Review
`
`Montfily Foq$: Fndqcrlno & Metabollc
`
`lnhlbltors of dipeptidyl
`peptidase IV: a novel approach for
`the preventisn and treatment of
`Type 2 diabetes?
`Carogn F Dacont, Bo Ahren & Jeru J Holst
`rfurnna dlufual W@t, funn ltdanc, thtvdxy d @bryn, DK-ZM
`CaptapNhw*
`Inhlblton of the enzyme dlpeptldyl peptldase lV (DPP lvi) are of Increaslng
`Inter6t to both dlabetologlsts and the pharmaeuucal inclustry alike, as
`they nEy home $tabllshsd as the next member of the oral anudlabeuc
`clasE of therap€utlc agents, deslgned to louer blood glucose and, posibly,
`prevent the progresslve lmpalrment of glucose nEtsbollsm In patlents wlth
`lmpalred glurose tolerance and Type 2 dlabetes, DPP lV has bercme a focus
`of sttentlon for drug deslgn, as lt has a plvotal role In the rapld degrada-
`Uon of at least two of the hormones releassd durlng food Ingstlon, a
`property that har wananted tj,le design of Inhlbltor.based drugs. At the
`molecular level, DPP lV cleave two amlno aclds from the N-terminus of the
`IntacL blologically actlve fonns of bth so.colled IncreUn hormone, gluca-
`gon-llke peptldal and glucos+dependent lmullnotroplc polypepgde (for
`merly known as gastrlc Inhlbitory polypeptlde), resulung In truncated
`metabolltes, whlch are largely Inactlve. Inhlbitionof theenatme, therefore,
`ls thought to Increase levels of the actlve forms of both lncretln hormon6,
`culminatlng In an Increase In lnsulin release after a meal, In a fully glucose-
`dep€ndant manner. DPP lV inhlbltors comblne several features of inter*t
`to the drug dslgn proa*t They can be readlly optlmlsed for thelr target
`and be deslgnd as low mol€cular weight, orally actlve entities compatlble
`wltfi once-dally admlnlstratlon,
`
`IQnmrU* apegUA$ pepddase, entudrmh o&, erzynn lnldbite, glrrcagortke F+Ude- l,
`$ucceCegenAan nsOnmoef pA1ryegUCe, lrumdru qal arI|ldtabdc agFtt
`Fryt Aph I'nsEs Dw ftfr4) t3(9):1@I-IlE
`
`r.Intrdu8tion
`
`Type 2 dtabcc li a component of.a dlsease cluster collecttvely kno*n as the meta-
`bollc qyndrome, compdslng of a varlety of dlsorders lncludtrg gfume tntolerance/
`tnsulin reslstance, a*ertal hypertruion, dyslpfdaernfa and obeslty. It has ernerged c
`one of the world's nqjor debtlitadng dtseases. A cler requlr€rnent
`for neryv and
`more effectlrre drugp for tlre preve;ndon and treatnent of Type 2 dlabeEs ls demon-
`strated by a combtnadon of the follortng polnts:
`. tlte well-eported ccaldlon ln the numbers of people sufferlng from tlrls dtsease
`duster
`r an overtly unsatltrctory, and sdll surprtstngly srnall, famlly of arrrcntly awllable
`fiutments, the outcotne of wldch leaves many pad€nts wttl a reduced qualtty of
`llfe beause of acrodated compltcadoru includtng cardtorarular pmblerns, retln-
`opathy, nephropathy and neuropattqr
`o a lack of avallable drugs for the pre.rertrion of the condldqr.
`
`2@4 @ AshhyPudlcatlorE Ld SN 1354-3784
`
`1001
`
`MYLAN Ex. 1010, Page 1
`
`

`
`lnhtultorsddlpe$Uyl petrlda$MImd apoadrfiotrsF€rrcntlmardueqrm
`
`ttof lpezdhbetes?
`
`Atmost all of todayi drug therapb for T1,pe 2 diahtes have
`been a result of the serendipltos discwery of the anddlabedc
`acttr&y of compounds whme predse mechanhms of acdon
`welt obscurt at the ttme of dtscway ard, in sorrre casas,
`rerndn unrsolved. This mars that many of the orrrendy
`anilable drugp have some dtntcally rdannt stde effecb, whlch
`may have been avolded had ratiorul drug delgn been pos$bte.
`Thts plchre may well nqvy be set to chmge due to the enrcr-
`gmce of a new ffiEnent modaltty ttrat h6 resulted from the
`ra$onal deslgn of a drug class based on tlre prectse knowledge
`of the saltent molecrilr target. h b not often Orat cltnlcal
`proof of ooncept (CPOC) of an enttrely new oral tredm€nt
`rnodallty emergel fora nqfor debtlttattng dbease. The htrtbl-
`tors of dlpepddyl pepddase IV (DPP M for rhe trearrnent of
`Type 2 dtaUetes do, however, repm$ent such a concept,
`
`z. Dipeptidyl peptJdase lV inhlbltorc as new
`
`Follorring promt$ng rsultr trn precltnical studles, matnly ln
`rodents, Amgn and colleagues tt,zl reported CPOC for the
`use of selecttve and spectllc lnhibltors of DPP [V to ueat
`Type 2 dlabetes. Thts srzyme ts respon$ble for the raptd
`degradatton ofthe bodys so-called tncretln hormones, gluca-
`gon-llke peptlde-l (Gff-t1 and gtucosedependent tnsultno-
`troptc polyp€pttde (GIP), whlch are lntryal components tn
`the phpiological conht of tnsrltn release and. themfore, ln
`the rqulatlon of blood glucose. Coruequently, the tntrlbltlon
`of thls enzyme wttl prevent the degradation of these impor-
`tant lncretln hormones, hadlng to enhancement of thelr
`physlologtcal effectr.
`
`elBad($u.rd
`In the late 1980s, the newly dixorroed gastrolntetlnal hor-
`mone GLP-I F.d was found to poises potent tnsultn-releas-
`Ing abilitle [+Z[, spurrtrg tntere$ tn ustng thls prytide
`therapeudcally to hrat dtabedc hyperglycaemta In addtdon
`to lts tnsultnotroplc actlorl GLP-I posswc a spectrum of
`actMttes (p-cell troplc/and-apoptodc, gtucagonmtatlc, appe.
`tite supprestn& gastdc enrptylng rate redudng lA]), which
`maker tt an apparently ideal anttdiabedc agent. In tte earty
`1990s. the ffrst reports of tB efrecrs tn padenb wrth Type 2
`dbb*es appered tg,t0l, R€rnarkably, mnttnuous tnfuston of
`GLP-I normaltsed glucose twels (both fasdng and post-
`prandal) tn thse tndtvtduals lll.l3i, even tn those wtth pmrly
`controlled dtabst$ long after sulfonylurea secondary fatlure
`n4. Slngle subcutangous lnJec$ons werg howerer, less effec-
`tlrre and glucose concentratlorE !,er€ not normallsed tl5,l6l,
`whereas the effects of contlnrrcus subcutsreous infudon for
`6week ln dlabedc pattents has subsequently been reported
`wtth very promtslng r€ults
`tl?I. Furtherrnore, buccal admlnts-
`tratlon of the pqttde showed tt to be effid€nt
`tn healthysub-
`Jects ard in padents wlrh ''&pe 2 dlabete tls,lol. Ths
`surprlstng and unexpected lnefrecttvenes of a str4le admtnls-
`tratlon of GLP-I tumed out to be due to a rapld lnactivatton
`
`of the pepttde h vfw. An erlter publkhed meettng abstracr
`had tndicated that GLP-1 could be N*ermtnally degaded by
`plasrna /z ylfrolzol, and subcequently, DPP ru tras shorrn to
`be capable of medtdng srctr cleavage ln ulbol2tl,later stud-
`la zuggested that DPP IV was likely to play a mqjor role tn
`regulatlng the metabollc f*e of GLP-I ln dw lz?-z1lt and lt
`rrvas abo reported that DPP W medtates the lnacttradon of
`GIP tzl,ert, Thse obenauons were conflrmed and extended
`to tnclude the endqenou pqtlde tn studirs ln whlch the
`eneyme acttvlty was selectlvely deleted I25-2s1.
`The pnlnctple of hamesslng the endogenous lncrettn hor-
`mones to treat Type 2 dtabetes w utrg DPP IV lnhtbtron
`was fbst descriH tn 1995 [zrl. The radonale ls that by lnhib-
`ttitts DPP IV actrvtty, levels of the tntact biologcally actlve
`forns of both hormones wil be lncreased hto the rangg
`shown to be theraparttcally useful tzgt. The beauty of thls
`apprech ts that the bodyb om normal homeoshdc mecha-
`nlsms are enhanced. Thus, the lntrtbttor can be glven and wllt
`result ln increased levelr of tnsettn hormoner and, thcfore,
`tmultn wlll be relered only when the body needs ft (t.e.,
`malnly tn relatlon to food tntake because the tncrettn hor-
`mones are released ln response to fhe preance of nutrlents ln
`the snall tntesUne) Fl. Moreover, because the tnnrth-releaslng
`effects of the increttns are glucose.dependent, lrsulln secre-
`tton ls only enhanced when blood glucose teryels rtse lg0l, ard
`the rtrk of hypoglycaernta ts mlnlmal. The concryt ls alco sup-
`Forted by resulg from anfmab wlth a genedc deledon of
`DPP IV (the CD26 knockout mou$ tz?D or wfrh a mutart,
`catalydcally lnacflve DPP IV molecule (the Ftscher rat l3ll),
`whlch bave tncreased cttve GLP-I and probably GIP levels,
`and lmprot'ed gluco$e tolennce
`
`z, Dip$idyl pqtidae lV idribitss as
`antfrypsr$Faerdc agents
`A number of acute studlm tn animal models harre exernpltfied
`the benefldal effeas of DPP IV hHblton on glucose lntol€r-
`snce 132-31[ and the rndts of dronic trcatrnsnt harc recently
`appeared t35-3q. These sudl€s conflrm that the efiecg of
`DPP ry hhbttors mdnly reflect the known pharrnacology of
`GLP-I. Although a reductlon tn food tntake and body wetght
`w6 seen ln reponse to thse drugs in two rat studts t35,361 lt
`would appear that most @rly report$ are srggesdve of little on
`no effect on body wetght, whlch ls ln contrast to GLP-I.
`Flowwer, even body wetght nzutrallty, lf proven cllnlcally,
`would dbtlngutsh DPP IV hhibrttors from the currently arntl-
`able theraptes, wtrlch tnoease bodywetght and probably e,:ac-
`erbde the vtctous cycle of events comprtshg Type 2 dtabete$.
`Encouragtngly, the first preltmtnary communtcatlon of a
`l-year ctlnical trtal wtth the tnhlbltor LAF-237 gtven ln com-
`btnadon wtth metformtn reported no wetght galn over the
`study perlod pol. The predtnical shrdie also mggest that
`lnsulin ss$tdvtty may be tmproved by duonlc DPP IV htrt-
`bltlorl posslbly as a re$lt of cluontc lowertng of blood glu-
`cose and a reddcdon of a phenomenon called glucose to:dctp
`rather ttran m a dtre ct efiect of the drug ltrelf, ref,ecltng one of
`
`1092
`
`frtpertOpn. hvetg. &uge(2ma) t3O)
`
`MYLAN Ex. 1010, Page 2
`
`

`
`the observatlons noted ln t}re 6-week study of GLP-I hfrrslon
`ttfl. Intrigutrryty, CD26 knockout mtce and DPP IV aenOent
`Ftsctrer rats ar€ protectd agalnst diet-trduced obestty ard
`hsultn rststanc€
`l4l,4z[, $uggestlng that tn the longer terrn,
`DPP IV tnhibttton may affect My-wetght control and
`energr hornectasts. DPP W hhbitor-mediated prsd\ndon
`of the bodyb endogerous GLP-1 may also srharrce the long-
`knorm effects of GLP-I tn t€rms of p-cell recue/prevwrdon
`ofaPoPtods, tndlcattng a use for thls drug cJass tr the pre*'en-
`don of Type 2 dhbrtes [Z9l and, ro a relatd property, ln fte
`prerrentbn of the worsring of the dbease. Indeed, duontc
`tratment wlth a DPP IV nfUHtor preserved lslet funcdon tn
`dlabsttc mice l39l and lmproved B-celt $urvtwl and tdet cetl
`neogeneSs tn str€ptontoc'tn dlabettc rea FSI
`The promise held by DPP IV hlrtbttors appear$ to be sesr
`tui the ffrst trtals ln padenn with Type 2 diab*es ll,zl. It ts par-
`da:larty noteworthy that th€s€
`studles shor thd, wtth a
`DPP IV inhibitor, lo*rertng of both fasdng and postprandfal
`blood sugar ts pmslble Ttrls ts lrnportant because lncresced
`faotlng and postpnndlal blood sugp" are both thought to con-
`tribute to elryaud glycosyhred tracnogloblr (FIUAtcl hre.lq a
`key wriable rdlecdng the average glfrcaerntc levels orcr seysal
`tnonthlt, known to be assoctated wtth the derclopmort of
`debltadng compUcadors of Type 2 dirab*es,
`The publtcadon of data from studlc of ) 3 months in
`length. and from more subctanttally dtabettc padents are
`arivalted tn order toJudge both ef;[cacy and lnddence of slde
`effects that may be orpe*ed from DPP ry hhbttors becruse
`the pattents ln both of Ahr&rb studles wse sttll in the erly
`stage of the dlseose and the treatnent was $ven for only
`4 weeks. Hourever, thse ls rsson to be opdmtsttc. Precltntcal
`studhs (e.g. t3sD tn dab€tlc mdents strorry that the d€cts of
`DPP IV tntrtUltors on glucoe tolerance become more marked
`as tlte dostng puiod contlnues, so tlrat the efricacy after
`4 welrs in the tnrrnan sfirdles reported thus far rnay well
`underettxnate the eventual steady-state dwt of DPP IV
`brhtbttton on farttng blood glucose !r parttorlar. Nevsthe.
`le, desplte the reladvely sbort tr€atrnglt pedod studted, a
`stgntflcant effect on HbAlc walr seen. The sarUng value of
`7 -4oA tat HbAlc, ar was eeen fn the cllnlcal studts of
`DPP IV tnhibition [t.zl, reflectg the mttd dtaberes of tha
`pdurt cohort Thb, on the other hand, mearu that any fall
`tn HbAlc would be smal!, In sptte of dgnfncant tmprove,
`molb tn glycaontc control, so lt ls all the more pleastrg tose
`a dgnlflcant reductlon tn HbAlc (of 0.5% to 6.9%) in these
`studle$. Tlre etrect of DPP IV tntrtUtuon b ereected to
`becqne less mqrked ar blood glucoae rehrn$ to norrrnl (the
`so-called glucose dependency t3ol), which ts tmportant tn llm-
`itlng one of the mostserlous of all stde effects of $ome calr€nt
`therapies (t.e., hypoglycaemia). Recentty reported prelirntnary
`flndings from longer-tem (12 weeks) monotherapy wtth
`LAF-237 tlll sho/v sustatned reducdons in HbAlc (tom a
`baseltne ralue of 8 to reach 'l,4Yo by the end of the study),
`sugsttng that tachyphylads dos not develop, wtth those
`patienb wlth trtgher baseltne (starUn$ HbAlc levets showtng
`
`I}emofL Afrar&]ldst
`
`the greatd reductloni thoe wtth a startlng level between
`7 and 8% fell 0.7o/o compared wtth placebo treatment, wtdle
`those between 8 and 9.57o d€cttned 1.2% relauvs to placebo.
`Furtherrnore, eady reports ftom 3- and l2-month cornblna-
`tlon th*apy of LAF-237 with metformtn also tndtcate that
`stgnlffcant reduclions tn FIbAlc lanels are mahtatned t{0,{41.
`HbAlc levels ln thce pattenb taking both LAF-237 and
`medormln were redued from a stardng lalue ot7,8 to?.2%.
`In the flnt 3 montjx n{[, and thts effect uas ustalned durtng
`an er.tendon of the study (FIUAlc at 7.3% after t yua") taot. lrr
`contrast, after an tntdal fall, HbAlc levels began to lncrere in
`the paderts takfng metformln alone, so that by tlre end of
`3 months lt was back to baseltne (7 .9%l tul, and contlnued
`to lncrease ln tlre entenrlon perlod to rurch 8.496 by I year
`t$1. Hou,ever, treatrnst of even tmpaired ghroe tolerance ts
`lmportant for reducLg the cardlovascular consequences of
`the metabollc syndrome [45.451.
`One tssue that ls oftsr ralsed ts the quesion of adverse stde
`efrecB, artslng dtler as a ooniequsroe of hhftllflng the cata-
`lytlc acttvtty of a nroleanle that ho other furrcdorn ln addttqn
`to dqradtng rcgula,tory pepddes, or because of the effect on
`multiple substrdes of DPP IV. Other tuncdons of DPP IV tl1
`lnclude a role ln the lmmune $ystern, whtr€
`tt has the capaclty
`to serve as a costlmulatory surface molecule lnflue.nctng T-cell
`a*tdry, althonglr In thls context lt ls uncqtaln whether the
`catalytlc activlty W I ls requtred. Morcowr, there is now
`knonrn to be a famlly of dosely rclated cnzyrn6, whtch rtrare
`DPP IV-ltke catalyttc acdvtty, tncluding tlre recently tdenti-
`ned DPP I tasl and DPP 9 fq, whtch mEr be repurslble for
`some of the functioru prevtously attrtbtrted to DPP IV mef.
`It ts poslble that some of the described DPP IV tnhtntors
`(hgue 1 and Tabh 1) rnay not be completely sdectlve for
`DPPIV, and mry lnfluerrce the aictivtty of other enzym€s,
`sucb as DPP 8 and DPP 9. In Ods context, erly data sugest,
`that DPP lV-selecUrre inhlbltors do not affect ln ulaoT-cell
`acthatton, whtle a DPP 8/9 hhtbttor and a nonsel€cdrrc
`lnhibttor do 1501, suggestlng that prevtously reported lmrnuno-
`logtcal effece of some DPP IV tnhlbttors could have bsr due
`to thelr dect on DPP I or DPP 9, raths tlrarr on DPP IV
`tlself. Other prrltmtnary ln y/w shrdle, reporttng Orat selec-
`tlve tntdbtdon of DPP 8/9 ts assctatedwtth pmfound toxlct-
`(aop) wtreras selecdrc
`ttes (rodents) or adverse stde €ff€cts
`tntrtbttton of DPP IV ts not [51t, suggest that the lsue of
`tnlrtbttor selecsvfty nust be addresed. The other gues$ur
`dat6 to whether DPP IV tntdbftton may be problemafic ln
`terrns of advewe slde efrects, whtch theorettcally rnay be
`expected from tnhtbttton of an enzyme wlth apparcntly muld-
`ple substratee, vh both the acctrmulatton ofadverse srbntrates
`and the tnhtbition of the formatton of bmefldal products
`(revtewea by lvlentlein I52l and lrmbetr etal. Jslll, On one
`hand, lnhlbldon of the multtple nrbstrates of an uuyrne may
`contrlbute to efrcacy (e.g., intrtbtton of angloteruhd,nvert-
`rng enzyme [ACE] possess efficacy due to the modutatton of
`at least two substrates, angotenstr I and bndykfntor). On the
`other han( tt ts pmdble that dranges ln the concentratlorrs of
`
`nl
`
`Eqat Opn, /rnEr03. Drug6(2(}(l4) 13(S)
`
`1@3
`
`MYLAN Ex. 1010, Page 3
`
`

`
`lnhlttltasddlpe$dyl peptl(heM a mvd appoach brtlre prsventlm ardtreatnpntof flpe 2diabetes?
`
`fo
`\00-ojd
`
`Valhe-pyndtsHe
`
`NVP.DPP.728
`
`o*""
`'F*d
`
`lsolflch€-lhlazoildd€
`
`u*NrUtv"
`r)-,
`
`F
`
`Figttu€ 1. $nc0^me of dpesldyl pep&hse w trfilHtors" Data a" taken fi'om tzot (valiregtrrolldHe). tszt (lslqrcin6.thlazofidkte),
`{ssl (N\P-0PP.728 and LAf-237) ard pzt(MK-0431).
`
`Table 1. Seleetlvlty data for dlpetridyt pepildase w tnhtbttors.
`
`&o/r((nn0
`
`Dpp I
`
`xFp9
`
`? ? ? ? >
`
`? ? ? 7 4
`
`xmM @ptmI
`?am*
`VallrFpyrrolkllde
`255t
`bolsdre.thiazolldlde {P32/98)
`7,mor
`NVP.DPP.728
`110,000
`90,000
`> 500,0m 210.000
`w-237
`>100,m >100,000
` 100,m
`MK{431
`8.0m
`18
` 100,m0
`D8ta an urken fi'om I97l (vdh$pyfiosd(ts aru lsoreucrns'$razo[dkh), lgsl (MyP-DPP"728 a'[l [At-231 and rr2l(MK-0431), .Trbse r'8ruos tre ,(.
`DPP| Dlpepddyl pepfidass; lcs: M€dlan
`Inhlbltsy @ncenBatlont FAPa: Flblbtaitacsratoh protefrc(sepase); ,(: lnhltrltldt cofftant P€P: Prdylerdopetrktsg
`(pr0l$otlgopsp$e€/pstprollrF
`chavlr€ en:yme): QPP: QukFcg|tcelt Frolhe dFptdaes,
`
`FARq
`
`? ? ? ? >
`
`> 10000
`
`? 1
`
`1?:6*
`2?
`3.5
`
`multtple endogsnous nrbstrates may be a souse of urnvanted
`stde efrects. It ts crlttcally tmportant that, when consld€rtng
`postble substratq for DPP [V, one dlfercntlate betwen
`suhrates that arc krpwn to be phydolo$cally relevant (.e.,
`endogenous substrates) and thoe that hare boen tdenttsed in
`assap & vtfro wlwe often htgh concsrtrrclons of substratos
`are offsed to the enzyme tn possibly aphystologlcal condt-
`ttons. Measurement of endogenors le'veh of subctrateg
`lnut'a after DPP IV tntrtbttton, provtdes the most relevant
`meflrod forJud$ngwhlctr substrdo arre relevnnt to the acdon
`of DPP IV tntrtUttors. hdoreover, ',rr shoutd rsnernber that
`even phptologkally rele\ant substrates may also have
`
`multtple mute of degradatton, so tlst the tnhtbttsr of DPP
`IV wtl not pretryn the metabollsm of these subsfates vta
`altemdtve routes. Ulttmately, only carenrl assessnent of efil-
`cacy versus dde efiects wttl deterrolne whether enzyme lnhibt-
`ton wlll become establislred therapy for any gtvm indicaflon.
`It b comfonhg to see ttrat the tnctdence of pnstds, a posdble
`cons€quencre of eubctance P accumuladon, was only tran-
`rtently erpertenced, and then only ln the study tr.tth the
`krhtbttor N\P'DPP-728 nt srA not trn those padenb recetv-
`tng LAF-237 tzt, suggesfing tlnt some other DPP IV sub-
`strates mEf flnd alternattve !out6 of dqradatlon once
`DPP IV becomes tnhlblted for a longer perto4 or that thrs
`
`EqqtOpln, hrcdg. &trge(200a) 13(9)
`
`MYLAN Ex. 1010, Page 4
`
`

`
`wat I compound{peclffc, rather than a clm*pedfic, effecL
`So far, few other slde effects have b€en reported afts 4 r,neels
`of admlnttradon of LAF-237 andNVP-728 to ntan [t.zl, and
`thls also sesns to be the cce regardkrg the prellmlnary reports
`on lZ-week LAF-237 monotheapy lt3l, and $month and
`l-year combtnatton therapy of LAF-237 wtth medormtn
`I{0111. Currently arrallable lniormation suggestr, therefore,
`that the drug clas appears to be weu-tolerated and thme slde
`dects reported haw been mtnor, trarrstent and compound,
`rather than clms spctflc.
`The fact that multtple subsrrsts for DPP IV are thought
`to e$dst may also help explafn the posttive effects of thse
`drugs on gllaaernfa. When we corutds that lslet functton ts
`rqulated not only by substrates and lncretln hormons but
`also by neflyg 1531, it can be sst how nrodutdon of other
`neumpepeddc tnay contrlbtrte to efficac1t. Sympathe$c,
`parasympathettc and sensory nerves are koonn to lrnervate
`the tslets. Tlese nerves not only harbour the classlcal neuro-
`transmttters aceryl choltne and noradrenattne but also sev-
`eral neuropeptldes are localtsed to tdet nen€
`termlnals.
`Thce neuropepttdes lnclude pftuftary adenlylate ryclase-
`actlvadng polypepttde (PACAP), gastrln-releestng peptlde
`(GRP) and vasoactlve tntesttnal polypepttde (VIP) rn para-
`qympatbedc nerve termlnals, galanln and neuropepttde Y
`[llPY) t" qympathettc nerw tenninals and calcltonln gene-
`rdatdd polypepUde (CGRP) tn sensory nerve teintnals, all
`of which harre been shsvrn to affect tslet funcdon ts3l. Bto-
`chemlcal studtg haw shown that several of thse lslet neuro-
`peptides are substratc for DPP IV and, thcefore, DPP IV
`lnhlbttton may be expected to prolong thelr half-ltfes and
`consquently thelr actton. The neuropeptides shown to be
`substrats for DPP IV tnclude PACAR VIP and GRP Is+sst,
`and for some of them at least, DPP IV seems to be r€le\rent
`phystologtcally (e.g., PACAP tiil). h ts, therefore, of rele-
`vance that a main funcdon of these neuropepddes is to stim-
`ul,ate lnsuUn seqetion ln a glucose-dep€ndent rnanner [s3.861.
`Furthermore, both PACAP and GRP sdmulate cdlular pro-
`llferatlon t5?-59t and tnhlbtt apoptosts 1601, whqeas PACAP
`has also been shown to prevent the development of$tr€pto-
`zotocln-tnduced dtabetes ln rats 16ll and to reduce the hyper-
`glycaernta tn models of tmpafred glucose tolerance and
`Type 2 aUfets ln rodents toat: Thereforr, an addldonal
`advantage of DPP IV tntrtUttton could be tlut the tslet
`effects of thme neumpeptldes are augmented, wldch may
`contribute to the beneffclal effect. In fact, ttrelr anttdtabedc
`acdon msy exdafn the ogertence of the clintcal studtm
`undertsken so far, tn rhat DPP IV rnh$ttton n.2,40,4ai{l
`sesms as efftctent as GLP-I analoguc [&661, at the doses
`ryorted, ln sptte of GLP-I concsttratlonr betng tncrered
`to a lower degree than pos$ble after analogue admlnlstra-
`don. However, lt mu,st be noted $d no dtrest head-to-head
`comprlsons of the mardmal antthypcglycasnlc efects (t.e.,
`efEcacy) have yet been reported. Furthermore, the contrlbu-
`tlon of these nzuropepddes to the benefictal effect of
`DPP ry hilbitlon ln relatlon to the contrlbudon of GLP-I
`
`'
`
`DemnAhrdh&Holst
`
`remalns to be ctabllshed. After acute DPP IV lnhtbldon, at
`least, all of'the beneflctal idfects on glucose tolerance appear
`to be mdtated vb GLP-I and GIP receptor dgnal[ng, as
`the glucme-lorerlng acdons of DPP [V tnhlblton were
`eltmlnded tn the double tncrsttn nsceptor knockout mouse,
`ln contrast to both the stngle tncrettn receptor knockout
`mlce, tn whtch DPP IV intrtbtdon doec lowo glucooe and
`lncrease plasma lnsultn levels FI. It remalns to be seen
`wheths after longer-term DPP IV tntrlbftton, the potential
`neuropepdde subctrates of DPP [V may contribute. Further-
`more, lt rvlll only be poostble to Judge thelr contrtbudon
`wlen analytfcal technlqus are developed, whtch allow the
`measuremsrt of endogenous lwets of the tntact and
`DPP IV-truncatd derlvative of these neuroprytlds.
`
`s. What may we rcgard as the key propertles
`of dipeptidyl peptidase Mnhibitors?
`
`s.i Eff-rcacy 6 monothfiapy: gtyrccylated
`haryloblnlonlwlng
`It h obvlous th* any newly eurergtng oral antldtabettc
`(OAD) should prore efftcdve versus placebo as mono-
`therapy. Ttrts r atfficutt toJudge from the Erbllshed 4-week
`trtds that are avatlable hcause steady-stde reductlons of
`HbAlc arc only ltkely to be mrourable after ) 3 montlu. It
`should be taken lnto account th* the reducton of HbAlc
`seen after 4 weeks of treatnent wtth the tnhlbiton NVP-
`DPP-728 and LAF-237, of 0.57o ttzl, wtll probably end up
`belng a $gnfncant underdlmate of fficacy on a long-term
`bads. When Judgfng efficienqr ft ts tmportant to ecmphaslse
`ttrc end-potnt HtAlc values contlate to the startlng value
`and that placebo comparlsors slnuld always be made. It
`stpuld also be ernphastsed that any rcduc$on ln FIbAlc ls
`Itmtted when the starttng ralue ls ltself lo*r, It ls, therefore
`encouraglng t}tat the prdhfnary ra.db after lZ*veek mon-
`otherapy with LAF-237 seem to suggst thaq whlle all
`pattents show tmprovemenr ln HbAlc levels, greater reduc-
`tlons are achievable by those wtth htgher starting values F3l.
`At prsent, based on the avallable lnformadon, tt ls llkely
`ttat DPP IV httlbttors wtl have equal efficacy as mono-
`therapy as €ldstlng OADs. and rnay be compedtlrre verss the
`ttrlazolidindlorn (TD) hsulln seruttlsers.
`
`3.2 Emcacy In more aduarmd fonm of Itse 2
`diabetos
`A long-term effect ln advancd Type 2 dtabete, when lnsutin
`secretlon ts severely lmpaired, wonld rely on a slgnl0cant
`effect of DPP IV tnhtbttors ln rducing glucose etrcrrrslons to
`a mlxed meal, prsumably as a Esult of GlP-l-tnduced lonr
`ertng of glucagon secredon, and posslbly a delay ln g6ah
`ernptylng. To date, thse have bem no c[tdcal r€ports of
`DPP IV tnhtbltus affectlng gastrtc ernpglng but teducd
`glucagon levels were repwted after 4 weeks of ffitrnent ln
`diabetic rubJects with LAF-237 t4. Reduced glucagon con-
`c€ntradons would lorer hepattc glucooe output durtng the
`
`etrytOFn. kwsdg. OrugFpoo4) 13(9)
`
`1095
`
`MYLAN Ex. 1010, Page 5
`
`

`
`lnhltt'tasd@dgl p€ptldeeM amrdapoafibrthepeventima]dtreaurortdType2dlabets?
`
`ustng the prototypal inhtbltor vallne.pyrmltdlde, wbet com-
`blnd wtth mdormln, hro grater effects on inprovtng
`glucose tolerance, futrg blood gluose and redudng wdght
`galn omped wlth etther compound alone l0gl, while the
`f,rst cltnlcat trlals seern to sugg€st th* combtoitng DPP IV
`tnhlbldon wtth metformln reduces FIbAlc h p6tlents other-
`wlse lnadequately controlled wtth medormln alone 140fi1.
`Other precltntcal $udtes tndtcate that the tong-ectlng DPP IV
`lntrtbltor K-579 comblnes well with glbenclamtde to r€duce
`the glycaendc rwponse to glucose loadfng wlthout etacerbd-
`ing hypoglycaernta {?tll wher€s prellmtnary studtes $rggest
`thd a synergisttc interactton between LAF-237 and ptoglita-
`zone may erdst t?U. If one adds to ttrls the gtucagon nrpprrcs-
`lnC e,tre.ts of DPP W nrhftttors I2l, the prollle for
`comblrutlon therapy starts to look mct encouraglng.
`
`pctprandlal phase. Efflcacy !n lswerlng gfucagon may hrfer
`that padents rnay be treated even when the p-cetl funcdonal
`mass ls reduced ln more advznced cases of T1'pe 2 dtabetes,
`and thts suggesdon ts supportd by preclLrlcal data. Thu,
`Posptstltk ct aI Wl meured slgn$tcant glucose-lowertng
`acdvlty tn severely dlabetlc, streptozotocln-treated rats rrcelv-
`tng the lnhtbttor P32/98 aortely and chmnlcally and con-
`cluded that DPP IV tnhlbttors may be effectve tn subJecrs
`wtth Type 1 dhbete and end-stage Type 2 Oaletes. In con-
`trast, another study tn dtabettc db/dbrrnce orily found a pd-
`tlve efrect of DPP ry hhtbttton tn the €arly stage of the
`dtsease but no stgniflcant eflif on glucose tolerarrce wa
`observed ln older arrlmals wlth severe lrlsullrn rFbtance [691.
`However, lt should be noted that ln the latter study, only the
`effect of acute DPP IV tntrtbttlon was emrnlned. In another
`study ln dlabettc ratJ, the beneflcial effects of DPP IV tnhfbF
`s.6$de'ffitproftts
`don condnued to lmprove wlth ttme, wtth anlmals strowtng
`greater lmprwements ln glucose tolerrrce after 12 qeeks
`Early urderstandable concerns that tnhlblttng the acdvlty of
`an enz)rme wlth muldple substrates fiedtng to tncreased
`compared wtth 4 wee&s of trstment [351. Therefce, more
`cqrcentradoru of the pmnt rubotrate and reduced formatlon
`severe dtabete may requlre contlnued e:.psure to the lnhtbt-
`of clearage products) wtll lead to problerns wlth regard to
`tor before an effect ts noted Onty Arcct dtntcal tnvesdgatlon
`ln pattents wlth dffferlng severlty of the dtsease wlll show
`stde efects appear not to be bome out by early trtals. The
`stde-effect proflle of DPP IV tnhlbitors, as has bem ascer-
`whether all patent groups $,tll respond to DPP IV hHbtton,
`as has been shorpn for GtP-l nq.
`talned so far, ls encouraglng.
`For emmple, narsea and vomtttng would app@r not to be
`&3 Effedon brrlorbldities
`a problem wlth DPP IV tnhtbttors a it ts for GLP-I recep-
`So Ar, alm6t all trcatrnen8 for Type 2 dtabet€s qcept met- tor agonbb, presumably because the rise ln intact, actlve
`formln have reultd tn lncrease toi body welght an oMors GLP-I observed is three- to ftvdold, and therefore belorr the
`comorbtdlty in the dlsords. The m{odty of d"ta crnertly threshold fu thts typlcal GlP-l-tnduced stde eff6t" Mlld,
`avatlable lndlcate ttrat DPP IV hhiblton wlll have no tmpact trarslent prurttus, seen wtth NVP-DPP-?28 ltl, ls likely to
`on body weight and thus wlll not suffer from the wetght- be compoundqdflc, and not due to, for example, cuhne-
`incradng side dect of nrlbnylurec, tlrtazolldlredlone send- ous substance P accumulatton, beeuse LAF-237 does not
`ttsqs and lrsulin. As prevtorsly mendoned, eady lndtcatiors seem to have thls stde effct {zl. Nasopharyn$tls, seen wtth
`from longu-term trlals sem to conllrm tln wetght-nartraltty NVP-DPP-728, was only rarely obsoved wlttr LAF-237.
`eFect of DPP IV tnhiblton tl0l. It will now also be of constder- However, tn prellmlnaqr communlcadons of 3-month
`able hrtertst to collect dda concernkrg the dect of DPP IV monotherapy with IAF-237 and the l-year study wlth
`tnhiblton on other relevurt co:morbldldes (e.g., blood pres- LAF-237 and metformln treabnent, some mentlon was
`surg other cardlorrasarlar rlsk factors, plauna llplds).
`made of a modest worsenlng of prs-edsting h]rpertenslon
`and mlld peripheral oedoma, cuspected to be treatrnent
`lV Inhlblton become
`3.4 Will dipo$ldyl Htide
`rebted lo,e$, underltntng the need for camful monttorlng of
`fist-llne tteragt fc llpe 2 dhlDtei?
`both cardtonascutar functton and flutd homeostasls. Moreo-
`It may be speculated that DPP IV fntrrtbttors wlll prorrtde ver, lt shadd be remernbered that, ln addtdqr to potstttal
`effecttve flrst-ltre therapy l29l based on a wlsh to tr@t dlabetfs mechantsm'based stde effectr (t.e., relatlng to the selecdve
`whilst p-cell mass remalns rdadvely healthy, \f/" *ry tmagtne lnhtbtdon of DPP IV), the possibiltty of slde effecr arbtng
`thts trefinent as life *yle changc !r cqnbtnatton with p-cell from non-mechanlsm-basd actloru carypt be excluded.
`support to begtr wtth, fol!il,vd by senslttscs !n later stagx of Thce could lnclude stde effecE caused by lnhltrltor nome-
`the dtsease.
`lecttvtty because, as prevlously mentloned, lnhtbttton of
`DPP 8/9 has shown profound toxlcttts ln ulw lstl. At
`3.5 Ability to be offered as part of combinatln
`praont, very ltttte dda are available regardlng the selectivtty
`thsfiapywlth exis$rlg therapi€s
`of ttre lntrtbtton cunently trn development (tann f), prdcu-
`It fs lkely ttnt DPP IV tnt*nton wtll cornbtne well wlth met- larly wtth respe* to DPP I and DPP 9, wtth data only bElng
`formln and TZD serrltlsers because lnteracBors betrvee,n avallable for MK-0431 lz4, Fwthermore, as the spectftc
`eldsttng lnsultn ecretagogues and tnsulln serstdsers ts lcrown functtoru of these more recently dercrtbed enzymes are sdll
`to be encouraghg and mechanl*lcally predtctable. Indeed, unknown,theconsequencesofanylnhtblttonofthetractlon
`precltntcal studte hne lrdlcated that DPP IV uhtbttton cannot be predtcted. Neveitheles, Grr€nt dx6 srrqgest that
`
`i:;. Exo€I.t Optn. lni6$19. trug6 (2004) t3(9)
`
`MYLAN Ex. 1010, Page 6
`
`

`
`LAF-237 ts well-tolerated, although tt should be emphastsed
`that r€ults
`from long-term studtes (> 4 weeks) are not avall-
`able other than as prellmtnary meetlng r€ports
`td0,{3,{q.
`
`4. How do dipeptidyl peptidase lV inhibirorc
`compare with glucagon.like peptlde-l
`anslogues?
`
`^t*.*-,*-
`DPP IV tnhlbltors are stmply onl GLP-I (t.e., ttrat they
`harns the potenttal of GLP-I h an orally acttve manner).
`However, on more carefirl enamlndlon other differencs
`between the soncepts emerge. Ftrst, we conslder the stmtlar-
`Itles between the two approaches.
`. Glucce dependency: GLP-I ts a glucose-deperdent tnsultn
`sesetagogue and suppressor of glucagon, meantng that
`sttmulatlon of tnsulln release and tnltlbtdon of glucagon
`wlll occur only at hypog$caerntc levels but nbt at nonno-
`glycaemlc lwels. In other words, the rlsk of hypqlycaernb
`as a result of etther p'rocess ls mfnknal. So br, these encqrr-
`agtng propsttes appear to be shared equa[y by the GLP-I
`analogues and the DPP IV hhlbitors.
`I p-Cell mass and functtonl Cunent 646 5,'ggcts GLP-I
`analogue and DPP IV tnhtbttors may share beneffdal
`effects lrn terms of presenrtng the populdlon of p-cells by
`lnhlbtdon of the rde of apoptcts and potefftadon of pro-
`Itferatlon of new p-cells 1sa,A1.
`
`Second, slgnl8cant dlfferences are apparent betrreen GLP-I
`analogues and DPP [V trhlblton.
`. Route of admlnktratton: GLP-I analogua are derlvadves
`of relattvely large motecular welght polypeptldc. Currently
`known analogprc are not orally available and arr ltkely to
`be ofrered by subcutaneou tqJectlon. In contrast, DPP IV
`tnhtbitor$ are small, non-popttde molecule, wldch are
`llkely to be formulated as tablets for oral adrntnlstrason.
`. Pharmacoklnettcs: GLP-I analoguc admnds$red sub-
`cutaneously are thought to have a pharmacoktnettc proflle
`that follom a 12- or 24-hqr grcle, whereby plasma con-
`cenffilons of drug relate to the tlme of admintstrdon of
`the compound together wlth prtnctples of protractton
`(bindtng of the drug to albumln or lnterrnolectrlar aggr€ga-
`tlors of sweral drug moleorlc). In contrasl DPP IV
`inhlbitors are not regarded as havtng a prltnary effect
`ln utva Rathq, thdr effects arp secondar5r to changes tn the
`levels of the lntact tncrettn hormones (arU o&er potenttal
`substrates). Thqefore, the dynamtc responsn to DPP IV
`inhtbltors must be as a result of qrhanced levels of the
`tntact