Gilead Sciences and Galapagos NV have announced their drug filgotinib met its primary endpoint in week 24 of two Phase III trials, Finch 1 and FINDCH 3, of rheumatoid arthritis patients.

In FINCH 3 a higher proportion of patients given 200mg or 100mg of filgotinib in combination with methotrexate (MTX) achieved an American College of Rheumatology 20% response (ACR20) at week 24, which was the trial’s endpoint, than receiving only MTX.

Also, a larger proportion patients in the two combination drug groups achieved ACR50, ACR70 and clinical remission at week 24, compared to patients receiving MTX monotherapy.

During the FINCH 3 trial, filgotinib was also studied alone. In addition to a higher proportion of the filgotinib monotherapy group achieving ACR20, ACR50 and ACR70, the drug inhibited the progression of structural damage and caused a greater reduction in the Health Assessment Questionnaire Disability Index than the MTX monotherapy group.

Data showed 81% of 200mg combination group, 80.2% of the 100mg group and 78.1% of the monotherapy group achieved ACR20, compared to 71.4% in the MTX group.

The rheumatoid arthritis patients studied in FINCH 3 are naïve to MTX. Although the endpoint is ACR20 at week 24, the study will continue for the remaining 28 weeks.

In FINCH 1, which studies patients with a prior inadequate response to MTX and its primary endpoint was achieving ACR20 at week 12, two doses of filgotinib in combination with MTX were compared to adalimumab combined with MTX and placebo.

At week 24, 76.6% of the 200mg dose group of filgotinib and MTX, 69.8% of the 100mg dose group and 70.8% of the adalimumab and MTX achieved ACR20 at week 12, compared to 49.9% for placebo.

Additionally, a larger proportion of filgotinib combination groups achieved ACR50 and ACR70 than the placebo and adalimumab with MTX.

Gilead chief scientific officer and head of research and development John McHutchison said: “Across the FINCH program, the data continue to support filgotinib’s potential as a JAK1 specific inhibitor that may provide clinically meaningful responses combined with a favorable safety profile in a wide range of people living with rheumatoid arthritis, including those in the early stages of disease and those who have tried standard therapies without success.”

Gilead and Galapagos are also investigating the safety and efficacy of filgotinib in other inflammatory indications, including psoriatic arthritis, ankylosing spondylitis, Crohn’s disease and ulcerative colitis.