Conference Coverage
JAK-1 inhibitors heading for validation in phase III trials
Key clinical point: Two new oral Janus kinase inhibitors selective for JAK-1 have shown promising efficacy and safety in separate phase II trials...
New results from several investigational oral Janus kinase inhibitor trials and an antifractalkine monoclonal antibody trial for patients with rheumatoid arthritis will be made available for the first time to attendees of the annual meeting of the American College of Rheumatology on Nov. 6 and 7 in San Diego.
Selective JAK-1 inhibitor upadacitinib
Two double-blind, randomized, controlled phase 3 studies of the oral, selective JAK-1 inhibitor upadacitinib (ABT-494) will be presented at the meeting, both involving once-daily extended-release formulations of the drug at 15 mg or 30 mg. The first trial, to be presented during an ACR abstract session on Monday, Nov. 6, showed that the drug met ACR 20 response criteria at significantly higher rates than did placebo at week 12 (63.8% for 15 mg, 66.2% for 30 mg, and 35.7% for placebo) in 661 patients with active RA and an inadequate response to conventional synthetic disease-modifying antirheumatic drugs (csDMARDs). Patients on the study drug also achieved low disease activity (28-joint Disease Activity Score using C-reactive protein [DAS28-CRP] of 3.2 or less) in higher proportions than did those who received placebo (48.4% for 15 mg, 47.9% for 30 mg, and 17.2% for placebo). More infections occurred in patients on 15 mg and 30 mg upadacitinib (29.0% and 31.5%, respectively), compared with placebo (21.3%), but there were no differences in serious infections. Three of the total four cases of herpes zoster infection were in patients taking upadacitinib.
A second upadacitinib trial, which involved patients on stable csDMARD therapy who could not tolerate or had disease refractory to a biologic DMARD, will be presented during a late-breaking poster session on Tuesday, Nov. 7. The study randomized 499 patients who had severe, refractory disease for a mean duration of 13 years. At 12 weeks, treatment with upadacitinib resulted in ACR 20 responses in 64.6% at 15 mg and 56.4% at 30 mg, compared with 28.4% for placebo. Responses at 12 weeks of 3.2 or less for DAS28-CRP also occurred at significantly higher rates of 43.3% for 15 mg and 42.4% for 30 mg, compared with 14.2% for placebo. Patients who were switched from placebo to active treatment at week 12 also achieved these responses at week 24, and the people who stayed on treatment with upadacitinib maintained or improved their response at week 24. More adverse events and infections tended to occur with upadacitinib at 30 mg than with 15 mg, and there were more herpes zoster infections with 30 mg (n = 4) vs. 15 mg (n = 1) and placebo (n = 1).
Antifractalkine monoclonal antibody
The Monday afternoon RA therapy abstract session will also feature the first-in-patient results at 52 weeks for the antifractalkine monoclonal antibody E6011 in an open-label phase 1/2 study of Japanese RA patients with active disease who had an inadequate response or intolerance to methotrexate or a TNF inhibitor. The results from the small trial of the biologic, which targets the chemokine that regulates chemotaxis and the adhesion of inflammatory cells that express CX3C chemokine receptor 1 (CX3CR1), indicate that the treatment has durable efficacy and is safe and well tolerated. Adverse events (AEs) developed in 84% of 28 patients who participated in the 52-week extension study, including a rate of 48% for treatment-emergent adverse events (TEAEs) and 14% for serious AEs. ACR 20 rates at week 52 ranged from 58% for 100 mg of E6011 to 73% for 200 mg and 60% for 400 mg.
Filgotinib safety in an extension trial
The long-term, open-label results from two phase 2b studies of the JAK-1 inhibitor filgotinib that’s in development for RA also will be presented during the same Monday abstract session. These safety data out to 84 weeks from the long-term extension study of the DARWIN 1 and 2 studies, called DARWIN 3, show that, among patients who received at least one dose of filgotinib 100 mg twice daily or 200 mg once daily in addition to methotrexate, the rate of TEAEs ranged from about 146 to 153 per 100 patient-years of exposure (PYE), including about 41-45 infections per 100 PYE. For filgotinib monotherapy, the rate of TEAEs was 150 per 100 PYE for 200 mg once daily, including 38 infections per 100 PYE.
Total cholesterol of 200-239 mg/dL occurred at a rate of about 79 per 100 PYE and a level of 240 mg/dL or greater was seen in 61-64 per 100 PYE for patients who took filgotinib plus methotrexate. Filgotinib monotherapy at 200 mg once daily gave rates of about 94 and 71 per 100 PYE for those respective total cholesterol levels.