Pharmacological properties : תכונות פרמקולוגיות

Pharmacodynamic Properties

5.1   Pharmacodynamic properties

Pharmacotherapeutic group: Immunosuppressants, interleukin inhibitors, ATC code: L04AC08 
Mechanism of action
Canakinumab is a human monoclonal anti-human interleukin-1beta (IL-1beta) antibody of the IgG1/k isotype. Canakinumab binds with high affinity specifically to human IL-1beta and neutralises the biological activity of human IL-1 beta by blocking its interaction with IL-1 receptors, thereby preventing IL-1 beta-induced gene activation and the production of inflammatory mediators.
Pharmacodynamic effects
CAPS, TRAPS, HIDS/MKD and FMF

ILA API MAR17 CL V6                                        REF EMA SmPC APP 2.3.17 In clinical studies, CAPS, TRAPS, HIDS/MKD and FMF patients who have uncontrolled overproduction of IL-1 beta show a rapid and sustained response to therapy with canakinumab, i.e. laboratory parameters such as high C-reactive protein (CRP) and serum amyloid A (SAA), high neutrophil and platelet counts, and leukocytosis rapidly returned to normal.

SJIA
Systemic juvenile idiopathic arthritis is a severe autoinflammatory disease, driven by innate immunity by means of pro-inflammatory cytokines, a key one being IL-1beta.
Common features of SJIA include fever, rash, hepatosplenomegaly, lymphadenopathy, polyserositis and arthritis. Treatment with canakinumab resulted in a rapid and sustained improvement of both the articular and the systemic features of SJIA with significant reduction of the number of inflamed joints, prompt resolution of fever and reduction of acute phase reactants in the majority of patients (see Clinical efficacy and safety).

Gouty arthritis
A gouty arthritis attack is caused by urate (monosodium urate monohydrate) crystals in the joint and surrounding tissue, which trigger resident macrophages to produce IL-1 beta via the “NALP3 inflammasome” complex. Activation of macrophages and concomitant over-production of IL-1 beta results in an acute painful inflammatory response. Other activators of the innate immune system, such as endogenous agonists of toll-like receptors, may contribute to the transcriptional activation of the IL-1 beta gene, initiating a gouty arthritis attack. Following canakinumab treatment, the inflammatory markers CRP or SAA and signs of acute inflammation (e.g. pain, swelling, redness) in the affected joint subside rapidly.

Clinical efficacy and safety
CAPS
The efficacy and safety of Ilaris have been demonstrated in patients with varying degrees of disease severity and different CAPS phenotypes (including FCAS/FCU, MWS, and NOMID/CINCA). Only patients with confirmed NLRP3 mutation were included in the pivotal study.

In the Phase I/II study, treatment with Ilaris had a rapid onset of action, with disappearance or clinically significant improvement of symptoms within one day after dosing. Laboratory parameters such as high CRP and SAA, high neutrophils and platelet counts normalised rapidly within days of Ilaris injection.

The pivotal study consisted of a 48-week three-part multicentre study, i.e. an 8-week open-label period (Part I), a 24-week randomised, double-blind, placebo-controlled withdrawal period (Part II), followed by a 16-week open-label period (Part III). The aim of the study was to assess efficacy, safety, and tolerability of Ilaris (150 mg or 2 mg/kg every 8 weeks) in patients with CAPS.

      Part I: A complete clinical and biomarker response to Ilaris (defined as composite of physician’s global assessment on autoinflammatory and on skin disease ≤ minimal and CRP or SAA values < 10 mg/litre) was observed in 97% of patients and appeared within 7 days of initiation of treatment. Significant improvements were seen in physician’s clinical assessment of autoinflammatory disease activity: global assessment of autoinflammatory disease activity, assessment of skin disease (urticarial skin rash), arthralgia, myalgia, headache/migraine, conjunctivitis, fatigue/malaise, assessment of other related symptoms, and patient’s assessment of symptoms.

      Part II: In the withdrawal period of the pivotal study, the primary endpoint was defined as the proportion of patients with a disease relapse/flare: none (0%) of the patients randomised to Ilaris flared, compared with 81% of the patients randomised to placebo.

      Part III: Patients treated with placebo in Part II who flared regained and maintained clinical and serological response following entry into the open-label Ilaris extension.
ILA API MAR17 CL V6                                        REF EMA SmPC APP 2.3.17 

Table 2      Tabulated summary of efficacy in Phase III trial, pivotal placebo-controlled withdrawal period (Part II)

Phase III trial, pivotal placebo-controlled withdrawal period (Part II) Ilaris          Placebo
N=15             N=16                p-value n(%)             n(%)

Primary endpoint (flare)
Proportion of patients with disease flare in              0 (0%)             13 (81%)       < 0.001 Part II

Inflammatory markers*
C-reactive protein, mg/l                                 1.10 (0.40)       19.93 (10.50)     < 0.001 Serum amyloid A, mg/l                                    2.27 (-0.20)      71.09 (14.35)      0.002 * mean (median) change from beginning of Part II

Two open-label, uncontrolled, long-term phase III studies were performed. One was a safety, tolerability, and efficacy study of canakinumab in patients with CAPS. The total treatment duration ranged from 6 months to 2 years. The other was an open-label study with canakinumab to evaluate the efficacy and safety in Japanese CAPS patients for 24 weeks, with an extension phase up to 48 weeks. The primary objective was to assess the proportion of patients who were free of relapse at week 24, including those patients whose dose was increased.

In the pooled efficacy analysis for these two studies, 65.6% of patients who had not previously been treated with canakinumab achieved complete response at 150 mg or 2 mg/kg, while 85.2% of patients achieved complete response at any dose. Of the patients treated with 600 mg or 8 mg/kg (or even higher), 43.8% achieved complete response. Fewer patients aged 2 to < 4 years achieved complete response
(57.1%) than older paediatric and adult patients. Of the patients who had achieved a complete response, 89.3% maintained response without relapsing.
Experience from individual patients who achieved a complete response following dose escalation to 600 mg (8 mg/kg) every 8 weeks suggests that a higher dose may be beneficial in patients not achieving complete response or not maintaining complete response with the recommended doses (150 mg or 2 mg/kg for patients ≥ 15 kg and ≤ 40 kg). An increased dose was administered more frequently to patients aged 2 to < 4 years and to patients with NOMID/CINCA symptoms compared with FCAS or MWS.

Paediatric population
The CAPS trials with Ilaris included a total of 80 paediatric patients with an age range from 2 to 17 years (approximately half of them treated on an mg/kg basis). Overall, there were no clinically meaningful differences in the efficacy, safety and tolerability profile of Ilaris in paediatric patients compared to the overall CAPS population . The majority of paediatric patients achieved improvement in clinical symptoms and objective markers of inflammation (e.g. SAA and CRP).

A 56-week, open-label study was conducted to assess the efficacy, safety and tolerability of Ilaris in paediatric CAPS patients ≤4 years of age. Seventeen patients (including 6 patients under the age of 2 years) were evaluated, using weight-based starting doses of 2-8 mg/kg. The study also evaluated the effect of canakinumab on the development of antibodies to standard childhood vaccines. No differences in safety or efficacy were observed in patients under the age of 2 years compared with patients aged 2 years ILA API MAR17 CL V6                                       REF EMA SmPC APP 2.3.17 and above. All patients who received non-live, standard of care childhood vaccinations (N=7) developed protective antibody levels.

TRAPS, HIDS/MKD and FMF
The efficacy and safety of Ilaris for the treatment of TRAPS, HIDS/MKD and FMF were demonstrated in a single, pivotal, phase III, 4-part study (N2301) consisting of three separate disease cohorts.
-    Part I: Patients in each disease cohort aged 2 years and older entered a 12-week screening period during which they were evaluated for the onset of disease flare.
-      Part II: Patients at flare onset were randomised into a 16-week double-blind, placebo-controlled treatment period during which they received either 150 mg Ilaris (2 mg/kg for patients with body weight ≤ 40 kg) subcutaneous (s.c.) or placebo every 4 weeks. Patients > 28 days but < 2 years of age were allowed to enter the study directly into an open-arm of part II as non-randomised patients (and were excluded from the primary efficacy analysis).
-      Part III: Patients who completed 16 weeks of treatment and were classified as responders were re- randomised into a 24-week, double-blind withdrawal period during which they received Ilaris 150 mg (2 mg/kg for patients ≤ 40 kg) s.c. or placebo every 8 weeks.
-      Part IV: All Part III patients treated with Ilaris were eligible to enter into a 72-week open-label treatment extension period.

A total of 185 patients aged 28 days and above were enrolled and a total of 181 patients aged       2 years and above were randomised in part II of the study.

The primary efficacy endpoint of the randomised treatment period (Part II) was the proportion of responders within each cohort who had resolution of their index disease flare at day 15 and did not experience a new flare during the remainder of the 16-week treatment period (defined as complete response). Resolution of the index disease flare was defined as having a Physician’s Global Assessment (PGA) of Disease Activity score < 2 (“minimal or no disease”) and CRP within normal range (≤ 10 mg/l) or reduction ≥ 70% from baseline. A new flare was defined as a PGA score ≥ 2 (“mild, moderate, or severe disease”) and CRP ≥ 30 mg/l. Secondary endpoints, all based on week 16 results (end of Part II), included the proportion of patients who achieved a PGA score of < 2, the proportion of patients with serological remission (defined as CRP ≤ 10 mg/l), and the proportion of patients with a normalised SAA level (defined as SAA ≤ 10 mg/l).

For the primary efficacy endpoint, Ilaris was superior to placebo for all three disease cohorts. Ilaris also demonstrated superior efficacy compared to placebo on the secondary endpoints of PGA < 2 and CRP ≤ 10 mg/l in all three cohorts. Higher proportions of patients had normalised SAA (≤ 10 mg/l) at week 16 with Ilaris treatment compared to placebo in all three cohorts, with a statistically significant difference observed in TRAPS patients (see Table 3 with study results below).


ILA API MAR17 CL V6                                       REF EMA SmPC APP 2.3.17 Table 3      Tabulated summary of efficacy in Phase III trial, pivotal, randomised, placebo- controlled treatment period (Part II)

Phase III trial, pivotal, randomised placebo-controlled treatment period (Part II) Ilaris                Placebo n/N (%)                 n/N (%)               p-value
Primary endpoint (disease flare) - Proportion of patients who had index disease flare resolution at day 15 and did not experience a new flare during the remainder of the 16-week treatment period FMF                                                19/31 (61.29)             2/32 (6.25)          < 0.0001* HIDS/MKD                                           13/37 (35.14)             2/35 (5.71)            0.0020* TRAPS                                              10/22 (45.45)             2/24 (8.33)            0.0050* Secondary endpoints (disease and inflammatory markers)
Physician Global Assessment < 2
FMF                                                20/31 (64.52)             3/32 (9.38)          < 0.0001** HIDS/MKD                                           17/37 (45.95)             2/35 (5.71)           0.0006** TRAPS                                              10/22 (45.45)             1/24 (4.17)           0.0028** C-reactive protein ≤ 10 mg/l
FMF                                                21/31 (67.74)             2/32 (6.25)          < 0.0001** HIDS/MKD                                           15/37 (40.54)             2/35 (5.71)           0.0010** TRAPS                                               8/22 (36.36)             2/24 (8.33)           0.0149** Serum amyloid A ≤ 10 mg/l
FMF                                                 8/31 (25.81)             0/32 (0.00)             0.0286 HIDS/MKD                                            5/37 (13.51)             1/35 (2.86)             0.0778 TRAPS                                               6/22 (27.27)             0/24 (0.00)           0.0235** n=number of responders; N=number of evaluable patients
* indicates statistical significance (one-sided) at the 0.025 level based on Fisher exact test **Indicates statistical significance (one-sided) at the 0.025 level based on the logistic regression model with treatment group and baseline PGA, CRP or SAA respectively, as explanatory variables for each cohort

Up-titration
In Part II of the study, patients treated with Ilaris who had persistent disease activity received an additional dose of 150 mg (or 2 mg/kg for patients ≤ 40 kg) within the first month. This additional dose could be provided as early as 7 days after the first treatment dose. All up-titrated patients remained at the increased dose of 300 mg (or 4 mg/kg for patients ≤ 40 kg) every 4 weeks.

In an exploratory analysis of the primary endpoint, it was observed that in patients with an inadequate response after the first dose, an up-titration within the first month to a dose of 300 mg (or 4 mg/kg) every 4 weeks further improved flare control, reduced disease activity and normalised CRP and SAA levels.


Paediatric patients:
Two non-randomised HIDS/MKD patients aged > 28 days but < 2 years were included in the study and received canakinumab. One patient had resolution of index flare by day 15 after receiving one single dose of canakinumab 2 mg/kg, but discontinued treatment after this first dose due to serious adverse events (pancytopenia and hepatic failure). This patient presented at study entry with a history of immune thrombocytopenic purpura and an active medical condition of abnormal hepatic function. The second patient received a starting dose of canakinumab 2 mg/kg and an add-on dose of 2 mg/kg at week 3, and was up-titrated at week 5 to receive a dose of 4 mg/kg administered every 4 weeks until the end of Part II of the study. Resolution of disease flare was achieved by week 5 and the patient had not experienced any new flare at the end of Part II of the study (week 16).
ILA API MAR17 CL V6                                        REF EMA SmPC APP 2.3.17 
SJIA
The efficacy of Ilaris for the treatment of active SJIA was assessed in two pivotal studies (G2305 and G2301). Patients enrolled were aged 2 to < 20 years (mean age of 8.5 years and mean disease duration of 3.5 years at baseline) and had active disease defined as ≥ 2 joints with active arthritis, fever and elevated CRP.

Study G2305
Study G2305 was a randomised, double-blind, placebo-controlled, 4-week study assessing the short-term efficacy of Ilaris in 84 patients randomised to receive a single dose of 4 mg/kg (up to 300 mg) Ilaris or placebo. The primary objective was the proportion of patients at day 15 who achieved a minimum 30% improvement in the paediatric American College of Rheumatology (ACR) response criterion adapted to include absence of fever. Ilaris treatment improved all paediatric ACR response scores as compared to placebo at days 15 and 29 (Table 4).

Table 4      Paediatric ACR response and disease status at days 15 and 29 
Day 15                                   Day 29
Ilaris           Placebo               Ilaris            Placebo
N=43              N=41                 N=43               N=41
ACR30                                   84%                10%                 81%                10% ACR50                                   67%                 5%                 79%                 5% ACR70                                   61%                 2%                 67%                 2% ACR90                                   42%                 0%                 47%                 2% ACR100                                  33%                 0%                 33%                 2% Inactive disease                        33%                 0%                 30%                 0% Treatment difference for all ACR scores was significant (p ≤ 0.0001) 
Results for the components of the adapted paediatric ACR which included systemic and arthritic components, were consistent with the overall ACR response results. At day 15, the median change from baseline in the number of joints with active arthritis and limited range of motion were -67% and -73% for Ilaris (N=43), respectively, compared to a median change of 0% and 0% for placebo (N=41). The mean change in patient pain score (0-100 mm visual analogue scale) at day 15 was -50.0 mm for Ilaris (N=43), as compared to +4.5 mm for placebo (N=25). The mean change in pain score among Ilaris treated patients was consistent at day 29.

Study G2301
Study G2301 was a randomised, double-blind, placebo-controlled withdrawal study of flare prevention by Ilaris. The study consisted of two parts with two independent primary endpoints (successful steroid taper and time to flare). In Part I (open label) 177 patients were enrolled and received 4 mg/kg (up to 300 mg) Ilaris administered every 4 weeks for up to 32 weeks. Patients in Part II (double-blind) received either Ilaris 4 mg/kg or placebo every 4 weeks until 37 flare events occurred.

Corticosteroid dose tapering:
Of the total 128 patients who entered Part I taking corticosteroids, 92 attempted corticosteroid tapering.
Fifty-seven (62%) of the 92 patients who attempted to taper were able to successfully taper their corticosteroid dose and 42 (46%) discontinued corticosteroids.

Time to flare:
Patients taking Ilaris in Part II had a 64% reduced risk of a flare event as compared to the placebo group (hazard ratio of 0.36; 95% CI: 0.17 to 0.75; p=0.0032). Sixty-three of the 100 patients entering Part II, whether assigned to placebo or canakinumab, did not experience a flare over the observation period (up to a maximum of 80 weeks).

Health-related and quality of life outcomes in studies G2305 and G2301 Treatment with Ilaris resulted in clinically relevant improvements in patients’ physical function and ILA API MAR17 CL V6                                        REF EMA SmPC APP 2.3.17 quality of life. In study G2305, the Childhood Health Assessment Questionnaire Least Squares means improvement was 0.69 for Ilaris vs placebo representing 3.6 times the minimal clinically important difference of 0.19 (p=0.0002). The median improvement from baseline to end of Part I of study G2301 was 0.88 (79%). Statistically significant improvements in the Child Health Questionnaire-PF50 scores were reported for Ilaris vs placebo in study G2305 (physical p=0.0012; psychosocial well-being p=0.0017).

Pooled efficacy analysis
Data from the first 12 weeks of Ilaris treatment from studies G2305, G2301 and the extension study were pooled to assess maintenance of efficacy. These data showed similar improvements from baseline to week 12 in the adapted paediatric ACR responses and its components to those observed in the placebo controlled study (G2305). At week 12, the adapted paediatric ACR30, 50, 70, 90 and 100 responses were: 70%, 69%, 61%, 49% and 30%, respectively and 28% of patients had inactive disease (N=178).

The efficacy observed in the studies G2305 and G2301 was maintained in the ongoing, open-label long- term extension study (data available through median of 49 weeks of follow-up). In this study, 25 patients who had a strong ACR response for a minimum of 5 months reduced their Ilaris dose to 2 mg/kg every 4 weeks and maintained a paediatric ACR100 response throughout the time the reduced dose was given
(median 32 weeks, 8-124 weeks).

Although limited, evidence from the clinical trials suggests that patients not responding to tocilizumab or anakinra, may respond to canakinumab.

SJIA in young adults
Efficacy of Ilaris in a subset of young adult SJIA patients aged 16 to 20 years was consistent with the efficacy observed for patients less than 16 years of age.

Gouty arthritis
The efficacy of Ilaris for the treatment of acute gouty arthritis attacks was demonstrated in two multicentre, randomised, double-blind, active-controlled studies in patients with frequent gouty arthritis (≥ 3 attacks in the previous 12 months) unable to use NSAIDs or colchicine (due to contraindication, intolerance or lack of efficacy). The studies were 12 weeks followed by 12-week double-blind extension.
A total of 225 patients were treated with subcutaneous Ilaris 150 mg and 229 patients were treated with intramuscular triamcinolone acetonide (TA) 40 mg at study entry, and when experiencing a new attack thereafter. The mean number of gouty arthritis attacks in the previous 12 months was 6.5. Over 85% of patients had comorbidity, including hypertension (60%), diabetes (15%), ischaemic heart disease (12%), and stage ≥ 3 chronic kidney disease (25%). Approximately one-third of the patients enrolled (76 [33.8%] in the Ilaris group and 84 [36.7%] in the triamcinolone acetonide group) had documented inability (intolerance, contraindication or lack of response) to use both NSAIDs and colchicine. Concomitant treatment with ULTs was reported by 42% of patients at entry.

The co-primary endpoints were: (i) gouty arthritis pain intensity (visual analogue scale, VAS) at 72 hours post-dose, and (ii) time to first new gouty arthritis attack.

For the overall study population, pain intensity was statistically significantly lower for Ilaris 150 mg compared with triamcinolone acetonide at 72 hours. Ilaris also reduced the risk of subsequent attacks (see Table 5).

Efficacy results in a subgroup of patients unable to use both NSAIDs and colchicine and who were on ULT, failed ULT or had a contraindication to ULT (N=101) were consistent with the overall study population with a statistically significant difference compared to triamcinolone acetonide in pain intensity at 72 hours (-10.2 mm, p=0.0208) and in reduction of risk of subsequent attacks (Hazard ratio 0.39, p=0.0047 at 24 weeks).

Efficacy results for a more stringent subgroup limited to current users of ULT (N=62) are presented in ILA API MAR17 CL V6                                       REF EMA SmPC APP 2.3.17 Table 5. Treatment with Ilaris induced a reduction of pain and reduced the risk of subsequent attacks in patients using ULT and unable to use both NSAIDs and colchicine, although the observed treatment difference compared to triamcinolone acetonide was less pronounced than with the overall study population.

Table 5      Efficacy for the overall study population and in a subgroup of patients currently using ULT and unable to use both NSAIDs and colchicine

Efficacy endpoint                          Overall study population; Unable to use both NSAIDs N=454             and colchicine; on ULT
N=62
Treatment of gouty arthritis attacks as measured by pain intensity (VAS) at 72 h Least Squares mean estimated                       -10.7                          -3.8 difference to triamcinolone acetonide
CI                                              (-15.4, -6.0)                 (-16.7, 9.1) p-value, 1-sided                                p < 0.0001*                    p=0.2798 Risk reduction of subsequent gouty arthritis attacks as measured by time to first new flare (24 weeks)
Hazard ratio to triamcinolone                       0.44                          0.71 acetonide
CI                                              (0.32, 0.60)                  (0.29, 1.77) p-value, 1-sided                                p < 0.0001*                    p=0.2337 * Denotes significant p-value < 0.025

Safety results showed an increased incidence of adverse events for canakinumab compared to triamcinolone acetonide, with 66% vs 53% of patients reporting any adverse event and 20% vs 10% of patients reporting an infection adverse event over 24 weeks.
Elderly population
Overall, the efficacy, safety and tolerability profile of Ilaris in elderly patients ≥ 65 years of age was comparable to patients < 65 years of age.

Patients on urate lowering therapy (ULT)
In clinical studies, Ilaris has been safely administered with ULT. In the overall study population, patients on ULT had a less pronounced treatment difference in both pain reduction and reduction in the risk of subsequent gouty arthritis attacks compared to patients not on ULT.

Immunogenicity
Antibodies against Ilaris were observed in approximately 1.5%, 3% and 2% of the patients treated with Ilaris for CAPS, SJIA and gouty arthritis, respectively. No neutralising antibodies were detected.
No apparent correlation of antibody development to clinical response or adverse events was observed.

There were no antibodies against Ilaris observed in TRAPS, HIDS/MKD and FMF patients treated with doses of 150 mg and 300 mg over 16 weeks of treatment.

Pharmacokinetic Properties

5.2 Pharmacokinetic properties
CAPS
Absorption
The peak serum canakinumab concentration (Cmax) occurred approximately 7 days following single subcutaneous administration of 150 mg in adult CAPS patients. The mean terminal half-life was 26 days.
Mean values for Cmax and AUCinf after a single subcutaneous dose of 150 mg in a typical adult CAPS patient (70 kg) were 15.9 µg/ml and 708 µg*d/ml. The absolute bioavailability of subcutaneously administered canakinumab was estimated to be 66%. Exposure parameters (such as AUC and Cmax) increased in proportion to dose over the dose range of 0.30 to 10.0 mg/kg given as intravenous infusion or from 150 to 600 mg as subcutaneous injection. Predicted steady-state exposure values (Cmin,ss, Cmax,ss, ILA API MAR17 CL V6                                       REF EMA SmPC APP 2.3.17 AUC,ss,8w) after 150 mg subcutaneous administration (or 2 mg/kg, respectively) every 8 weeks were slightly higher in the weight category 40-70 kg (6.6 µg/ml, 24.3 µg/ml, 767 µg*d/ml) compared to the weight categories < 40 kg (4.0 µg/ml, 19.9 µg/ml, 566 µg*d/ml) and > 70 kg (4.6 µg/ml, 17.8 µg/ml, 545 µg*d/ml). The expected accumulation ratio was 1.3-fold following 6 months of subcutaneous administration of 150 mg canakinumab every 8 weeks.

Distribution
Canakinumab binds to serum IL-1 beta. The distribution volume (Vss) of canakinumab varied according to body weight. It was estimated to be 6.2 litres in a CAPS patient of body weight 70 kg.

Elimination
The apparent clearance (CL/F) of canakinumab increases with body weight. It was estimated to be 0.17 l/day in a CAPS patient of body weight 70 kg and 0.11 L/day in a SJIA patient of body weight 33 kg.
After accounting for body weight differences, no clinically significant differences in the pharmacokinetic properties of canakinumab were observed between CAPS and SJIA patients.

There was no indication of accelerated clearance or time-dependent change in the pharmacokinetic properties of canakinumab following repeated administration. No gender or age-related pharmacokinetic differences were observed after correction for body weight.

TRAPS, HIDS/MKD and FMF
Bioavailability in TRAPS, HIDS/MKD and FMF patients has not been determined independently.
Apparent clearance (CL/F) in the TRAPS, HIDS/MKD and FMF population at body weight of 55 kg (0.14 l/d) was comparable to CAPS population at body weight of 70 kg (0.17 l/d). The apparent volume of distribution (V/F) was 4.96 l at body weight of 55 kg.

After repeated subcutaneous administration of 150 mg every 4 weeks, canakinumab minimal concentration at week 16 (Cmin) was estimated to be 15.4 ± 6.6 g/ml. The estimated steady state AUCtau was 636.7 ± 260.2 μg*d/ml.

SJIA
Bioavailability in SJIA patients has not been determined independently. Apparent clearance per kg body weight (CL/F per kg) was comparable between the SJIA and CAPS population (0.004 l/d per kg). The apparent volume of distribution per kg (V/F per kg) was 0.14 l/kg.

After repeated administration of 4 mg/kg every 4 weeks the accumulation ratio of canakinumab was 1.6 fold in SJIA patients. Steady state was reached after 110 days. The overall predicted mean (±SD) for Cmin,ss, Cmax,ss and AUC,ss4w were 14.7±8.8 μg/ml, 36.5 ± 14.9 μg/ml and 696.1 ± 326.5 μg*d/ml, respectively.

The AUCss4w in each age group was, 615, 707 and 742 µg*d/ml for 2-3, 4-5, 6-11, and 12-19 years old, respectively. When stratified by weight, a lower (30-40%) median of exposure for Cmin,ss (11.4 vs 19 µg/ml) and AUCss (594 vs 880 µg*d/ml) for the lower bodyweight category (≤ 40 kg) vs the higher bodyweight category (> 40 kg) was observed.

Based on the population pharmacokinetic modelling analysis, the pharmacokinetics of canakinumab in young adult SJIA patients aged 16 to 20 years were similar to those in patients less than 16 years of age.
Predicted canakinumab steady state exposures at a dose level of 4 mg/kg (maximum 300 mg) in patients over the age of 20 years were comparable to those in SJIA patients younger than 20 years of age.

Gouty arthritis population
Bioavailability in gouty arthritis patients has not been determined independently. Apparent clearance per ILA API MAR17 CL V6                                       REF EMA SmPC APP 2.3.17 kg body weight (CL/F per kg) was comparable between the gouty arthritis and CAPS population (0.004 l/d/kg). Mean exposure in a typical gouty arthritis patient (93 kg) after a single subcutaneous 150 mg dose (Cmax: 10.8 µg/ml and AUCinf: 495 µg*d/ml) was lower than in a typical 70 kg CAPS patient (15.9 µg/ml and 708 µg*d/ml). This is consistent with the observed increase in CL/F with body weight.

The expected accumulation ratio was 1.1-fold following subcutaneous administration of 150 mg canakinumab every 12 weeks.

Paediatric population
Peak concentrations of canakinumab occurred between 2 to 7 days (Tmax) following single subcutaneous administration of canakinumab 150 mg or 2 mg/kg in paediatric patients 4 years of age and older. The terminal half-life ranged from 22.9 to 25.7 days, similar to the pharmacokinetic properties observed in adults. Based on the population pharmacokinetic modelling analysis, the pharmacokinetics of canakinumab in children aged 2 to < 4 years were similar to those in patients 4 years of age and older.
Subcutaneous absorption rate was estimated to decrease with age and appeared to be fastest in the youngest patients. Accordingly, Tmax was shorter (3.6 days) in younger SJIA patients (2-3 years) compared to older SJIA patients (12-19 years; Tmax 6 days). Bioavailability (AUCss) was not affected.

An additional pharmacokinetics analysis showed that the pharmacokinetics of canakinumab in 6 paediatric CAPS patients under the age of 2 years were similar to the pharmacokinetics in paediatric patients 2-4 years of age. Based on the population pharmacokinetic modelling analysis, the expected exposures after a dose of 2 mg/kg were comparable across the CAPS paediatric age groups, but were approximately 40% lower in paediatric patients of very low body weight (e.g. 10 kg) than in adult patients (150 mg dose).
This is consistent with the observations of higher exposure in higher body weight groups in CAPS patients.

In TRAPS, HIDS/MKD and FMF, exposure parameters (trough concentrations) were comparable across age groups from 2 to < 20 years old following subcutaneous administration of canakinumab 2 mg/kg every 4 weeks.

Pharmacokinetic properties are similar in CAPS, TRAPS, HIDS/MKD, FMF and SJIA paediatric populations.

Elderly population
No change in pharmacokinetic parameters based on clearance or volume of distribution were observed between elderly patients and adult patients < 65 years of age.