Objectives: To evaluate further in a phase III, double blind trial the efficacy of infliximab in patients with active psoriatic arthritis (PsA), as observed in the smaller IMPACT trial. Methods: 200 patients with active PsA unresponsive to previous treatment were randomised to infusions of infliximab 5 mg/kg or placebo at weeks 0, 2, 6, 14, and 22. Patients with inadequate response entered early escape at week 16. The primary measure of clinical response was ACR20. Other measures included Psoriatic Arthritis Response Criteria (PsARC), Psoriasis Area and Severity Index (PASI), and dactylitis and enthesopathy assessments. Results: At week 14, 58% of patients receiving infliximab and 11% of those receiving placebo achieved an ACR20 response and 77% of infliximab patients and 27% of placebo patients achieved PsARC (both p<0.001). Among the 85% of patients with at least 3% body surface area psoriasis involvement at baseline, 53/83 (64%) patients receiving infliximab had at least 75% improvement in PASI compared with 2/87 (2%) patients receiving placebo at week 14 (p<0.001). These therapeutic effects were maintained through the last evaluation (week 24). Fewer infliximab patients than placebo patients had dactylitis at week 14 (18% v 30%; p = 0.025) and week 24 (12% v 34%; p<0.001). Fewer infliximab patients (22%) than placebo patients (34%) had active enthesopathy at week 14 (p = 0.016); corresponding figures at week 24 were 20% and 37% (p = 0.002). Infliximab was generally well tolerated, with a similar incidence of adverse events in each group. Conclusions: Infliximab 5 mg/kg through 24 weeks significantly improved active PsA, including dactylitis and enthesopathy, and associated psoriasis.

Objective: To assess the efficacy and safety of golimumab in patients with active psoriatic arthritis (PsA).Methods: Adult patients with PsA who had at least 3 swollen and 3 tender joints and active psoriasis were randomly assigned to receive subcutaneous injections of placebo (n = 113), golimumab 50 mg (n = 146), or golimumab 100 mg (n = 146) every 4 weeks through week 20. Efficacy assessments through week 24 included the American College of Rheumatology 20% improvement criteria (ACR20), the Psoriasis Area and Severity Index (PASI) in patients in whom at least 3% of the body surface area was affected by psoriasis at baseline, the Short Form 36 Health Survey (SF‐36), the disability index of the Health Assessment Questionnaire (HAQ), the Nail Psoriasis Severity Index (NAPSI), the physician's global assessment of psoriatic nail disease, and enthesitis (using the PsA‐modified Maastricht Ankylosing Spondylitis Enthesitis Score [MASES] index).Results: At week 14, 48% of all patients receiving golimumab, 51% of patients receiving golimumab 50 mg, and 45% of patients receiving golimumab 100 mg achieved an ACR20 response (the primary end point), compared with 9% of patients receiving placebo (P < 0.001 for all comparisons). Among the 74% of patients in whom at least 3% of the body surface area was affected by psoriasis at baseline, 40% of those in the golimumab 50 mg group and 58% of those in the golimumab 100 mg group had at least 75% improvement in the PASI at week 14 (major secondary end point), compared with 3% of placebo‐treated patients (P < 0.001 for both doses). Significant improvement was observed for other major secondary end points (the HAQ and the SF‐36), the NAPSI, the physician's global assessment of psoriatric nail disease, and the PsA‐modified MASES index in each golimumab group compared with placebo. This efficacy was maintained through week 24. Golimumab was generally well tolerated.Conclusion: Treatment with golimumab at doses of 50 mg and 100 mg significantly improved active PsA and associated skin and nail psoriasis through week 24.

Objectives Apremilast, an oral phosphodiesterase 4 inhibitor, regulates inflammatory mediators. Psoriatic Arthritis Long-term Assessment of Clinical Efficacy 1 (PALACE 1) compared apremilast with placebo in patients with active psoriatic arthritis despite prior traditional disease-modifying antirheumatic drug (DMARD) and/or biologic therapy. Methods In the 24-week, placebo-controlled phase of PALACE 1, patients (N=504) were randomised (1:1:1) to placebo, apremilast 20 mg twice a day (BID) or apremilast 30 mg BID. At week 16, patients without ≥20% reduction in swollen and tender joint counts were required to be re-randomised equally to either apremilast dose if initially randomised to placebo or remained on their initial apremilast dose. Patients on background concurrent DMARDs continued stable doses (methotrexate, leflunomide and/or sulfasalazine). Primary outcome was the proportion of patients achieving 20% improvement in modified American College of Rheumatology response criteria (ACR20) at week 16. Results At week 16, significantly more apremilast 20 mg BID (31%) and 30 mg BID (40%) patients achieved ACR20 versus placebo (19%) (p<0.001). Significant improvements in key secondary measures (physical function, psoriasis) were evident with both apremilast doses versus placebo. Across outcome measures, the 30-mg group generally had higher and more consistent response rates, although statistical comparison was not conducted. The most common adverse events were gastrointestinal and generally occurred early, were self-limiting and infrequently led to discontinuation. No imbalance in major adverse cardiac events, serious or opportunistic infections, malignancies or laboratory abnormalities was observed. Conclusions Apremilast was effective in the treatment of psoriatic arthritis, improving signs and symptoms and physical function. Apremilast demonstrated an acceptable safety profile and was generally well tolerated. Clinical trial registration number NCT01172938.

Introduction: Rheumatoid arthritis (RA) is a complex and clinically heterogeneous autoimmune disease. Currently, the relationship between pathogenic molecular drivers of disease in RA and therapeutic response is poorly understood. Methods: We analyzed synovial tissue samples from two RA cohorts of 49 and 20 patients using a combination of global gene expression, histologic and cellular analyses, and analysis of gene expression data from two further publicly available RA cohorts. To identify candidate serum biomarkers that correspond to differential synovial biology and clinical response to targeted therapies, we performed pre-treatment biomarker analysis compared with therapeutic outcome at week 24 in serum samples from 198 patients from the ADACTA (ADalimumab ACTemrA) phase 4 trial of tocilizumab (anti-IL-6R) monotherapy versus adalimumab (anti-TNFα) monotherapy. Results: We documented evidence for four major phenotypes of RA synovium – lymphoid, myeloid, low inflammatory, and fibroid - each with distinct underlying gene expression signatures. We observed that baseline synovial myeloid, but not lymphoid, gene signature expression was higher in patients with good compared with poor European league against rheumatism (EULAR) clinical response to anti-TNFα therapy at week 16 (P =0.011). We observed that high baseline serum soluble intercellular adhesion molecule 1 (sICAM1), associated with the myeloid phenotype, and high serum C-X-C motif chemokine 13 (CXCL13), associated with the lymphoid phenotype, had differential relationships with clinical response to anti-TNFα compared with anti-IL6R treatment. sICAM1-high/CXCL13-low patients showed the highest week 24 American College of Rheumatology (ACR) 50 response rate to anti-TNFα treatment as compared with sICAM1-low/CXCL13-high patients (42% versus 13%, respectively, P =0.05) while anti-IL-6R patients showed the opposite relationship with these biomarker subgroups (ACR50 20% versus 69%, P =0.004). Conclusions: These data demonstrate that underlying molecular and cellular heterogeneity in RA impacts clinical outcome to therapies targeting different biological pathways, with patients with the myeloid phenotype exhibiting the most robust response to anti-TNFα. These data suggest a path to identify and validate serum biomarkers that predict response to targeted therapies in rheumatoid arthritis and possibly other autoimmune diseases. Trial registration: ClinicalTrials.gov NCT01119859

Introduction: The efficacy of pegloticase, a polyethylene glycol (PEG)-conjugated mammalian recombinant uricase, approved for chronic refractory gout, can be limited by the development of antibodies (Ab). Analyses from 2 replicate, 6-month, randomized controlled trials were performed to characterize Ab responses to pegloticase. Methods: Anti-pegloticase, anti-PEG, and anti-uricase Ab were determined by validated enzyme-linked immunosorbent assays. Ab titers were analyzed for possible relationships with serum pegloticase concentrations, serum uric acid (sUA) lowering, and risk of infusion reactions (IRs). Results: Sixty-nine (41%) of 169 patients receiving pegloticase developed high titer anti-pegloticase Ab (> 1:2430) and 40% (67/169) developed anti-PEG Ab; 1 patient receiving placebo developed high titer anti-pegloticase Ab. Only 14% (24/169) of patients developed anti-uricase Ab, usually at low titer. In responders, patients showing sustained UA lowering, mean anti-pegloticase titers at week 25 (1:837 ± 1687 with biweekly and 1:2025 ± 4506 with monthly dosing) were markedly lower than in nonresponders (1:34,528 ± 42,228 and 1:89,658 ± 297,797, respectively). Nonresponder status was associated with reduced serum pegloticase concentrations. Baseline anti-pegloticase Ab, evident in 15% (31/212) of patients, did not predict subsequent loss of urate-lowering response. Loss of sUA response preceded IRs in 44 of 56 (79%) pegloticase-treated patients. Conclusions: Loss of responsiveness to pegloticase is associated with the development of high titer anti-pegloticase Ab that increase clearance of pegloticase and are associated with a loss of the sUA lowering effect and increased IR risk. Pre-infusion sUA can be used as a surrogate for the presence of deleterious anti-pegloticase Ab. Trial registration: NCT00325195. Registered 10 May 2006, NCT01356498. Registered 27 October 2008.