methylene and 20 ( s ) substitutions produced a highly selective analog with its primary action on bone . fig2 shows that 2md has activity similar to that of 1 , 25 - dihydroxyvitamin d 3 ( 1 , 25 ( oh ) 2 d 3 ), the natural hormone , in stimulating intestinal calcium transport in vitamin d - deficient rats given a dose of drug by oral gavage for 7 consecutive days followed by assay using the everted gut sac technique . values represent means ± standard error . fig3 clearly demonstrates that 2md is 100 times more potent than 1 , 25 ( oh ) 2 d 3 on bone , i . e . the mobilization of bone calcium . blood serum calcium was measured 24 hours following the last dose in the rats as described in fig2 . values represent mean ± standard error . fig4 shows that 2md is extraordinarily effective in building bone mass in ovariectomized rats as compared to the native hormone without increasing serum calcium concentration ( table 1 ). this is as yet an unprecedented new finding for a vitamin d compound . fig5 illustrates that 2md is 10 - 50 times more potent than 1 , 25 ( oh ) 2 d 3 on hl - 60 cell differentiation , making it an excellent candidate for the treatment of psoriasis and cancer , especially against leukemia , neuroblastoma , retinoblastoma , melanoma , colon cancer , breast cancer and prostate cancer . table 1 and fig6 a illustrate that 2md is very effective in increasing bone of ovariectomized , old female rats at 32 pmol given 2 times per week as compared to 1 , 25 ( oh ) 2 d 3 given at high doses ( 250 or 500 pmol ) 3 times per week . note : 2md also increases % ash in the femur . values in the figure are mean ± standard error . table 2 and fig6 b show that 2md increases breaking strength in the femurs ( cortical strength ) and crushing strength in the vertebra ( trabecular strength ) of animals shown in table 1 . values in the figure are mean ± standard error . fig7 - 9 show a six - week toxicity study in rats and demonstrate that 2md appears safe at up to 35 pmol / day . fig1 shows that in rhesus monkeys , a single oral dose of 29 μg ( 1 . 73 μg / kg ) does not cause significant elevation of serum calcium concentration , suggesting even greater safety in primates . fig1 , 12a and 12 b show that 2md given at 1 . 8 pmol / day is highly effective in increasing the bone density in normal adult female rats . not only does 2md increase cancellous ( trabecular ) bone , but it also increases the density of the cortical ( shaft ) bone as well . fig1 a and 13b show that the remarkable increase in both cortical and cancellous bone are achieved with no adverse effect in either the body weight or serum calcium levels of the animals . thus , this work shows that 2md can be safely used not only in ovariectomized animals but also in normal animals at a dose that is effective in increasing bone density . competitive binding of the analogs to the porcine intestinal receptor was carried out by the method described by dame et al . ( biochemistry 25 , 4523 - 4534 , 1986 ). the differentiation of hl - 60 promyelocytic cells into monocytes was determined as described by ostrem et al . ( j . biol . chem . 262 , 14164 - 14171 , 1987 ). the intestinal calcium transport and bone mobilization studies were carried out as described by sicinski et al . ( j . med . chem . 41 , 4662 - 4674 , 1998 ) and suda et al . ( j . nutr . 100 , 1049 - 1052 , 1970 ). interpretation of the biological activity data ( fig1 - 13 ) the in vivo tests of increasing serum calcium of rats on a zero calcium diet provides an insight to osteoblastic or bone activity of 2md . the dose response curves show that 2md is at least 80 - 100 times more potent than 1 , 25 ( oh ) 2 d 3 in raising calcium in the plasma via the stimulation of the osteoblasts ( fig3 ). at the same time , the activity of 2md on intestinal calcium transport is approximately equal that of 1 , 25 -( oh ) 2 d 3 ( fig2 ). therefore , these data show 2md to have selective activity on bone . 2md is about as active as 1 , 25 ( oh ) 2 d 3 in binding to the vitamin d receptor ( fig1 ). however , it is between 10 - 50 times more active than 1 , 25 -( oh ) 2 d 3 in causing differentiation of the promyelocyte , hl - 60 , into the monocyte ( fig5 ). this result suggests that 2md will be very effective in psoriasis because it has direct cellular activity in causing differentiation and in suppressing growth . it also indicates that it will have significant activity as an anti - cancer agent , especially against leukemia , neuroblastoma , retinoblastoma , melanoma , colon cancer , breast cancer and prostate cancer . the most important result , however , is that 2md is extremely effective not only in restoring bone mass of ovariectomized , old female breeder rats as shown in fig4 and 6 and tables 1 and 2 , but it causes an increase in bone mass above that of sham - operated controls . this illustrates that 2md is very likely having an anabolic effect on bone or increasing bone formation . importantly , the increased bone mass provided by 2md translates into marked increases in bone strength . this increased strength to fracture in femur shows cortical strength while increased strength to crush fractures of vertebra illustrates trabecular ( cancellous ) bone strength ( table 2 and fig6 a and 6b ). interestingly , even the percent ash is unexpectedly increased further by 2md . of great importance is that at the dosage levels used in this study , there was no change in serum calcium in the animals that showed the marked elevation of bone mass . this argues that a window of safety exists between the use of 2md to increase bone mineral content and the action of 2md in elevating serum calcium . preliminary safety tests carried out on two different occasions have revealed that female rats on a high calcium chow diet tolerate 35 pmol / day of 2md without elevating serum calcium , reducing body weight or causing mineralization of the kidney ( see fig7 - 9 ). further , preliminary studies in rhesus monkeys indicates that primates tolerate 2md extremely well since a dose of as much as 29 μg of this compound was given as a single dose to an 8 kg rhesus monkey without appreciably elevating serum calcium concentration ( fig1 ). these and other tests indicate that primates will tolerate 2md extremely well which may give a very large window between efficacy and the danger of hypercalcemia in man . these results illustrate that 2md is an excellent candidate for an anti - osteoporosis therapy ( both prevention and treatment ) and that it may be useful in a number of other circumstances such as autoimmune diseases , cancer , and psoriasis . the studies described in fig1 - 13 demonstrate that 2md can also increase bone mass in normal female rats ( see section entitled : “ building bone mass of normal individuals ” below ). beginning with arrival in the facility , rats were fed a purified rodent diet (“ diet 11 ”) prepared in - house ( suda et al , 1970 , j . nutr ., 100 : 1049 - 1052 ) and containing 0 . 47 % calcium , 0 . 3 % phosphorus and 1 . 6 iu vitamin d 3 / g . to maintain consistent body weights ( monitored weekly ), rats were fed a total of 150 g diet / week , i . e . 21 . 5 g / day / rat . compounds compound source lot vehicle spectrum , new brunswick , nj sn0332 ( neobee m - 5 oil ) 2md tetrionics , madison , wi 010745111 rats were dosed daily beginning 5 - 6 weeks post - surgery . neobee oil ( vehicle ) or 2md were delivered to the back of the tongue in 100 μl . the dosing solution concentrations were adjusted monthly based on group - average body weights . at predose and at 1 , 2 , 4 , 6 , 10 , 11 , 18 and 25 weeks after dose , blood was collected 24 hr . after the most recent dose from the tail artery of ether - anesthetized rats . serum was diluted in 0 . 1 % lanthum chloride and the concentration of calcium determined by atomic absorption spectrometry . the values shown are averages for all rats , and include standard errors . both total body bmd and appendicular ( right distal and proximal femur ) bmd were determined by dual - energy x - ray absorptiometry ( lunar dpxα - madison , wis . ; small animal software - version 1 . 0e ) at weeks 0 , 8 , 16 , and 24 . appendicular bmd was performed as described ( haffa et al , 2000 , j . bone min . res . 15 : 872 ). the values shown are averages for all rats and include standard errors . total body bmd increased above vehicle - control animals in adult female rats given the 2md orally ( fig1 ). this increase was observed as soon as eight weeks and continued over the course of 24 weeks . increases in cancellous bone bmd were the most pronounced , with an increase of 14 % observed after 24 weeks in rats given 2md ( fig1 a ). cortical bone bmd also increased in similar fashion to that observed for the total body ( fig1 b ). these positive effects of 2md occurred in the absence of any change in body weight ( fig1 a ) or any change in serum calcium ( fig1 b ). 2md is obviously effective in increasing bone mass of intact normal female rats . by “ normal ” it is meant a subject that is not afflicted with or has not been diagnosed with a metabolic bone disease or any other disease / disorder that results in a decrease over time of bone mass . further , 2md increases both cancellous ( 14 %) and cortical ( 6 %) bone . because it has been previously demonstrated that 2md acts anabolically on bone , it is believed that 2md may be used to increase bone mass of normal healthy children , adolescents , young adults and / or mature adults . this would result in skeleton that would survive the bone loss of aging and the menopause . in that sense , it can be used as a prophylaxis or preventative measure against fractures resulting from the bone loss of metabolic bone diseases , especially osteoporosis . in addition to osteoporosis , circumstances where 2md could be used as a prophylaxis method include treatment of amenorrheic females . furthermore , 2md could be used in normal subjects when high bone mass is desired , such as athletes . it is envisioned that 2md can be used to increase bone mass of horses especially race horses and in astronauts preparing for a long journey under weightless conditions . it may also be applicable in agriculture for preventing and / or reducing bone fractures as well as increasing eggshell strength in laying hens , preventing and / or reducing bone fractures in cows especially lactating cows , and preventing and / or reducing bone fractures in pigs especially sows being used for rapid farrowing . typical commercially significant laying hens include chickens , turkeys , ducks , geese , pheasants , grouse , ostrich and quail . for treatment purposes , the compound of this invention ( 2md ) defined by formula i may be formulated for pharmaceutical applications as a solution in innocuous solvents , or as an emulsion , suspension or dispersion in suitable solvents or carriers , or as pills , tablets or capsules , together with solid carriers , according to conventional methods known in the art . any such formulations may also contain other pharmaceutically - acceptable and non - toxic excipients such as stabilizers , anti - oxidants , binders , coloring agents or emulsifying or taste - modifying agents . the compound 2md may be administered orally , topically , parenterally or transdermally . the compound 2md is advantageously administered by injection or by intravenous infusion or suitable sterile solutions , or in the form of liquid or solid doses via the alimentary canal , or in the form of creams , ointments , patches , or similar vehicles suitable for transdermal applications . doses of from about 0 . 01 μg per day to about 100 μg per day , preferably from about 0 . 1 μg per day to about 10 μg per day of the compound 2md are appropriate for treatment purposes in humans , such doses being adjusted according to the disease to be prevented or treated , its severity and the response of the subject as is well understood in the art . doses of from about 0 . 0001 μg per day to about 700 μg per day of the compound 2md are appropriate for treatment purposes in animals . since the compound exhibits specificity of action , each may be suitably administered alone , or together with graded doses of another active vitamin d compound — e . g . 1α - hydroxyvitamin d 2 or d 3 , or 1α , 25 - dihydroxyvitamin d 3 — in situations where different degrees of cell differentiation , bone mineral mobilization and / or calcium transport stimulation is found to be advantageous . compositions for use in the above - mentioned treatment and / or prophylaxis of humans or animals aimed at maintaining or increasing bone mass or in other applications such as psoriasis and other malignancies comprise an effective amount of the 2 - methylene - 20 ( s )- 19 - nor - vitamin d compound as defined by the above formula i as the active ingredient , and a suitable carrier . an effective amount of such compound for use in accordance with this invention is from about 0 . 01 μg to about 50 μg per gram of composition , and may be administered topically , transdermally , orally or parenterally in dosages of from about 0 . 01 μg per day to about 100 μg per day in humans , and preferably from about 0 . 1 μg per day to about 10 μg per day in humans . in animals , an effective amount of such compound for use in accordance with this invention is from about 0 . 01 μg to about 50 μg per gm of composition , and may be administered topically , transdermally , orally or parenterally in dosages of from about 0 . 0001 μg per day to about 700 μg per day . the compound 2md may be formulated as creams , lotions , ointments , topical patches , pills , capsules or tablets , or in liquid form as solutions , emulsions , dispersions , or suspensions in pharmaceutically innocuous and acceptable solvent or oils , and such preparations may contain in addition other pharmaceutically innocuous or beneficial components , such as stabilizers , antioxidants , emulsifiers , coloring agents , binders or taste - modifying agents . the compound 2md is advantageously administered in amounts sufficient to effect the differentiation of promyelocytes to normal macrophages , and / or in amounts needed to prevent bone loss , maintain bone mass or increase bone mass . dosages as described above are suitable , it being understood that the amounts given are to be adjusted in accordance with the severity of the disease , and the condition and response of the subject as is well understood in the art . the formulations of the present invention comprise an active ingredient in association with a pharmaceutically acceptable carrier therefore and optionally other therapeutic ingredients . the carrier must be “ acceptable ” in the sense of being compatible with the other ingredients of the formulations and not deleterious to the recipient thereof . formulations of the present invention suitable for oral administration may be in the form of discrete units as capsules , sachets , tablets or lozenges , each containing a predetermined amount of the active ingredient ; in the form of a powder or granules ; in the form of a solution or a suspension in an aqueous liquid or non - aqueous liquid ; or in the form of an oil - in - water emulsion or a water - in - oil emulsion . formulations for rectal administration may be in the form of a suppository incorporating the active ingredient and carrier such as cocoa butter , or in the form of an enema . formulations suitable for parenteral administration conveniently comprise a sterile oily or aqueous preparation of the active ingredient which is preferably isotonic with the blood of the recipient . formulations suitable for injection comprise a sterile oily or aqueous preparation , or a suspension or conjugate of the active ingredient . formulations suitable for topical administration include liquid or semi - liquid preparations such as liniments , lotions , applicants , oil - in - water or water - in - oil emulsions such as creams , ointments or pastes ; or solutions or suspensions such as drops ; or as sprays . the formulations may conveniently be presented in dosage unit form and may be prepared by any of the methods well known in the art of pharmacy . by the term “ dosage unit ” is meant a unitary , i . e . a single dose which is capable of being administered to a patient as a physically and chemically stable unit dose comprising either the active ingredient as such or a mixture of it with solid or liquid pharmaceutical diluents or carriers .
this invention provides pharmaceutical uses for 2 - methylene - 19 - nor - 20 - 1α , 25 - dihydroxyvitamin d 3 . this compound is characterized by high bone calcium mobilization activity demonstrating preferential activity on bone . this results in a novel therapeutic agent for the treatment and prophylaxis of diseases where bone formation is desired , particularly osteoporosis . this compound also increases both breaking strength and crushing strength of bones evidencing use in conjunction with bone replacement surgery such as hip and knee replacements , as well as use by normal subjects when high bone mass is desired .