COSMOS Study - Guselkumab Efficacy at 1 Year in Psoriatic Arthritis

Jack Cush, MD

Feb 24, 2022 6:33 pm

Guselkumab, an IL-2319-subunit antibody, was studied in active psoriatic arthritis (PsA) patients who had a previously inadequate response (IR) to tumour necrosis factor inhibitors (TNFi) and after 1 year was shown to significantly improved joint and skin manifestations and physical function.

A total of 285 active, TNFi-IR, PsA (≥3 swollen and ≥3 tender joints) patients were randomised (2:1) to subcutaneous guselkumab 100 mg or placebo and were serially assessed through week 44. Placebo treated patients were crossed over to guselkumab at week 24. The primary endpoint was the change in ACR20.

TNFi failures inlcuded 88% with one prior and 12% with prior TNFi.

An ACR20 response was significantly higher in those receiving guselkumab (44% vs 20%) than placebo (multiplicity-adjusted p<0.001) at week 24 and was also significantly superior in multiple secondary endpoint measures.

At week 48, the ACR20 response was 58% in the guselkumab group; notably >80% of week 24 responders maintained an ACR20 response at week 48.

Serious adverse events were seen in 3.7%/0.5% of GUS patients compared to 3.1%/0% of PBO patients. Serious infections were rare (0.5% GUS Vs. 0% in PB). There were no deaths or opportunistic infections.

The data suggests a favurable benefit–risk profile for GUS through 1 year.

fficacy and safety of guselkumab in patients with active psoriatic arthritis who are inadequate responders to tumour necrosis factor inhibitors: results through one year of a phase IIIb, randomised, controlled study (COSMOS)