NCT03783026: MOSAIC

A Study to Evaluate the Impact of Apremilast on Magnetic Resonance Imaging (MRI) Outcomes in Adults With Psoriatic Arthritis

Completed Phase 4 Results posted Last updated 21 February 2025

What this trial tests

Phase 4 trial testing Apremilast in Psoriatic Arthritis in 123 participants. Completed in 11 May 2022.

Timeline

6 February 2019

Primary endpoint
26 October 2021

11 May 2022

Quick facts

Lead sponsor	Amgen
Phase	Phase 4
Status	Completed
Study type	INTERVENTIONAL
Allocation	na
Design	single group
Masking	none
Primary purpose	treatment
Enrollment	123
Start date	6 February 2019
Primary completion	26 October 2021
Estimated completion	11 May 2022
Sites	36 locations across Denmark, Italy, Russia, Belgium, Austria, United Kingdom, Germany, Canada

Drugs / interventions tested

• Apremilast (APREMILAST) — full drug profile →

Conditions studied

• Psoriatic Arthritis — all drugs for Psoriatic Arthritis →

Sponsor

Amgen — full company profile →

Who can join

18 and older, any sex, with Psoriatic Arthritis. Patients with the condition only — healthy volunteers not accepted.

Results — posted to ClinicalTrials.gov

Per-arm endpoint measurements with 95% confidence intervals where reported. Source: trial results section.

Change From Baseline in the Composite Score of BME, Synovitis, and Tenosynovitis Assessed by PsAMRIS at Week 24 Primary · Baseline and week 24

PsAMRIS is a validated MRI scoring system that assesses metacarpophalangeal, proximal interphalangeal, and distal interphalangeal joints of fingers 2 to 5 of the most affected hand (the hand with the greater inflammatory burden of swollen joints and/or dactylitis). Synovitis, flexor tenosynovitis, and bone marrow edema were scored from 0 (none/normal) to 3 (severe) at each joint. The total scores for synovitis and tenosynovitis range from 0 to 36 and the total score for BME ranges from 0 to 72 since both proximal and distal regions of each joint were scored. The PsAMRIS composite inflammatio

Group	Value	95% CI
Apremilast	-2.32	-4.73 – 0.09

Change From Baseline in the Composite Score of BME, Synovitis, and Tenosynovitis Assessed by PsAMRIS at Week 48 Secondary · Baseline and week 48

PsAMRIS is a validated MRI scoring system that assesses metacarpophalangeal, proximal interphalangeal, and distal interphalangeal joints of fingers 2 to 5 of the most affected hand (the hand with the greater inflammatory burden of swollen joints and/or dactylitis). Synovitis, flexor tenosynovitis, and bone marrow edema were scored from 0 (none/normal) to 3 (severe) at each joint. The total scores for synovitis and tenosynovitis range from 0 to 36 and the total score for BME ranges from 0 to 72 since both proximal and distal regions of each joint were scored. The PsAMRIS composite inflammatio

Group	Value	95% CI
Apremilast	-2.91	-5.45 – -0.37

Change From Baseline in the Composite Score of BME and Synovitis Assessed by PsAMRIS at Weeks 24 and 48 Secondary · Baseline and weeks 24 and 48

PsAMRIS is a validated MRI scoring system that assesses metacarpophalangeal, proximal interphalangeal, and distal interphalangeal joints of fingers 2 to 5 of the most affected hand (the hand with the greater inflammatory burden of swollen joints and/or dactylitis). Synovitis and bone marrow edema were each scored from 0 (none/normal) to 3 (severe) at each joint. The total score for synovitis ranges from 0 to 36 and the total score for BME ranges from 0 to 72 since this is scored at both proximal and distal regions of each joint. The PsAMRIS composite score of BME and synovitis is calculated

Week 24

Group	Value	95% CI
Apremilast	-1.19	-2.89 – 0.50

Week 48

Group	Value	95% CI
Apremilast	-1.54	-3.53 – 0.46

Change From Baseline in the PsAMRIS Total Inflammation Score at Weeks 24 and 48 Secondary · Baseline and weeks 24 and 48

PsAMRIS is a validated MRI scoring system that assesses metacarpophalangeal, proximal interphalangeal, and distal interphalangeal joints of fingers 2 to 5 of the most affected hand. Synovitis, flexor tenosynovitis, and bone marrow edema were each scored from 0 (none/normal) to 3 (severe) at each joint. Periarticular inflammation was scored 0 (absent) or 1 (present) separately at volar and dorsal aspects of the same 12 joints. The scores for synovitis and tenosynovitis range from 0 to 36, the score for BME is from 0 to 72 and the periarticular inflammation score is from 0 to 24. The PsAMRIS t

Week 24

Group	Value	95% CI
Apremilast	-3.62	-7.11 – -0.12

Week 48

Group	Value	95% CI
Apremilast	-4.35	-8.14 – -0.56

Change From Baseline in Bone Marrow Edema Assessed by PsAMRIS at Weeks 24 and 48 Secondary · Baseline and weeks 24 and 48

Bone marrow edema (BME) is a buildup of fluid inside the bones. The OMERACT PsAMRIS scoring system assesses BME at the proximal and distal regions of MCP, PIP, and DIP joints of fingers 2 to 5 of the most affected hand. BME is assessed on a scale of 0-3 based on the proportion of bone with edema, compared to the assessed bone volume (articular surface to a depth of 1 cm), judged on all available images; where 0: no edema; 1: 1-33% of bone edema; 2: 34-66% of bone edema; 3: 67-100% of bone edema. The overall score ranges from 0 (none) to 72 (severe). A negative change from baseline indicates im

Week 24

Group	Value	95% CI
Apremilast	-0.22	-0.83 – 0.38

Week 48

Group	Value	95% CI
Apremilast	-0.39	-1.14 – 0.37

Change From Baseline in Synovitis Assessed by PsAMRIS at Weeks 24 and 48 Secondary · Baseline and weeks 24 and 48

PsAMRIS is a validated MRI scoring system that assesses metacarpophalangeal, proximal interphalangeal, and distal interphalangeal joints of fingers 2 to 5 of the most affected hand (the hand with the greater inflammatory burden of swollen joints and/or dactylitis). Synovitis is inflammation of the synovial membrane, connective tissue that lines the inside of the joint. Synovitis was scored from 0 to 3 at MCP, PIP and DIP joints of fingers 2 to 5 (total of 12 joints), where score 0 is normal, and a score of 1 is mild, 2 is moderate, and 3 is severe. The overall synovitis score ranges from 0 (

Week 24

Group	Value	95% CI
Apremilast	-0.47	-1.11 – 0.16

Week 48

Group	Value	95% CI
Apremilast	-0.65	-1.39 – 0.10

Change From Baseline in Tenosynovitis Assessed by PsAMRIS at Weeks 24 and 48 Secondary · Baseline and Weeks 24 and 48

PsAMRIS is a validated MRI scoring system that assesses metacarpophalangeal, proximal interphalangeal, and distal interphalangeal joints of fingers 2 to 5 of the most affected hand (the hand with the greater inflammatory burden of swollen joints and/or dactylitis). Tenosynovitis is inflammation of the protective sheath (synovial membrane) that surrounds tendons. Flexor tenosynovitis was scored from 0 to 3 at MCP, PIP and DIP joints of fingers 2 to 5 (total of 12 joints) where a score of 0 is none; 1: \< 1/2 tendon thickness; 2: ≥ 1/2 and \< 1 tendon thickness; 3: ≥ 1 tendon thickness. The ov

Week 24

Group	Value	95% CI
Apremilast	-0.64	-1.10 – -0.19

Week 48

Group	Value	95% CI
Apremilast	-0.78	-1.15 – -0.40

Change From Baseline in Periarticular Inflammation Assessed by PsAMRIS at Weeks 24 and 48 Secondary · Baseline and weeks 24 and 48

PsAMRIS is a validated MRI scoring system that assesses metacarpophalangeal, proximal interphalangeal, and distal interphalangeal joints of fingers 2 to 5 of the most affected hand (the hand with the greater inflammatory burden of swollen joints and/or dactylitis). Periarticular inflammation refers to inflammation of the tissues surrounding the joint, including the periosteum and the entheses, but not the tendon sheaths. Periarticular inflammation was scored 0 (absent) or 1 (present) separately at volar and dorsal aspects of the same 12 joint regions as evaluated for synovitis and flexor ten

Week 24

Group	Value	95% CI
Apremilast	-0.49	-0.90 – -0.07

Week 48

Group	Value	95% CI
Apremilast	-0.59	-1.04 – -0.13

Change From Baseline in the PsAMRIS Total Damage Score at Weeks 24 and 48 Secondary · Baseline and weeks 24 and 48

PsAMRIS is a validated MRI scoring system that assesses MCP, PIP, and DIP joints of fingers 2 to 5 of the most affected hand. Bone erosion (loss of bone) was assessed at the distal and proximal regions of each joint on a scale of 0 to 10, based on the proportion of eroded bone compared to the assessed bone volume, where 0 is no erosion; 1: 1-10% of bone eroded; 2: 11-20%, etc. The total erosion score is from 0 (none) to 240 (severe). Bone proliferation (abnormal bone formation in the periarticular region) was scored at each joint as 0 (absent) or 1 (present). The total proliferation score is

Week 24

Group	Value	95% CI
Apremilast	0.22	-1.10 – 0.53

Week 48

Group	Value	95% CI
Apremilast	0.50	-0.38 – 1.38

Change From Baseline in Bone Erosion Assessed by PsAMRIS at Weeks 24 and 48 Secondary · Baseline and weeks 24 and 48

PsAMRIS is a validated MRI scoring system that assesses metacarpophalangeal, proximal interphalangeal, and distal interphalangeal joints of fingers 2 to 5 of the most affected hand. Bone erosion (loss of bone) was assessed at the distal and proximal regions of each joint on a scale of 0-10, based on the proportion of eroded bone compared to the assessed bone volume, judged on all available images: 0: no erosion; 1: 1-10% of bone eroded; 2: 11-20%, etc. The assessed bone volume is from the articular surface (or its best estimated position if absent) to a depth of 1 cm. The total erosion score

Week 24

Group	Value	95% CI
Apremilast	-0.01	-0.06 – 0.05

Week 48

Group	Value	95% CI
Apremilast	0.03	-0.04 – 0.10

Change From Baseline in Bone Proliferation Assessed by PsAMRIS at Weeks 24 and 48 Secondary · Baseline and weeks 24 and 48

PsAMRIS is a validated MRI scoring system that assesses metacarpophalangeal, proximal interphalangeal, and distal interphalangeal joints of fingers 2 to 5 of the most affected hand. Bone proliferation (abnormal bone formation in the periarticular region such as at the entheses and across the joint) was scored at each joint as 0 (absent) or 1 (present). The total proliferation score ranges from 0 (none) to 12 (present at all joints). A negative change from baseline indicates improvement. This endpoint was analyzed using a MMRM with baseline value, scanner type and time as independent variable

Week 24

Group	Value	95% CI
Apremilast	0.01	-0.01 – 0.03

Week 48

Group	Value	95% CI
Apremilast	0.02	-0.02 – 0.07

Change From Baseline in Swollen Joint Count (SJC) at Weeks 24 and 48 Secondary · Baseline and weeks 24 and 48

A total of 76 joints (including the distal interphalangeal joints of the fingers and toes) were examined for swelling.

Week 24

Group	Value	95% CI
Apremilast	-5.8	± 7.11

Week 48

Group	Value	95% CI
Apremilast	-6.3	± 8.02

Adverse events — posted to ClinicalTrials.gov

Time frame: From first dose of study drug up to 28 days after last dose; up to 52 weeks.. Reporting threshold: 5%. Adverse-event reports describe events observed during the trial — not all are caused by the drug.

Apremilast

Serious: 6/122 (5%)

Deaths: 0/123

Serious adverse events (8 terms)

Reaction	System	Apremilast
Angina pectoris	Cardiac disorders	—
Non-cardiac chest pain	General disorders	—
COVID-19 pneumonia	Infections and infestations	—
Pneumonia	Infections and infestations	—
Acetabulum fracture	Injury, poisoning and procedural complications	—
Fall	Injury, poisoning and procedural complications	—
Pelvic fracture	Injury, poisoning and procedural complications	—
Asthma	Respiratory, thoracic and mediastinal disorders	—

Other adverse events (6 terms — click to expand)

Reaction	System	Apremilast
Diarrhoea	Gastrointestinal disorders	—
Nausea	Gastrointestinal disorders	—
Headache	Nervous system disorders	—
Nasopharyngitis	Infections and infestations	—
Dyspepsia	Gastrointestinal disorders	—
Psoriasis	Skin and subcutaneous tissue disorders	—

Most-reported serious reactions: Angina pectoris, Non-cardiac chest pain, COVID-19 pneumonia, Pneumonia, Acetabulum fracture, Fall, Pelvic fracture, Asthma.

Data from ClinicalTrials.gov NCT03783026 adverse events section.

Sponsor's own description

This study is designed to assess the efficacy of apremilast, either in monotherapy or with stable methotrexate, on imaging outcomes in adults with active psoriatic arthritis with less than 5 years of disease duration (since diagnosis), and who are naïve to biologic therapies.

Publications & conference data

3 peer-reviewed publications reference this trial (live from Europe PMC):

1. Biomarkers of Response to Biologic Therapy in Juvenile Idiopathic Arthritis.
   Choida V, Hall-Craggs M, Jebson BR, Fisher C, et al · · 2020 · cited 11× · PMID 33603671 · DOI 10.3389/fphar.2020.635823
2. Effect of apremilast on hand and whole-body MRI assessments of inflammation in patients with psoriatic arthritis (MOSAIC): a phase 4, multicentre, single-arm, open-label study.
   Østergaard M, Boesen M, Maksymowych WP, Lambert RG, et al · · 2025 · cited 5× · PMID 39488216 · DOI 10.1016/s2665-9913(24)00232-7
3. Effect of apremilast on whole-body magnetic resonance imaging of peripheral and axial inflammation in patients with psoriatic arthritis.
   Østergaard M, Lambert RGW, Maksymowych WP, Boesen M, et al · · 2026 · PMID 42191498 · DOI 10.1016/j.ard.2026.04.010