Gilead Sciences and Galapagos have presented long-term midphase data on filgotinib in patients with active psoriatic arthritis. The analysis shows responses seen at 16 weeks were sustained out to 52 weeks after the initiation of treatment.
With JAK1 inhibitor filgotinib now nearing approval in rheumatoid arthritis, Gilead and Galapagos have used the virtual congress of the European League Against Rheumatism (EULAR) to present the findings of a number of studies involving the drug. Rheumatoid arthritis remains the big opportunity, but the partners are also targeting a clutch of other indications that analysts at Jefferies think could collectively bring in sales of $3 billion a year.
Active psoriatic arthritis is part of that strategy. Having linked filgotinib to a better response rate than placebo in the original phase 2 readout, Gilead and Galapagos used EULAR to showcase a long-term update and subgroup analysis.
The long-term update supports the durability of filgotinib in the indication. Of the participants who experienced a 50% improvement in symptoms measured by an American College of Rheumatology scale over the first 16 weeks of the trial, 93% still cleared that efficacy bar as of week 52. More than one-third of nonresponders at week 16 went on to experience a 50% improvement by the end of the long-term follow up. Filgotinib also drove lasting improvements against other measures of efficacy.
Gilead and Galapagos presented the long-term data alongside an analysis of how different subgroups of patients responded to filgotinib over the first 16 weeks of the trial. The analysis linked filgotinib to improved symptoms regardless of sex, weight, disease duration and activity, and prior treatment use.
A third EULAR abstract detailed the effect of filgotinib on inflammatory biomarkers. Galapagos Chief Medical Officer Walid Abi-Saab highlighted the biomarker study in a statement.
“We are particularly encouraged by the innovative analysis of the impact of filgotinib at the molecular level, which indicates the drug is acting rapidly to reduce the hallmarks of inflammation in this condition,” Abi-Saab said.
Gilead initiated a phase 3 trial of filgotinib in active psoriatic arthritis late last year. The trial was due to deliver data in the first half of 2022, but that timeline was brought into question after COVID-19 led to a temporary pause in enrollment. Gilead has since resumed recruitment.