SPIRIT P1 Study - Ixekinumab Sustains Efficacy at 52 Weeks in Psoriatic Arthritis Save

Ixekinumab (IXE) is an IGG4 monoclonal antibody bindings with high affinity to IL -17A.  Currently marketed at Taltz and approved for use in chronic plaque psoriasis, the agent is also being developed for use in psoriatic arthritis.

Today the results of the week 52, phase 3 SPIRIT P1 study were presented by Dr. Philip Mease and showed IXE to be superior to placebo (PBO) in achieving ACR 20 response in bDMARD-naive active PsA patients.

This current analysis was the extension of the earlier week 24 results.  The current report evaluated the efficacy and safety of IXE in the same group of patients over 52 weeks of treatment.

Of 417 active biologic naive PsA patients randomized to receive IXE 80 mg, IXE 40mg, adalumumab (ADA) or placeboe (PBO), 381 entered the Extension Period (EP) from weeks 24-52.

During EP patient recieved IXE 80 mg q4 weeks vs q2 weeks. ADA and PBO groups were rerandomized as well. During the EP IXE treated patients continued to demonstrate clinically significant improvement of arthritis, dactylitis and enthesitis as well as skin manifestations across all treatment groups.  Impressive PASI 75 and PASI 90 were observed.

Frequency of treatment related AE were comparable to the initial 4 weeks SPIRIT P1 trial, and the majority of AEs were mild to moderate in severity.

Serious adverse events were seen in 12 out of 304 patient who completed the study. Overall, the safety profile at 52 weeks was considered comparable to the initial 24 weeks study and the phase 3 UNCOVER trials  in cutaneous psoriasis alone.