doi: 10.1111/fcp.12079
Fundamental & Clinical Pharmacology
ORIGINAL ARTICLE
Single- and multiple-dose tolerability and pharmacokinetics of the CRTH2 antagonist setipiprant in healthy male subjects Patricia N. Sidhartaa*, Zuzana Diamantb, Jasper Dingemansea a Department of Clinical Pharmacology, Actelion Pharmaceuticals Ltd., Gewerbestrasse 16, 4123 Allschwil, Switzerland b Centre for Human Drug Research, Zernikedreef 8, 2333, CL Leiden, The Netherlands
Keywords CRTH2, entry-into-human study, multiple dose, pharmacokinetics, setipiprant, single dose
Received 5 April 2013; revised 3 April 2014; accepted 11 April 2014
*Correspondence and reprints: [email protected]
ABSTRACT
Chemoattractant receptor-homologous molecule expressed on T helper (Th) 2 cells (CRTH2) is a G-protein-coupled receptor for prostaglandin D2 (PGD2), a key mediator in inflammatory disorders such as asthma and allergic rhinitis. In this study, we investigated the single- and multiple-dose tolerability and pharmacokinetics (PKs) of setipiprant, an orally active, potent, and selective CRTH2 antagonist. This randomized, double-blind, placebo-controlled study was performed in two parts in healthy male subjects. In study Part A, single oral doses of up to 2000 mg setipiprant or placebo were given to sequential groups of eight subjects each. Additionally, the impact of food on the PKs was investigated in one-dose group. In study Part B, two groups of subjects received 500 or 1000 mg setipiprant or placebo b.i.d. during 5.5 days. At regular intervals, tolerability variables and plasma and urine levels of setipiprant were determined. Setipiprant was well tolerated after single- and multiple-dose administration. Headache was the most frequently reported adverse event. No treatment effect on tolerability variables was observed. After single- and multiple-dose administration, setipiprant was rapidly absorbed and followed a biphasic elimination pattern with an elimination half-life between 10 and 18 h. Steady-state conditions were reached after 2–3 days and setipiprant did not accumulate. Exposure to setipiprant was lower in the presence of food. Urinary excretion of unchanged setipiprant did not exceed 7% of the administered dose. In this entry-into-human study, setipiprant showed good tolerability and a favorable PK profile, thus warranting its development in the treatment of inflammatory disorders.
INTRODUCTION The prostanoid prostaglandin D2 (PGD2) is an important pro-inflammatory mediator involved in the pathophysiology of immunoglobulin (IG) E-dependent responses, characteristic of an array of allergic diseases such as asthma, atopic dermatitis and allergic rhinitis [1–4]. In sensitized patients, PGD2 is produced through de novo synthesis via the 5-lipoxygenase pathway of arachidonic acid by dendritic cells, mast cells and T helper
690
(Th)2 cells upon exposure to relevant allergens. Subsequently, this bioactive mediator can exert its proinflammatory activities related to allergic diseases through interaction with various G-protein-coupled receptors (GPCR) [1,5,6]. CRTH2 receptors, which have been recently discovered, are expressed on Th2 cells, eosinophils and basophils all being key effector cells in allergic responses [7]. In vitro, activation of CRTH2 induced migration of these cells. CRTH2 has been suggested to be a reliable marker for circulating Th2 cells [8]. Further, activation of CRTH2 by PGD2 induced te Francßaise de Pharmacologie et de The rapeutique ª 2014 Socie Fundamental & Clinical Pharmacology 28 (2014) 690–699
691
Setipiprant in healthy male subjects
interleukin (IL)-4, IL-5 and IL-13 production of Th2 cells in humans [9–11]. Both IL-4 and IL-13 induce adhesion molecule expression on the endothelial cell layer of blood vessels, leading to increased adhesiveness for eosinophils and activated Th2 cells. IL-5 mobilizes eosinophil precursors from the bone marrow, leading to eosinophilia. IL-13 is a key factor for tissue remodeling and airway hypersensitivity [12,13]. CRTH2 antagonists are drugs currently in clinical development, interacting with the CRTH2 receptor on inflammatory cells. As such, CRTH2 antagonists may counteract the pathophysiological effects of PGD2, the subsequent recruitment of Th2 cells, eosinophils, and basophils, and the production of the pro-inflammatory products at a high hierarchical level [5,14–16]. Thus, CRTH2 antagonism would be expected to have a controlling effect on both short- and long-term aspects of the allergic inflammation [7]. Based on their mechanistic properties and systemic activity, CRTH2 antagonists may be suitable for the treatment of allergic diseases, such as allergic asthma that presents in up to 80% with concomitant allergic rhinitis (the so-called combined allergic rhinitis and asthma syndrome (CARAS) or rhinasthma patients) [17]. Present guidelines recommend topical corticosteroids as first-line therapy for both asthma and (concomitant) allergic rhinitis [17,18] and targeted therapy with systemic leukotriene receptor antagonists (LTRA) as second-line treatment for rhinasthma [17]. CRTH2 antagonists act more upstream within the inflammatory cascade of allergic conditions and, hence, are expected to be more efficacious than LTRA offering a safe alternative to topical corticosteroids, with the comfort of oral medication [19]. Setipiprant (ACT-129968) (2-(2-(1-naphthoyl)-8-fluoro-3,4-dihydro-1H-pyrido[4,3-b]indol-5(2H)-yl)acetic acid), a tetrahydropyridoindole derivative, is a new, potent, orally active, selective antagonist of CRTH2 [20]. Setipiprant showed effective blockade of PGD2induced activation of eosinophils and basophils, inhibited cytokine secretion by PGD2-stimulated human Th2 cells, and inhibited the migration of eosinophils toward PGD2 in several studies in vitro [20]. The inhibition of eosinophil migration was also demonstrated in a rat model of lung eosinophilia. Thus, setipiprant could be a promising approach to the treatment of allergic inflammatory disorders. In this entry-into-human study, we investigated the tolerability and pharmacokinetics (PKs) of single and multiple ascending doses of this new compound in te Francßaise de Pharmacologie et de The rapeutique ª 2014 Socie Fundamental & Clinical Pharmacology 28 (2014) 690–699
healthy male subjects over a wide dose range and in the presence and absence of food. MATERIALS AND METHODS Study subjects In this study (AC-060-101/EudraCT number 2006006777-25), 73 male subjects were included after giving written informed consent. Subjects had to be between 18 and 45 years of age could only receive one treatment and were not allowed to re-enter another dose group. Subjects were healthy as assessed by medical history, physical examination, ECG, vital signs and clinical laboratory tests. They could not participate if they smoked, had a prior history of drug or alcohol abuse, were allergic to any drugs, were using any medication or had participated in another clinical trial during the 3-month period preceding the screening examination. The study followed the principles of the Declaration of Helsinki and Good Clinical Practice, and the protocol was approved by an independent Ethics Committee (CME, Leiden, the Netherlands). Study design The study had a two-part (a single ascending dose part and a multiple ascending dose part, respectively), single-center, randomized, double-blind, placebo-controlled design. Part A (the single ascending dose part) consisted of seven successive groups of eight healthy subjects receiving a single dose of setipiprant. In each dose group, after an overnight fast, six subjects received setipiprant in ascending doses of 5, 25, 100, 200, 400, 1000 and 2000 mg setipiprant, while two subjects received a matching placebo. To investigate the effect of food on the tolerability and PKs of setipiprant, subjects in the 200 mg dose-level group returned to the clinic after a 1–2 weeks washout and received the same single administration of study treatment after consuming a high-fat, high-calorie standardized breakfast [21]. Subjects stayed in the clinic from approximately 12 h before until 48 h after the intake of study drug, during which time tolerability assessments were performed and blood samples were taken for the determination of PK parameters. Urine was collected during two 24-h intervals after drug intake. Part B (the multiple ascending dose part) consisted of two successive groups of eight subjects receiving multiple doses of setipiprant for 5.5 days. In each dose
692
group, 6 subjects received a dose of 500 mg or 1000 mg setipiprant b.i.d. and two subjects received matching placebo in fasted condition. Subjects received their first dose of study drug in the morning on Day 1 and the last study drug in the morning on Day 6. The doses and dosing regimen were selected based on the results of Part A and were based on the rationale to establish a wide dose range at which setipiprant would be well tolerated. The area under the plasma concentration–time curve during a dosing interval (AUCs) of the highest dose of 1000 mg setipiprant b.i.d. was, based on simulation of steady-state conditions, not to exceed the AUCs of the highest tolerated dose in Part A (i.e., 2000 mg). To ensure safety of the subjects, an intermediate dosing regimen (i.e., 500 mg setipiprant b.i.d.) was selected to be investigated prior to initiation of the 1000 mg setipiprant b.i.d. group. Subjects stayed in the clinic from approximately 12 h before the first study drug intake until 48 h after the last study drug intake (total of 9 days), during which time tolerability assessments were performed and blood samples were taken for the determination of PK parameters. Similarly, urine was collected during 12 h following the first and last drug intake for determination of PK parameters. After each dose group, the tolerability was evaluated to decide whether the next higher-dose group could proceed. Part B was started after evaluation of Part A of the study. End-of-study assessments were performed within 48 h after the last blood sample was taken for PK. Tolerability measurements All adverse events (AE) that occurred after drug administration and up to the end-of-study examination were recorded together with the intensity, time of onset, duration and relationship to the treatment. Part A: A physical examination and body weight measurements were performed at screening and at the end-of-study. Vital signs (supine and standing systolic and diastolic blood pressure and pulse rate) were measured at screening, immediately prior to and 1, 2, 4, 9, 24 and 36 h after study drug administration, and at the end-of-study. A 12-lead ECG was recorded at screening, immediately prior to and 1, 2, 4, 9 and 24 h after study drug administration, and at the endof-study. Routine laboratory parameters (blood and urine) were assessed at screening, immediately prior to study drug intake, 24 h after study drug administration, and at the end-of-study. For the 200 mg dose group, a follow-up visit was conducted within 48 h
P.N. Sidharta et al.
after last blood sampling in the fasted condition, which included physical examination, body weight measurement, vital signs, 12-lead ECG and routine laboratory parameters. Part B: A physical examination and body weight measurement were performed at screening and at the end-of-study. Vital signs (supine and standing systolic and diastolic blood pressure and pulse rate) were measured at screening, immediately prior to and 1, 2, 3 and 5 h after first drug administration, predose from Day 1 evening administration to Day 6 morning administration and 1, 2, 3, 5, 12 and 24 h after last administration on Day 6 (morning administration) and at the end-of-study. A 12-lead ECG was recorded at screening, on Day 1 immediately prior to and 2, 3 and 5 h after first drug administration, predose Day 1 evening administration, predose Day 2, 4 and 6 morning administration, and 2, 3, 5, 12 and 24 h after last administration on Day 6 (morning administration) and at the end-ofstudy. Routine laboratory parameters (blood and urine) were assessed at screening, predose to the morning drug intake on Day 1, 4, 6 and at the end-of-study. Pharmacokinetic assessments For the determination of setipiprant in plasma, venous blood samples (4 mL each) were collected in tubes containing EDTA as anticoagulant. Following centrifugation at 1500 g for 10 min at 4 °C, plasma was separated and frozen at 40 °C pending analysis. Samples were protected from light at all times. In Part A, plasma samples were taken predose on Day 1 and 0.5, 1, 1.5, 2, 3, 4, 5, 6, 9, 13, 18, 24, 36 and 48 h after drug intake. In Part B, plasma samples were collected immediately prior to first dose on Day 1, 0.5, 1, 1.5, 2, 3, 4, 5, 6 and 9 h postmorning dose on Day 1, predose starting from Day 1 evening administration up to Day 6 morning administration and 0.5, 1, 1.5, 2, 3, 4, 5, 6, 9, 12, 14, 20, 24, 36 and 48 h postmorning dose on Day 6. For the determination of setipiprant in urine, urine was collected during two 24-h intervals after study drug intake in Part A, and during 12 h after the first and last drug administration in Part B. After each collection interval, the total volume was measured and an aliquot of 24 mL was taken and stored at 40 °C pending analysis. Bioanalytical methods Samples were protected from light at all times. For the quantification of setipiprant in plasma, two calibration te Francßaise de Pharmacologie et de The rapeutique ª 2014 Socie Fundamental & Clinical Pharmacology 28 (2014) 690–699
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ranges were used. The low and high calibration ranges were validated for 1–1000 and 20–20000 ng/mL, respectively. For determination of setipiprant in plasma in the low calibration range, 300 lL of methanol containing a concentration of 30 ng/mL internal standard (i.e., deuterated analogue of setipiprant) was added to a 100 lL plasma sample. The samples were mixed and centrifuged, and 200 lL of supernatant was transferred to and autosampler vial. For the determination of setipiprant in plasma in the high calibration range, 300 lL of methanol containing a concentration of 600 ng/mL internal standard was added to a 100 l plasma sample. The samples were mixed and centrifuged, and 100 lL of supernatant was diluted with 900 lL acetonitrile/water (50/50 v/v) and 10 lL was transferred to an autosampler vial. For determination of setipiprant in urine, samples were mixed and centrifuged for 10 min at approximately 1500 g and 8 °C. To an aliquot of 100 lL human urine, 300 lL of methanol containing a concentration of 100 ng/mL internal standard was added. Subsequently, samples were mixed for 5 min and centrifuged for 20 min at approximately 1500 g. Of this, 5 lL of the filtrate was injected onto the column. During the analysis, all samples were stored at 8 °C in the autosampler tray. Quantification of setipiprant was performed using a validated liquid chromatography coupled to tandem mass spectrometry assay operating in the positive ionization detection mode. For plasma, the interday coefficients of variation were below 8.0 and 7.0% and intraday coefficients of variation were below 13.7 and 9.8%, for the low and high calibration range, respectively. For urine, the interday and intraday coefficients of variation were below 6.0 and 8.5%, respectively. Data analysis Tolerability parameters were analyzed descriptively. Per study part, all placebo-treated subjects in the different treatment groups were pooled for analysis of tolerability. Calculation of model-independent PK parameters of setipiprant was performed using Professional WinNonlin version 5.2. (Pharsight Corp., Mountain View, CA, USA). The maximum observed plasma concentration (Cmax) and the time to the occurrence of Cmax (tmax) were obtained directly from the plasma concentration– time curves. The area under the plasma concentration–time curve from time zero to time t of the last measured concentration above the limit of quantification (LOQ) (AUC0–t) was calculated according to the linear trapezoidal rule using the measured concentrate Francßaise de Pharmacologie et de The rapeutique ª 2014 Socie Fundamental & Clinical Pharmacology 28 (2014) 690–699
tion–time values above the LOQ. The area under the plasma concentration–time curve from zero to infinity (AUC0–∞) was calculated by combining AUC0–t and AUCextra. AUCextra represents an extrapolated value obtained by Ct/kZ, where Ct is the last plasma concentration measured above the LOQ and kZ represents the elimination rate constant determined by log-linear regression analysis of the measured plasma concentrations of the terminal elimination phase. The half-life of setipiprant was calculated as follows: t½ = ln 2/kZ. Additionally in part B, trough levels of setipiprant were used to investigate the time to attainment of steady-state conditions. This was carried out by visual inspection of the mean trough plasma concentration– time profile. AUCs was calculated according to the linear trapezoidal rule using the measured concentration–time values above the LOQ during one dosing interval. The accumulation index was calculated by dividing AUCs on Day 6 by the AUCs on Day 1. All AUC and Cmax values were assumed to be log-normally distributed. From the setipiprant urine concentrations, the percentage of total dose excreted in urine and the renal clearance (CLR) were calculated. CLR was calculated by dividing the total amount of unchanged drug excreted during the collection interval t after study drug intake by AUC0–t. The % of total dose excreted unchanged in urine was calculated as: (the total amount excreted/ dose administered) 9 100%. Statistical analysis Dose proportionality of setipiprant PKs was explored by comparing Cmax and AUC values, corrected for dose and log transformed, using a power model described by Gough et al. [22]. Furthermore, the individual Cmax and AUC values were log-normalized, dose-corrected, and subjected to linear regression using GraphPad Prism software version 5 (GraphPad Software Inc., La Jolla, CA, USA). Differences in the plasma PK variables Cmax and AUC0–∞ in Part A between fasted and fed state were investigated using the two-sided 90% confidence interval (CI) of the ratio of geometric means. RESULTS Single ascending doses In Part A of the study, 56 healthy male subjects (age range: 18–41 years) were included. All subjects received study drug according to the protocol, completed the study and were included in the tolerability
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and PK analysis. The demographics were similar in all dose groups studied. No serious adverse events (SAEs) were reported in Part A of the study. Under fasted conditions, of the 42 subjects treated with setipiprant, 21 subjects reported a total of 30 AEs, whereas of the 14 subjects treated with placebo, three reported a total of six AEs. In the presence of food, the same numbers of AEs (i.e., 4) were reported when compared with the same subjects in the fasted condition. Overall, few AEs were reported of which headache was reported the most frequently (i.e., 15 cases; Table I). No dose–response relationship was detected for any AE. All AEs were of mild intensity and resolved without sequelae. No treatment-related pattern was detected to suggest an effect of setipiprant on vital signs, clinical laboratory (including liver function test parameters) or urinalysis parameters. No treatment-emergent ECG abnormalities were identified or reported by the investigator. There were no clinically relevant differences compared with placebo in mean PQ, QT and QTc intervals. In addition, the absence of any ECG abnormalities was confirmed by an independent reviewer. Setipiprant could be detected in plasma after a single dose of 5 mg. Following this dose, most of the individual plasma concentration–time profiles showed irregular absorption. Therefore, Cmax and tmax results in this dose group should be interpreted with caution. The plasma concentration–time profiles of setipiprant revealed that, in general, peak plasma concentrations were reached between 2 and 3 h after administration
Plasma concentration setipiprant (ng/mL)
15 000 2000 mg 1000 mg 400 mg 200 mg 100 mg 25 mg 5 mg
12 500 10 000 7500 5000 2500 0 0
4
8
12 16 20 24 28 32 36 40 44 48
Scheduled time (h)
Figure 1 Mean plasma concentration vs. time profiles of setipiprant in healthy subjects (n = 6 per group).
(Figure 1). Thereafter, the disposition of setipiprant followed a rapid distribution phase and a slower phase of elimination, with an apparent terminal half-life of approximately 10 h. A summary of the PK parameters is presented in Table II. A graphical representation of exploration for dose proportionality of the PK of setipiprant is shown in Figure 2. Results of the Gough test indicated that dose had an effect on Cmax and AUC0–∞. Therefore, the PKs of setipiprant after single-dose administration were not dose proportional over the tested dose range. At higher doses, a less-than-doseproportional increase in Cmax and AUC0–∞ occurred. Based on the plasma concentration–time profile, a b.i.d.
Table I Overview of reported main adverse events (AEs) by treatment after single-dose (Part A) or multiple-dose (Part B) administration of setipiprant or placebo. Part A
Part B
Treatment (mg setipiprant or placebo)
Treatment (mg setipiprant or placebo b.i.d.)
200 5
25
Headache
2
Dizziness
–
Diarrhea
Placebo
Placebo
fasted
fed
500
1000
Placebo
3
–
1
1
3
2
1
1
–
–
1
–
–
2
–
–
–
–
–
–
–
–
2
–
–
–
–
1
–
–
–
–
–
–
–
–
–
1
–
–
–
1
–
–
1
–
–
–
–
–
–
–
–
–
–
–
2
–
–
–
–
–
–
1
1
100
fasted
200 fed
400
1000
2000
–
–
2
3
1
3
–
1
–
–
1
1
–
–
1
–
–
–
Abdominal pain
–
–
–
–
–
Dyspepsia
–
–
–
1
–
Malaise
–
–
–
1
–
–
Somnolence
1
–
–
–
–
Catheter-site-
–
–
–
–
–
–
–
–
–
–
–
related reaction Catheter-site pain
Number of subjects reporting AEs in Part A: for setipiprant N = 6 per dose or placebo N = 14 for fasted and N = 2 for fed condition; in Part B N = 6 per group. Only AEs reported by more than one subject are displayed. AEs reported more than once by the same subject were counted once.
te Francßaise de Pharmacologie et de The rapeutique ª 2014 Socie Fundamental & Clinical Pharmacology 28 (2014) 690–699
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Setipiprant in healthy male subjects
Table II Plasma pharmacokinetic parameters of single-dose setipiprant in healthy subjects. Dose (mg)
Condition
N
Cmax (ng/mL)
tmax (h)
5
Fasted
6
21.1 (11.3, 39.7)
4.0 (2.1–6.0)
155 (85.5, 282)
188 (102, 344)
8.2 (4.4, 15.6)
25
Fasted
6
209 (171, 254)
3.0 (2.1–5.0)
1431 (1128, 1816)
1459 (1153, 1845)
8.3 (6.5, 10.6)
100
Fasted
6
1140 (673, 1932)
2.6 (1.5–5.0)
5383 (4034, 7182)
5444 (4097, 7233)
10 (9.1, 11.0)
200
Fasted
6
2449 (1792, 3347)
2.1 (2.1–5.0)
9704 (6362, 14799)
9792 (6433, 14905)
Fed
6
619 (411, 934)
5.0 (5.0–6.0)
4766 (3578, 6348)
4895 (3666, 6538)
400
Fasted
6
4154 (2952, 5847)
3.0 (2.1–5.0)
18200 (13317, 24872)
18312 (13411, 25006)
9.3 (7.7, 11.2)
1000
Fasted
6
8322 (5047, 13723)
2.6 (1.5–4.0)
33895 (24589, 46723)
34159 (24720, 47202)
10.2 (7.2, 14.6)
2000
Fasted
6
12629 (6566, 24292)
1.8 (1.1–5.0)
48904 (25596, 93437)
49507 (25987, 94312)
10.7 (8.3, 13.7)
AUC0–t (ng h/mL)
t1/2 (h)
AUC0–∞ (ng h/mL)
10 (8.9, 11.3) 10.6 (9.6, 11.8)
Data are expressed as geometric means (and 95% CI) or for tmax the median (and range).
100
AUC0-α∞ α∞/dose (ng.h/ml/mg)
15 10 5
80 60 40 20
dosing regimen would be appropriate for further clinical studies. After a high-fat, high-calorie standardized breakfast, the absorption of setipiprant was slower compared with fasted conditions as indicated by a median tmax that shifted from approximately 2 h in the fasted condition to 5 h in the fed condition. Under fed conditions, Cmax and AUC0–∞ decreased by approximately 75 and 50%, respectively. Geometric mean ratios (and 90% CI) were 0.25 (0.18–0.38) and 0.5 (0.36–0.69) for Cmax and AUC0–∞. The apparent terminal half-life did not change and remained approximately 10 h (Table II). For all dose groups,
Fundamental & Clinical Pharmacology
ORIGINAL ARTICLE
Single- and multiple-dose tolerability and pharmacokinetics of the CRTH2 antagonist setipiprant in healthy male subjects Patricia N. Sidhartaa*, Zuzana Diamantb, Jasper Dingemansea a Department of Clinical Pharmacology, Actelion Pharmaceuticals Ltd., Gewerbestrasse 16, 4123 Allschwil, Switzerland b Centre for Human Drug Research, Zernikedreef 8, 2333, CL Leiden, The Netherlands
Keywords CRTH2, entry-into-human study, multiple dose, pharmacokinetics, setipiprant, single dose
Received 5 April 2013; revised 3 April 2014; accepted 11 April 2014
*Correspondence and reprints: [email protected]
ABSTRACT
Chemoattractant receptor-homologous molecule expressed on T helper (Th) 2 cells (CRTH2) is a G-protein-coupled receptor for prostaglandin D2 (PGD2), a key mediator in inflammatory disorders such as asthma and allergic rhinitis. In this study, we investigated the single- and multiple-dose tolerability and pharmacokinetics (PKs) of setipiprant, an orally active, potent, and selective CRTH2 antagonist. This randomized, double-blind, placebo-controlled study was performed in two parts in healthy male subjects. In study Part A, single oral doses of up to 2000 mg setipiprant or placebo were given to sequential groups of eight subjects each. Additionally, the impact of food on the PKs was investigated in one-dose group. In study Part B, two groups of subjects received 500 or 1000 mg setipiprant or placebo b.i.d. during 5.5 days. At regular intervals, tolerability variables and plasma and urine levels of setipiprant were determined. Setipiprant was well tolerated after single- and multiple-dose administration. Headache was the most frequently reported adverse event. No treatment effect on tolerability variables was observed. After single- and multiple-dose administration, setipiprant was rapidly absorbed and followed a biphasic elimination pattern with an elimination half-life between 10 and 18 h. Steady-state conditions were reached after 2–3 days and setipiprant did not accumulate. Exposure to setipiprant was lower in the presence of food. Urinary excretion of unchanged setipiprant did not exceed 7% of the administered dose. In this entry-into-human study, setipiprant showed good tolerability and a favorable PK profile, thus warranting its development in the treatment of inflammatory disorders.
INTRODUCTION The prostanoid prostaglandin D2 (PGD2) is an important pro-inflammatory mediator involved in the pathophysiology of immunoglobulin (IG) E-dependent responses, characteristic of an array of allergic diseases such as asthma, atopic dermatitis and allergic rhinitis [1–4]. In sensitized patients, PGD2 is produced through de novo synthesis via the 5-lipoxygenase pathway of arachidonic acid by dendritic cells, mast cells and T helper
690
(Th)2 cells upon exposure to relevant allergens. Subsequently, this bioactive mediator can exert its proinflammatory activities related to allergic diseases through interaction with various G-protein-coupled receptors (GPCR) [1,5,6]. CRTH2 receptors, which have been recently discovered, are expressed on Th2 cells, eosinophils and basophils all being key effector cells in allergic responses [7]. In vitro, activation of CRTH2 induced migration of these cells. CRTH2 has been suggested to be a reliable marker for circulating Th2 cells [8]. Further, activation of CRTH2 by PGD2 induced te Francßaise de Pharmacologie et de The rapeutique ª 2014 Socie Fundamental & Clinical Pharmacology 28 (2014) 690–699
691
Setipiprant in healthy male subjects
interleukin (IL)-4, IL-5 and IL-13 production of Th2 cells in humans [9–11]. Both IL-4 and IL-13 induce adhesion molecule expression on the endothelial cell layer of blood vessels, leading to increased adhesiveness for eosinophils and activated Th2 cells. IL-5 mobilizes eosinophil precursors from the bone marrow, leading to eosinophilia. IL-13 is a key factor for tissue remodeling and airway hypersensitivity [12,13]. CRTH2 antagonists are drugs currently in clinical development, interacting with the CRTH2 receptor on inflammatory cells. As such, CRTH2 antagonists may counteract the pathophysiological effects of PGD2, the subsequent recruitment of Th2 cells, eosinophils, and basophils, and the production of the pro-inflammatory products at a high hierarchical level [5,14–16]. Thus, CRTH2 antagonism would be expected to have a controlling effect on both short- and long-term aspects of the allergic inflammation [7]. Based on their mechanistic properties and systemic activity, CRTH2 antagonists may be suitable for the treatment of allergic diseases, such as allergic asthma that presents in up to 80% with concomitant allergic rhinitis (the so-called combined allergic rhinitis and asthma syndrome (CARAS) or rhinasthma patients) [17]. Present guidelines recommend topical corticosteroids as first-line therapy for both asthma and (concomitant) allergic rhinitis [17,18] and targeted therapy with systemic leukotriene receptor antagonists (LTRA) as second-line treatment for rhinasthma [17]. CRTH2 antagonists act more upstream within the inflammatory cascade of allergic conditions and, hence, are expected to be more efficacious than LTRA offering a safe alternative to topical corticosteroids, with the comfort of oral medication [19]. Setipiprant (ACT-129968) (2-(2-(1-naphthoyl)-8-fluoro-3,4-dihydro-1H-pyrido[4,3-b]indol-5(2H)-yl)acetic acid), a tetrahydropyridoindole derivative, is a new, potent, orally active, selective antagonist of CRTH2 [20]. Setipiprant showed effective blockade of PGD2induced activation of eosinophils and basophils, inhibited cytokine secretion by PGD2-stimulated human Th2 cells, and inhibited the migration of eosinophils toward PGD2 in several studies in vitro [20]. The inhibition of eosinophil migration was also demonstrated in a rat model of lung eosinophilia. Thus, setipiprant could be a promising approach to the treatment of allergic inflammatory disorders. In this entry-into-human study, we investigated the tolerability and pharmacokinetics (PKs) of single and multiple ascending doses of this new compound in te Francßaise de Pharmacologie et de The rapeutique ª 2014 Socie Fundamental & Clinical Pharmacology 28 (2014) 690–699
healthy male subjects over a wide dose range and in the presence and absence of food. MATERIALS AND METHODS Study subjects In this study (AC-060-101/EudraCT number 2006006777-25), 73 male subjects were included after giving written informed consent. Subjects had to be between 18 and 45 years of age could only receive one treatment and were not allowed to re-enter another dose group. Subjects were healthy as assessed by medical history, physical examination, ECG, vital signs and clinical laboratory tests. They could not participate if they smoked, had a prior history of drug or alcohol abuse, were allergic to any drugs, were using any medication or had participated in another clinical trial during the 3-month period preceding the screening examination. The study followed the principles of the Declaration of Helsinki and Good Clinical Practice, and the protocol was approved by an independent Ethics Committee (CME, Leiden, the Netherlands). Study design The study had a two-part (a single ascending dose part and a multiple ascending dose part, respectively), single-center, randomized, double-blind, placebo-controlled design. Part A (the single ascending dose part) consisted of seven successive groups of eight healthy subjects receiving a single dose of setipiprant. In each dose group, after an overnight fast, six subjects received setipiprant in ascending doses of 5, 25, 100, 200, 400, 1000 and 2000 mg setipiprant, while two subjects received a matching placebo. To investigate the effect of food on the tolerability and PKs of setipiprant, subjects in the 200 mg dose-level group returned to the clinic after a 1–2 weeks washout and received the same single administration of study treatment after consuming a high-fat, high-calorie standardized breakfast [21]. Subjects stayed in the clinic from approximately 12 h before until 48 h after the intake of study drug, during which time tolerability assessments were performed and blood samples were taken for the determination of PK parameters. Urine was collected during two 24-h intervals after drug intake. Part B (the multiple ascending dose part) consisted of two successive groups of eight subjects receiving multiple doses of setipiprant for 5.5 days. In each dose
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group, 6 subjects received a dose of 500 mg or 1000 mg setipiprant b.i.d. and two subjects received matching placebo in fasted condition. Subjects received their first dose of study drug in the morning on Day 1 and the last study drug in the morning on Day 6. The doses and dosing regimen were selected based on the results of Part A and were based on the rationale to establish a wide dose range at which setipiprant would be well tolerated. The area under the plasma concentration–time curve during a dosing interval (AUCs) of the highest dose of 1000 mg setipiprant b.i.d. was, based on simulation of steady-state conditions, not to exceed the AUCs of the highest tolerated dose in Part A (i.e., 2000 mg). To ensure safety of the subjects, an intermediate dosing regimen (i.e., 500 mg setipiprant b.i.d.) was selected to be investigated prior to initiation of the 1000 mg setipiprant b.i.d. group. Subjects stayed in the clinic from approximately 12 h before the first study drug intake until 48 h after the last study drug intake (total of 9 days), during which time tolerability assessments were performed and blood samples were taken for the determination of PK parameters. Similarly, urine was collected during 12 h following the first and last drug intake for determination of PK parameters. After each dose group, the tolerability was evaluated to decide whether the next higher-dose group could proceed. Part B was started after evaluation of Part A of the study. End-of-study assessments were performed within 48 h after the last blood sample was taken for PK. Tolerability measurements All adverse events (AE) that occurred after drug administration and up to the end-of-study examination were recorded together with the intensity, time of onset, duration and relationship to the treatment. Part A: A physical examination and body weight measurements were performed at screening and at the end-of-study. Vital signs (supine and standing systolic and diastolic blood pressure and pulse rate) were measured at screening, immediately prior to and 1, 2, 4, 9, 24 and 36 h after study drug administration, and at the end-of-study. A 12-lead ECG was recorded at screening, immediately prior to and 1, 2, 4, 9 and 24 h after study drug administration, and at the endof-study. Routine laboratory parameters (blood and urine) were assessed at screening, immediately prior to study drug intake, 24 h after study drug administration, and at the end-of-study. For the 200 mg dose group, a follow-up visit was conducted within 48 h
P.N. Sidharta et al.
after last blood sampling in the fasted condition, which included physical examination, body weight measurement, vital signs, 12-lead ECG and routine laboratory parameters. Part B: A physical examination and body weight measurement were performed at screening and at the end-of-study. Vital signs (supine and standing systolic and diastolic blood pressure and pulse rate) were measured at screening, immediately prior to and 1, 2, 3 and 5 h after first drug administration, predose from Day 1 evening administration to Day 6 morning administration and 1, 2, 3, 5, 12 and 24 h after last administration on Day 6 (morning administration) and at the end-of-study. A 12-lead ECG was recorded at screening, on Day 1 immediately prior to and 2, 3 and 5 h after first drug administration, predose Day 1 evening administration, predose Day 2, 4 and 6 morning administration, and 2, 3, 5, 12 and 24 h after last administration on Day 6 (morning administration) and at the end-ofstudy. Routine laboratory parameters (blood and urine) were assessed at screening, predose to the morning drug intake on Day 1, 4, 6 and at the end-of-study. Pharmacokinetic assessments For the determination of setipiprant in plasma, venous blood samples (4 mL each) were collected in tubes containing EDTA as anticoagulant. Following centrifugation at 1500 g for 10 min at 4 °C, plasma was separated and frozen at 40 °C pending analysis. Samples were protected from light at all times. In Part A, plasma samples were taken predose on Day 1 and 0.5, 1, 1.5, 2, 3, 4, 5, 6, 9, 13, 18, 24, 36 and 48 h after drug intake. In Part B, plasma samples were collected immediately prior to first dose on Day 1, 0.5, 1, 1.5, 2, 3, 4, 5, 6 and 9 h postmorning dose on Day 1, predose starting from Day 1 evening administration up to Day 6 morning administration and 0.5, 1, 1.5, 2, 3, 4, 5, 6, 9, 12, 14, 20, 24, 36 and 48 h postmorning dose on Day 6. For the determination of setipiprant in urine, urine was collected during two 24-h intervals after study drug intake in Part A, and during 12 h after the first and last drug administration in Part B. After each collection interval, the total volume was measured and an aliquot of 24 mL was taken and stored at 40 °C pending analysis. Bioanalytical methods Samples were protected from light at all times. For the quantification of setipiprant in plasma, two calibration te Francßaise de Pharmacologie et de The rapeutique ª 2014 Socie Fundamental & Clinical Pharmacology 28 (2014) 690–699
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ranges were used. The low and high calibration ranges were validated for 1–1000 and 20–20000 ng/mL, respectively. For determination of setipiprant in plasma in the low calibration range, 300 lL of methanol containing a concentration of 30 ng/mL internal standard (i.e., deuterated analogue of setipiprant) was added to a 100 lL plasma sample. The samples were mixed and centrifuged, and 200 lL of supernatant was transferred to and autosampler vial. For the determination of setipiprant in plasma in the high calibration range, 300 lL of methanol containing a concentration of 600 ng/mL internal standard was added to a 100 l plasma sample. The samples were mixed and centrifuged, and 100 lL of supernatant was diluted with 900 lL acetonitrile/water (50/50 v/v) and 10 lL was transferred to an autosampler vial. For determination of setipiprant in urine, samples were mixed and centrifuged for 10 min at approximately 1500 g and 8 °C. To an aliquot of 100 lL human urine, 300 lL of methanol containing a concentration of 100 ng/mL internal standard was added. Subsequently, samples were mixed for 5 min and centrifuged for 20 min at approximately 1500 g. Of this, 5 lL of the filtrate was injected onto the column. During the analysis, all samples were stored at 8 °C in the autosampler tray. Quantification of setipiprant was performed using a validated liquid chromatography coupled to tandem mass spectrometry assay operating in the positive ionization detection mode. For plasma, the interday coefficients of variation were below 8.0 and 7.0% and intraday coefficients of variation were below 13.7 and 9.8%, for the low and high calibration range, respectively. For urine, the interday and intraday coefficients of variation were below 6.0 and 8.5%, respectively. Data analysis Tolerability parameters were analyzed descriptively. Per study part, all placebo-treated subjects in the different treatment groups were pooled for analysis of tolerability. Calculation of model-independent PK parameters of setipiprant was performed using Professional WinNonlin version 5.2. (Pharsight Corp., Mountain View, CA, USA). The maximum observed plasma concentration (Cmax) and the time to the occurrence of Cmax (tmax) were obtained directly from the plasma concentration– time curves. The area under the plasma concentration–time curve from time zero to time t of the last measured concentration above the limit of quantification (LOQ) (AUC0–t) was calculated according to the linear trapezoidal rule using the measured concentrate Francßaise de Pharmacologie et de The rapeutique ª 2014 Socie Fundamental & Clinical Pharmacology 28 (2014) 690–699
tion–time values above the LOQ. The area under the plasma concentration–time curve from zero to infinity (AUC0–∞) was calculated by combining AUC0–t and AUCextra. AUCextra represents an extrapolated value obtained by Ct/kZ, where Ct is the last plasma concentration measured above the LOQ and kZ represents the elimination rate constant determined by log-linear regression analysis of the measured plasma concentrations of the terminal elimination phase. The half-life of setipiprant was calculated as follows: t½ = ln 2/kZ. Additionally in part B, trough levels of setipiprant were used to investigate the time to attainment of steady-state conditions. This was carried out by visual inspection of the mean trough plasma concentration– time profile. AUCs was calculated according to the linear trapezoidal rule using the measured concentration–time values above the LOQ during one dosing interval. The accumulation index was calculated by dividing AUCs on Day 6 by the AUCs on Day 1. All AUC and Cmax values were assumed to be log-normally distributed. From the setipiprant urine concentrations, the percentage of total dose excreted in urine and the renal clearance (CLR) were calculated. CLR was calculated by dividing the total amount of unchanged drug excreted during the collection interval t after study drug intake by AUC0–t. The % of total dose excreted unchanged in urine was calculated as: (the total amount excreted/ dose administered) 9 100%. Statistical analysis Dose proportionality of setipiprant PKs was explored by comparing Cmax and AUC values, corrected for dose and log transformed, using a power model described by Gough et al. [22]. Furthermore, the individual Cmax and AUC values were log-normalized, dose-corrected, and subjected to linear regression using GraphPad Prism software version 5 (GraphPad Software Inc., La Jolla, CA, USA). Differences in the plasma PK variables Cmax and AUC0–∞ in Part A between fasted and fed state were investigated using the two-sided 90% confidence interval (CI) of the ratio of geometric means. RESULTS Single ascending doses In Part A of the study, 56 healthy male subjects (age range: 18–41 years) were included. All subjects received study drug according to the protocol, completed the study and were included in the tolerability
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and PK analysis. The demographics were similar in all dose groups studied. No serious adverse events (SAEs) were reported in Part A of the study. Under fasted conditions, of the 42 subjects treated with setipiprant, 21 subjects reported a total of 30 AEs, whereas of the 14 subjects treated with placebo, three reported a total of six AEs. In the presence of food, the same numbers of AEs (i.e., 4) were reported when compared with the same subjects in the fasted condition. Overall, few AEs were reported of which headache was reported the most frequently (i.e., 15 cases; Table I). No dose–response relationship was detected for any AE. All AEs were of mild intensity and resolved without sequelae. No treatment-related pattern was detected to suggest an effect of setipiprant on vital signs, clinical laboratory (including liver function test parameters) or urinalysis parameters. No treatment-emergent ECG abnormalities were identified or reported by the investigator. There were no clinically relevant differences compared with placebo in mean PQ, QT and QTc intervals. In addition, the absence of any ECG abnormalities was confirmed by an independent reviewer. Setipiprant could be detected in plasma after a single dose of 5 mg. Following this dose, most of the individual plasma concentration–time profiles showed irregular absorption. Therefore, Cmax and tmax results in this dose group should be interpreted with caution. The plasma concentration–time profiles of setipiprant revealed that, in general, peak plasma concentrations were reached between 2 and 3 h after administration
Plasma concentration setipiprant (ng/mL)
15 000 2000 mg 1000 mg 400 mg 200 mg 100 mg 25 mg 5 mg
12 500 10 000 7500 5000 2500 0 0
4
8
12 16 20 24 28 32 36 40 44 48
Scheduled time (h)
Figure 1 Mean plasma concentration vs. time profiles of setipiprant in healthy subjects (n = 6 per group).
(Figure 1). Thereafter, the disposition of setipiprant followed a rapid distribution phase and a slower phase of elimination, with an apparent terminal half-life of approximately 10 h. A summary of the PK parameters is presented in Table II. A graphical representation of exploration for dose proportionality of the PK of setipiprant is shown in Figure 2. Results of the Gough test indicated that dose had an effect on Cmax and AUC0–∞. Therefore, the PKs of setipiprant after single-dose administration were not dose proportional over the tested dose range. At higher doses, a less-than-doseproportional increase in Cmax and AUC0–∞ occurred. Based on the plasma concentration–time profile, a b.i.d.
Table I Overview of reported main adverse events (AEs) by treatment after single-dose (Part A) or multiple-dose (Part B) administration of setipiprant or placebo. Part A
Part B
Treatment (mg setipiprant or placebo)
Treatment (mg setipiprant or placebo b.i.d.)
200 5
25
Headache
2
Dizziness
–
Diarrhea
Placebo
Placebo
fasted
fed
500
1000
Placebo
3
–
1
1
3
2
1
1
–
–
1
–
–
2
–
–
–
–
–
–
–
–
2
–
–
–
–
1
–
–
–
–
–
–
–
–
–
1
–
–
–
1
–
–
1
–
–
–
–
–
–
–
–
–
–
–
2
–
–
–
–
–
–
1
1
100
fasted
200 fed
400
1000
2000
–
–
2
3
1
3
–
1
–
–
1
1
–
–
1
–
–
–
Abdominal pain
–
–
–
–
–
Dyspepsia
–
–
–
1
–
Malaise
–
–
–
1
–
–
Somnolence
1
–
–
–
–
Catheter-site-
–
–
–
–
–
–
–
–
–
–
–
related reaction Catheter-site pain
Number of subjects reporting AEs in Part A: for setipiprant N = 6 per dose or placebo N = 14 for fasted and N = 2 for fed condition; in Part B N = 6 per group. Only AEs reported by more than one subject are displayed. AEs reported more than once by the same subject were counted once.
te Francßaise de Pharmacologie et de The rapeutique ª 2014 Socie Fundamental & Clinical Pharmacology 28 (2014) 690–699
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Table II Plasma pharmacokinetic parameters of single-dose setipiprant in healthy subjects. Dose (mg)
Condition
N
Cmax (ng/mL)
tmax (h)
5
Fasted
6
21.1 (11.3, 39.7)
4.0 (2.1–6.0)
155 (85.5, 282)
188 (102, 344)
8.2 (4.4, 15.6)
25
Fasted
6
209 (171, 254)
3.0 (2.1–5.0)
1431 (1128, 1816)
1459 (1153, 1845)
8.3 (6.5, 10.6)
100
Fasted
6
1140 (673, 1932)
2.6 (1.5–5.0)
5383 (4034, 7182)
5444 (4097, 7233)
10 (9.1, 11.0)
200
Fasted
6
2449 (1792, 3347)
2.1 (2.1–5.0)
9704 (6362, 14799)
9792 (6433, 14905)
Fed
6
619 (411, 934)
5.0 (5.0–6.0)
4766 (3578, 6348)
4895 (3666, 6538)
400
Fasted
6
4154 (2952, 5847)
3.0 (2.1–5.0)
18200 (13317, 24872)
18312 (13411, 25006)
9.3 (7.7, 11.2)
1000
Fasted
6
8322 (5047, 13723)
2.6 (1.5–4.0)
33895 (24589, 46723)
34159 (24720, 47202)
10.2 (7.2, 14.6)
2000
Fasted
6
12629 (6566, 24292)
1.8 (1.1–5.0)
48904 (25596, 93437)
49507 (25987, 94312)
10.7 (8.3, 13.7)
AUC0–t (ng h/mL)
t1/2 (h)
AUC0–∞ (ng h/mL)
10 (8.9, 11.3) 10.6 (9.6, 11.8)
Data are expressed as geometric means (and 95% CI) or for tmax the median (and range).
100
AUC0-α∞ α∞/dose (ng.h/ml/mg)
15 10 5
80 60 40 20
dosing regimen would be appropriate for further clinical studies. After a high-fat, high-calorie standardized breakfast, the absorption of setipiprant was slower compared with fasted conditions as indicated by a median tmax that shifted from approximately 2 h in the fasted condition to 5 h in the fed condition. Under fed conditions, Cmax and AUC0–∞ decreased by approximately 75 and 50%, respectively. Geometric mean ratios (and 90% CI) were 0.25 (0.18–0.38) and 0.5 (0.36–0.69) for Cmax and AUC0–∞. The apparent terminal half-life did not change and remained approximately 10 h (Table II). For all dose groups,
