NZ319819A

NZ319819A - Calcitriol derivatives and their uses

Info

Publication number: NZ319819A
Application number: NZ319819A
Authority: NZ
Inventors: Hector F Deluca; Heinrich K Schnoes; Zu Yun Cai; Mary E Phelps; Connie M Smith
Original assignee: Wisconsin Alumni Res Found
Priority date: 1995-09-21
Filing date: 1996-09-20
Publication date: 2000-02-28
Also published as: CA2229316A1; HUP9802303A3; NO981282L; JP3372259B2; EP1021401A1; HUP9802303A2; NO981282D0; AU717238B2; MX9801943A; AU7242696A; JPH11511475A; NZ501318A; CA2229316C; KR19990063628A; KR100327922B1; WO1997011053A1

Abstract

A vitamin D derivative providing for the gradual in vivo release of a biologically active vitamin D compound and thereby regulating the in vivo availability and activity profile of the biologically active vitamin D compound, having the structure 1 Where R5 and R6 represent hydrogen, or taken together R5 and R6 are methylene R is represented by the structure 2 where Z is selected from various hydrocarbon groups with provisos to exclude prior art. Also claimed is a method of regulating the activity profile of a vitamin D compound where the hydroxy group at carbon 25, and a selected acyl group or a hydrocarbyloxycarbonyl group attached to the oxygen of the hydroxy group at carbon 25 will provide a modified vitamin D derivative that will prolong the in vivo activity profile of the vitamin D compound.

Description

<div class="application article clearfix" id="description"> -1 - CALCITRIOL DERIVATIVES AND THEI^tT^ 8^9 Background of the Invention A divisional specification NZ 501318 has been filed out of the piesent specification This invention relates to biologically active vitamin D compounds, and more particularly to vitamin D compounds with 5 hydrolyzable groups at one or more of the 1, 3 and 25 carbon positions, such as esters of la,25-dihydroxyvitamm D3 or esters of 1,25-dihyaroxyvitamin D3 analogs, and their use to regulate over time the function of l,25(OH)2D3 (or of l,25(OH)2 D3 analogs) during the treatment of a variety of diseases such as 10 osteoporosis, renal osteodystrophy, hypoparathyroidism or proliferative skm disorders The la-hydroxylated metabolites of vitamin D — most importantly la,25-dihydroxyvitamm D3 and la,25-dihydroxyvitamm D2 -- are known as highly potent regulators of 15 calcium homeostasis in animals and humans With the discovery of lcx,25-dihydroxyvitamin D3 as the active form of the vitamin has come an intense investigation of analogs of this hormonal form of vitamin D with the intent of finding analogs that have selective biological activity As a consequence, many structural 20 analogs of these metabolites, such as compounds with different side chain structures, different hyaroxylation patterns, or different stereo chemistry, have been prepared and tested Important examples of such analogs are la-hydroxyvitamin D3, la-hydroxyvitamm D2, various side chain fluonnated derivatives 25 of la,25-dihydroxyvitamin D3, 19-nor-vitamin D compounds, and side chain homologated analogs Several of these known compounds exhibit highly potent activity m vivo or in vitro, and some of these have been found to exhibit an interesting separation of activities in cell differentiation and calcium 30 regulation This difference in activity provides these compounds WO 97/11053 PCT/US96/15184 - 2 - with advantageous therapeutic activity profiles and thus some of these compounds are m use, or have been proposed for use, m the treatment of variety of diseases such as renal osteodystrophy vitamin D-resistant rickets osteoporosis, psoriasis, and certain 5 malignancies Various forms of osteoporosis are known e g , postmenopausal senile and steroid-induced osteoporosis one of the characteristics of which is the loss of bone mass Females at the time of menopause suffer a marked loss of bone mass giving 10 rise ultimately to osteopenia, which in turn gives nse to spontaneous crush fractures of the vertebrae and fractures of the long bones This disease is generally known as postmenopausal osteoporosis and presents a major medical problem, both m the United States and most other countries where the life-span of 15 females reaches ages of at least 60 and 70 years Generally the disease which is often accompanied by bone pain and decreased physical activity, is diagnosed by one or two vertebral crush fractures with evidence of diminished bone mass It is known that this disease is accompanied by diminished ability to absorb 20 calcium decreased levels of sex hormones especially estrogen and androgen, and a negative calcium balance Similar symptoms of bone loss characterize senile osteoporosis and steroid-induced osteoporosis the latter being a recognized result of long term glucocorticoid (cortico-steroid) 25 therapy for certain disease states Methods of treating osteoporosis have varied considerably but to date no totally satisfactory treatment is yet known A conventional treatment is to administer a calcium supplement to the patient However, calcium supplementation by itself has not 30 been successful in preventing or cunng the disease Another Mimosa 17 50 00 I WO 97/11053 PCT/US96/15I84 - 3 - conventional treatment is the injection of sex hormones especially estrogen, which has been reported to be effective m preventing the rapid loss of bone mass experienced in postmenopausal women This technique, however, has been 5 complicated by the fear of its possible carcinogenicity Other treatments for which variable results have been reported, have included a combination of vitamin D in large doses, calcium and fluoride The pnmary problem with this approach is that fluoride induces structurally unsound bone, called woven bone, 10 and in addition, produces a number of side effects such as increased incidence of fractures and gastrointestinal reaction to the large amounts of fluonde administered Another suggested method is to block bone resorpbon by injecting calcitonin or providing phosphonates 15 US Patent No 4,255,596 suggests the use of vanous metabolites of vitamin D3 for increasing calcium absorption and retention within the body of mammals displaying evidence of or having a physiological tendency toward loss of bone mass The metabolites specifically named m that patent. 1 e . la-20 hydroxyvitamm D3, la-hydroxyvitamm D2. la 25- dihydroxyvitamin D3 (calcitnol) la,25-dihydroxyvitamin D2 and 1,24,25-tnhydroxyvitamm D3. although capable of the activity descnbed and claimed in that patent, can however, also cause hypercalcemia especially if used with the conventional calcium 25 supplement Calcitnol treatment has also been found to be effective in reducing bone loss m women with postmenopausal osteoporosis b> increasing intestinal calcium absorption and reducing bone resorption Alona et al, "Calcitriol In The Treatment Of Postmenopausal Osteoporosis". Amer Jour of 30 Med Vol 84 March, 1988 pp 401-408 Again, however. Mimosa 17 50 00 WO 97/11053 PCT/US96/15184 - 4 - Alona et al discouraged the use of oral dosages of calcitnol due to the nsk of hypercalcemia Therefore use of calcitnol to treat osteoporosis has not been widely accepted Another important consideration is that in vivo calcitnol 5 is produced slowly and continuously by the kidney and thus is available throughout the day and night When given by mouth or by injection, large amounts are available to the tissues initially but little is left after 2-4 hours due to metabolism and excretions A process whereby calcitnol can be made available m 10 vivo more slowly and more continuously would avoid peaks and valleys in the availability of calcitnol thereby providing an effective in vivo level of the compound over a more prolonged period of time and also avoiding or substantially reducing episodes of hypercalcemia that often result from the sudden I 5 availability of excessive amounts of the substance Summary of the Invention The present invention provides a method for modulating and regulating the in vivo activity of biologically active vitamin D compounds, such as calcitnol or analogs of calcitnol More 20 specifically this invention provides modified vitamin D compounds that exhibit a desirable and highly advantageous pattern of biological acitivity m vivo namelv, the more gradual onset and more prolonged duration of activity As a consequence of such advantageous properties, these compounds represent 25 novel therapeutic agents for the treatment of all diseases where vitamin D compounds have been shown effective, such as metabolic bone diseases or proliferative skin disorders (e g psonasls) and they should prove especially useful for the treatment of diseases where bone formation is desired, such as 30 osteoporosis (postmenopausal, senile or steroid-induced), osteomalacia or renal osteodystrophy Mimosa 17 50 00 I WO 97/11053 PCTAJS96/15184 - 5 - Structurally, the key feature of the modified vitamin D compounds having these desirable biological attributes is that they are derivatives of la,25-dihydroxyvitamin D3, or derivatives of 1 a,25-dihydroxyvitamin D3 analogs, in which a hydrolyzable 5 group is attached to the hydroxy group at carbon 25 and, optionally to any other of the hydroxy groups present in the molecule Depending on various structural factors — eg the type, size, structural complexity — of the attached group these derivatives are thought to hydrol>ze to la 25-dihydroxyvitamin 10 D3, or to a la,25-dihydroxyvitarmn D3 analog at different rates m vivo, thus providing for the "slow release of the biologically active vitamin D compound (1 e 1 25-dihydroxyvitamin D3 or an analog thereof) m the body The "slow release" in vivo activity profiles of such 15 compounds can, of course, be further modulated by the use of mixtures of derivatives (e g mixtures of different derivatives of 1 25-dihydroxyvitamm D3, or different derivatives of 1,25- dihydroxyvitamm D3 analogs) or the use of mixtures consisting of one or more vitamin D derivative together with undenvatized 20 vitamin D compounds It is important to stress that the critical structural feature of the vitamin derivatives identified above is the presence of a hydrolyzable group attached to the hydroxy group at carbon 25 of the molecule The presence of a hydrolyzaole group at that 25 position imparts on the resulting derivatives the desirable "slow-release" biological activity profile mentioned above Other hydroxy functions occurring in the molecule (e g hydroxy' functions at carbons 1 or 3) may be present as free hydroxy groups, or one or more of them may also be denvatived with a 30 hydrolyzable group The fact that the introduction of a Mimosa 17 50 00 WO 97/11053 PCT/US96/15184 - 6 - hydrolyzable group at carbon 25 of the vitamin D molecule markedly modulates the in vivo biological activity pattern of the re&ulting derivative was not appreciated previously The realization of the importance of this specific modification and 5 the demonstration of its marked and highly beneficial biological effects form the basis of this invention The "hydrolyzable group' present in the above-mentioned derivatives is preferably an acyl group, i e a group of the type Q1CO-, where Qi represents hydrogen or a hydrocarbon radical 10 of from 1 to 18 carbons that may be straight chain, cyclic branched, saturated or unsaturated Thus, for example the hydrocarbon radical may be a straight chain or branched alky' group, or a straight chain or branched alkenyl group with one or more double bonds, or it may be an optionally substituted 15 cycloalkyl or cycloalkenyl group, or an aromatic group, such as substituted or unsubstituted phenyl, benzyl or naphthyl Especially preferred ^cyl groups are alkanoyl or alkenoyl groups, of which some typical examples are forrml, acetyl, propanoyl, hexanoyl, isobutyryl 2-butenoyl, palmito\ 1 or oleoyl Another 20 suitable type of hydrolyzable group is the hydrocarbyloxycarbonyl group i e a group of the type Q2-0-C0 where Q2 is a C\ to Cig hydrocarbon radical as defined above Exemplary of such hydrocarbon radicals are methyl, ethv] propyl, and higher straight chain or branched alkyl and alkenyl radicals, as well as 25 aromatic hvdrocarbon radicals such as phenyl or benzoyl Among the modified vitamin D compounds having the desirable in vivo bioactivity profile indicated above, an especially important and preferred class are certain acyl ester derivatives of calcitnol. i e the calcitriol denvatives characterized by the 30 following general structure Mimosa 17 50 00 I WO 97/11053 PCT/US96/15184 - 7 - x'o OX? 10 15 20 25 where Xi and X2, independently represent hydrogen or an acyl group, and where X3 represents an acyl group as previously defined Two other very important groups of modified vitamin D compounds are the corresponding acyl esters of the calcitnol side chain homologs, and the acyl denvatives of the 19-nor-1.25-dihydroxyvitamin D analogs The present invention, therefore, provides a series of modified vitamin D compounds that are useful for the treatment of metabolic bone disease (such as the vanous forms of osteoporosis, osteomalacia, osteodystrophy etc) or of differentiative diseases such as psonasis or malignancies More specifically, a method of treating such diseases compnses the administration of an effective amount of the above-indicated acyl ester denvatives of la. 25-dihydroxyvitamin D3 or of the corresponding denvatives of la,25-dihydroxyvitamin D3 analogs The above compounds may be administered alone or in combination with other pharmaceutically acceptable agents Dosages of from not less than about 0 5p.g per day to not more than about 10p.g per day of the individual compound per -^e, or in combinations, are generally effective This method has the distinct advantage that it will restore bone mass due to the conversion of these compounds to calcitnol which has been Mimosa 17 50 00 WO 97/11053 PCT/US96/15184 - 8 - proven to be effective m the treatment of osteoporosis Further, these compounds advantageously will be less likely to cause hypercalcemia or hypocalcemia then the undenvatized compounds even if the compound is administered continuously 5 on a daily basis, as long as the appropriate compounds and dosages are used, it being understood that the compounds and the dosage levels will be adjusted dependent upon the response of the subject as monitored by methods known to tho*>e skilled in the art 10 The above method, involving the administration of the indicated dosages of these compounds is effective in restoring or maintaining bone mass, and thus provides a novel method for the treatment or prevention of vanous forms of osteoporosis such as postmenopausal osteoporosis, senile osteoporosis and steroid-15 induced osteoporosis It will be evident that the method will find ready application for the prevention or treatment of disease states other than those named, in which the loss of bone mass is an indication Also, it will be further evident that the method will find ready application for the prevention or treatment of 20 hypercalcemia and hypocalcemia as the rate of conversion of these analogs, l e the m vivo hydroxylation process, can be controlled and regulated in the manner described above Brief Description of the Drawings Fig 1 is a graph illustrating the activity of di- and tn- 25 acetates of la,25-dihydroxyvitamin D3 on serum calcium, and particularly illustrates the milligrams percent calcium found in blood over time and Fig 2 is a graph similar to Fig 1 except illustrating the activity of a 25-mono-acetate of la,25-dihydroxyvitamin D3 on 30 serum calcum Mimosa 17 50 00 • WO 97/11053 PCT/US96/I5184 - 9 - Disclosure of the Invention The present invention provides novel modified vitamm D compounds which are useful in. the treatment of metabolic bone diseases, such as osteoporosis, as well as other disease states 5 These modified vitamin D compounds are hydrolyzable in vivo to calcitnol. or analogs of calcitnol, over a penod of time following administration and as a consequence regulate the in vivo availability of active calcitnol, or analogs of calcitnol thereby .Uso modulating their activity profile m vivo The term "activity 10 profile" refers to the biological response over time of vitamin D compounds such as calcitnol or analogs of calcitnol Individual modified compounds or mixtures of such compounds, can be administered to "fine tune" a desired time course of response As used herein the term "vitamin D compound' 15 encompasses compounds which have the C-nng D-nng and 3J5-hydroxycyclohexane A-nng of vitamin D interconnected by the 5,7 aiene doable bond system of vitamin D together with any side chain attached to the D-nng In other words, the vitamin D compounds encompassed herein include those having a 'vitamin 20 D nucleus compnsmg substituted or unsubstituted A-, C- and D-nngs interconnected by a 5, 7 diene double bond system typical of vitamin D together with a side chain attached to the D-nng As used herein the term "modified vitamin D compound" encompasses any vitamin D compound m which one or more of 25 the hydroxy functions present m such a compound are modified by derivatization with a hydrolyzable group A 'hydrolyzable group' is a hydroxy-modifying group that can be hydrolyzed in vilo, so as to regenerate the free hydroxy functions Mimosa 17 50 00 < WO 97/11053 PCT/US96/15184 - 10 - In the contcxt of this disclosure, the term hydrolyzable group preferably includes acyl and hydrocarbyloxycarbonyl groups, i e groups of the type Qi CO- and Q2-0-CO, respectively, where 91 and Q2 have the meaning defined earlier 5 Structurally, the modMied vitamin D compounds encompassed may be represented by the formula 10 15 X'O where r5 and R6 each represent hydrogen, or taken together ana Ae represent a methylene group 20 The side chain group R in the above-shown structure represents a steroid side chain of the structure below \/z 25 ' J where the stereochemical center (corresponding to C-20 in steroid numbering) may have the R or £ configuration, (1 e either the natural configuration about carbon 20 or the opposite unnatural configuration), and where Z is selected from Y, -OY. 30 -CH2OY, -C a CY and -CH = CHY. where the double bond may have the cis or trans geometry, and where Y is selected from a radical of the structure Mimosa 17 50 00 * WO 97/11053 PCT/US96/15I84 - 11 - R1 R2 r3 \/ / * — (CH2)m— c— (CH2),t—c —OX 5 where m and n. independently, represent the integers from 0 to 5. where Ri is selected from hydrogen OX^, fluoro, tnfluoromethyl, and C1-5- alkyl which may be straight chain or branched and, optionally, bear a hydroxy substituent, and where r2 is selected from hydrogen, fluoro, tnfluoromethyl and C^.5 10 alkyl. which may be straight-cham or branched, and optionally, bear a hydroxy substituent, and where R3 and R4, independently represent tnfluoromethyl or C1-5 alkyl which may be straight chain or branched and, optionally, bear a hydroxy substituent, and where Ri and r2, taken together, represent an oxo group or 15 an alkylidene group. =cr2r2, or =cr2r3, or the group -(CH2)P-, where p is an integer from 2 to 5 and where R3 and R4 taken together, represent the group -(CH2)q- where q is an integer from 2 to 5 In the above-shown structures Xi, X2 and X4 independently represent hydrogen, an acyl group or a 20 hydrocarbyloxycarbonyl group, arid X3 represents an acyl group or a hydrocarbyloxycarbonyl group, as previously defined herein Some specific examples of such modified vitamin D compounds include calcitnol denvatives such as 25 la,25(OH)2-D3-l,3.25-Tnacetate where Xi=X2=X3=CH3CO, la,25(OH)2-D3-l,3,25-Tnhexanoate where Xi=X2=X3=CH3(CH2)4 CO. Mimosa 17 50 00 f WO 97/11053 PCT/US96/I5184 12 - 1 a.25(OH)2-D3-1,3,25-Tnnonanoate where Xi=X2=X3=CH3(CH2)7CO. lcc,25(0H)2-D3-25-Acetate where Xi=X2=H and X3=CH3CO 10 15 20 The following examples which are meant to be illustrative only, describe the process of synthesis of modified vitamin D compounds In these examples, specific compounds identified by Arabic numerals (e g compounds 1. 2, 3. etc ) refer to the structures so numbered below Additionally, examples are provided which are illustrative of the distinctive biological characteristics of the new compounds, such characteristics serving as a basis for the application of these compounds ill the treatment of metabolic bone disease and other vitamin D responsive diseases such as psoriasis OX 25 30 x'o ox2 1 Xi 1) II Co II a 1 Xi = X2 = X3 = CH3CO 2. Xi = X2 = X3 = CH3{CH2UCO 4 Xi = X2 = X3 ■= CHslCHzbCO 5 XI = X2 = (CH-)2CHCO. X3 = K Mimosa 17 50 00 WO 97/11053 PCT/US9S/15184 - 13 - £ XI = X2 = CH3(CH2)4CO. X3 = H 2 X» = X2 = C6H5CO. X3 = H £ XI = X2 = H X3 = CH3CO 5 EXAMPLE 1 The Preparation of Mono. Di and Tn-Esters of la,25-(OH)2-D3 Experimental Spectra were obtained on the following instruments Ultraviolet 10 (UV) absorption spectra were taken with Perkin-Elmer Lambda 3B UV/vis spectrophotometer Nuclear magnetic resonance (NMR) spectra were recorded at 400 or 500 MHz with a Bruker DMX spectrometer Chemical shifts (5) are reported downfield from internal Me4Si (5 0 00) Mass spectra were recorded at 70 15 eV on a Kratos MS-50 TC instrument equipped with a Kratos DS-55 data system Preparative thin layer chromotography (pic) was earned out with Merk 1-mm F-254 silica gel plates and E Merk 0 25 mm F-254 silica gel plates 20 General Procedure for Preparation of Triesters Preparation of la,25(OH)2-D3 1,3,25-Triacetate (2) X1 = X2 = X3 = CH3CO A solution of glacial acetic acid (0 05mL, 0 87mmol) trifluoroacetic anhydnde (0 05mL 0 35mmol) was stirred at room temperature 3 5 h Then la,25(OH)2-D3 QJ (0 3 mg, 0 00072mmol) m 0 4 25 mL dry THF was added to above solution at 0°C The reaction mixture was stirred at 0°C for 0 5h and then at room temperature for 2h The solvent was removed under reduced pressure to afford a crude product that was punfied twice by preparative thin layer chromatography (pic, 15% 30 EtOAc/hexane) to give a pure compound (2) (0 122mg, 31 3% yield) UV. ). max 265 nm (Et OH) 1 H NMR (CDCI3) 5. 0 51 (s. Mimosa 17 50 00 WO 97/11053 PCT/US96/15I84 - 14 - 3H, C 16-CH3), 0 92(d, J=5 0 Hz. 3H. C21-CH3). 1 42 (s. 6H C26 27-CH3), 1 98. 2 04. 2 06 (s. 9H. CH3CO-), 5 04 (s 1H. Cj9 E-H). 5 18 (m, 1H. C3-H). 5 31 (s 1H. C19 Z-H), 5 48 (t, J=6 Hz. Ci-H), 5 91 (6 35 (dd, J=10 Hz, C6 7-H) MS m/z 542 (M+) 482 5 (M+ -60). 422 (M+ -2 x 60). 362 (M+ 3 x 60) la,25 (OH)2-D3 1,3,25-Trihexanoate (3) X1=X2=X3=CH3(CH2)4 CO To hexanoic acid (0 15mL, 1 20mmol) was added tnfluoroacetic anhydnde (0 lmL 0 71mmol). The mixture was 10 stirred at room temperature for 4h (the solution became pale brown) After la 25(OH)2-D3 QJ (0 4 mg 0 00096mmol) in O 2mL dry THF was added, the reaction mixture was stirred ?t room temperature for 5h, or until complete (as monitored by thin layer chrornotography) The product (2J (0 217mg 31 72% 15 yield) was worked-up as in the previous example and punfied by pic (3 times, 8% EtOAc/Skellysolve B) UV, a. max 265 3nm, 245nm (shoulder) (EtOH) JH NMR (CDCI3) 5. 0 51. (s. 3H. C18-CH3). 0 89 (t, J=6 3 Hz, 9H. CH3(CH2)4 CO). 0 92 (d. J=6 3 Hz, 3H, C21-CH3), 1 42 (s, 6H, C2627-CH3). 5 14 (s. 1H. C,9 E-H). 20 5 18 (m. 1H, C3-H), 5 32 (s, 1H, C19 Z-H). 5 47 (t. J=6 3 Hz, 1H, CrH). 5.91. 6 34 (dd. J=ll 15 Hz C67-H). MS m/z 710 (M+), 594 (M+-116 C5H11COOH). 478 (M*-2 x 116), 362 (M+-3 x 116) la.25(OHJ2-D3 1,3,25-Tnnonanoate (4) X1=X2=X3=CH3(CH2)7CO 25 To nonanoic acid (0 2mL, 1 145mmol) was added tnfluoroacetic anhydride (0 08mL, 0 566mmol) and the mixture was stirred at room temperature for 4h After la 25(OH)2-D3 CI) (0 4mg. 0 00096mmol) in dry THF (0 2mL) was added, the reaction mixture was stirred at room temperature for 4h, or until Mimosa 17 50 00 I WO 97/11053 PCT/US96/15184 - 15 - complete (as determined by TLC) The usual work-up gave product (4J (0 283mg, 35 2% yield) UV, X max 265 3 nm 243 9nm (shoulder) (EtOH). *H NMR (CDCI3) 5, 0 51 (s. 3H, C18-CH3). 0 88 (t. J=6 2 Hz. 9H. CH3 (CH2)7CO-). 0 92 (d. J=6 3 5 Hz, 3H, C21-CH3). 1 42 (s. 6H, C26.27-CH3). 5 04 (s, 1H C19 E-H), 5 18 (m 1H, C3-H). 5 32 (s. 1H, C19 Z-H) 5 49 ft, J=6 2 Hz. 1H, Ci-H), 5 91, 6 34 (dd. J=ll 36 Hz, 2H C67-H) MS m/z 836 (M+). 67S (M+-15S, CH3(CH2)7COOH), 520 (M+-2 x 158). 362 (M+-3 x 158) 10 General Procedure for Preparation of Diesters Preparation of la,25(OH)2-D3 1,3-diisobutyrate (5) X1=X2=(CH3)2CHCO, X3=H, A solution of isobutync acid (0 06mL, 0 647mmol), N.N-dicyclohexylcarbodimide (35 55mg 0 173mmol), 4- 15 pyrrolidinopyrldine (6 12mg. 0 041mmol) and la,25(OH)2-D3 CD (0 4mg 0 00096mmol) m 0 15mL dry dichloromethane was stirred at room temperature overnight (12h) The white precipitate formed was filtered and the residue washed with dichloromethane The combined organic solution was 20 concentrated and the crude product was punfied twice by p 1 c (25% EtOAc/skellysove B) to give a pure product (5) (2r6mg, 55 33% yield) UV ?. max 266 5nm, 244nm (shoulder). *H NMR (CDCI3) 8, 0 49 (s. 3H, CiS-CH3), 0 93 (d. J=6 25 Hz. 3H. C2r CH3). 1 14 (t, J=6 3 Hz, 12H. (CH3)2CHC0-) 1 21 (s. 6H. C2B27-25 CH3). 5 05 (s. Cig E-H). 5 17 (m. 1H. C3-H), 5 35 (s, 1H. C19 Z-H) 5 5 (t J=6 3 Hz, 1H, Ci -H). 5 91. 6 35 (dd, J=ll 35 Hz. 2H C67-H) MS m/z 556 (M+), 468 (M+-88.CH3)2CHCOOH). 380 (M+-2 x 88). 362 (M+-2 x 88 - H20) Mimosa 17 50 00 WO 97/11053 PCT/US96/15184 - 16 - la,25(OH)2-D3 1,3-Dihexanoate (6), X1=X2=CH3(CH2)4CO, X3=H. A solution of n-hexanoic acid (0 15mL, 1 19mmol). N N-dicyclohexylcarbodimide (73 66mg, 0.358mmol), 4- pyrrolidmopyndine (4 45mg. 0 03mmol). and la.25(OH)2-D3 (1) 5 {0 5mg. 0 0012mmol) in 0 lmL dry dichloromethane was stirred at room temperature overnight (12h) After work-up as in the preceding example, the crude product was purified by p 1 c (3 times 15% EtOAc/skellysolve B) to give pure compound (£3 (0 079mg, 10 74% yield) UV, X max 263 6nm, 240nm (EtOH) 10 'H NMR (CDCI3) 5. 0 51 (s, 3H. C18-CH3). 0 89 (t, J=6 4 Hz. 6H. CH3(CH2).jCO-) 0 93 (d. J=6 25 Hz, 3H, C2i-CH3). 121 (s. 6H C2627-CH3). 5 04 (s. 1H C19 E-H) 5 18 (m. 1H, C3-H). 5 30 (s. 1H, C]9 Z-H). 5 49 (t J=6 2 Hz. 1H, Ci-H). 5 92. 6 34 (dd J=ll 26. 2H. C6.7-H) MS m/z 612 (M+). 496 (M+-l 16. 15 CH3(CH2)4COOH5, 478 (M+-l 16-H20), 380 (M+-2 x 116), 362 (M+-2 x II6-H2O) la,25(OH)2-D3 1,3-Diben^oate (7) X1=X2=CeHsCO. X3=H A solution of benzoic acid (15 53mg 0 127mmol), N.N-20 dicyclohexylcarbodimide (42 64mg, 0 206mmol), 4- pyrrolidinopyndine (2 13mg. 0 0144mmol), and la.25(OH)2D3 (1) (0 51mg. 0 00l23mmol) in dry dichloromethane (0 4mL) was stirred at room temperature for I6h After work-up as above, the crude product was punfied by p 1 c (2 times. 8% 25 EtOAc/skellysolve B) to give a pure compound (7) (0 123mg, 16 4% yield) UV. I max 265 4 nm, 230 5nm (EtOH) 'H NMR (CDCI3) 5. 0 28 (s, 3H Ci8-CH3). 0.91 (d, J=5 0 Hz, C2i-CH3), 1 21 (s. 6H. C26 27-CH3). 5 13 (s. 1H. Cl9 E-H). 5 47 (s. 1H. C19 Z-H). 5 51 (m. 1H. C3-H). 5 82 (t, J=6 2 Hz, 1H, Cj-H), 5 93, Mimosa 17 50 00 I WO 97/11053 PCT/US96/15184 - 17 - 6 45 (dd. J=10, C6 7-H), 7 41. 7 54. 8 04 (m. 10 H. Ar-H) MS m/z 624 (M+), 606 (M+-H20), 502 (M+-122 C6H5COOH). 380 (M+-2 x 122), 362 (M+-2 x 122-H20) 5 la,25(OH)2-D3 25-Acetate (8) X^X^H, X3=CH3CO la,25(OH)2-D3 1,3,25-Triacetate (2J (0 168 mg. 0 00031mmol) was dissolved in lmL of 0 6% methanolic solution of potassium carbonate After the mixture was stirred at room temperature for 2h (or until complete by TLC), the solvent was removed 10 under reduced pressure The crude product was punfied by p 1 c (50% EtOAc/hexane) to give the pure product (g) (0 056mg 39 4% yield) UV X max 265nm (EtOH). NMR (CDCI3). 8. 0 54 (s 3H, C18-CH3). 0 92 (d. J=5 Hz. C21-CH3). 1 42 (s, 6H, C2627-CH3). 1 98 (s. 3H, CH3CO). 4 24 (m. 1H. C3-H). 15 4 44 (t, J=6Hz. CrH). 5 01 (s. 1H Cjg E-H) 5 34 (s. 1H. C19 Z- H). 6 02. 6 39 (dd. J=10 Hz, 2H. Ce 7-H). MS m/z 458 (M*}. 440 (M+-H20) 422 (M+-2 x HoO) 398 (M+-60.CH3COOH), 380 (M+-60-H20), 362 (M+-60-2 x H20) 20 EXAMPLE 2 This example illustrates the serum calcium response of rats over time to three compounds, namely, la,25(OH)2D3- 1.3,25-triacetate, la25(0H)2D3-1.3-diacetate, and la.25(OH)2D3 (unestenfied) 25 In this biological test, rats were fed a calcium-containing (0 47% calcium), vitamin D-deficient diet for a period of 8 weeks to deplete them of vitamin D They were then provided a single oral dose of 1,000 pmol or 1 nanomole of each of the compounds, and serum calcium was determined by bleeding the Mimosa 17 50 00 WO 97/11053 PCT/US96/15184 - 18 - rats at the various times as shown in Table 1 Figure 1 is a graph illustrating the data of Table 1 Because calcium is present m the diet and hence their intestine the nse in serum calcium largely represents intestinal calcium absorption The results 5 show clearly that the 1,3-diacetate and un-estenfied calcitnol produce essentially the same time course of response, illustrating that acetylation of the C-l and C-5 hydroxy groups does not significantly alter the biological response presumably because the acyl groups at these positions are removed rapidly, 10 e g by digestive enzymes In marked contrast the tnacetate did not begin to show a response until 12 to 18 hours post-dose, peaking at 24 hours Thus, the 25-acetate group probably remained intact over a more prolonged penod and was then slowly hydrolyzed inside the body Thus the triacetate clearly 15 delays utilization of the calcitiiol indicating that the in vivo activity profile of the parent calcitnol can be changed very markedly by acylation of the C-25-hydroxy group TABLE 1 (A) (B) (C) Time Control I Diacetate Triacetate 0 Hours 4 3 = 0 07 8 Hours 6 06 ± 0 89 5 42 = 0 90 4 06 ± 0 3S 12 Hours 7 39 ± 0 10 6 50 ± 0 13 4 70 i 0 12 18 Hours 6 97 ± O 51 6 24 = 0 51 5 91 ± 0 30 24 Hours 6 45 = 0 50 5 98 - 0 43 67:054 48 Hours 4 43 = 0 18 5 59 = 0 80 5 11 ± 0 48 5 10 ± 0 43 20 All data = Mean z S D (A) from (B). N S diff (A) from (C). at 8 hrs. 12 hrs, p<0 001 Mimosa 17 50 00 O WO 97/11053 PCT/US96/I5184 - 19 - EXAMPLE 3 This example illustrates the serum calcium response of rats over time to two compounds, namely la.25(OH)2D3 20 (unestenfied) and lcc,25(OH)2D3-25-acetate, administered by three different methods, namely, orally (oral), intramuscularly (I M ), and subcutaneously (Sub Cu ) In this test. 1 nanomole of each compound was given to vitamin D deficient rats fed a 0 47% calcium, 0 3% P diet in 0 1 25 ml propylene glycol 95%/5vo ethanol There were at least 4 rats per group Serum calcium was determined at the various times shown in Table 2 following a single dose given by the indicated route Figure 2 is a graph illustrating the data of Table 2 The results are in accord with those of Example 2 Regardless of 30 route of administration l,25(OH)2D3-25-acetate shows a more gradual onset of in vivo activity and a delayed peak of activity Thus, the 25-monoacetate clearly delays utilization of the calcitnol confirming that the presence of a C-25-O-acyl group has a pronounced effect on the activity pattern and time course 35 of response of a biologically active vitamin D compound TABLE 2 Serum Calcium Response to 1.25-(OH)2D3 and its 25-Acetate Serum Calcium (mg/100 ml) Administration ComDOund Route Pay.l Dav 3 Dav 6 Dav 10 None (Control) 5 9±0 34 - 5 7±0 34 5 2±0 63 1.25-(OH)2D3 Oral 9 33±0 41 - 8 6±0 52 7 15±0 68 1 25- (OH)2D3 25-Acetate Oral 7 70±0 11 8 87±06 8 54±0 15 8 83±0 71 I M 8 10+0 24 9 17±0 53 9 77±0 3 - •• Sub Cu 7 78±0 28 9 00±0 28 9 84±0 39 - Mimosa 17 50 00 1 WO 97/11053 PCT/US96/I5184 - 20 - The modified vitamin D compound or combinations thereof can be readily administered as sterile parenteral solutions by injection or intravenously, or by alimentary canal m the form of oral dosages or trans-dermally, or by suppository 5 Doses of from about 0 5 micrograms to about 10 micrograms per day or modified vitamin D compound per se, or in combination with other modified vitamin D compounds, the proportions of e<ach of the compounds in the combination being dependent upon the particular disease state being addressed and the degree 10 of bone mineralization and/or bone mobilization desired, are generally effective to practice the present invention In all cases sufficient amounts of the compound should be used to restore bone mass Amounts in excess of about 10 micrograms per day of modified vitamin D compound, or the combination of that 15 compound with other modified vitamin D compounds, are generally unnecessary to achieve the desired results, may result m hypercalcemia, and may not be an economically sound practice In practice the higher doses are used where therapeutic treatment of a disease state is the desired end while 20 the lower doses are generally used for prophylactic purposes, it being understood that the specific dosage administered in any given case will be adjusted in accordance with the specific compounds being administered, the disease to be treated, the condition of the subject and the other relevant medical facts that 25 may modify the activity of the drug or the response of the subject, as is well known by those skilled in the art In general either a single daily dose or divided daily dosages may be employed, as is well known in the art Dosage forms of the various compounds can be prepared 30 by combining them with non-toxic pharmaceutically acceptable earners to make either immediate release or slow release formulations, as is well known in the art Such carriers may be either solid or liquid such as. for example, com starch, lactose, Mimosa 17 50 00 I • WO 97/13053 PCT/US96/15I84 - 21 - sucrose, peanut oil, olive oil, sesame oil and propylene glycol If a solid carrier is used, the dosage form of the compounds may be tablets, capsules, powders, troches or lozenges If a liquid earner is used, soft gelatin capsules, or syrup or liquid 5 suspensions, emulsions or solutions may be the dosage form The dosage form may also contain adjuvants, such as preserving stabilizing, wetting or emulsifying agents, solution promoters, etc They may also contain other therapeutically valuable substances Mimosa 17 50 00 I WO 97/11053 PCT/US96/1S184 - 22 The modified vitamin D compounds may also include any of the following compounds in which one or more hydroxy functions that may be present are modified by denvatization with a group hydrolyzable in vivo 10 - P stands for hydrogen, alkyl or acyl, 15 - X represents part of the side-chain of vitamin D or of one of its established analogues, - Y and Y\ which may be the same or different, stand for hydrogen or alkyl or, when taken together, represent an alkylidene group, or form a carbocyclic nng, 20 - W and W", which may be the same or different, stand for hydrogen or alkyl or, when taken together, represent an alkylidene group, or form a carbocyclic nng, - one of the carbon atoms of the central part corresponding to positions 14, 13,17 or 20, together with the R and R' substituents connected to it, rruy be 25 replaced by an oxygen (O), a sulfur (S) or a nitrogen beanng an R substituent (NR) - R and R' (i e , R, Ri, R2, R'2. R3. R'3. R4. R'4, R5. R's) • when located in a relative 1,3-position along the central chain, such as Ri and R3 or R'3, R2 or R'2 and R4 or R*4, R3 or R'3 and R5 or R's, taken Mimosa 17 50 00 * WO 97/11053 PCT/US96/15184 together wrth three adjacent atoms of the central chain, which correspond to positions B, 14,13 or 14,13.17 or 13.17, 20, respectively, can form a saturated or unsaturated carbocyclic or heterocyclic 3-, 4-, 5-, 6- or 7-membered nng 5 also including cases whereby gemina! substituted R and R' taken together form a cyclic unsaturated bond, under the proviso that when Ri and R's form a 6-membered carbocylic ring of the following nature (1) unsubstituted and saturated (2) rnonosubstituted at C-11 or (3) having a double bond between C-9 and C-11, R2 and R4 do not form 10 s five-membered carbocyclic nng when Rs is methyl, etnyl or ethenyl o when located in a relative 1,2-position (1 e , vicinal) along the central chain, such as R1 and R2 or R'2, R2 or R'2 and R3 or R'3, R3 or R3 and R4 or R'4, R4 or R'4 and R5 or R'5, and when not being part of a nng as described above, taken together with two adjacent atoms of the central 15 chain, which correspond to positions 8,14 or 14,13 or 13,17 or 17,20, respectively, can form a saturated or unsaturated carbocyclic or heterocyclic 3-, 4-, 5-, 5- or 7-membered nng, also including cases whereby geminal substituted R and R' taken together form a cyclic unsaturated bond 20 • when located in a relative 1,1-position (1 e , geminal) along the central chain, such as Ra and R'2, or R3 and R'3, or R4 and R'4 or R5 and R's, and when not being part of a nng as descnbed dDove, taken together with the carbon beanng the R and R' substituents can form either a saturated or unsaturated carbocyclic or heterocyclic 3-, 4-, 5-, or 25 6-membered nng • which may be the same or different, and when they are not forming a nng or a bond as descnbed above, stand for hydrogen or a lower alkyl group, or when taken together in the case of geminal substitution represent a lower alkylidene group Mimosa 17 50 00 t WO 97/11053 PCT/US96/15184 -24 - In the context of the invention the expression "lower alkyl group" inaicates a straight or branched saturated or unsaturated carbon chain containing from 1 to 7 carbon atoms, and "lower alkylidene group" indicates a straight or branched saturated or unsaturated carbon chain containing from 1 5 to 7 caroon atoms, which is connected to one of the mam chain a(oms 14, 13. 17 and/or 20 through a double bond In the context of the invention part of the side-chain of vitamin D or of one of rts established analogues stands for a 2 to 15 carbon atom substituted aikyl chain especially as present in vrtamin D2 (C-22 to C-28) or D3 (C-22 to 10 C-27) or partially modified as shown below wrth the vitamin D numbenng, espsc.ally - hydroxyl substituent at one or more posrtions, for instance 24, 25 and/or 25 and/or - methyl or ethyl substituent in one or more positions, for instance 24, 26 15 and/or 27 and/or - halogen substituent(s) at one or more posrtions for instance perfluorated a' positions 26 and/or 27 or difluorated at position 24 and/or - additional carbon atom(s) especially C24 between the positions 24 and 25, with tne same substitution pattern mentioned above and/or 20 - esters denvatives of one or more hydroxyl substituents mentioned above and/or - changing one or more carbon atoms for an oxygen, nrtrogen or sulfur atom for instance at the positions 22,23 or 24 and/or - cyclized between the carbon atoms 26 and 27 by one bond (cyclopropane) 25 or by the intenrr.ediacy of 1 to 4 carbon atoms, the nng can be saturated, unsaturated or aromatic and may optionally be substituted at any possiDls position(s) with the substituent mentioned above and/or Mimosa 17 50 00 WO 97/11053 PCT/US96/15184 - 25 - - cyclized between the carbon atoms 26 and 27 by 1 to 4 atoms to form a heterocyclic nng, including aromatic, which may optionally be substitutad at any possible position with the substituent mentioned above and/or - unsaturated with one or more double or tnple C-C bond(s), these 5 unsaturated chains may be substituted al any possible position by the substituents mentioned above and/or - epoxide function can be present between carbon atoms 22,23 or 23,24 or 24,25 or 25,26, these epoxidized chains can be saturated or unsaturated and may be substituted at any possible positions with the substituents 10 merited above and/or - two or more of the carbon atoms of the side chain can be linked by s. s-ngle bond or by the inte'mediacy of a one to five carbon or oxygen, nitrogen or stjlfur atoms to form a 3-7 membered saturated or unsaturated earbo^ydic or heterocyclic including aromatic nng which may optimally be substiuted at 15 any possible position by substituents mentioned above and/or - subst'trted at one or more positions by saturated, unsaturated caroocychc, heterocyclic or aromatic nng which can be substituted at any possible position(s) With the substituents mentioned above - isomenc forms of the substituted chain, 20 Hence the invention relates to a senes of analogues with widely varying structures. Most often the compounds of the invention are represented by one of the formulas Mimosa 17 50 00 WO 97/11053 PCT/US96/I5184 - 26 - where * - X, Y, Y\ W and W have the same meaning as above, ~ Z represents a saturated or unsaturated hydrocarbon chain consisting of 20 Zero (hence Z represents a bond between two 1,3-reiated carbon atoms of the central chain), one, two, three or four atoms, which may all be substituted and/or replaced by a heteroatom such as oxygen, sulfur and nitrogen - Ri, R2. R'2, R3. R'a. R4. R'4, RS. R'S 25 • which may be the same or different, stand for hydrogen or lower alkyl, such as methyl, ethyl or n-propyl Among those are preferred the cyclic denvatives ol type Mimosa 17 50 00 WO 97/11053 PCT/US9&15184 - 27 - wherein - n is an -nteger equal to 2 or 3, - X represents one of the following vitamin D side-chain parts (4-hydroxy-20 4-methyl)pentyl, (R)- or (S)-(3-hydroxy-4-methyl)pentyl, (3'-hydroxy-3'- methyi)butyloxy, (4-hydroxy-4-ethyl)hexyl, (4-hydroxy-4-methyl)-2-pentynyl, (4'-hydroxy-4'-ethyl)hexyloxy, 4,5-epoxy, 4-methyl-2-pentynyl, 4-hydroxy-4-ethyl-2-hexynyl, (3-methyl-2,3-epoxy)-butyloxy, (3-hyaroxy-3-ethyl)-pentyloxy, (4-hyaroxy-4-ethyI)-hexyloxy 25 - Y,Y',W and W' are the same and represent hydrogen, or taken together represent a methylene group =CH2, - Ri, R2, R'2, R3, R'3. R4. R*4. R5 and R's, which may be the same or different, stand for hydrogen or methyl Mimosa 17 50 00 28 </div>

Claims

<div class="application article clearfix printTableText" id="claims">



CLAIMS 

1 A vitamin D denvative providmg for the gradual in vivo release of a biologically active vitamin D compound and thereby regulating the in vivo availability and activity profile of the biologically active vitamin D compound, said vitamm D denvative having the structure where R5 and R6 each represent hydrogen, or taken together R5 and R6 xepresent a methylene group, and where R is represented by the structure where the stereochemical center at carbon 20 m the side cham may have the R or S configuration, and where Z is selected from Y, -OY, -CH2OY, -C s C Y and -CH = CHY, where the double bond may have the cis or trans stereochemical configuration, and where Y is selected from a radical of the structure 

R1 R2 p3 

\/ / 

—(CH2)„ — C— (CHjV-c— ox3 

where m and n, independently, represent the integers from 0 to 5, where R1 is selected from the group consisting of hydrogen, OX4, fluoro, tnfluoromethyl, and C^- alkyl, which may be straight cham or branched and, optionally, bear a hydroxy' substituent, and where R2 is selected from the group consisting of hydrogen, fluoro, tnfluoromethyl and C1.5 alkyl, which may be stiaight-chain or branched, and optionally, bear a hydroxy substituent, and where each of R3 and R4, is selected from 

tnfluoromethyl and Ci_5 alkyl, which may be straight chain or branched and optionally bear a hydroxy substituent, and where R1 and R2, taken together, represent an oxo group, or an alkylidene group, =CR2R2, =CR2R3, 01 the group -(CH2)P-. where p is an integer from 2 to 5, and where R3 and R4, taken together, represent the group -(CH2)q-, where q is an integer from 2 to 5, and where X1, X2, and X4 are each hydrogen, an acyl group, or a hydrocarbyloxycarbonyl group, and where X3 represents an acyl group or a hydrocarbyloxycarbonyl group, with the proviso that X3 cannot be acetyl (CH3CO-) when m is 2, n is 0, R1 and R2 are both hydrogen, R3 and R4 are both methy, R5 and R6 together represent a methylene group and (a) X1 is hydrogen and X2 is acetyl, or (b) X2 is hydrogen and X1 is acetyl, or (c) X1 and X2 are both hydrogen, 

1 1 l or (d) X and X are both acetyl, and with the further proviso that X cannot be -COCH2CH2COOH or -COCH2CH2COOCH3 when m is 2, n is 0, R1 and R2 are both hydrogen, R3 and R4 are both methyl, R5 and R6 together represent a methylene group, and X1 and X2 are both hydrogen, and with the additional proviso that X3 cannot be acetyl when m is 2, n is 0, R1 is -OX4 where X4 is acetyl, R2 is hydrogen, RJ and R4 are both methyl, R5 and R6 together lepresent a methylene group, and X1 and X2 are both acetyl
2 A vitamm D derivative according to claim 1 wherein said acyl group or hydrocarbyloxycarbonyl group has a structure that prolongs the in vivo activity profile of said active vitamin D compound as compared to the in vivo activity profile of said active vitamin D compound without said acyl or hydrocarbyloxycarbonyl group
3 A calcitnol derivative providing for the gradual release of active calcitnol m vivo, said denvative having the formula x'o 

'OX2 

ox- 

30 

1 17 

where X and X independently represent hydrogen, an acyl group or a hydrocarbyloxycarbonyl group, and where X is an acyl group or a hydrocarbyloxycarbonyl group, and with the proviso that X3 cannot be acetyl (CH3CO-) when (a) X1 is hydrogen and X2 is acetyl, or (b) X2 is hydrogen and X1 is acetyl, or (c) X1 and X2 are both hydrogen, or (d) X1 and X2 are both acetyl, and with the further proviso that X3 cannot be -COCH2CH2COOH or -COCH2CH2COOCH3 when X1 and X2 are both hydrogen
4 A compound according to claim 3 wherem the acyl group is a C) to Cj8 alkanoyl group
5 A compound according to claim 3 wherein X3 is an acyl group selected from the group consistmg of formyl, acetyl, propanoyl and butanoyl 

1 9
6 A compound according to claim 3 wherein X and X both represent hydrogen
7 A compound according to claim 6 wherem X3 represents a Ci to C]8 alkanoyl group
8 1 ex,25-dihydroxyvitamin D3-l,3525-Trihexanoate
9 1 ou25-dihydroxyvitamin D3-1,3,25-Trinonanoate
10 la,25-dihydroxyvitamin D3-25-formate
11 A method of regulating the activity profile of a vitamin D compound which comprises selecting a vitamin D compound having a hydroxy group at carbon 25 and having a desirable in vivo therapeutic activity, 

selectmg an acyl group or a hydrocarbyloxycarbonyl group which when attached to the oxygen of the hydroxy group at caroon 25 will provide a modified vitamin D derivative that will prolong the in vivo activity profile of said active vitamin D compound by hydrolyzmg m vivo at a desired rate to said active vitamin D compound, and modifying the vitamin D compound by derivatizmg the hydroxy group at carbon 25 with said acyl group or a hydrocarbyloxycarbonyl group, to obtain said modified vitamin D denvative having the formula 

319 

where R5 and R6 each represent hydrogen, or taken together R5 and R6 represent a methylene group, and where R is represented by the structure where the stereochemical center at carbon 20 in the side cham may have the R or S configuration, and where Z is selected from Y, -OY, -CH2OY. -C = CY and -CH = CHY, where the double bond may have the cis or trans stereochemical configuration, and where Y is selected from a radical of the structure where m and n, independently, represent the integers from 0 to 5, where R1 is selected from the group consisting of hydrogen, OX4, fluoro, tnfluoromethyl, and C1.5- alkyl, which may be straight cham or branched and, optionally, bear a hydroxy substituent, and where R2 is selected from the group consisting of hydrogen, fluoro, 

tnfluoromethyl and C1.5 alkyl, which may be straight-chain or branched, and optionally, bear a hydroxy substituent, and where each of R3 and R4, is selected from tnfluoromethyl and C1.5 alkyl, which may be straight chain or branched and optionally bear a hydroxy substituent, and where R1 and R2, taken together, represent an oxo group, or an alkylidene group, =:CR2R2, =CR2R3, or the group -(CH2)P-, where p is an integer from 2 to 5, and where R3 and R4, taken together, represent the group -(CH2)q-, 

319 a i where q is an integer fiom 2 to 5, and where X1, X2, and X4 are each hydrogen, an acyl group, or a hydrocarbyloxycarbonyl group, and where X3 represents an acyl group or a hydrocarbyloxycarbonyl group
12 The method of claim 11 wherem X1, X2, X3, and X4 independently represent an acyl group or a hydrocarbyloxycarbonyl group
13 The method of claim 11 wherem X3 is acyl or a hydrocarbyloxycarbonyl group and X1, X2 and X4 each represent hydrogen
14 The method of claim 11 where X1, X2 and X4 are each hydrogen or an acyl group, and X3 is an acyl group
15 The method of claim 14 where the acyl group is acetyl
16 The method of claim 14 where the acyl group is propanoyl, butanoyl or hexanoyl
17 The method of claim 14 where each of X1, X2, X3 and X4 is acetyl
18 The method of claim 14 where X1, X2 and X4 are each hydrogen and X3 

is acyl
19 The method of claim 18 where X3 is acetyl
20 The method of claim 11 wherein said denvatized vitamin D compound has the formula x'o ua where X1 and X2 are each hydrogen, an acyl group or a hydrocarbyloxycarbonyl group and where X3 represents an acyl group or a hydrocarbyloxycarbonyl group
21 The method of claim 20 where X1 and X2 are each hydrogen or an acyl 

■2 

group, and X is an acyl group
22 The method of claim 21 where the acyl group is acetyl 

33
23 A method of modulatmg the activity profile of a vitamin D compound, comprising the steps of selecting a vitamin D compound havmg an -OH group attached at carbon 25 and havmg an m vivo therapeutic activity profile, and prolonging the activity profile of said vitamin D compound by 

(a) selectmg a group -OX3 where X3 is hydrolyzable in vivo to the -OH group at a desired rate, and 

(b) providmg a modified form of said vitamin D compound havmg the group -OX attached at carbon 25
24 The method of claim 23 wherein the hydrolyzable X3 is an acyl group
25 The method of claim 23 wherem the hydrolyzable X3 is CH3CO
26 The method of claim 23 wherein the hydrolyzable X3 is CH3(CH2)4CO
27 The method of claim 23 wherem the hydrolyzable X3 is CH3(CH2)7CO
28 The method of claim 23 wherem the hydrolyzable X3 is a hydrocarbyloxycarbonyl group
29 The method of claim 23 wherein the hydrolyzable X3 is formyl
30 The method of claim 23 wherein said vitamin D compound has the formula methylene group, and where R is represented by the structure 

Y 

34 

where the stereochemical center at carbon 20 in the side chain may have the R or S configuration, and where Z is selected from Y, -OY, -CH2OY, -C = CY and -CH = CHY, where the double bond may have the cis or trans stereochemical configuration, and where Y is selected from a radical of the structure 

R1 R2 ^3 

\/ / 

— (CH2)m— C— (CH2)n—c—OX3 

\r4 

where m and n, independently, represent the integers from 0 to 5, where R1 is selected from the group consisting of hydrogen, OX4, fluoro, tnfluoromethyl, and C1.5- alkyl, which may be straight chain or branched and, optionally, bear a hydroxy substituent, and wheie R2 is selected from the group consisting of hydrogen, fluoro, tnfluoromethyl and C1.5 alkyl, which may be straight-chain or branched, and optionally, bear a hydroxy substituent, and where each of R3 and R4, is selected from tnfluoromethyl and C1.5 alkyl, which may be straight chain or branched and optionally bear a hydroxy substituent, and where R1 and R2, taken together, represent an oxo group, or an alkylidene group, =CR2R2, =CR2R3, or the group -(CH2)P-, where p is an integer from 2 to 5, and where R3 and R4, taken together, represent the group -(CH2)q-, where q is an integer from 2 to 5, and where X1, X2, and X4 are each hydrogen, or a hydrolyzable group, and where X3 represents hydrogen 



</div>