Gilead Sciences and Galapagos announced positive topline results from SELECTION, a randomized, double-blind, placebo-controlled, Phase 2b/3 trial evaluating the efficacy and safety of the investigational, oral, once-daily, selective JAK1 inhibitor filgotinib in 1,348 biologic-na?ve or biologic-experienced adult patients with moderately to severely active ulcerative colitis (UC).

Filgotinib 200 mg achieved all primary endpoints in the study, inducing clinical remission at Week 10 and maintaining clinical remission at Week 58 in a significantly higher proportion of patients compared with placebo. Filgotinib 100 mg did not achieve statistically significant clinical remission at Week 10.

In this trial, clinical remission was defined as an endoscopic subscore of 0 or 1, rectal bleeding subscore of 0, and ≥ 1 point decrease in stool frequency from baseline to achieve a subscore of 0 or 1. Among the biologic-na?ve cohort (Cohort A induction trial; n=659), 52 percent of patients had a baseline Mayo Clinic Score (MCS) of nine or higher. In the biologically-experienced cohort (Cohort B induction trial; n=689), 74 percent of patients had a baseline MCS of nine or higher, and 51 percent were previously treated with two different classes of biologics (TNFα antagonists and an integrin receptor antagonist).

Among biologic-na?ve patients, a statistically significant higher proportion of patients achieved clinical remission at Week 10 when treated with filgotinib 200 mg (26.1 percent, p=0.0157) compared with placebo (15.3 percent). Among biologic-experienced patients, a statistically significant higher proportion of patients achieved clinical remission at Week 10 when treated with filgotinib 200 mg (11.5 percent, p=0.0103) compared with placebo (4.2 percent).

Patients who achieved clinical response or remission after 10 weeks of treatment with filgotinib 100 mg or 200 mg were subsequently re-randomized to their induction dose of filgotinib or placebo in a 2:1 ratio and treated through Week 58 (maintenance trial, n=558). Both doses of filgotinib achieved the primary endpoint in this maintenance trial. At Week 58, 37.2 percent of biologic-na?ve and biologic-experienced patients receiving filgotinib 200 mg achieved clinical remission, compared with 11.2 percent treated with placebo (p?0.0001).

Of patients receiving filgotinib 100 mg, 23.8 percent achieved clinical remission at Week 58, compared with 13.5 percent treated with placebo (p=0.0420).

In the induction trial of biologic-na?ve patients, the incidence of serious adverse events was similar across treatment groups (200 mg: 1.2 percent; 100 mg: 4.7 percent; placebo: 2.9 percent). In the induction trial of biologic-experienced patients, the incidence of serious adverse events was also similar across treatment groups (200 mg: 7.3 percent; 100 mg: 5.3 percent; placebo: 6.3 percent). There were no deaths in either induction cohort.

In the maintenance trial, 4.5 percent of patients treated with filgotinib 200 mg experienced a serious adverse event, compared with none for their corresponding placebo; 4.5 percent of patients treated with filgotinib 100 mg experienced a serious adverse event, compared with 7.7 percent for their corresponding placebo.

Rates of serious infections, herpes zoster, venous thrombosis, pulmonary embolism and gastrointestinal perforation were low and comparable across treatment groups in both the induction and maintenance phases of the study. Two deaths were observed in the filgotinib 200 mg treatment group in the maintenance trial. One patient with pre-existing asthma died due to asthma exacerbation, and the second patient with pre-existing atherosclerosis died due to left ventricular heart failure per autopsy report. Neither death was assessed as related to study drug by the investigator.

“We are encouraged by the early response as an induction therapy and the durable efficacy as a maintenance therapy observed in the SELECTION trial,” said Merdad Parsey, MD, PhD, Chief Medical Officer, Gilead Sciences. “Patients with moderate to severe ulcerative colitis can struggle to effectively manage their disease. These topline data suggest that filgotinib could play a role in helping more patients achieve a meaningful and sustained improvement in treatment response with an oral therapy.”

“We are pleased to see that SELECTION results indicate that filgotinib can help ulcerative colitis patients, including those refractory to treatment, achieve and sustain remission for more than one year,” said Dr. Walid Abi-Saab, Chief Medical Officer, Galapagos. “We believe that the results point to an efficacy and safety profile consistent with prior studies with filgotinib, and offer a meaningful contribution to the patient data with filgotinib from other inflammatory conditions. We look forward to presenting more detailed results to the scientific community.”

UC is a chronic, idiopathic inflammatory disease affecting the colon and often involves periods of remission interspersed with periods of active disease. Common symptoms of UC are bloody diarrhea and rectal urgency. UC is often diagnosed in people of working age who can face debilitating flares in their symptoms and progression of disease overtime. An estimated 40 percent of patients experience a relapse annuallyi and do not achieve sustained remission.

Detailed results from the SELECTION trial will be submitted for presentation at a future scientific conference.

Filgotinib is an investigational agent and is not approved by the FDA or any other regulatory authority for any use. Regulatory submissions of filgotinib for the treatment of rheumatoid arthritis are currently under review by the FDA, European Medicines Agency, and Japan’s Ministry of Health, Labour and Welfare. The efficacy and safety of filgotinib have not been established.