Petitioner Amerigen Pharmaceuticals Ltd.
`Petitioner Mylan Pharmaceuticals Inc. - Exhibit 1007 - Page 1
`
`

`
`2 88
`
`Br-_vrme. Stain’. Hoiién at al.
`
`patients with bladder overttctivity [Yarlteret al. 1995]. The
`utility of this agent is restricted by a high incidence of
`adverse effects. such as dryness of the mouth [Cardozo el
`al. 1987].
`No currently available therapeutic agent has a selec-
`tive action on the muscarinic receptors of the bladder. A
`drug with a high antimuscarinic potency and a more blad-
`der-selectivt: action is therefore desired. Preclinical data
`have shown that
`tolterodine ((R)-N,N-diisopropyl—3-(2-
`hydroxy-5-methylphenyl]-3-phenylpropanamineJ exerts a
`high antirnuscarirtic potency in guinea pig and human
`detrusor muscle [Naerger et al. 1995, Nilvebrant et al.
`1994]. It has also been shown that tolterodine displays a
`favorable tissue selectivity for the urinary bladder over
`salivary glands in the anesthetized cat [Gillberg et al.
`I994-_|.
`Preliminary studies in healthy volunteers suggest that
`tolterodine ‘exerts a marked inhibitory effect on mictuiition
`[Stahl et al. 1995]. The objective of the present study was
`to determine the pharrnttcoltirtetics, pharrnacodynamics,
`and safety of tolterodine following single oral and intrave-
`nous (i.v.) doses in healthy volunteers. A secondary aim
`was to identify major urinary metabolites of tolterodine
`following oral administration and to quantify urinaryffecal
`excretion (mass balance).
`
`Subjects, material and methods
`
`.S'tud_v di-rigs
`
`Tolterodine is a weak base (_pKa 9.9) with an oc-
`tanollphosphate buffer partition coefl'icient (log D") at room
`temperature of 1.8 at pll 7.3 (data on file [Phannacia &
`Upjohn ABM. For the purposes of this study, tolterodine
`("as the tartrate salt) was prepared as water solutions (150
`ml] for use in dose escalation studies while a solution of
`("lC)-tolterodine (labelled in the ot-position. 95% radio-
`chemical purity). together with unlabelled tolterodine. was
`prepared lbrdetennination ofmass balance. Oral solutions
`of tolterodine were prepared by the Pharmacy. Lund Uni-
`versity Hospital. Sweden. while
`i.v.
`solutions of
`tolterodine were prepared by Pharmacia and Upjohn AB,
`Stockholm. Sweden.
`
`S i.th_,t'r*cr5
`
`A total of 23 male Caucasian volunteers were in-
`
`cluded in the 3 parts ofthe study (oral dose escalation, i.v.
`administration, and mass balance determination). All vol-
`unteers were judged to be healthy by clinical examination,
`electrocardiography. and evaluation of laboratory parame-
`ters prior to study enrolment. Seventeen volunteers partici-
`pated in the oral dose escalation studies. Their mean (i
`standard deviation, SD} demographic characteristics were:
`age 33 i 7 years, body weight 7? i 10 kg. and height 1.8]
`
`i 0.04 In. Eight of these subjects subsequently received
`tolterodine i.v., while 6 additional volunteers received
`(“Cl-tolterodine orally for deterrnination of mass balance.
`The mean (1: SD) demographic characteristics of these 6
`volunteers were: age 45 i 6 years. body weight 75 i 4 kg.
`and height 1.80 i 0.06 m. Each participant provided in-
`formed written consent and the study protocol was ap-
`proved by the Ethics Committee ofthe University ofLund,
`Sweden.
`
`Stttdy design
`
`The subjects fasted overnight (from I0 p.m.) before
`drug administration and they abstained from food until a
`standardized lunch was given (4 h after drug administra-
`tion). No other drugs were allowed for 2 weeks prior to and
`48 h after each administration. In addition, smoking and
`the consumption of alcohol and caffeine—containing bever-
`ages were restricted prior to and for 48 h after drug intake.
`In the dose escalation part of the study. tolterodine
`was given as a single oral dose of0.2. 0.4. 0.8. 1.6, 3.2. 6.4.
`or 12.8 mg. Two subjects per dose were included in the
`lower dose interval (0.2 — .l.6 mg). while 8 subjects re-
`ceived 3.2, 6.4 and 12.8 mg, respectively. Blood samples
`(10 ml} were drawn into Vacutajnertubes without additives
`prior to and at 0.33, 0.66, 1.2, 3, 4, 6. 8. and 24 b after drug
`administration. After coagulation at room temperature for
`approximately 0.5 — l h the blood samples were centrifuged
`(1,000 g for 10 min). Serum was immediately separated,
`frozen. and stored at -20° C pending analysis. Urine was
`collected quantitatively 0 — 24 h and 24 — 48 h after
`tolterodinc dosage. Heart rate and blood pressure (supine)
`were simultaneously recorded by an automatic. noninva-
`sive, digital blood pressure meter (UA-751 , A and D Com-
`pany Ltd, Japan). Nearpoint of vision was determined
`using a RAF nearpoint rule {Clement Clarke Ltd., UK).
`Stimulated salivation was measured with a slightly modi-
`fied method used by Dollery et al. H976]. The subjects
`chewed 1
`tablet of paraffin (Orion Diagnostica. Espoo.
`Finland) alternately on the left and right side of the mouth
`for 5 min. All saliva was carefully collected i.n a plastic cup
`and weighed in order to calculate salivation flow (g)'5 rnini.
`Measurement of heart rate, blood pressure, nearpoint of
`vision and stimulated salivation were performed prior to
`and at 0.25, 0.75, 1.25, 1.75. 2.25. 2.75. 3.25, 3.75.-1.75.
`5.25. 5.75, 6.25, 6.75, 7.25, and 7.75 h after the administra-
`tion of tolterodinc.
`
`Eight ofthe 17' subjects included in the dose escalation
`also received tolterodine i.v. Two subjects received s5-trtin
`infusion of tolterodine 0.64 mg while all 8 subjects re-
`ceived an i.v. infusion oftolterodine 1.28 mg over I0 min.
`Blood samples {It} ml] were drawn prior to and lrninedi-
`ately after the infusion, and at 0.33, 0.66. l. 2, 3, -'-l, 6. 8.
`and 24 h after completion of the infusion. Quantitative
`collection of urine and measurement of heart rate. blood
`
`Petitioner Mylan Pharmaceuticals Inc. - Exhibit 1007 - Page 2
`Petitioner Mylan Pharmaceuticals Inc. - Exhibit 1007 - Page 2
`h
`
`

`
`Toi.rerod.fne PK and PD
`
`289
`
`pressure. nearpoint of vision, and stimulated salivation
`were perfonned as described above.
`An additional 6 subjects were included in the mass
`balance investigation. Each subject received a single 5 mg
`(I 10 ttCil oral dose of (""C)-tolterodine. Fecal samples
`were coliected quantitatively in 24 h intervals for 7" days
`and urine in the intervals 0 ~ 4. 4 — 3, 3 — 24, 24 —43, 48 —
`72, 72 — 96. 96 -120. 120- 144, and 144 ~168 h after drug
`administration. Urine samples (0 — 24 h] used for identifi-
`cation oftolterodine metabolites were adjusted to pH 3.5 ~
`4.0 with 2 M H2504 in 0.5 M ascorbic acid to prevent
`oxidative processes. All serum. urine and fecal samples
`were stored frozen at —20“' C until analysis.
`All spontaneously reported adverse events were re-
`corded and laboratory parameters were again determined
`for all volunteers at study end.
`
`.—tttol__vtit'tn’ procedure
`
`Tolterodine concentrations in serum and urine were
`
`determined using gas ehromatographyimass spectrometry.
`with adeuterated analogue as the internal standard. Urinary
`concentrations oftolterodine were also assessed following
`incubation of samples with [3-glucuronidase (Boehringer
`Mannheim. Germany). Tolterodine and its internal stand-
`ard were synthesized by the Department of Medicinal
`Chemistry. Pharmacia and Upjohn AB. Stockholm, Swe-
`den. The analytes were extracted from 1 — 2 ml of alltalised
`(pH [1 — 14) sample into 5 ml pentanefdiethyl ether (1 : 3
`vfvl. After evaporation of the organic phase to dryness. in
`a stream of nitrogen. the residue was derivatized with 50
`ill BSTFA (N.O—lJis—(trirneLhylsilyl}—trifluuroacetan1ide).
`Separation was achieved on a fused silica capillary column
`(HP Ultra 1 or 2, 25 in ~ 0.22 mm, 0.33 pm"). using
`temperature programming. Detection was performed with
`an HP 5970 or 59?} MSD mass selective detector (Hewlett
`Packard. USA). The ions mfz 382 and m/z 387 were
`focused for single—io1't monitoring of tolterodine and its
`internal standard. respectively. Standard curves prepared
`in serum were linear within the range 0.5 — 50 jig/l. The
`limit of detection was 0.5 ttg/l. The interday variation for
`tolterodine in the concentration range 1.9 — 47.2 ttgfl was
`< 7‘/‘i-.~ and the accuracy varied between 100 and 111%.
`Measurements of total radioactivity were perforrned
`in aliquots of the oral solution and urine. Samples were
`diluted with Ultirna Gold (Packard. USA) and radioactivity
`measured by liquid scintillation spectrornetry (Canberra
`Packard TR 2500, USA). Fecal samples were homogenized
`in water (3 A -'1 times the fecal weight) and aliquots were
`dried and combusted t Packard Sample Oxidizer Model
`30?. USA). Radioactivity was subsequently measured in
`CarbosorbfPertnafluor (Packard. USA) by liquid scintilla-
`tion spectrometry.
`Urinary metabolites were extracted on Arnberlite
`XAD—2 ti? X 180 mm. conditioned with methanol and
`
`water). eluted with methanol, and concentrated under re-
`duced pressure. The different metabolites were fraction-
`ated by preparative reversed-phase liquid cliromatography
`on a Prep Pak column packed with 6 pm Nova Pak C18
`particles (Waters Mi1lipore.MA.l.lSA).The analytes were
`eluted withamethanol gradient in waterand the radioactive
`fractions were collected and concentrated. Radioactive
`
`fractions were further purified on an analytical reversed-
`phase column and finally analyzed by Frit-FAB liquid
`chromatography/mass spectrometry. Unconjugated meta-
`bolites were silylated and analyzed by gas chromatogra-
`phyhnass spectrometry with electron impact ionisation.
`
`Dora oaat'_vst'.t
`
`All data are expressed as mean 4; SD, except where
`indicated. Noncontpartmentttl analysis was performed us-
`ing PCNonlin {version 4.2} for €)t.II‘:iVflSClllaI‘ administra-
`tion [Statistical Consultants 1986]. The area under the
`serum concentratiort—tirne curve was obtained by linear
`trapezoidal approximation [Gibaldi and Perrier 1982'] with
`extrapolation to int-“tnity by dividing the last predicted data
`point by the terminal slope. lz (derived from the 3 — 2-1 h
`interval). Oral clearance tCL/Fl. assuming complete ab-
`sorption, and tetrninal hall’—]ife (tug) were calculated ac-
`cording to standard methods [Rowland and Tozer 1995 |.
`In the regression analysis. a biexponential model
`(equations 1 and 2} |Gibaldi and Perrier 1932] was fitted
`simultaneously to iv. and oral serum concentration data tin
`order to stabilize the model and to get a better estimate of
`bioavailabilityl:
`
`Cm:R,.tt :”—"[__t__[l_L_it_tJ]_e.lt. 1']
`
`(H
`
`1.--6.)”-I]
`
`is t during the infusion and becomes the
`where El
`constant tint‘ ttltirtttion of infusion) after cessation of the
`infusion.
`
`Generally. a lag.—time (ting) needed to be included for
`oral data. The model was titted to the databy weighted least
`squares regression using the weighting factor
`lfc3c;.l.~..
`which assumes that the coefficient‘ of variation (CV) of
`error on the concentration measurements was constant.The
`
`choice of model was made with respect to several criteria
`to assess the goodness offit of the models to experimental
`data. These criteria were as follows: the objective function.
`the scatter of the plot of the residuals, and the precision of
`each parameter. The volume oftlistrihution at steat|y~stttte
`(V55). systemic serum clearance (CL). absorption ltallllife
`([1333). bioavailability (F) and mean residence time (MR'|'l
`
`nu-
`
`Petitioner Mylan Pharmaceuticals Inc. - Exhibit 1007 - Page 3
`Petitioner Mylan Pharmaceuticals Inc. — Exhibit 1007 — Page 3
`
`

`
`Bryrme. Srahl, Hailén er al.
`
`Tolile 1’
`Pertinent. kinetic est imntes. obtained after simultaneous fit. of oral data (3.2. 6.4. and 12.8 rr1g)a1-id infusion data (1.28 mg) after administration
`of tolterodine to healthy volunteers.
`
`Parameter
`
`Mean
`
`3.3 n1g;n=41
`Range
`
`CV (Lil:-J
`
`Mean
`
`fi.4mg;n=3:
`Range
`
`CV (92)
`
`Mean
`
`12.8 mg§n=51
`Range
`
`CV (‘lift
`
`C.....tttg,r11
`1.1.1,. 1111
`F (+751
`v.ggttr1tg;1
`CL 1 l1"lI.’ltg'1
`mar 1111
`1.,;;.t11)
`C'L{Ft|1’h1'l-tgl“
`
`5.23
`11.3"
`43
`1.4
`r1.:15
`4.1
`3.3
`La‘
`
`<03 - 1.1
`t1.r- 1.0
`23 -74
`0.9- 1.5
`0,24 - one
`2.9- 5.7
`2.4.52
`(1.311 - 3.1
`
`14
`19
`51
`25
`2'1
`44
`11
`53
`
`9.6“
`0.9”
`34
`1.4
`0.37
`4.2
`3.3
`2.4“
`
`2.5- 17
`0.1-1.5
`2:1 -43
`1.1 - 1.6
`11.23 — 0.47
`2.3-2.0
`2.3-5.3
`0.55 -5.4
`
`53
`33
`33
`is
`34
`57
`51
`133
`
`25"
`mt
`33
`1.3
`0.43
`3.0
`2.4
`1.7"
`
`6.8-5-1
`0.3-2.0
`10- so
`1.1-1.4
`0.32 - 0.52
`2.7 -4
`2.1 -2.9
`1171- 4.11
`
`5:.
`53
`55
`13
`111
`9.3
`13
`in
`
`‘ = based on '1' subjects. “‘ = based on 8 subjects, ‘ = estimated by noncoinpanmental analysis. " = based on 15 subjects. C...-.,,. = peak serum concentmtioii.
`t,,,_—,., = time to Chm. F = bioavailability. V55 = volume of distribtttion at steady—state, CL = systemic serum clearance. MRT —.= mean residence time.
`l1r_‘|;1 = elimination ha|f—lifc. CLJF = urul clearttnce. CV = coefficient of variation
`
`Serum concentration lime
`1'
`Fig.
`profiles of toltcrodine after 6.4 mg
`oral (panel A) and L28 mg intrave-
`nous {panel B) single—dose admini-
`stration t1l' tolterodine to 8 healthy
`volunteers.
`
`E
`
`5
`
`100
`
`‘i
`5111
`
`51
`E
`
`A '
`
`100
`
`S
`I:
`3111
`
`E1
`
`2a
`
`0
`
`o
`
`2
`
`4
`Tzne (h)
`
`B
`
`s
`
`D
`
`u
`
`T." (h)
`
`were estimated according to standard equations [Gibaldi
`and Perrier 1982!.
`Radioactivity in urine and feces. was determined quan-
`littttively and described as a function ot' time.
`
`Results
`
`All subjects complied with the study protocol and
`completed the trial. Since only '3 subjects per dose level
`were included for the lower oral doses of0.2 — [.6 mg this
`
`presentation will emphasize the pliannacokinetics and
`pharniacodynamics after tolterodine doses of 3.2, 6.4. and
`l2.8 mg (8 volunteers per group).
`
`P11111'111ac‘c1ll'i11eIii-.1‘
`
`Phanrtacokinetic parameters from the r1oncon1p:1rt—
`mental analysis and the sintultaneotts fit to oral and i.v. data
`are presented in Table l and serum concentration time
`
`profiles after 6.4 mg oral and 1.28 mg i.v. administration
`in Figure l. Tolterodine was rapidly absorbed at all close
`levels. time to peak serum levels {tum} following oral
`administration was 0.8 - 1.1 h. A proportional increase in
`mean peak serum concentration (Cmafl (6.2 — 25 ttgfl) was
`observed at doses of 3.2 - l2.8 mg. CL./F showed high
`interindividual variabiiity (range 0.38 -— 5.4 lfhfkgi Without
`any obvious close relationship. Mean 11/: was constant (2.5
`— 3.0 h} with increasing dose. After a mean ting ot’0.3 i 0.3
`h, tolterodine was absorbed with a l.|f2,a of 0.4 i 0.3 h. The
`initial distribution phase was rapid Etlflgg < 0.33 hi.
`Bioavailability exhibited high variability between indi-
`viduals, ranging from [0 to 74%, white V515 and CL ranged
`from 0.9 to 1.6 l/kg and from 0.23 to 0.52 lfhflcg, respec-
`tively. On the basis of these results. MRT and elimination
`half—life (11,-‘2[3] were estimated to be 3 ~ 7 h and '3 — 3 l1.
`respectively. Rena] excretion of unchanged tolterodi ne was
`< I % during the first 48 h and was independent ofdose and
`route of administration. Similar results were obtained when
`
`urine samples were incubated with [3-glucuronidase prior
`to analysis.
`
`Petitioner Mylan Pharmaceuticals Inc. - Exhibit 1007 - Page 4
`Petitioner Mylan Pharmaceuticals Inc. — Exhibit 1007 — Page 4
`h1_
`
`

`
`
`
`Tnliavacidine PK and PD
`
`29}
`
`0 tolterodirie
`
`H ""'Hi\r
`
`Q
`
`Q
`
`identified urinary metabo-
`Fig, .7.
`lites after a single 5 mg oral dose of
`(“Ci-tolterodine in healthy volun-
`teers.
`All
`metabolites
`(and
`tolterodine) were also identified as
`glucuronides. The position of (NC)-
`labelling is
`indicated U‘)
`in the
`tolterodine molecule.
`
`
`
`Muss balance and metabolism
`
`a retention time corresponding to that of intact tolterodine
`was observed.
`
`Within 7 days from drug administration. 94:l: 2.5% of
`the total amount of radioactivity administered was recov-
`ered (7? _i: 4.0% and 17 i 3.5% in urine and feces, respec-
`tively}. Most of the radioactivity (74 :t 5.8%} was excreted
`in urine and feces within 24 ll.
`The structures of tolterocline metabolites identified in
`the 0 — 24 h urine samples are shown in Figure 2. Although
`the relative concentrations of the metabolites varied be-
`
`tween subjects. the carboxylic acid metabolite (Na) and
`the dealkylated carboxylic acid metabolite (Nb) were con-
`sistently the predominant metabolites in all samples ana-
`I yzed. The latter 2 metabolites accounted for 80 i 17% of
`total urinary radioactivity (Na, 51 i 14.0%, IVb. 29 i
`6.0%). The remaining 20% of radioactivity were accounted
`for by the hydroxylated metabolite (Ha) along with its
`dealkylated form (llb),
`intact
`toltcrodine. dealkylated
`toiterodine and their glucttronide conjugates. Fecal sam-
`ples contained 2 major metabolites with similar retention
`times to the [Va and Nb metabolites, while no peak with
`
`Pharmat"od_vnanii'('.t'
`
`The effects of tolterodine 3.2, 6.4, and l2.8 mg on
`
`mean heart rate. nearpoint ofvision, and stimulated saliva-
`tion are shown in Figure 3. Tolterodine was associated with
`a dose—dependent increase in heart rate. the onset of which
`was fairly rapid with time to maximal effect around 1.3 —
`[.8 h. The maximum increase in liean rate observed in
`volunteers who received toltcrodine 12.8 mg was 19 i 5
`beatsimin. Neaxpoint of vision was not affected at doses of
`3.2 and 6.4 mg, although considerable intetindividttal vari-
`ability was apparent. In contrast, a mean increase of 3'2 mm
`was observed at a dose of 12.8 mg. Following :1 transient
`increase in stimulated salivatiort (most probably as a result
`of water intake. 300 ml. and the slightly bitter (iral solu-
`tion), a rapid decrease in salivary flow was observed. The
`maximum decrease in salivary tiow was attained within 1.3
`-1.8 h after drug administration and at 12.8 mg an almost
`
`Petitioner Mylan Pharmaceuticals Inc. - Exhibit 1007 - Page 5
`Petitioner Mylan Pharmaceuticals Inc. — Exhibit 1007 — Page 5
`
`

`
`292
`
`Br_wme, Strain’. Haifén et at.
`
`Fig. 3 Mean ti SEM) heart rate
`(panel A}. nearpoint of vision {panel
`B) and stimulated salivation {panel
`C)
`time profiles after single oral
`doses of tollerodirte 3.2 mg (trian-
`gles), 6.4 mg (sqttarcsi and |2.8 mg
`{circles} in healthy volunteers (3
`subjects in each dose group}.
`
` § t
`
`
`oSNaatpoirltofvisiotflmn) 8s§
`
`
`complete inhibition of stimulated salivation was achieved.
`No clinically significant changes in either systolic or dia-
`stolic blood pressure were seen in any subject.
`
`Com'crttratt'rm —t'e5p(utse t‘e.’ttftotl.tItt';J
`
`The heart rate and salivation responses paralleled the
`tolterodine serum concentration time curves. pealr.
`re-
`sponses were observed around rum and declined with the
`elintinalion of tolterodine. There was a slight delay be-
`tween serum concentrations and heart rate response. but no
`apparent hysteresis for the effect on stimulated saiivation.
`In Figure 4 the relationship between effects on heart rate
`and stimulated salivation ve.rsus serum concentrations of
`
`tolterodine has therefore been illustrated by a log~linea1'
`regression line (slope 2.5 (based on salivation data)). The
`Figure illustrates the lack of selectivity between the 2
`measured effects. However, a considerable difference in
`
`the maximal degree of the responses was seen. Maximal
`changes in heart rate and stimulated salivarion observed
`after 12.8 mg were about +30% and -90%. respectively. ol’
`me pre—dose value. Figure 5 shows the salivary response
`versus serum concentrations after oral and i.v. administra-
`
`tion of tolterodine. Although comparable scrum tolterodi t'lE‘
`concentrations were achieved after oral and i.v. administra-
`
`tion. only small decreases in stimulated salivation were
`observed after i.v. infusion compared with the oral route.
`Figures 4 and 5 are based on observation up to 4 hours after
`dose.
`
`Petitioner Mylan Pharmaceuticals Inc. - Exhibit 1007 - Page 6
`Petitioner Mylan Pharmaceuticals Inc. — Exhibit 1007 — Page 6
`
`

`
`Tolrerodine PK and PD
`
`293
`
`B0
`
`75
`
`
`
`
`
`Heartrate[boats/min] a
`
`Salivation{g/5min)
`
`Serum concentration (troll)
`
`Salivallon
`
`(Q15min}
`
`Fii:. 4 Mean heart rate (open symbols) and salivation (filled symbols}
`response versus serum concentration of toltcrodtne after single oral doses
`or 3.2 mg t1.riaI‘1g|es}.fi.4 mg {squares} and 12.8 mg lfcirctcsl. Note that
`the 15 min salivation recording has been omitted.
`
`,-
`
`Ti.ilci‘(:ht'i'i r_\‘
`
`No severe adverse events were reported during the
`study. The most frequentiy repulted adverse events were
`dry mouth (3.2 mg. 6 subjects. 6.4 mg. 7’ subjects. 12.8 mg,
`8 subjects). rrticturition difficulties (6.4 mg, 1 subject, 12.8
`mg,
`ti subjects), disturbed accommodation (12.8 mg, 3
`subjects) and gastrointestinal problems (12.8 mg, 2 sub-
`jects). Micturition difficulties persisted for up to 16 h after
`administration of rolterodine 12.8 mg. No central nervous
`system adverse effects or clinically significant changes in
`laboratory parameters were noted during the study.
`
`Discussion
`
`the absolute bioavailability of
`The finding .,that
`tolterodine was highly variable [ranging from 10 to 74%)
`and independent of dose showed either that the drug was
`incompletely absorbed. or that tolterodine was subject to
`presystentic elimination. Since 77% of the given radioac-
`tive dose was excreted in urine. :1 high oral absorption is
`implied. The absorption of tolterodine was rapid and Crnagq
`was reached within 1
`It of drug administration suggesting
`that the absorption occurred mainly in the small intestine,
`since tlte average transit time through this section of the
`gastrointestinal tract is around 3 h {Davies at al. 1986]. The
`partition coefficiettt for tolterodine (log D 1.82) indicates
`that
`the drug will pass readily across biological rnetn~
`brancs, a process that did not appear to be saturable, since
`CLIP remained constant (Table 1}. Overall, these data
`suggested that tolterodine undergoes extensive and vari-
`
`Serum concentration (pg/I)
`
`serum concentrntiort of
`Fig. 5 Mean sallvation response versus
`tolterodine ttfiersingleoral doses of3.2 mgtlilled triangles}. 6.-tmglfilled
`squares) and 12.8 mg llillcd circles) and aftcra single i.v. irtliusion ol' L33
`mg (open circles) in healthy volunteers. Note that the 15-min oral saliva-
`tion recording has been omitted,
`
`able hepatic firsbpass metabolism, rather than incomplete
`absorption.
`Tolterodine was rapidly distributed with :1 tiggg of <
`20 min (in most cases around 5 min}. V55; ranged from 0.5)
`to 1 .6ltkg. which is in general agreement withthe relatively
`moderate lipophilic Characteristics ofthe compottnd. These
`data imply that < 5% of the parent compound remained in
`the systemic circulation at stcady—state, and that tolterodinc
`penetrates tissue membranes.
`After administration of (”C)—tolterodine. toes of the
`total dose of radioactivity was excreted renally already
`within 24 It. These findings show that the rnetabolism of
`tolterodine was a fairly rapid process, ttn|3 of tolterodine
`was 2 — 3 h. The primary metabolism was through 2
`different pathways: oxidation ofthe 5-methyl group andtor
`N~deallcylatiort {Figure 1). The two carboxycylic acid me-
`tabolites. I\/a and Nb. accounted for approximately 80%
`of the radioactivity recovered in urine.
`Systemic clearance oftolterodine ranged from 0.23 to
`0.52 1fl1!'l<g- However. «i 1% of the administered dose was
`excreted unchanged in urine. irrespective of route of ad-
`ministration. Biliary excretion did not contribute signifi-
`cantly to the elimination of tolterodinc since the drug was
`not detectable in feces. These findings suggested that he-
`patic metabolism is the main route ofelirnination and that
`metabolism oftolterodine is almost complete. Assuming a
`blood : serum concentration ratio of unity and a hepatic
`blood [low of
`1.5
`lftnitt,
`the hepatic extraction of
`tolterodine was in the range of 20 — -"if.l%. However. the
`
`Petitioner Mylan Pharmaceuticals Inc. - Exhibit 1007 - Page 7
`Petitioner Mylan Pharmaceuticals Inc. — Exhibit 1007 — Page 7
`
`

`
`estimated bioavailability [10 — 70%) clearly suggested
`variable lirst-pass elimination, which may reflect differ-
`ences between subjects with respect to metabolic capacity.
`The systemic clearance ofsubject 16 (0.23 lfhfkg) was thus
`notably lower than the overall average, and ltflfl of
`tolterodine in this subject was considerably longer (5.3 h).
`This dissimilarity was probably due to differences in he-
`patic metabolic capacity. Recently, Stahl et al. [1995]
`reported a subject with a lljfzfi of 15 h following asirtgle 6.4
`mg oral dose of tolterodine. The metabolic phenotype of
`this
`subject was
`subsequently characterized. using
`mepltenytoin and debrisoquine — two probe drugs that are
`well established for determination of the polymorphically
`distributed cytochromes P450 2Cl9 and P450 2D6
`(CYPECIQ and CYP2Dti} {Bertilsson i995]. The subject
`was classified as an extensive tnetabolizcr of mephenytoin
`and a poor ntetabolizer of debrisoquinc. which indicates
`that CYPZD6 may be involved in the metabolic clearance
`oftoltcrodine.
`
`Since it is difficult to obtain consecutive response
`measurements on the bladder over time. we assessed
`known antimuscarinic effects — such as increases in heart
`
`rate and nearpoint of vision and decrease in stimulated
`salivation — in order to characterize the pharmacological
`effects of tolterodine. While the absence ofa placebo group
`in this study limited the interpretation of the effects of
`tolterodine, overall Irends could be observed. At a dose of
`12.8 mg the maximum increase in heart rate was ll]
`beatsfmin and an almost total
`inhibition of stimulated
`salivation occurred. Both responses were superirnposable
`and suggest that the concentrations of tolterodine at an
`approximate half maximal response. on heart rate and
`salivation, were about 6 — S ugfl. The differences in mag-
`nitude might
`indicate that muscarinic M3 receptors in
`glands are more sensitive to blockade than M: receptors in
`the heart. However, there was an overlap between the
`serum concentrations where the respective responses oc-
`curred, which is in agreement with preclinical findings that
`did not demonstrate selectivity for a single muscarinic
`receptor subtype [Nilvebrant et al. I996].
`Data from a urodynamic study in healthy volunteers
`by Strthl er al. [I 995] showed that at single 6.4 mg oral dose
`of tolterodine exerts a powerful inhibitory effect on mic-
`turition. both subjectively and objectively. The reported
`rapid onset ofan effect on the bladder is in agreement with
`the pharmacoltinetic data in this study. Stahl and colleagues
`concluded that a dose of 6.4 mg would be too high for use
`in 21 future patient population. No effect on accommodation
`for nearvision was found at the dose used by Stahl et al.,
`while at a dose of 3.2 mg Ito apparent effect on heart rate
`and only a slight inhibition of stimulated salivatlon was
`found.
`in contrast to the salivary response, the effect of
`tolterodine on urodynamic parameters did not change
`markedly between I and 5 h after drug ttdrninistration
`[Stahl ct al. 1995]. The cause of the reiatively longer
`duration of the bladder response is at present unclear.
`
`Bl"yl1l‘l€. Stohl, Hnllén er al.
`
`However, data from preclinical studies in the anesthetized
`cat have shown a more shallow dose-response relationship
`for effect on the bladder compared with effect on salivation
`[Gillberg et al. 19941. If there is a similar dosc—response
`relationship in man this might be associated with the sub-
`jective reports of persistent rnicturition difficulties for up
`to 16 h after drug administration in this study.
`There was a large discrepancy between the observed
`effect and tolterodine serum concentrations after oral and
`i.v. administration. This was evident for decreased saliva-
`
`tion as well as increased heart rate. This suggested a major
`contribution from an active metabolite(s) besides the phar-
`macological activity of tolterodine. Since the salivation
`response profile closely followed the tolterodine serum
`concentration time curve it seems likely that the pharma-
`cokinetics of the active metabolitetsl is formation rate—lim-
`ited. The effect on salivation might have a pharrnacody-
`namic IC.5o value at metabolite concentrations correspond-
`ing to 6 — 8 ttgfl of parent tolterodine after oral dosage l but
`not after i.v. administration).
`The incidence of adverse effects was less frequent at
`lower doses and typical antitnuscarinic adverse effects
`were clearly dose—related up to l2.8 mg. In view of the
`adverse events profile. clinical laboratory and vital signs
`data, tolterodine was judged to be well tolerated at all dose
`levels up to 12.8 rug.
`
`Acknowledgements
`
`We thank Dr. Karl-Erilt Andersson and Dr. Bengt Sparf for their
`valuable contributions to the development of these initial humttn pharma-
`cological studies. We are grateful to R.N . Gertrud Lurtdquist for hcrslril ful
`assistance.
`
`REFERENCES
`
`Anderssou K-5 1993 The pharmacology of lower urinaty tract smooth
`muscles and penile. erectile tissues. Pharrnacol Rev ~'.l_'i.- 253-30$
`Bertflsmn L 1995 Gcographicalfutlerracial differences in polymorphic
`drug oxidation — Current state of knowledge ot'cytuctu-omes P450
`(CYP) 2D5 and 2Cl9. Clin Pharmacol-tinet 29: |92—2[l'-J
`B!at'un.s‘.l'G. Lahib KB. Ml't‘.ltal‘lk.l'. Za_w*ct'A.-31H 1980 Cystomeuic response
`to pro]:-hantel ine in datrusor hyperrefleit ia: therapeutic implications.
`I Urol I24.‘ 259-262
`
`Cardozo LD, Cooper D, Versi E I987 Ottybutynin chloride in the man-
`agement of idiopathic dettusor instability. Ncurourol Urodyn lfi;
`256-257
`
`f)£1'l’l"£-?.\' SS. Hnn{t' JG. Furct JW I936 Transit of pharmaceutical dosage
`forms in the small intestine. Gut 27: 386-892
`Dollcry CT. Du-vr'e.t D5’. Draffan GH . Dargt'e HJ. Dean CR. Rru'cl‘..’L. Clo: 9
`RA, Murray 5 [976 Clinical phannacology and pharmacokjnetics
`of clonidine. Clin Pharrnacol Ther I9: I I-15
`Gt'bal.<.l't' M. Perrier D I932 Pharmacukineljcs (2nd ed"). Deklter. New
`York
`
`Giltberg P—G. Madfri A-R. Sparf B 1994 Toltcrodinc —'a new agent with
`tissue effect selectivity for urinary bladder. Neurourol Urodyn I3.‘
`435-436
`
`Petitioner Mylan Pharmaceuticals Inc. - Exhibit 1007 - Page 8
`Petitioner Mylan Pharmaceuticals Inc. — Exhibit 1007 — Page 8
`h1.
`
`

`
`Tolterodiiw PK and PD
`
`295
`
`Naergci-H . Fry CH . Niivebrairr L I 995 Effect of tolterodine on electrically
`induced contractions of isolated human detrusor muscle from stable
`and unstable bladders. Netttourol Urodyn 14: 524-526
`N1'lw»br'ant L, Gias G, Iii.-rssnn ii. Spar)’3 1994 The in vitro pharmacologi-
`cal profile of lnlterodine — a new agent for the treatment of urinary
`urge incontinence. Neurourol Urodyn I3.‘ 433435
`Ni'.'i'elii'mt.r L. Sundquists. Gillberg F-G 1996 Toiterodine is not subtype
`(ml-m5) selective but exltibils functional bladder selectivity in
`vivo. Neurourol Urodyn 15: 310-3] 1
`Rowlamf M. Tozer TN 1995 Clinical pharmacokinetics: concepts. and
`applications (3rd ed). Williams and Wilkins. London
`Stalin’ MMS. Elrsrréim B. Sparf B. Matrfasson A. Anderssorr K-1? 1995
`Uroclynamic and other effects of toiterodine — a novel antimus-
`Uurinic drug for treatment of derrusnr overzlctivity. Ncurourol Uro-
`dyn M: 647-655
`
`Smrisrit-at C'0n.mlian.r.r .litc'.' I986 Pcnonlin and nor1lirIS4: Software for the
`statistical analysis of nonlinear models. Am Statistician 4:’): 52
`Sumfwall A. Versnran J’. Srr'indberg B 1913 Fate of erneproniurn brnniide
`in man in relation to its pharrnacological effects. Eur J Clin Phar-
`rnace|i5:l91—]9S
`
`Uim.s're'n U. z‘lnder.9sm.- K-If I9??? The effects of erneprone on intravcsical
`and inn'a—urethral pressures in women with urgency incontinence.
`ScandJUrolNephro1H.'
`|03—l(}9
`
`Vase CW, .l“oi'n’ GC, Grufgsoir SJW. Ha.s'kiiis NJ, Pl‘(Jh‘f M 198 I Pharma-
`Colcinetics of prupantheline bromide in normal man. Br! Llrol I26.
`81-85
`
`I"ar'i‘re:- YE. Goa KL, Firrim A 1995 Oxybulynin: a review of its pharma-
`codynamic and pharnmcokinetic properties and its lherapeutir use
`in diztrusor instability. Drugs Aging 6: 243-262
`
`to
`
`ac.
`
`Petitioner Mylan Pharmaceuticals Inc. - Exhibit 1007 - Page 9
`Petitioner Mylan Pharmaceuticals Inc. — Exhibit 1007 — Page 9