Janssen Research & Development, LLC (Janssen) announced today longer-term results from a Phase 2 study investigating TREMFYA® (guselkumab), the first selective antiinterleukin- (IL)-23 monoclonal antibody to show positive results in the treatment of active psoriatic arthritis.
According to findings presented at the 2017 American College of Rheumatology/Association of Rheumatology Health Professionals (ACR/ARHP) Annual Meeting, more than 70 percent of patients receiving guselkumab 100 mg subcutaneous injections achieved at least a 20 percent improvement in signs and symptoms of disease (ACR 20) using observed data at week 56. These data follow initial results that showed 66.3 percent of patients treated with guselkumab achieved an ACR 20 response at week 24, the primary endpoint of the study, compared with 31 percent of patients receiving placebo (p<0.001). 1 Based on the Phase 2 study results, Janssen has initiated two Phase 3 studies to evaluate the efficacy and safety of guselkumab in the treatment of patients with active psoriatic arthritis who may have been previously treated with anti-tumor necrosis factor (TNF) alpha therapies (DISCOVER-1), and in patients who have not received prior treatment with a biologic therapy (DISCOVER-2).
In September, the Committee for Medicinal Products for Human Use (CHMP) adopted a positive opinion recommending marketing authorisation in the European Union for the use of guselkumab in the treatment of adults with moderate to severe plaque psoriasis who are candidates for systemic therapy.
“Patients with active psoriatic arthritis live with substantial disease burden, experiencing joint pain, swelling and stiffness, along with painful skin plaques associated with psoriasis,” said Atul Deodhar, M.D., MRCP, FACP, FACR, Professor of Medicine, Oregon Health & Science University and study steering committee member. “It is encouraging to see that patients receiving this IL-23 inhibitor demonstrated improvement in symptoms of active psoriatic arthritis at week 24, and results were maintained through one year with guselkumab therapy. I look forward to future results from the Phase 3 trials.”
The Phase 2 study met all primary and secondary endpoints with statistical significance at week 24. At week 24, patients in the placebo group crossed over to receive guselkumab, and patients originally randomised to active treatment continued guselkumab therapy, both groups receiving every eight-week therapy (after 2 starter doses at weeks 0 and 4) with the final injection administered at week 44.
At week 56, based on the observed data, signs and symptoms of psoriatic arthritis including tender and swollen joints, pain and physical function [measured by the health assessment questionnaire-disability index (HAQ-DI) score], levels of skin clearance (PASI improvements) and patient-reported quality of life outcomes (measured by the SF-36 questionnaire) improved through week 24 and were maintained through week 56 in patients treated with guselkumab.
Selected efficacy endpoints at week 56 showed:
 ACR 20 and ACR 50 responses were achieved by 74 percent and 53 percent of patients in the guselkumab group, respectively.
 85 percent of patients in the guselkumab group demonstrated a PASI 75 response.
 78 percent of patients in the guselkumab group demonstrated a PASI 90 response (near complete skin clearance).
 57 percent of patients in the guselkumab group demonstrated a PASI 100 response (complete skin clearance).
 Mean improvements in HAQ-DI scores (which range from 0-3.0) were 0.55 for the guselkumab group.
 Patients in the guselkumab group experienced significant improvements in inflammation of the fingers and toes (dactylitis) and sites at which tendons or ligaments attach to bone (enthesitis), as well as measures of physical and mental health as reported by the SF-36 assessment tool.
Post-week 24, there were no observed differences in adverse event (AE) rates among patients with differing lengths of exposure to guselkumab. Through week 56, 40 percent of all patients experienced AEs, the most common of which were infections. Serious AEs were reported in six percent of patients and included one myocardial infarction and one malignancy (basal cell carcinoma). There were no deaths.
“We are proud to have introduced guselkumab, an important new treatment option for patients living with moderate to severe plaque psoriasis,” said Newman Yeilding, M.D., Head of Immunology Development, Janssen. “We are also eager to continue the study of guselkumab in the treatment of active psoriatic arthritis through the Phase 3 programmes, recognising that one-third of patients diagnosed with plaque psoriasis will unfortunately develop psoriatic arthritis.”
Guselkumab received U.S. Food and Drug Administration (FDA) approval in July for the treatment of adults with moderate to severe plaque psoriasis who are candidates for systemic therapy or phototherapy.