APOTEX ET AL. - EXHIBIT 1056
`Apotex Inc. et al. v. Novartis AG IPR2017-00854
`
`

`

`FTY720 IN DE NOVO KIDNEY TRANSPLANT PATIENTS
`
`of 4 to 5 days.” Similar pharmacokinetic results were
`also measured in a multiple-dose study of FTY720 in
`stable renal transplant patients.“
`In this report, we describe the results ofa phase II
`trial involving a larger number of patients than previ-
`ously studied, thereby permitting an assessment of the
`safety and preliminary efficacy and pharmacokinetic
`properties oi'FTY72t) with repeated dosing in de novo
`renal transplant patients. In addition to noncompart-
`mental pharmacokinetic analysis of the FTY72CI blood
`concentration data. we conducted a population
`pharmacokinetic analysis to aid in identifying clinical
`factors that might affect the blood concentrations of the
`drug.
`
`METHODS
`
`Study Design
`
`Pharmacokinetic assessments ofFTY720 were made in
`
`patients who had undergone de novo renal transplan—
`tation. The trial involved patients from multiple cen-
`ters in the European Union. Brazil, Canada, and the
`United States. and the design was randomized. open
`label, active controlled. and time staggered. In addition
`to the pharmacokinetic study. measurements of safe ty.
`tolerability. and preliminary efficacy were conducted.
`The study was approved by the institutional review
`boards within countries that participated in the
`studies.
`
`Recipients of primary cadaveric or non—human leu-
`kocyte antigen {non-HLA] identical living donor kid-
`neys were randomized within 24 hours of transplanta-
`tion to 1 of 5 groups given a 3-drug regimen consisting
`of oral CsA microemulsion [Neoral formulation,
`Novartis. East Hanover, NJ}. corticosteroids, and either
`oral FTY720 or oral MMF. Patients in group 1 received
`FTY720 as an initial 1-mg dose, followed the next
`morning by [MS—mg daily maintenance doses. Patients
`in group 2 were given an initial dose of 2 reg/kg of
`FTY720 after renal tranSplantation, followed by a 0.5
`mg daily maintenance dose. Those in groups 3 and 4 re-
`ceived a first dose of4 mg. followed by daily mainte
`nance doses of either 1.0 mg or 2.5 mg. respectively. To
`permit a comparison between FTY720 treatment and
`alternative therapy. patients allocated to group 5 were
`given daily doses ofMMF 2 g in divided doses instead
`of FTY720. In each patient, the study medication was
`administered for 12 weeks. Patients were included
`
`only after it had been determined that their allografts
`were functional.
`
`Blood Collection for Determination
`of FTY‘720 and Metabolites
`
`Samples of whole blood were drawn into ethylene-
`diaminetetraacetic acid—containing tubes. Blood sam—
`ples were frozen within 50 minutes of venipuncture
`and stored at +20°C pending analysis. Samples for
`analysis of FTY720 whole-blood trough levels were
`drawn 5 minutes before the initial dose of FTY720. 5
`minutes before the administration of the first FTY720
`
`maintenance dose, and 5 minutes before predeter-
`mined weekly doses during the 12-week treatment
`period. During the posttreatment follow-up period. ad-
`ditional blood sampling was performed for those pa-
`tients who had maintained a consistent 4-week regi—
`men ofFTY720 at 2, 6. 1t}. 24. 48. 72, and 95 hours after
`the last dose of FTY72D. Further samples were ob—
`tained at weeks ‘13, 14. ‘15, and 15 during the 12-week
`posttreatment follow-up period or ’1. 2, 3. and 4 weeks
`after discontinuation of study medication for those pa-
`tients who discontinued FTY720 prior to the conclu-
`sion of the 12-week treatment period. After FTY720
`was initiated, in a subset of4 patients. the whole-blood
`concentrations ofthe FTY720 metabolites. M2 and M3.
`were determined once weekly.
`In all patients, trough blood samples for measure-
`ment oszA whole-blood concentrations were also col-
`
`lected throughout the treatment period to permit CsA
`therapeutic drug monitoring and dosage adjustment as
`necessary. These samples were drawn prior to the
`morning dose of CsA and study medication at. day 2.
`weekly during the 12-week treatment period. and
`every 4 weeks thereafter.
`
`Drug Assay
`
`FTY7ZU and its metabolites were analyzed in whole
`blood by a validated liquid chromatography method
`with tandem mass spectrometry [HPLCJ’MSI’MSJ in se-
`lected reaction monitoring mode using atmospheric
`pressure chemical ionization (APCI) as an interface."
`[2H]FTY720 was used as an internal standard. For
`FTY720. as well as its internal standard and metabo-
`lites. the APCI conditions were as follows:
`
`Sheath gas pressure: nitrogen, 30 to 40 psi
`Capillary temperature: 175 to 200W}
`Vaporizer temperature: 400 to 430°C
`Corona discharge: 5 ILLA
`
`Mass spectrometer conditions:
`
`PHARMACOKINETICS
`
`1 269
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`

`sneer/mac ET AL
`
`Manifold temperature: 70°C. selected reaction monitoring
`Detection: positive ions
`Dynode: 15 kV
`Electron multiplier: 1000 to 1530 V
`Collision energy: ‘19 to —23 Ev
`Collision gas: argon, 3.0 mTorr
`Mass resolution: 0.7 emu
`
`Scan time: 0.2 to 0.5 seconds for FTY72t], {:H]FTY?20,
`and M2 and M3 metabolites {FTY72CI1 parent miz 303.2.
`daughter mfz 255.0;
`[2H]FTY7201 parent miz 312.1.
`daughter mfz 259,2; M2: parent ITU'Z 310.3. daughter min
`142.9: M3: parent 11132 262.2. daughter min 199.1]
`
`Within-study assay validation was performed by
`analysis of quality control samples together with the
`study samples. The limit of quantitation for FTYTZD
`was 0.075 1'13me and 0.3 ngi’mL for both metabolites
`{M2fM3}. The method was validated extensively with
`a mean accuracy and precision for different nominal
`concentrations of 104% to 109% and 5% to 15%, re-
`spectively. Whole~blood concentrations of USA were
`measured by radioimmunoassay.
`
`Noncompartmental Pharmacokinetic
`Analysis of FTY720, Metabolites
`(M2, M3], and Cyclosporine
`
`Noncompartmental pharmacokinetic parameters were
`determined using Microsoft Excel (Redmond, Wash)
`and WinNonlin Pro Version 3.1 [PharsighL Mountain
`View, Calif] computer programs. The pharmacokinetic
`parameters derived from the observed datawere trough
`steady-state blood concentration {C5,}, steady-state
`AUC [AUCH]. CLIP, terminal phase rate constant {it},
`and tm. The observed FTY720 blood trough C5,. were
`used to assess dose proportionality and to derive the
`FTY720 AUG” (C,, X I] and CUF. which was calculated
`as
`
`
`g_ Dose
`F ' AUCH'
`The time to [3,, [t,,] was determined by visual inspec-
`tion of the meantime course ofFTYPZO concentrations
`in each treatment group. The FTY720 blood concentra-
`tions fi‘om each patient between L, and week 12 [day
`84] were compiled and median steady~state concentra-
`tion calculated for each patient. The FTY720 blood
`concentrations in the posttreatrnent terminal elimina-
`tion phase were used to determine the terminal phase
`t,,2 of FTY720 in each treatment group. These ap-
`proaches were used for the pharmacokinetic evalua-
`tions of the FTY720 metabolites, M2 and M3.
`The observed CsA blood CS, values from each patient
`were pooled and used to assess the effect of FTY720
`treatment on steady-state pharmacokinetics of CsA.
`
`1270 o I Clio Pbarmacol 2005;45:1268-1278
`
`Only those (left concentrations, coinciding with the
`steady-state FTY720 period [days 42454], were em-
`ployed in formal statistical analysis using the linear
`mixed-effect model (PRDC MIXED] implemented in
`SAS.
`
`Population Pharmacokinelic
`Modeling ofF'I'Y720
`
`Population pharmacokinetic modeling was used to ex-
`plore the relationship between FTYTZD pharmaco—
`kinetics and covariates of patient demographics, indi-
`ces of hepatic and renal function, effects of diabetes.
`and comedication with beta‘biockers. This analysis
`was specifically used to understand the role of
`covariates in the pharmacokinetic variability of
`FTY720 in de novo renal transplant patients.
`The pharmacokinetic model used to best describe
`the FTY720 concentration-time profile” was a 1~
`compartment model with first-order absorption and
`elimination. The concentration of FTY720 after a sin-
`gle oral administration was estimated by“
`
`Conc =
`
`Dose x ka
`‘y,— x { ka - k]
`
`9:" ,,
`
`—e""'l,
`
`where F, ka. CL, V, and k [calculated as 5%] are the frac-
`tion of oral dose bioavailability, residual rate constant
`[assumed to represent absorption rate constant].
`plasma clearance, central volume of distribution, and
`terminal rate constant [assumed to represent elimina-
`tion rate constant] for each patient, respectively. The
`pharmacokinetic parameters estimated in the
`pharmacostatistical model were apparent CLIP, appar-
`ent WP. and ice. The covariates included in the analysis
`were body weight, gender. age, race. baseline
`creatinine. albumin, alkaline phosphatase [ALP].
`aspartate aminotransferese [AST]. alanine amino-
`transferase [ALT], total bilirubin. history of diabetes,
`and coadministration of beta«biockers.
`
`In the model-building process, covariates were
`added into or removed from the model based on maxi-
`mum likelihood ratio tests. with a significance level of
`1%, and by means of diagnostic plots. The model~
`building process comprised several steps. Initially, the
`statistical significance of covariates added to the base
`model individually was based on changes in the mini-
`mum objective function [AMOF = 3.84. P: .05]. In the
`next step. all significant covariates were then evaluated
`by adding them in combination on pharmacokinetic
`parameters of the base model, Comparison of 2 nested
`models [where 1 model is entirely contained within a
`second model] was based on change in AMDF. agree-
`ment between predicted and observed concentrations.
`
`

`

`FTl’720 IN DE NOVO KIDNE Y TRANSPLANT PATIENTS
`
`and the magnitude and randomness of residual values.
`The uMOF produced by adding a covariate to the
`model approximates a chi-square distribution with 11
`degrees of freedom, where n equals the difference in
`the number ofparameters between the models.
`To model the intrasubject variability, an error model
`with both multiplicative [£1] and additive [£2] errors
`was assumed. The model was Y = [51] + [31] - £1 + 82,
`where Y and [511 were the observed and predicted con—
`centrations, respectively. and E1 and s2 were 2 inde-
`pendent normal random variates with a common zero
`mean and unknown variances 612 and 622,
`
`respectively.
`The intersubject variability of CLIF and W? was
`modeled by exponential random effects as follows:
`
`and
`
`CLIP intersubject variability =
`[typical value ofCL/F] x exp[ni),
`
`Vi'F intersubicct variability =
`[typical value of VtF'l x expinzl.
`
`The random effects {its} were assumed to be normally
`distributed but with arbitrary correlation between ns.
`The intersubject variation of ka was not estimated due
`to the lack of samples prior to attainment of Cum; sarn~
`ples were typically taken 12 to 24 hours postdose.
`To estimate the effects of continuous covariates on
`
`CLIF and VIF. each average parameter value was multi-
`plied by [covariatefi For assessing the effect of dichot—
`omous covariates. each average value was multiplied
`by Emma”. The magnitude of the covariate effect was
`determined based on the data, and covariates of the
`continuous type were typically standardized, divided
`by their corresponding medians prior to model fitting.
`Parameters in all investigated population models
`were estimated using double-precision NDNMEM Ver-
`sion V, Level 1.1 (NONNTEM Project Group. San Fran-
`cisco. Calif]. The first-order conditional method with
`the interaction option (METHOD = 1 INTERACTION]
`was used in all calculations.
`
`Prior to evaluation ofcovariate effects, the following
`dose-(CLEF) relationship was added to the base model
`to test for close proportionality:
`
`Typical value of CLIF = [average CLIF] x [Dosel‘h
`
`Linear mixed-effect models were used to evaluate the
`
`dose proportionality and time dependency of FTY720
`pharmacokinetics by comparing C1,, at 7 different visits
`[days 42. 49. 56. 53, 70. 77, and B4).
`The concordance between the observed steady-state
`FTYYZU concentrations and population model—derived
`
`average (3 was tested to complement the model valida-
`tion using a bootstrap procedure. The possible
`influence ofFTY720 coadministration on the C“ oszA
`was evaluated using linear mixed-effect models.
`
`Relationship Between Eflicacy and
`FTY720 Steady-State Concentrations
`
`The first occurrence of biopsy—confirmed rejection
`within 12 weeks ofedministration oftbe initial dose of
`FTY72t} was matched to the FTY7ZD blood concentra-
`
`tion most proximal to the time ofrejection. The median
`steady-state FTY720 concentrations from each subject
`were pooled and summarized using median, 25th, and
`75th percentile statistics. The statistics were classified
`according to the efficacy outcome of the presence or
`absenca oi'biopsy-confirmed rejection.
`For each patient. the Kruskal—Wallis test was used to
`determine the relationship between the first biopsy-
`confirmed rejection in the initial 12 weeks of FTY720
`administration and the median steady-state FTY720
`blood concentration.
`
`Hematological, clinical biochemical, and cardiovas—
`cular parameters and other indicators of drug safety
`were monitored and recorded throughout the course of
`the study.
`
`RESULTS
`
`Pharmacokinetic Resuhs
`
`Demographic and baseline data for the study subjects
`are shown in Table I. Sample makeup by race of pa—
`tients given FTYTZD was 73% Caucasian, 11% African
`American. 3% Asian. and 12% Other. Based on the ob-
`served time course of trough FTY720 blood concentra-
`tions during the 12-week dosing period. a plateau was
`reached by day 42 [week 5], giving rise to sustained
`blood levels for the remainder of the dosing period
`[Figure 1]. Therefore. tss was judged to occur on week 7
`[Figure 1], and 155 patients who successfully com-
`pleted 7 weeks of therapy were included in the
`noncompartmental pharmacokinetic analysis of
`FTY72t]. This included 4|]. 40, 38. and 37 patients in
`each of groups 1 through 4, respectively. A total of 163
`subjects were included in the population
`pherrnacokinetic analysis of FTY720 (Table I). A total
`of 196 patients were used in pharmacokinetic calcula—
`tions of CsA, of which 42. 4‘1, 39, 37. and 37 patients
`were allocated to groups 1 through 5. respectively.
`Among the study sample, a medical history related to
`diabetes was recorded in 31 patients. and 91 subjects
`received treatment with beta-blockers.
`
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`SKEHIANECETAL
`
`Table I Baseline Demographic
`Statistics ofPatients Given FTY720
`
`Mean : SD
`
`[Range]
`
`Gender
`Age. y
`Weight. kg
`Albumin. gi’L
`Alkaline phosphatase. UXL
`Bilirubin. umolt’L
`Creatinine, umolx’L“
`Aspartate aminotransferase. UI'L
`Alanine eminotransferase. UfL
`
`91 M. 72 F
`46.3 111.8
`70.9 1 15.5
`341] i 4.4
`64.1 1' 29.4
`7.3 i 4.3
`471 i 225
`24.6 t 26.5
`22.3 i 35.3
`
`(19-59]
`{so-115]
`[25-45]
`{18—102}
`(1-39}
`[114-1432]
`[7-283]
`[3-373]
`
`After completion of FTY720 closing. terminal phase
`[1.2 was determined in most of the study subjects. Ex-
`tended values were observed, with mean values gener-
`ally exceeding 200 hours across all 4«dose regimens of
`FTY720 [Table [1]. The pharmacokinetic results de-
`rived from noncompartmental analysis indicated that
`CLIF is low (Table II] in relation to average hepatic
`blood flow.
`_
`Median FTY720 Csswere 1.0. 1.9, 4.0. and 8.8 ngtmL
`in groups 1 through 4. respectively. In general. the
`FTY720 AUG“ and {355 rose in proportion to the mainte-
`nance dose [Table II]. and no significant departure from
`close proportionality was observed. FTY720 has 2 pre-
`dominant, inactive metabolites, M2 and M3? In the ex-
`
`amination ofFTY720 metabolite levels [Figure 1, Table
`Ill], the majority ofthe blood samples yielded undetect-
`able M2 blood concentrations. However. at the highest
`dose of FTY720 (2.5 mg daily], the M2 metabolite C.fi
`was measured in all 4 patients and attained approxi—
`mately 6% of the levels of corresponding circulating
`FTY720 [corrected for molecular weight [MW]]. In con-
`trast to M2. the M3 metabolite was detected in all pa-
`tients from the 4 treatment groups. The observed M3
`steady-state concentrations increased proportionally
`with the increasing dose of FTY720. Relative to
`FTY720, M3 C... corresponded to approximately 60%
`of circulating FTY720. The t“: of both metabolites was
`similar to those values observed for FTY720 (Tables II
`and III].
`
`The effect of baseline ALP (Table IV] and body
`weight. both ofwhich were positively and significantly
`associated with CLIF and VIP, respectively. were the
`only covarietes retained in the final pharmaco-
`statisticsl model (Table V]. Other covariates. including
`age. gender. indices of hepatic and renal function, and
`history ofdiabetes, had no significant effect on F‘TY720
`CLt’F [Table IV]. The population determinations of CU
`
`1272 II IClin Pharmacol 2005;45:1268-1278
`
`twp-ind
`
`“‘1“:
`
`0 T naiuauzasourorro H manummmm
`mew)
`11m {11)
`mop-ma
`
`
`
`Figure 1. Mean {SD} Fl Y72U. M2. and M3 blood concentration ver-
`sus time profiles.
`
`F, WP. and t..2 were 10.8 Mb. 3280 L. and 210 h. respec-
`tively [Table V], and were in good agreement with the
`results from noncompartmental analysis [Table II]. The
`predicted C.s derived from CUP estimates in the popu-
`lation analysis were in good agreement with the ob-
`served FTY720 C5. [Figure 2]. The intersubject varia-
`tion of CLfF' was 55%. and the intrasubject variation of
`FTY720 concentrations was 28%. The mean and me-
`
`dian values from bootstrapping agreed well with the
`NONMEM estimates.
`
`

`

`FTY720 IN DE NO V0 KIDNEY TRANSPLANT PATIENTS
`
`Table II Steady-State FTY720 Pharmacokinetic Parameters Following
`12-Week Dosing With 025-, 0.5-, 1-, and 2.5-mg Maintenance Doses of FTY720
`
`
`
` P‘I‘YF’ZU Maintenance Dose. mg AUDI“. 113- liJmLll CLfF, Lr‘hh tm. h: [Range]
`
`
`
`
`
`201 (35—1434)
`10.8
`30 {87]
`Group it. 0.25 mg [n = 40]
`187 [81-810]
`11.8
`52 {59]
`Group 2.0.5 mg [n : 40}
`221 [75-872]
`13.2
`102 [50]
`Group 3.1 mg in = 38]
`
`Group 4. 2.5 mg [1'1 = 37} 227 {97-707} 225 {55] 1.4.8
`
`
`Thrruina] elimination phase I.” was assessed during the washout period {days 04412}.
`a. Mean (tilt coefficient of variation].
`b. Geometric mean.
`c. Harmonic mean trmlga]: n: 3201.25 mg). n = 3501.5 11131.31 = 29 (1 mg). and n: 31 [2.3 mg].
`
`Table III Steady-State Metabolite Concentrations and Terminal Phase Half-Life During Washout Period
`
` M2M2 M3 M3 FTY720 Group and Dose
`
`Harmonic Mean 11m h [Range]
`Median C“, ngi‘mL {Range}
`
`
`
`309n=1
`
`455.1269.1156‘ n = 3
`0.61 [0.46—1.03] 11 = 4
`Group 1. 0.25 mg daily
`0.85 [0.71-1.07] n = 4
`219 (so-rot} n = 4
`Group 2. 0.5 mg daily
`244 [so-632] n = 4
`2.03 {1.33—2.42} n = 4
`0.34 n = 1
`Group 3.1 mg daily
`181. 72. ?Q It: 3
`247 (193-519) 11 = 4
`5.06 {4.42-5.21} 11 = 4
`Group 4. 2.5 mg daily
`0.57 [0.37-0.77] 11:4
`a. Hate from individual patients.
`
`0.45 n :1
`
`No significant differences were found in CsA Cw
`among all 5 treatment groups [Figure 3]. Thus, simulta-
`neous administration of FTY720 did not appear to in-
`fluence the CSA Cgs when compared to the GSA Cs. ob-
`tained when USA was coadm‘mistered with MMF to
`
`patients in group 5 [Figure 3]. Both within- and
`between-subject variability in USA concentrations dur-
`ing the day 42 to 84 interval were 29%. Consistentwith
`the standard practice of reducing CsA dosing during
`the first 3 to 4 months posttransplant, a significant de-
`cline in CsA blood concentrations over time was ob-
`
`served across all 5 treatment groups as the study pro-
`gressed [Figure 3].
`To determine ifFTY720 concentration within a dose
`
`cohort provided additional information on the prob-
`ability of rejection, FTYF’ZO steady-state blood concen-
`trations were classified according to the presence or ab-
`sence of'oiopsy-confirmed rejection within dose strata
`[Figure 4]. At any given dose level, the acute rejection
`outcome was not associated with a low exposure level
`of FTY720.
`
`Table IV Demographic and Baseline Clinical
`Covariates on FTY720 Steady-State Blood
`Concentrations and Associated Levels of Significance
`Based on Pearson‘s Correlation Coefficient
`
`
`
` Covariate P Value
`
`Age group [30-30. 31-50, 50+ years]
`Gender
`
`Race (Caucasian vs non-Caucasian)
`Baseline body weight
`Serum creatinino [<2. 2-3. 3+}
`Albumin
`
`,
`
`Alkaline phosphatase
`Aspartale aminotransferase
`Alanine aminotransfcrasc
`
`.241
`.637
`
`.582
`.587
`.821
`.860
`
`.012
`.‘155
`.291
`
`.924
`Prior history of diabetes
`The corresponding P values for cmatinine versus 0“ comparisons on days
`49, 56. and 7? were as followa: r: .001. P: .907: r: .051 . P: .549: and r:
`—.Ui33. P = .9132.
`
`Suspected FTY720-Relsted Adverse Events
`
`During the early dosing phase up to month 3. the over-
`all incidence of suspected drug-related adverse events
`
`was 38% for patients receiving FTY720 and 37% for
`those receiving MMF. Reduction in circulating lym—
`phocytes was observed in all FTY720 dose groups, and
`a positive relationship with dose was observed for its
`degree and duration (Figure 5}. The decrease in abso-
`
`PHARMACOKINETICS
`
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`

`SKEHIANEC ET AL
`
`Table V Parameters and Final Estimates Used and Generated in the Final Model
`
`
`
` Pharmacoldnetic Parameter Covariate Mode] Parameter Estimated Value Standard Error Population Variation. %
`
`
`
`
`
`
`
`
`
`our. oh
`
`{9, x [opener
`
`we. L
`
`Ka. h'1
`
`{92 x [body weightffiflflflh
`
`93
`
`a.
`34
`
`92
`35
`
`93
`
`Inter-subject variation
`
`CLJ'IF
`V/F
`Cov{CUF, ViFl
`
`Variation for residual error
`
`Multiplicative
`Additive
`Body weight in kg: alkaline phosphatase {ALP} in UIL.
`3. Changes in minimum objective function [AMDF = 9.173].
`ll ANIOF =17.ZED.
`
`55
`
`4c
`
`10.3
`0.303
`
`32st
`0.534
`
`0.473
`
`0.301
`0.161
`0.0996
`
`0.0792
`0.00443
`
`0.495
`0.104
`
`115
`0.141
`
`0.133
`
`0.0399
`0.0340
`0.0255
`
`[1.00537
`0.00157
`
`m Cunt-Ill mm
`0M I {II- i!)
`2” W]
`0m 7 (II-fl}
`ME!”
`ON 3W3)
`”3!”!
`a“ I (no?)
`2:01:31]
`cm 5 sum
`as m
`
`
`
`
`malty
`
`+ Gm:
`‘9'- Ground
`
`Cm
`mu
`
`m m o
`
`ne
`5m
`
`M s
`
`o.
`am
`
`
`
`cycmponm.:1me
`
`8 u
`
`on
`
`2
`
`.I
`Eon
`I:
`
`3on
`'D
`
`I.D
`
`E'u
`En.
`
`Median observed 653. nngL
`
`10
`
`as
`
`an
`
`25
`
`Figure 2. Concordance plot of model-predicted and observed
`steady-state FTY720 blood concentrations.
`
`Figure 3. Mean t SD cyciosporine blood concentrations Iversus time
`course during and offer 12-week dosing regimen with FT 1’729.
`
`lute lymphocyte count. however, was not progressive.
`with a new lower, albeit stable, level being attained
`within 3 days of starting therapy [Figure 5]. There was
`only 1 case in which study medication was discontin-
`ued due to low peripheral blood lymphocyte count.
`which occurred in group 2. to all FTY720 dose groups.
`absolute lymphocyte counts returned to baseline val~
`ues within 4 weeks of discontinuation of FTY720
`(Figure 5].
`The incidence ofa bradycardia reported as an ad-
`verse event was increased in the highest FTY720 dose
`
`groups {Figure 5], but the magnitude ofthe decrease in
`measured heart rate from baseline was similar in all
`
`dose groups. The onset of decreased heart rate was tem-
`porally related to administration of the first dose of
`FTY720. In the majority of cases, the decrease in heart
`rate was asymptomatic and resolved without medical
`intervention. FTY720 was discontinued due to a
`bradycardia adverse event in only ‘1 patient in group 4.
`Atrial fibrillation was reported in 6 patients random-
`ized to FTY720. with 5 cases occurring in patients
`treated with the highest dose [group 4]. However. 4 of
`
`1274 I IClin Pharmacol 2005;45:1258-1278
`
`

`

`FTY720 IN DE NO VD KlDNE Y TRANSPLANT PATIENTS
`
`
`
`
`(109m 8
`aLymphocytes
`
`
`
`
`
`Visit
`
`
`Figure 5. Absolute lymphocyte counts in groups It
`through 4
`{FTY72U dose groups} and group 5 {MMF dose group). BL, baseline
`count: D. day: W Week; E. examination number: EDT. and of treat-
`ment; E03. and ofstudy; MMR mycophsnotote mofettt.
`
`Mutnmummwx
`III!
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`I1
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`1.0 MM!mum:
`mam:
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`reject
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`
`Figure 4. Box plots of FTY720 steody~stote concentrations catego-
`rized by FTY720 dose group {G} and eficocy outcome measured as
`biopsy—confirmed acute rejection ofkt'o'ney allogrofts, where reject tn-
`dtrotes rejected ottogrofts. and intact representsfunctional cllogrofls.
`The median value is deported as a horizontal line through the box.
`and the upper and lower lines represent the third quurtite (75th per—
`centile) and first quartile {25th percentile}. respectively.
`
`these patients had significant preexisting cardiovascu-
`lar comorbidity. Two cases of atrial fibrillation were
`considered by the investigators to be drug related. One
`case of hypertension was considered by the investiga-
`tor to be drug related [FTY720 1.0-mg dose group],
`although this was not thoughtto be a serious adverse
`event.
`
`Over the 3-month period after chronic FTY720 dos-
`ing in this study, 19 patients (11.4%] experienced in~
`creases in serum creatinine concentration. in these pa-
`tients, two-thirds of these increases coincided with
`signs of acute rejection or borderline histology on bi~
`opsy. Fourteen percent of the cases of increased blood
`creatinine were considered by the investigators to be
`possibly study drug related Most of the cases of in-
`creased blood creatinine Were mild to moderate in se~
`
`verity, and FTY'I’ZD was diacontinued for these events
`in only 10% of the cases.
`
`DISCUSSION
`
`Similar to results previously reported in a phase [study
`in which renal transplant patients were administered
`single doses,“ FTY720 at steady state in de novo renal
`transplants was found to possess a long terminal phase
`t1;2 as a result ofa large apparent WP [Figure 1, Tables 11
`and III]. FTY720 possesses structural features. such as
`an octyl side chain, that would tend to impart signifi-
`cant lipophilicity to the molecule and cause it to attain
`high tissue concentrations. The long t1,2 also occurred,
`in part. due to its relatively low apparent CLtF‘. The ex-
`
`tended tM of FTYTZD was consistent with its prolonged
`tm, where 5 [“2 of approximately 200 hours is equiva-
`lent to the value of7 weeks obtained from visual exami-
`
`nation of the data (Figure 1). The fluctuation ofF'I‘YTZO
`at steady state was small due to the short dosing inter-
`val (24 hours} relative to the long tm‘ Hence, trough
`concentration, or any other concentration obtained
`over the dosing interval, represents a reasonable esti-
`mate of C“.
`This is the first report to describe the plasma con-
`centrations of the major metabolites of FTY720, M2
`and M3. in humans after chronic administration of
`FT-Y72{}. Because the metabolites possessed similar
`
`PHARMACOKINETICS
`
`1 275
`
`

`

`SKERJANEC ETAL
`
` Heart
`
`
`rate,.bomflnin
`
`”MMWHHMVII‘W
`ILMMMMWIVI
`WI
`'fl
`(In
`(H!
`II
` IIBIIB
`
`
`
`Visit
`
`Figure 5. Heart rate in groups 1 through 4 {FTYF’ZO dose groups)
`and group 5 {MMF dose group}. BL. baseline count; D. day. W. week:
`E, examination number; EDT. and of treatment.- E05. and of study.-
`MMF. myrophenoiote mafia-til.
`
`values of t.., to the parent drug {Figure 1, Tables II and
`III}, it appears that the elimination of metabolites from
`blood is formation rate dependent. Because the
`FTY720 metabolites are devoid of immunosuppressive
`activity} pharmacoidnetic monitoring of M2 and M3 in
`patients receiving FTY720 in future studies is probably
`not warranted.
`
`Similar to results ofthe single-dose phase I study. in
`the present study. a 1-compertrnentmodel was deemed
`sufficient to characterize the pharmacokinetic parame-
`ters of FTY720 when given orally. Given the large WF
`of FTY720 observed in all subjects in this study [Table
`V}. it might be surprising that a 1-compartment model
`conformed well to the data. In a recent pharmac0+
`kinetictdynarnic report involving cynomoigus mon-
`keys after single oral and intravenous doses of FTY72EI.
`it was demonstrated that a 3-compartment model best
`described the pharmacokinetics of the drug when
`given intravenously.“ in these monkeys. it was appar-
`ent that the absorption phase after oral administration
`obscured the appearance of the multiple compart-
`ments in the blood concentration versus time curves.
`which may explain why the data in the present study
`conformed well to a 1-bempsrtoient model.fi Based on
`the study in monkeys. in which the tmu after oral doses
`was of similar magnitude to that seen in humans. the
`terminal to! after intravenous doses matched that of
`oral doses. It'therefore seems likely that the terminal t...2
`determined in our renal transplant patients represents
`net elimination of drug and not the absorption phase.
`In this study, the number of subjects used in the
`FTY720 population analysis was higher than in the
`noncompartmental analysis. This illustrates one ofthe
`advantages of the population approach. as it allows use
`
`.1276 . [Clin Pharmacol 2005;45:1263-12'm
`
`oi'concentrations from any point on the concentration-
`time profile.
`Population pharmacokinotics and use of'NDNMEM
`is a robust method that can he used to evaluate clinical
`factors that can influence drug CL andfor V.” Indeed.
`this approach was used to screen factors that could in-
`fluence the pharmacokinetics of tacrolimus““ and
`CsA.“ In our evaluation of FTY720. perhaps not unex-
`pectedly. the WP was positively related to the patient's
`body weight in the population analysis [Table V]. This
`relationship is consistent with FTYYED's liphophilic
`character and extensive distribution throughout the
`body. With respect to CLtF.
`the only significant
`covariate identified in the population analysis was
`with ALP (Tables IV and V]. However. the inclusion of
`ALP in the final model contributed minimally to the re-
`duction of overall variability [approximately 1%].
`Thus, this relationship between AL? and CLIF has no
`meaningful clinical significance.
`The CsA blood concentrations were not signifi-
`cantly different when coadministered with FTY720 or
`MMF‘ [Figure 3]. although these results suggest that
`neither drug influences. the pharmacokinetics of CsA.
`the present study design does not permit a definitive
`conclusion because CsA blood concentrations were ti-
`trated according to their blood levels by therapeutic
`drug monitoring. The trend of declining trough CsA
`blood concentrations over the course of the study is
`consistent with standard posttranSplantation manage—
`ment with continuous CsA dose adjustment toward
`targeted CsA blood levels.
`The analysis of the relationship between the
`FTY720 Cs: and efficacy endpoint. defined as biopsy-
`confirmed rejection. indicated that at any given dose
`level. an outcome of acute rejection was not associated
`with reduced FTY720 trough C” [Figure 4]. Unlike
`CsA. which requires therapeutic drug monitoring as
`part of the posttransplant treatment regimen. data from
`this study suggest that monitoring of FTY72D trough
`blood concentrations. when given as part of a triple
`immunosuppressive regimen, would not improve the
`outcome of drug efficacy in de novo renal transplant
`patients. Lack of an identifiable minimal threshold
`concentration.
`in combination with predictable
`pharinacokinetic profiles across multiple doses over
`prolonged treatment periods. is a potentially favorable
`pharmacokinetic propertoni' FTY72t} compared to
`other immunosuppressive drugs used for the
`prevention of rejection in'organ transplantation.
`Similar to preclinical animal models”“" and in the
`completed phase I trial.” the pharmacologic effect of
`FTY720 on decreasing the peripheral
`lymphocyte
`counts was observed. This effect occurred within the
`
`

`

`FTY72D IN DE NOVO KIDNEY TRANSPLANT PATIENTS
`
`first day of dosing with FTY720 [Figure 5}. One of the
`pharmacological effects of the drug is to modify cellu-
`lar trafficking of lymphocytes. resulting in their se~
`questration in secondary lymphoid tissues such as
`lymph nodes and Payers patchesfm'13 This reduced
`availability of circulating lymphocytes for migratitm to
`transplanted tissues forms the basis for action of the
`drug as an immunomodulating agent. The reduction in
`lymphocyte levels reached a new baseline level within
`1. week of commencement of administration of
`FTY720. which is much faster than the terminal tm of
`the drug might predict (Figure 5]. In monkeys.
`the
`pharmacokinetic-dynamic effect seemed to be local~
`lead in a central compartment because blood concen-
`trations rather than tissue concentrations were well
`correlated with effect.“ If this model is also applicable
`to the human condition. this would explain the short
`time to maximal effect relative to the long terminal
`phase tug] which is highly dependent on FTY720
`binding to tissues with low perfusion rates.
`In a previous report. there was a transient; mild de~
`crease in heart rate associated with high single doses of
`FTY720 when administered to renal transplant pa-
`tients.” In a preliminary phase Imultiple-dose study in
`which drug was given for 28 days to stable renal trans-
`plant patients, this decrease in heart rate was found to
`have subsided with repeated administration of the
`drug [Novartis. data on file]. With repeat closing for 3
`months1 a self-limiting reduction in heart rate was also
`observed immediately after commencing dosing with
`FTY720 o