Table of Contents

• Trial overview
• Psoriatic arthritis studies
• Skin disease studies
• Oral ulcer and mouth sore studies
• Pediatric and long-term follow-up studies
• Key endpoints and what they mean

Trial overview

The clinical trial data for Apremilast show studies in several inflammatory diseases, mainly psoriatic arthritis and conditions with painful oral ulcers.^[1][2] Most of the studies are Phase 3 trials, which are larger studies that compare treatment effects in more people.^[1][2] One study in epidermolysis bullosa simplex is Phase 2, which is usually an earlier study step with fewer participants.^[3]

The studies include both interventional trials and long-term extension research.^[4] Interventional means the researchers give a study treatment and then measure the results.^[4] Some trials compare Apremilast with placebo, while others use it as an active comparator in studies of other medicines.^[5][6]

Psoriatic arthritis studies

Several trials focus on psoriatic arthritis, a condition that affects both the skin and joints.^[1][7] In one large Phase 3 study, adults with psoriatic arthritis who had not taken biologic medicines were enrolled, and the main result was the proportion of people reaching ACR20 at Week 16.^[1] ACR20 means at least 20% improvement in arthritis symptoms.^[1]

Another Phase 3 trial studied adults with psoriatic arthritis who already had stable minimal disease activity and looked at how far systemic immunosuppressive treatment could be tapered without symptoms returning.^[2] This study measured minimal disease activity at 12 months and also looked at the mean PASDAS score at month 12.^[2] PASDAS is a combined score that helps show how active the disease is.^[2]

A separate Phase 3 study in active psoriatic arthritis compared deucravacitinib with placebo and included Apremilast as an active comparator arm.^[7] The study population included people who were either biologic-naïve or had previously received TNFα inhibitor treatment.^[7] The main outcome was ACR20, which measures improvement in joint disease.^[7]

Skin disease studies

Apremilast also appears in several Phase 3 plaque psoriasis studies as a comparison treatment.^[5][6] These trials studied people with moderate-to-severe plaque psoriasis, which is a skin condition that causes thick, scaly patches.^[5][6]

In these psoriasis studies, the main endpoints were usually sPGA 0/1 and PASI-75 at Week 16.^[5][6] sPGA 0/1 means the skin was rated clear or almost clear, and PASI-75 means at least 75% improvement in the psoriasis score.^[5][6] These studies were completed and included large numbers of participants, showing that Apremilast was used as a standard treatment in head-to-head comparison research.^[5][6]

Two other completed Phase 3 psoriasis trials, ONWARD1 and ONWARD2, also used Apremilast placebo in the study design while testing ESK-001 against placebo.^[8][9] Their shared primary endpoint was the proportion of patients reaching PASI-75 and sPGA 0/1 at Week 16.^[8][9]

Oral ulcer and mouth sore studies

Some of the most patient-focused studies in this data look at oral ulcers, which are painful sores in the mouth.^[4][10] One Phase 3 study enrolled children and adolescents with oral ulcers linked to Behçet’s disease and compared Apremilast with placebo through Week 12.^[4] The main endpoint was the area under the curve for the number of oral ulcers from baseline to Week 12, which means the study tracked ulcer burden over time, not just at one visit.^[4]

Another Phase 3 trial studied children with active juvenile psoriatic arthritis and compared Apremilast with placebo.^[10] The main endpoint was ACR Pedi 30 from baseline to Week 16, which means at least 30% improvement in a child’s arthritis symptoms.^[10] This study included pediatric subjects 5 to less than 18 years of age.^[10]

A further Phase 3 trial studied severe recurrent aphthous stomatitis, also called severe recurrent mouth ulcers, in patients who were resistant or intolerant to colchicine.^[11] The main endpoint was sustained complete response, meaning no oral ulcer at the Week 12, Week 14, and Week 16 visits.^[11] This study compared Apremilast with placebo and also included racecadotril as another treatment arm.^[11]

Pediatric and long-term follow-up studies

One open-label Phase 3 extension study followed children with oral ulcers associated with Behçet’s disease or with active juvenile psoriatic arthritis after they had finished earlier studies.^[12] Open-label means both the researchers and the participants knew which treatment was given.^[12] This study focused on long-term safety rather than short-term treatment response.^[12]

The safety measures in this long-term study included adverse events, suicide risk screening with the Columbia-Suicide Severity Rating Scale, Tanner staging, body weight, height, body mass index, vital signs, and laboratory values.^[12] Tanner staging is a way to assess normal physical development during puberty.^[12] These details show that some Apremilast research is not only about symptom improvement but also about longer-term growth and safety in children.^[12]

Another Phase 2 study looked at Apremilast in people older than 6 years with generalized epidermolysis bullosa simplex, a rare skin condition.^[3] The study used a challenge-dechallenge-rechallenge design, which means treatment is given, stopped, and then started again to see whether the effect changes in a clear pattern.^[3] The goal was to assess efficacy in a very small group of 20 participants.^[3]

Key endpoints and what they mean

Across these trials, the main endpoints measure how much the disease improves and whether the treatment is safe to use.^[1][4][11] In joint disease, the trials commonly use ACR20 or ACR Pedi 30, which are response scores showing improvement in arthritis symptoms.^[1][10] In skin disease, the studies often use PASI-75 and sPGA 0/1, which help show how clear the skin becomes.^[5][6]

For mouth ulcer studies, the researchers measure the number of ulcers over time or the chance of complete ulcer healing at several visits.^[4][11] For long-term pediatric research, the focus shifts to safety, growth, and general health checks.^[12] This mix of outcomes shows that Apremilast is being studied in both short-term efficacy trials and longer follow-up studies in children and adults.^[1][12]