MAUI, HAWAII – As it grows increasingly likely that oral Janus kinase inhibitors will constitute a major development in the treatment of rheumatoid arthritis, with a bevy of these agents becoming available for that indication, rheumatologists are asking questions about the coming revolution. Like, when should these agents be used? What are the major safety and efficacy differences, if any, within the class? How clinically relevant is JAK selectivity? And which JAK inhibitor is the best choice?
Bruce Jancin/MDedge News
Dr. Roy M. Fleischmann (L) and Dr. Mark Genovese
on these and other related questions at the 2019 Rheumatology Winter Clinical Symposium.
These issues take on growing relevance for clinicians and their RA patients because two oral small molecule JAK inhibitors – tofacitinib (Xeljanz) and baricitinib (Olumiant) – are already approved for RA, and three more – upadacitinib, filgotinib, and peficitinib – are on the horizon. Indeed, AbbVie has already filed for marketing approval of once-daily upadacitinib for RA on the basis of an impressive development program featuring six phase 3 trials, with a priority review decision from the Food and Drug Administration anticipated this fall. Filgotinib is the focus of three phase 3 studies, one of which is viewed as a home run, with the other two yet to report results. Peficitinib is backed by two positive phase 3 trials, although its manufacturer will at least initially seek marketing approval only in Japan and South Korea. And numerous other JAK inhibitors are in development for a variety of indications.
When should a JAK inhibitor be used?
That’s easy, according to Roy M. Fleischmann, MD: If the cost proves comparable, it makes sense to turn to a JAK inhibitor ahead of a tumor necrosis factor inhibitor or other biologic.
He noted that in the double-blind, phase 3 SELECT-COMPARE head-to-head comparison of upadacitinib at 15 mg/day, adalimumab (Humira) at 40 mg every other week, versus placebo, all on top of background methotrexate, upadacitinib proved superior to the market-leading tumor necrosis factor inhibitor in terms of both the American College of Rheumatology–defined 20% level of response (ACR 20) and 28-joint Disease Activity Score based on C-reactive protein (DAS28-CRP).
“The results were very dramatic,” noted Dr. Fleischmann, who presented the SELECT-COMPARE findings at the 2018 annual meeting of the American College of Rheumatology.
Moreover, other major trials have shown that baricitinib at 4 mg/day was superior in efficacy to adalimumab, and tofacitinib and peficitinib were “at least equal” to anti-TNF therapy, he added.
“These numbers are clinically meaningful – not so much for the difference in ACR 20, but in the depth of response: the ACR 50 and 70, the CDAI. I think these drugs are better than adalimumab,” declared Dr. Fleischmann, codirector of the division of rheumatology at Texas Health Presbyterian Medical Center, Dallas.
Mark Genovese, MD, concurred.
“I think that for most patients who don’t have a lot of other comorbidities, they would certainly prefer to take a pill over a shot. And if you have a drug that’s more effective than the standard of care and it comes at a reasonable price point – and ‘reasonable’ is in the eye of the beholder – but if I can get access to it on the formulary, I’d have no qualms about putting them on a JAK inhibitor before I’d move to a TNF inhibitor,” said Dr. Genovese, professor of medicine and director of the rheumatology clinic at Stanford (Calif.) University.
Upadacitinib elicited a better response at 30 mg than at 15 mg once daily in the phase 3 program; however, both speakers indicated they’d be happy with access to the 15-mg dose, should the FDA go that route, since it has a better safety profile.
Dr. Genovese was principal investigator in the previously reported multicenter FINCH2 trial of filgotinib at 100 or 200 mg/day in RA patients with a prior inadequate response to one or more biologic disease-modifying antirheumatic drugs.
“Impressive results in a refractory population,” he said. “I don’t see a big difference in safety between 100 and 200 mg, so I’d opt for the 200 because it worked really well in patients who had refractory disease.”