Johnson & Johnson reports that its once-daily oral peptide icotrokinra improved joint disease in adults with psoriatic arthritis in a phase 3 trial called ICONIC-PsA 1. At week 16, 58% of people taking the 200 mg dose reached an ACR20 response, meaning at least 20% improvement in joint measures, against 41% on placebo.
Icotrokinra is a peptide designed to block the interleukin-23 receptor. The results were announced on 7 November and are being presented as a late-breaking poster at the American College of Rheumatology (ACR) Convergence meeting this week.
How the trial worked
The study randomised 552 biologic-naive adults with active psoriatic arthritis, meaning they had not been treated with biologic drugs before. They received icotrokinra 200 mg, icotrokinra 400 mg or placebo once a day. A fourth group received the injected antibody ustekinumab as a safety reference. Placebo patients were moved onto icotrokinra at week 16.
What the results showed
On the 200 mg dose, ACR20 at week 16 was 58% against 41% on placebo (p=0.002). The 400 mg dose reached 52%, which was not a statistically significant difference from placebo (p=0.052). Among people with qualifying skin involvement, 57% on either dose reached clear or almost clear skin (IGA 0/1) against 14% on placebo.
The company release also reports, for the 200 mg dose at week 16, ACR50 of 29% against 16% and a 90% improvement in the psoriasis skin score (PASI 90) in 37% against 6%. By week 24, 69% on the 200 mg dose had reached ACR20.
Through week 16, adverse events were reported by 44% of people on 200 mg, 52% on 400 mg, 41% on placebo and 51% on ustekinumab. The abstract states that no new safety signals were identified through week 24.
What is still unknown
The results come from a company release and a conference abstract, and the full trial has not been published in a peer-reviewed journal. Only 24 weeks of data are reported, and after week 16 there is no placebo group to compare against because placebo patients switched to treatment. The ustekinumab arm served as a safety reference, so the trial does not compare how well the two work.
Icotrokinra is approved in the United States for moderate-to-severe plaque psoriasis but not for psoriatic arthritis. A second phase 3 trial, ICONIC-PsA 2, is testing it in people who have already used biologics. OrientSciences worked from the Johnson & Johnson release and the ACR abstract and did not read a full paper.