CLINICAL PHARMACOLOGY
Mechanism Of Action
Adalimumab binds specifically to TNF-alpha and blocks its interaction with the p55 and p75 cell surface TNF receptors. Adalimumab also lyses surface TNF expressing cells in vitro in the presence of complement. Adalimumab does not bind or inactivate lymphotoxin (TNF-beta). TNF is a naturally occurring cytokine that is involved in normal inflammatory and immune responses. Elevated levels of TNF are found in the synovial fluid of patients with RA, JIA, PsA, and AS and play an important role in both the pathologic inflammation and the joint destruction that are hallmarks of these diseases. Increased levels of TNF are also found in psoriasis plaques. In Ps, treatment with adalimumab may reduce the epidermal thickness and infiltration of inflammatory cells. The relationship between these pharmacodynamic activities and the mechanism(s) by which adalimumab exerts its clinical effects is unknown.
Adalimumab also modulates biological responses that are induced or regulated by TNF, including changes in the levels of adhesion molecules responsible for leukocyte migration (ELAM-1, VCAM-1, and ICAM-1 with an IC50 of 1-2 X 10-10 M).
Pharmacodynamics
After treatment with adalimumab, a decrease in levels of acute phase reactants of inflammation (C- reactive protein [CRP] and erythrocyte sedimentation rate [ESR]) and serum cytokines (IL-6) was observed compared to baseline in patients with rheumatoid arthritis. A decrease in CRP levels was also observed in patients with Crohn's disease and ulcerative colitis. Serum levels of matrix metalloproteinases (MMP-1 and MMP-3) that produce tissue remodeling responsible for cartilage destruction were also decreased after adalimumab administration.
Pharmacokinetics
The maximum serum concentration (Cmax) and the time to reach the maximum concentration (Tmax) were 4.7 ± 1.6 μg/mL and 131 ± 56 hours respectively, following a single 40 mg subcutaneous administration of adalimumab to healthy adult subjects. The average absolute bioavailability of adalimumab estimated from three studies following a single 40 mg subcutaneous dose was 64%. The pharmacokinetics of adalimumab were linear over the dose range of 0.5 to 10.0 mg/kg following a single intravenous dose.
The single dose pharmacokinetics of adalimumab in RA patients were determined in several studies with intravenous doses ranging from 0.25 to 10 mg/kg. The distribution volume (Vss) ranged from 4.7 to 6.0 L. The systemic clearance of adalimumab is approximately 12 mL/hr. The mean terminal half-life was approximately 2 weeks, ranging from 10 to 20 days across studies. Adalimumab concentrations in the synovial fluid from five rheumatoid arthritis patients ranged from 31 to 96% of those in serum.
In RA patients receiving 40 mg adalimumab every other week, adalimumab mean steady-state trough concentrations of approximately 5 μg/mL and 8 to 9 μg/mL, were observed without and with methotrexate (MTX), respectively. MTX reduced adalimumab apparent clearance after single and multiple dosing by 29% and 44% respectively, in patients with RA. Mean serum adalimumab trough levels at steady state increased approximately proportionally with dose following 20, 40, and 80 mg every other week and every week subcutaneous dosing. In long- term studies with dosing more than two years, there was no evidence of changes in clearance over time.
Adalimumab mean steady-state trough concentrations were slightly higher in psoriatic arthritis patients treated with 40 mg adalimumab every other week (6 to 10 μg/mL and 8.5 to 12 μg/mL, without and with MTX, respectively) compared to the concentrations in RA patients treated with the same dose.
The pharmacokinetics of adalimumab in patients with AS were similar to those in patients with RA.
In patients with CD, the loading dose of 160 mg adalimumab on Week 0 followed by 80 mg adalimumab on Week 2 achieves mean serum adalimumab trough levels of approximately 12 μg/mL at Week 2 and Week 4. Mean steady-state trough levels of approximately 7 μg/mL were observed at Week 24 and Week 56 in CD patients after receiving a maintenance dose of 40 mg adalimumab every other week.
In patients with UC, the loading dose of 160 mg adalimumab on Week 0 followed by 80 mg adalimumab on Week 2 achieves mean serum adalimumab trough levels of approximately 12 μg/mL at Week 2 and Week 4. Mean steady-state trough level of approximately 8 μg/mL was observed at Week 52 in UC patients after receiving a dose of 40 mg adalimumab every other week, and approximately 15 μg/mL at Week 52 in UC patients who increased to a dose of 40 mg adalimumab every week.
In patients with Ps, the mean steady-state trough concentration was approximately 5 to 6 μg/mL during adalimumab 40 mg every other week monotherapy treatment.
Population pharmacokinetic analyses in patients with RA revealed that there was a trend toward higher apparent clearance of adalimumab in the presence of anti-adalimumab antibodies, and lower clearance with increasing age in patients aged 40 to >75 years.
Minor increases in apparent clearance were also predicted in RA patients receiving doses lower than the recommended dose and in RA patients with high rheumatoid factor or CRP concentrations. These increases are not likely to be clinically important.
No gender-related pharmacokinetic differences were observed after correction for a patient's body weight. Healthy volunteers and patients with rheumatoid arthritis displayed similar adalimumab pharmacokinetics.
No pharmacokinetic data are available in patients with hepatic or renal impairment.
In Study JIA-I for patients with polyarticular JIA who were 4 to 17 years of age, the mean steady-state trough serum adalimumab concentrations for patients weighing <30 kg receiving 20 mg adalimumab subcutaneously every other week as monotherapy or with concomitant MTX were 6.8 μg/mL and 10.9 μg/mL, respectively. The mean steady-state trough serum adalimumab concentrations for patients weighing ≥30 kg receiving 40 mg adalimumab subcutaneously every other week as monotherapy or with concomitant MTX were 6.6 μg/mL and 8.1 μg/mL, respectively.
Clinical Studies
Rheumatoid Arthritis
The efficacy and safety of adalimumab were assessed in five randomized, double-blind studies in patients ≥18 years of age with active rheumatoid arthritis (RA) diagnosed according to American College of Rheumatology (ACR) criteria. Patients had at least 6 swollen and 9 tender joints. Adalimumab was administered subcutaneously in combination with methotrexate (MTX) (12.5 to 25 mg, Studies RA-I, RA-III and RA-V) or as monotherapy (Studies RA-II and RA-V) or with other disease-modifying anti-rheumatic drugs (DMARDs) (Study RA-IV).
Study RA-I evaluated 271 patients who had failed therapy with at least one but no more than four DMARDs and had inadequate response to MTX. Doses of 20, 40 or 80 mg of adalimumab or placebo were given every other week for 24 weeks.
Study RA-II evaluated 544 patients who had failed therapy with at least one DMARD. Doses of placebo, 20 or 40 mg of adalimumab were given as monotherapy every other week or weekly for 26 weeks.
Study RA-III evaluated 619 patients who had an inadequate response to MTX. Patients received placebo, 40 mg of adalimumab every other week with placebo injections on alternate weeks, or 20 mg of adalimumab weekly for up to 52 weeks. Study RA-III had an additional primary endpoint at 52 weeks of inhibition of disease progression (as detected by X-ray results). Upon completion of the first 52 weeks, 457 patients enrolled in an open-label extension phase in which 40 mg of adalimumab was administered every other week for up to 5 years.
Study RA-IV assessed safety in 636 patients who were either DMARD-naive or were permitted to remain on their pre-existing rheumatologic therapy provided that therapy was stable for a minimum of 28 days. Patients were randomized to 40 mg of adalimumab or placebo every other week for 24 weeks.
Study RA-V evaluated 799 patients with moderately to severely active RA of less than 3 years duration who were ≥18 years old and MTX naïve. Patients were randomized to receive either MTX (optimized to 20 mg/week by week 8), adalimumab 40 mg every other week or adalimumab /MTX combination therapy for 104 weeks. Patients were evaluated for signs and symptoms, and for radiographic progression of joint damage. The median disease duration among patients enrolled in the study was 5 months. The median MTX dose achieved was 20 mg.
Clinical Response
The percent of adalimumab treated patients achieving ACR 20, 50 and 70 responses in Studies RA- II and III are shown in Table 2.
Table 2. ACR Responses in Studies RA-II and RA-III (Percent of Patients)
Response | Study RA-II Monotherapy (26 weeks) | Study RA-III Methotrexate Combination (24 and 52 weeks) |
Placebo | Adalimumab 40 mg every other week | Adalimumab 40 mg weekly | Placebo/MTX | Adalimumab/MTX 40 mg every other week |
N=110 | N=113 | N=103 | N=200 | N=207 |
ACR20 | | | | | |
Month 6 | 19% | 46%* | 53%* | 30% | 63%* |
Month 12 | NA | NA | NA | 24% | 59%* |
ACR50 | | | | | |
Month 6 | 8% | 22%* | 35%* | 10% | 39%* |
Month 12 | NA | NA | NA | 10% | 42%* |
ACR70 | | | | | |
Month 6 | 2% | 12%* | 18%* | 3% | 21%* |
Month 12 | NA | NA | NA | 5% | 23%* |
* p<0.01, adalimumab vs. placebo |
The results of Study RA-I were similar to Study RA-III; patients receiving adalimumab 40 mg every other week in Study RA-I also achieved ACR 20, 50 and 70 response rates of 65%, 52% and 24%, respectively, compared to placebo responses of 13%, 7% and 3% respectively, at 6 months (p<0.01).
The results of the components of the ACR response criteria for Studies RA-II and RA-III are shown in Table 3. ACR response rates and improvement in all components of ACR response were maintained to week 104. Over the 2 years in Study RA-III, 20% of adalimumab patients receiving 40 mg every other week (EOW) achieved a major clinical response, defined as maintenance of an ACR 70 response over a 6-month period. ACR responses were maintained in similar proportions of patients for up to 5 years with continuous adalimumab treatment in the open- label portion of Study RA-III.
Table 3. Components of ACR Response in Studies RA-II and RA-III
| Study RA-II | Study RA-III |
Parameter (median) | Placebo N=110 | Adalimumaba N=113 | Placebo/MTX N=200 | Adalimumaba/MTX N=207 |
| Baseline | Wk 26 | Baseline | Wk 26 | Baseline | Wk 24 | Baseline | Wk 24 |
Number of tender joints (0-68) | 35 | 26 | 31 | 16* | 26 | 15 | 24 | 8* |
Number of swollen joints (0-66) | 19 | 16 | 18 | 10* | 17 | 11 | 18 | 5* |
Physician global assessmentb | 7.0 | 6.1 | 6.6 | 3.7* | 6.3 | 3.5 | 6.5 | 2.0* |
Patient global assessmentb | 7.5 | 6.3 | 7.5 | 4.5* | 5.4 | 3.9 | 5.2 | 2.0* |
Painb | 7.3 | 6.1 | 7.3 | 4.1* | 6.0 | 3.8 | 5.8 | 2.1* |
Disability index (HAQ)c | 2.0 | 1.9 | 1.9 | 1.5* | 1.5 | 1.3 | 1.5 | 0.8* |
CRP (mg/dL) | 3.9 | 4.3 | 4.6 | 1.8* | 1.0 | 0.9 | 1.0 | 0.4* |
a 40 mg adalimumab administered every other week b Visual analogue scale; 0 = best, 10 = worst c Disability Index of the Health Assessment Questionnaire; 0 = best, 3 = worst, measures the patient's ability to perform the following: dress/groom, arise, eat, walk, reach, grip, maintain hygiene, and maintain daily activity * p<0.001, adalimumab vs. placebo, based on mean change from baseline |
The time course of ACR 20 response for Study RA-III is shown in Figure 1.
In Study RA-III, 85% of patients with ACR 20 responses at week 24 maintained the response at 52 weeks. The time course of ACR 20 response for Study RA-I and Study RA-II were similar.
Figure 1. Study RA-III ACR 20 Responses over 52 Weeks
In Study RA-IV, 53% of patients treated with adalimumab 40 mg every other week plus standard of care had an ACR 20 response at week 24 compared to 35% on placebo plus standard of care (p<0.001). No unique adverse reactions related to the combination of adalimumab and other DMARDs were observed.
In Study RA-V with MTX naïve patients with recent onset RA, the combination treatment with adalimumab plus MTX led to greater percentages of patients achieving ACR responses than either MTX monotherapy or adalimumab monotherapy at Week 52 and responses were sustained at Week 104 (see Table 4).
Table 4. ACR Response in Study RA-V (Percent of Patients)
Response | MTXb N=257 | Adalimumabc N=274 | Adalimumab/MTX N=268 |
ACR20 | | | |
Week 52 | 63% | 54% | 73% |
Week 104 | 56% | 49% | 69% |
ACR50 | | | |
Week 52 | 46% | 41% | 62% |
Week 104 | 43% | 37% | 59% |
ACR70 | | | |
Week 52 | 27% | 26% | 46% |
Week 104 | 28% | 28% | 47% |
Major Clinical Responsea | 28% | 25% | 49% |
a Major clinical response is defined as achieving an ACR70 response for a continuous six month period b p<0.05, adalimumab/MTX vs. MTX for ACR 20 p<0.001, adalimumab/MTX vs. MTX for ACR 50 and 70, and Major Clinical Response c p<0.001, adalimumab/MTX vs. adalimumab |
At Week 52, all individual components of the ACR response criteria for Study RA-V improved in the adalimumab/MTX group and improvements were maintained to Week 104.
Radiographic Response
In Study RA-III, structural joint damage was assessed radiographically and expressed as change in Total Sharp Score (TSS) and its components, the erosion score and Joint Space Narrowing (JSN) score, at month 12 compared to baseline. At baseline, the median TSS was approximately 55 in the placebo and 40 mg every other week groups. The results are shown in Table 5. Adalimumab/MTX treated patients demonstrated less radiographic progression than patients receiving MTX alone at 52 weeks.
Table 5. Radiographic Mean Changes Over 12 Months in Study RA-III
| Placebo/ MTX | Adalimumab/ MTX 40 mg every other week | Placebo/ MTX adalimumab/ MTX (95% Confidence Interval*) | P-value** |
Total Sharp score | 2.7 | 0.1 | 2.6 (1.4, 3.8) | <0.001 |
Erosion score | 1.6 | 0.0 | 1.6 (0.9, 2.2) | <0.001 |
JSN score | 1.0 | 0.1 | 0.9 (0.3, 1.4) | 0.002 |
* 95% confidence intervals for the differences in change scores between MTX and adalimumab. ** Based on rank analysis |
In the open-label extension of Study RA-III, 77% of the original patients treated with any dose of adalimumab were evaluated radiographically at 2 years. Patients maintained inhibition of structural damage, as measured by the TSS. Fifty-four percent had no progression of structural damage as defined by a change in the TSS of zero or less. Fifty-five percent (55%) of patients originally treated with 40 mg adalimumab every other week have been evaluated radiographically at 5 years. Patients had continued inhibition of structural damage with 50% showing no progression of structural damage defined by a change in the TSS of zero or less.
In Study RA-V, structural joint damage was assessed as in Study RA-III. Greater inhibition of radiographic progression, as assessed by changes in TSS, erosion score and JSN was observed in the adalimumab/MTX combination group as compared to either the MTX or adalimumab monotherapy group at Week 52 as well as at Week 104 (see Table 6).
Table 6. Radiographic Mean Change* in Study RA-V
| | MTXa N=257 | Adalimumaba,b N=274 | Adalimumab/ MTX N=268 |
52 Weeks | Total Sharp score | 5.7 (4.2, 7.3) | 3.0 (1.7, 4.3) | 1.3 (0.5, 2.1) |
| Erosion score | 3.7 (2.7, 4.8) | 1.7 (1.0, 2.4) | 0.8 (0.4, 1.2) |
| JSN score | 2.0 (1.2, 2.8) | 1.3 (0.5, 2.1) | 0.5 (0.0, 1.0) |
104 Weeks | Total Sharp score | 10.4 (7.7, 13.2) | 5.5 (3.6, 7.4) | 1.9 (0.9, 2.9) |
| Erosion score | 6.4 (4.6, 8.2) | 3.0 (2.0, 4.0) | 1.0 (0.4, 1.6) |
| JSN score | 4.1 (2.7, 5.4) | 2.6 (1.5, 3.7) | 0.9 (0.3, 1.5) |
* mean (95% confidence interval) a p<0.001, adalimumab/MTX vs. MTX at 52 and 104 weeks and for adalimumab/MTX vs. adalimumab at 104 weeks b p<0.01, for adalimumab/MTX vs. adalimumab at 52 weeks |
Physical Function Response
In studies RA-I through IV, adalimumab showed significantly greater improvement than placebo in the disability index of Health Assessment Questionnaire (HAQ-DI) from baseline to the end of study, and significantly greater improvement than placebo in the health-outcomes as assessed by The Short Form Health Survey (SF 36). Improvement was seen in both the Physical Component Summary (PCS) and the Mental Component Summary (MCS).
In Study RA-III, the mean (95% CI) improvement in HAQ-DI from baseline at week 52 was 0.60 (0.55, 0.65) for the adalimumab patients and 0.25 (0.17, 0.33) for placebo/MTX (p<0.001) patients. Sixty-three percent of adalimumab -treated patients achieved a 0.5 or greater improvement in HAQ-DI at week 52 in the double-blind portion of the study. Eighty-two percent of these patients maintained that improvement through week 104 and a similar proportion of patients maintained this response through week 260 (5 years) of open-label treatment. Mean improvement in the SF-36 was maintained through the end of measurement at week 156 (3 years).
In Study RA-V, the HAQ-DI and the physical component of the SF-36 showed greater improvement (p<0.001) for the adalimumab/MTX combination therapy group versus either the MTX monotherapy or the adalimumab monotherapy group at Week 52, which was maintained through Week 104.
Juvenile Idiopathic Arthritis
Study JIA-I
The safety and efficacy of adalimumab were assessed in a multicenter, randomized, withdrawal, double-blind, parallel-group study in 171 patients who were 4 to 17 years of age with polyarticular JIA. In the study, the patients were stratified into two groups: MTX-treated or non- MTX-treated. All patients had to show signs of active moderate or severe disease despite previous treatment with NSAIDs, analgesics, corticosteroids, or DMARDS. Patients who received prior treatment with any biologic DMARDS were excluded from the study.
The study included four phases: an open-label lead in phase (OL-LI; 16 weeks), a double-blind randomized withdrawal phase (DB; 32 weeks), an openlabel extension phase (OLE-BSA; up to 136 weeks), and an open-label fixed dose phase (OLE-FD; 16 weeks). In the first three phases of the study, adalimumab was administered based on body surface area at a dose of 24 mg/m2 up to a maximum total body dose of 40 mg subcutaneously (SC) every other week. In the OLE-FD phase, the patients were treated with 20 mg of adalimumab SC every other week if their weight was less than 30 kg and with 40 mg of adalimumab SC every other week if their weight was 30 kg or greater. Patients remained on stable doses of NSAIDs and or prednisone (≤0.2 mg/kg/day or 10 mg/day maximum).
Patients demonstrating a Pediatric ACR 30 response at the end of OL-LI phase were randomized into the double blind (DB) phase of the study and received either adalimumab or placebo every other week for 32 weeks or until disease flare. Disease flare was defined as a worsening of ≥30% from baseline in ≥3 of 6 Pediatric ACR core criteria, ≥2 active joints, and improvement of >30% in no more than 1 of the 6 criteria. After 32 weeks or at the time of disease flare during the DB phase, patients were treated in the open-label extension phase based on the BSA regimen (OLE- BSA), before converting to a fixed dose regimen based on body weight (OLE-FD phase).
Study JIA-I Clinical Response
At the end of the 16-week OL-LI phase, 94% of the patients in the MTX stratum and 74% of the patients in the non-MTX stratum were Pediatric ACR 30 responders. In the DB phase significantly fewer patients who received adalimumab experienced disease flare compared to placebo, both without MTX (43% vs. 71%) and with MTX (37% vs. 65%). More patients treated with adalimumab continued to show pediatric ACR 30/50/70 responses at Week 48 compared to patients treated with placebo. Pediatric ACR responses were maintained for up to two years in the OLE phase in patients who received adalimumab throughout the study.
Psoriatic Arthritis
The safety and efficacy of adalimumab was assessed in two randomized, double-blind, placebo controlled studies in 413 patients with psoriatic arthritis (PsA). Upon completion of both studies, 383 patients enrolled in an open-label extension study, in which 40 mg adalimumab was administered every other week.
Study PsA-I enrolled 313 adult patients with moderately to severely active PsA (>3 swollen and >3 tender joints) who had an inadequate response to NSAID therapy in one of the following forms: (1) distal interphalangeal (DIP) involvement (N=23); (2) polyarticular arthritis (absence of rheumatoid nodules and presence of plaque psoriasis) (N=210); (3) arthritis mutilans (N=1); (4) asymmetric PsA (N=77); or (5) AS-like (N=2). Patients on MTX therapy (158 of 313 patients) at enrollment (stable dose of ≤30 mg/week for >1 month) could continue MTX at the same dose. Doses of adalimumab 40 mg or placebo every other week were administered during the 24-week double-blind period of the study.
Compared to placebo, treatment with adalimumab resulted in improvements in the measures of disease activity (see Tables 7 and 8). Among patients with PsA who received adalimumab, the clinical responses were apparent in some patients at the time of the first visit (two weeks) and were maintained up to 88 weeks in the ongoing open-label study. Similar responses were seen in patients with each of the subtypes of psoriatic arthritis, although few patients were enrolled with the arthritis mutilans and ankylosing spondylitis-like subtypes. Responses were similar in patients who were or were not receiving concomitant MTX therapy at baseline.
Patients with psoriatic involvement of at least three percent body surface area (BSA) were evaluated for Psoriatic Area and Severity Index (PASI) responses. At 24 weeks, the proportions of patients achieving a 75% or 90% improvement in the PASI were 59% and 42% respectively, in the adalimumab group (N=69), compared to 1% and 0% respectively, in the placebo group (N=69) (p<0.001). PASI responses were apparent in some patients at the time of the first visit (two weeks). Responses were similar in patients who were or were not receiving concomitant MTX therapy at baseline.
Table 7. ACR Response in Study PsA-I (Percent of Patients)
| Placebo N=162 | Adalimumab* N=151 |
ACR20 | | |
Week 12 | 14% | 58% |
Week 24 | 15% | 57% |
ACR50 | | |
Week 12 | 4% | 36% |
Week 24 | 6% | 39% |
ACR70 | | |
Week 12 | 1% | 20% |
Week 24 | 1% | 23% |
* p<0.001 for all comparisons between adalimumab and placebo |
Table 8. Components of Disease Activity in Study PsA-I
| Placebo N=162 | Adalimumab* N=151 |
Parameter: median | Baseline | 24 weeks | Baseline | 24 weeks |
Number of tender jointsa | 23.0 | 17.0 | 20.0 | 5.0 |
Number of swollen jointsb | 11.0 | 9.0 | 11.0 | 3.0 |
Physician global assessmentc | 53.0 | 49.0 | 55.0 | 16.0 |
Patient global assessmentc | 49.5 | 49.0 | 48.0 | 20.0 |
Painc | 49.0 | 49.0 | 54.0 | 20.0 |
Disability index (HAQ)d | 1.0 | 0.9 | 1.0 | 0.4 |
CRP (mg/dL)e | 0.8 | 0.7 | 0.8 | 0.2 |
* p<0.001 for adalimumab vs. placebo comparisons based on median changes a Scale 0-78 b Scale 0-76 c Visual analog scale; 0=best, 100=worst d Disability Index of the Health Assessment Questionnaire; 0=best, 3=worst; measures the patient's ability to perform the following: dress/groom, arise, eat, walk, reach, grip, maintain hygiene, and maintain daily activity. e Normal range: 0-0.287 mg/dL |
Similar results were seen in an additional, 12-week study in 100 patients with moderate to severe psoriatic arthritis who had suboptimal response to DMARD therapy as manifested by ≥3 tender joints and ≥3 swollen joints at enrollment.
Radiographic Response
Radiographic changes were assessed in the PsA studies. Radiographs of hands, wrists, and feet were obtained at baseline and Week 24 during the doubleblind period when patients were on adalimumab or placebo and at Week 48 when all patients were on open-label adalimumab. A modified Total Sharp Score (mTSS), which included distal interphalangeal joints (i.e., not identical to the TSS used for rheumatoid arthritis), was used by readers blinded to treatment group to assess the radiographs.
Adalimumab-treated patients demonstrated greater inhibition of radiographic progression compared to placebo-treated patients and this effect was maintained at 48 weeks (see Table 9).
Table 9. Change in Modified Total Sharp Score in Psoriatic Arthritis
| Placebo N=141 | Adalimumab N=133 |
Week 24 | Week 24 | Week 48 |
Baseline mean | 22.1 | 23.4 | 23.4 |
Mean Change ± SD | 0.9 ± 3.1 | -0.1 ± 1.7 | -0.2 ± 4.9* |
* <0.001 for the difference between adalimumab, Week 48 and Placebo, Week 24 (primary analysis) |
Physical Function Response
In Study PsA-I, physical function and disability were assessed using the HAQ Disability Index (HAQ-DI) and the SF-36 Health Survey. Patients treated with 40 mg of adalimumab every other week showed greater improvement from baseline in the HAQ-DI score (mean decreases of 47% and 49% at Weeks 12 and 24 respectively) in comparison to placebo (mean decreases of 1% and 3% at Weeks 12 and 24 respectively). At Weeks 12 and 24, patients treated with adalimumab showed greater improvement from baseline in the SF-36 Physical Component Summary score compared to patients treated with placebo, and no worsening in the SF-36 Mental Component Summary score. Improvement in physical function based on the HAQ-DI was maintained for up to 84 weeks through the open-label portion of the study.
Ankylosing Spondylitis
The safety and efficacy of adalimumab 40 mg every other week was assessed in 315 adult patients in a randomized, 24 week double-blind, placebocontrolled study in patients with active ankylosing spondylitis (AS) who had an inadequate response to glucocorticoids, NSAIDs, analgesics, methotrexate or sulfasalazine. Active AS was defined as patients who fulfilled at least two of the following three criteria: (1) a Bath AS disease activity index (BASDAI) score ≥4 cm, (2) a visual analog score (VAS) for total back pain ≥ 40 mm, and (3) morning stiffness ≥ 1 hour. The blinded period was followed by an openlabel period during which patients received adalimumab 40 mg every other week subcutaneously for up to an additional 28 weeks.
Improvement in measures of disease activity was first observed at Week 2 and maintained through 24 weeks as shown in Figure 2 and Table 10.
Responses of patients with total spinal ankylosis (n=11) were similar to those without total ankylosis.
Figure 2. ASAS 20 Response By Visit, Study AS-I
At 12 weeks, the ASAS 20/50/70 responses were achieved by 58%, 38%, and 23%, respectively, of patients receiving adalimumab, compared to 21%, 10%, and 5% respectively, of patients receiving placebo (p <0.001). Similar responses were seen at Week 24 and were sustained in patients receiving open-label adalimumab for up to 52 weeks.
A greater proportion of patients treated with adalimumab (22%) achieved a low level of disease activity at 24 weeks (defined as a value <20 [on a scale of 0 to 100 mm] in each of the four ASAS response parameters) compared to patients treated with placebo (6%).
Table 10. Components of Ankylosing Spondylitis Disease Activity
| Placebo N=107 | Adalimumab N=208 |
Baseline mean | Week 24 mean | Baseline mean | Week 24 mean |
ASAS 20 Response Criteria* | | | | |
Patient's Global Assessment of Disease Activitya* | 65 | 60 | 63 | 38 |
Total back pain* | 67 | 58 | 65 | 37 |
Inflammationb* | 6.7 | 5.6 | 6.7 | 3.6 |
BASFIc* | 56 | 51 | 52 | 34 |
BASDAId score* | 6.3 | 5.5 | 6.3 | 3.7 |
BASMIe score* | 4.2 | 4.1 | 3.8 | 3.3 |
Tragus to wall (cm) | 15.9 | 15.8 | 15.8 | 15.4 |
Lumbar flexion (cm) | 4.1 | 4.0 | 4.2 | 4.4 |
Cervical rotation (degrees) | 42.2 | 42.1 | 48.4 | 51.6 |
Lumbar side flexion (cm) | 8.9 | 9.0 | 9.7 | 11.7 |
Intermalleolar distance (cm) | 92.9 | 94.0 | 93.5 | 100.8 |
CRPf* | 2.2 | 2.0 | 1.8 | 0.6 |
a Percent of subjects with at least a 20% and 10-unit improvement measured on a Visual Analog Scale (VAS) with 0 = “none” and 100 = “severe” b mean of questions 5 and 6 of BASDAI (defined in ‘d’) c Bath Ankylosing Spondylitis Functional Index d Bath Ankylosing Spondylitis Disease Activity Index e Bath Ankylosing Spondylitis Metrology Index f C-Reactive Protein (mg/dL) * statistically significant for comparisons between adalimumab and placebo at Week 24 |
A second randomized, multicenter, double-blind, placebo-controlled study of 82 patients with ankylosing spondylitis showed similar results.
Patients treated with adalimumab achieved improvement from baseline in the Ankylosing Spondylitis Quality of Life Questionnaire (ASQoL) score (-3.6 vs. -1.1) and in the Short Form Health Survey (SF-36) Physical Component Summary (PCS) score (7.4 vs. 1.9) compared to placebo-treated patients at Week 24.
Adult Crohn's Disease
The safety and efficacy of multiple doses of adalimumab were assessed in adult patients with moderately to severely active Crohn's disease, CD, (Crohn's Disease Activity Index (CDAI) ≥ 220 and ≤ 450) in randomized, double-blind, placebo-controlled studies. Concomitant stable doses of aminosalicylates, corticosteroids, and/or immunomodulatory agents were permitted, and 79% of patients continued to receive at least one of these medications.
Induction of clinical remission (defined as CDAI < 150) was evaluated in two studies. In Study CD-I, 299 TNF-blocker naïve patients were randomized to one of four treatment groups: the placebo group received placebo at Weeks 0 and 2, the 160/80 group received 160 mg adalimumab at Week 0 and 80 mg at Week 2, the 80/40 group received 80 mg at Week 0 and 40 mg at Week 2, and the 40/20 group received 40 mg at Week 0 and 20 mg at Week 2. Clinical results were assessed at Week 4.
In the second induction study, Study CD-II, 325 patients who had lost response to, or were intolerant to, previous infliximab therapy were randomized to receive either 160 mg adalimumab at Week 0 and 80 mg at Week 2, or placebo at Weeks 0 and 2. Clinical results were assessed at Week 4.
Maintenance of clinical remission was evaluated in Study CD-III. In this study, 854 patients with active disease received open-label adalimumab, 80 mg at week 0 and 40 mg at Week 2. Patients were then randomized at Week 4 to 40 mg adalimumab every other week, 40 mg adalimumab every week, or placebo. The total study duration was 56 weeks. Patients in clinical response (decrease in CDAI ≥70) at Week 4 were stratified and analyzed separately from those not in clinical response at Week 4.
Induction Of Clinical Remission
A greater percentage of the patients treated with 160/80 mg adalimumab achieved induction of clinical remission versus placebo at Week 4 regardless of whether the patients were TNF blocker naïve (CD-I), or had lost response to or were intolerant to infliximab (CD-II) (see Table 11).
Table 11. Induction of Clinical Remission in Studies CD-I and CD-II (Percent of Patients)
| CD-I | CD-II |
Placebo N=74 | Adalimumab 160/80 mg N=76 | Placebo N=166 | Adalimumab 160/80 mg N=159 |
Week 4 | | | | |
Clinical remission | 12% | 36%* | 7% | 21%* |
Clinical response | 34% | 58%** | 34% | 52%** |
Clinical remission is CDAI score < 150; clinical response is decrease in CDAI of at least 70 points. * p<0.001 for adalimumab vs. placebo pairwise comparison of proportions ** p<0.01 for adalimumab vs. placebo pairwise comparison of proportions |
Maintenance Of Clinical Remission
In Study CD-III at Week 4, 58% (499/854) of patients were in clinical response and were assessed in the primary analysis. At Weeks 26 and 56, greater proportions of patients who were in clinical response at Week 4 achieved clinical remission in the adalimumab 40 mg every other week maintenance group compared to patients in the placebo maintenance group (see Table 12). The group that received adalimumab therapy every week did not demonstrate significantly higher remission rates compared to the group that received adalimumab every other week.
Table 12. Maintenance of Clinical Remission in CD-III (Percent of Patients)
| Placebo | 40 mg adalimumab every other week |
N=170 | N=172 |
Week 26 | | |
Clinical remission | 17% | 40%* |
Clinical response | 28% | 54%* |
Week 56 | | |
Clinical remission | 12% | 36%* |
Clinical response | 18% | 43%* |
Clinical remission is CDAI score < 150; clinical response is decrease in CDAI of at least 70 points. * p<0.001 for adalimumab vs. placebo pairwise comparisons of proportions |
Of those in response at Week 4 who attained remission during the study, patients in the adalimumab every other week group maintained remission for a longer time than patients in the placebo maintenance group. Among patients who were not in response by Week 12, therapy continued beyond 12 weeks did not result in significantly more responses.
Ulcerative Colitis
The safety and efficacy of adalimumab were assessed in adult patients with moderately to severely active ulcerative colitis (Mayo score 6 to 12 on a 12 point scale, with an endoscopy subscore of 2 to 3 on a scale of 0 to 3) despite concurrent or prior treatment with immunosuppressants such as corticosteroids, azathioprine, or 6-MP in two randomized, double-blind, placebo-controlled clinical studies (Studies UC-I and UC-II). Both studies enrolled TNF-blocker naïve patients, but Study UC-II also allowed entry of patients who lost response to or were intolerant to TNF- blockers. Forty percent (40%) of patients enrolled in Study UC-II had previously used another TNF-blocker.
Concomitant stable doses of aminosalicylates and immunosuppressants were permitted. In Studies UC-I and II, patients were receiving aminosalicylates (69%), corticosteroids (59%) and/or azathioprine or 6-MP (37%) at baseline. In both studies, 92% of patients received at least one of these medications.
Induction of clinical remission (defined as Mayo score ≤ 2 with no individual subscores > 1) at Week 8 was evaluated in both studies. Clinical remission at Week 52 and sustained clinical remission (defined as clinical remission at both Weeks 8 and 52) were evaluated in Study UC-II.
In Study UC-I, 390 TNF-blocker naïve patients were randomized to one of three treatment groups for the primary efficacy analysis. The placebo group received placebo at Weeks 0, 2, 4 and 6. The 160/80 group received 160 mg adalimumab at Week 0 and 80 mg at Week 2, and the 80/40 group received 80 mg adalimumab at Week 0 and 40 mg at Week 2. After Week 2, patients in both adalimumab treatment groups received 40 mg every other week (eow).
In Study UC-II, 518 patients were randomized to receive either adalimumab 160 mg at Week 0, 80 mg at Week 2, and 40 mg eow starting at Week 4 through Week 50, or placebo starting at Week 0 and eow through Week 50. Corticosteroid taper was permitted starting at Week 8.
In both Studies UC-I and UC-II, a greater percentage of the patients treated with 160/80 mg of adalimumab compared to patients treated with placebo achieved induction of clinical remission. In Study UC-II, a greater percentage of the patients treated with 160/80 mg of adalimumab compared to patients treated with placebo achieved sustained clinical remission (clinical remission at both Weeks 8 and 52) (Table 14).
Table 14. Induction of Clinical Remission in Studies UC-I and UC-II and Sustained Clinical Remission in Study UC-II (Percent of Patients)
| Study UC-I | Study UC-II |
Placebo N=130 | Adalimumab 160/80 mg N=130 | Treatment Difference (95% CI) | Placebo N=246 | Adalimumab 160/80 mg N=248 | Treatment Difference (95% CI) |
Induction of Clinical Remission (Clinical Remission at Week 8) | 9.2% | 18.5% | 9.3%* (0.9%, 17.6%) | 9.3% | 16.5% | 7.2%* (1.2%, 12.9%) |
Sustained Clinical Remission (Clinical Remission at both Weeks 8 and 52) | N/A | N/A | N/A | 4.1% | 8.5% | 4.4%* (0.1%, 8.6%) |
Clinical remission is defined as Mayo score ≤ 2 with no individual subscores > 1. CI=Confidence interval * p<0.05 for adalimumab vs. placebo pairwise comparison of proportions |
In Study UC-I, there was no statistically significant difference in clinical remission observed between the adalimumab 80/40 mg group and the placebo group at Week 8.
In Study UC-II, 17.3% (43/248) in the adalimumab group were in clinical remission at Week 52 compared to 8.5% (21/246) in the placebo group (treatment difference: 8.8%; 95% confidence interval (CI): [2.8%, 14.5%]; p<0.05).
In the subgroup of patients in Study UC-II with prior TNF-blocker use, the treatment difference for induction of clinical remission appeared to be lower than that seen in the whole study population, and the treatment differences for sustained clinical remission and clinical remission at Week 52 appeared to be similar to those seen in the whole study population. The subgroup of patients with prior TNF-blocker use achieved induction of clinical remission at 9% (9/98) in the adalimumab group versus 7% (7/101) in the placebo group, and sustained clinical remission at 5% (5/98) in the adalimumab group versus 1% (1/101) in the placebo group. In the subgroup of patients with prior TNF-blocker use, 10% (10/98) were in clinical remission at Week 52 in the adalimumab group versus 3% (3/101) in the placebo group.
Plaque Psoriasis
The safety and efficacy of adalimumab were assessed in randomized, double-blind, placebo- controlled studies in 1696 adult subjects with moderate to severe chronic plaque psoriasis (Ps) who were candidates for systemic therapy or phototherapy.
Study Ps-I evaluated 1212 subjects with chronic Ps with ≥10% body surface area (BSA) involvement, Physician's Global Assessment (PGA) of at least moderate disease severity, and Psoriasis Area and Severity Index (PASI) ≥12 within three treatment periods. In period A, subjects received placebo or adalimumab at an initial dose of 80 mg at Week 0 followed by a dose of 40 mg every other week starting at Week 1. After 16 weeks of therapy, subjects who achieved at least a PASI 75 response at Week 16, defined as a PASI score improvement of at least 75% relative to baseline, entered period B and received open-label 40 mg adalimumab every other week. After 17 weeks of open label therapy, subjects who maintained at least a PASI 75 response at Week 33 and were originally randomized to active therapy in period A were re-randomized in period C to receive 40 mg adalimumab every other week or placebo for an additional 19 weeks. Across all treatment groups the mean baseline PASI score was 19 and the baseline Physician's Global Assessment score ranged from “moderate” (53%) to “severe” (41%) to “very severe” (6%).
Study Ps-II evaluated 99 subjects randomized to adalimumab and 48 subjects randomized to placebo with chronic plaque psoriasis with ≥10% BSA involvement and PASI ≥12. Subjects received placebo, or an initial dose of 80 mg adalimumab at Week 0 followed by 40 mg every other week starting at Week 1 for 16 weeks. Across all treatment groups the mean baseline PASI score was 21 and the baseline PGA score ranged from “moderate” (41%) to “severe” (51%) to “very severe” (8%).
Studies Ps-I and II evaluated the proportion of subjects who achieved “clear” or “minimal” disease on the 6-point PGA scale and the proportion of subjects who achieved a reduction in PASI score of at least 75% (PASI 75) from baseline at Week 16 (see Table 15 and 16).
Additionally, Study Ps-I evaluated the proportion of subjects who maintained a PGA of “clear” or “minimal” disease or a PASI 75 response after Week 33 and on or before Week 52.
Table 15. Efficacy Results at 16 Weeks in Study Ps-I Number of Subjects (%)
| Adalimumab 40 mg every other week | Placebo |
N = 814 | N = 398 |
PGA: Clear or minimal* | 506 (62%) | 17 (4%) |
PASI 75 | 578 (71%) | 26 (7%) |
* Clear = no plaque elevation, no scale, plus or minus hyperpigmentation or diffuse pink or red coloration Minimal = possible but difficult to ascertain whether there is slight elevation of plaque above normal skin, plus or minus surface dryness with some white coloration, plus or minus up to red coloration |
Table 16. Efficacy Results at 16 Weeks in Study Ps-II Number of Subjects (%)
| Adalimumab 40 mg every other week | Placebo |
N = 99 | N = 48 |
PGA: Clear or minimal* | 70 (71%) | 5 (10%) |
PASI 75 | 77 (78%) | 9 (19%) |
* Clear = no plaque elevation, no scale, plus or minus hyperpigmentation or diffuse pink or red coloration Minimal = possible but difficult to ascertain whether there is slight elevation of plaque above normal skin, plus or minus surface dryness with some white coloration, plus or minus up to red coloration |
Additionally, in Study Ps-I, subjects on adalimumab who maintained a PASI 75 were re- randomized to adalimumab (N = 250) or placebo (N = 240) at Week 33. After 52 weeks of treatment with adalimumab, more subjects on adalimumab maintained efficacy when compared to subjects who were rerandomized to placebo based on maintenance of PGA of “clear” or “minimal” disease (68% vs. 28%) or a PASI 75 (79% vs. 43%).
A total of 347 stable responders participated in a withdrawal and retreatment evaluation in an open-label extension study. Median time to relapse (decline to PGA “moderate” or worse) was approximately 5 months. During the withdrawal period, no subject experienced transformation to either pustular or erythrodermic psoriasis. A total of 178 subjects who relapsed re-initiated treatment with 80 mg of adalimumab, then 40 mg eow beginning at week 1. At week 16, 69% (123/178) of subjects had a response of PGA “clear” or “minimal”.