MADRID – The Janus kinase inhibitor tofacitinib had a safety profile mostly similar to that of biologic drugs in a review of more than 8,600 U.S. rheumatoid arthritis patients enrolled in a national registry during 2012-2017, the first 5 years when tofacitinib was on the U.S. market.
Mitchel L. Zoler/MDedge News
Dr. Joel M. Kremer
The “reassuring” safety performance of tofacitinib (Xeljanz) compared with biologic agents used to treat rheumatoid arthritis (RA) in these registry data notably showed a similar rate of venous thromboembolism (VTE) with tofacitinib treatment compared with biologic drugs, Joel M. Kremer, MD, reported at the European Congress of Rheumatology. It is an important finding because of recent concerns raised about VTE incidence among patients taking tofacitinib or another Janus kinase (JAK) inhibitor, he noted. The registry analysis Dr. Kremer presented showed that patients treated with tofacitinib had slightly more than double the rate of herpes zoster, compared with patients on biologic agents, a finding consistent with prior reports that tofacitinib treatment linked with an almost threefold increased rate of herpes zoster when compared with placebo-treated patients in a series of clinical trials (Arthritis Rheumatol. 2014 Oct;66[10]:2675-84). None of the herpes zoster activations identified in the registry patients on tofacitinib were rated as “serious,” noted Dr. Kremer , professor of medicine at Albany (N.Y.) Medical College.
The analysis he presented used data collected in the Corrona Rheumatoid Arthritis registry during November 2012, the month when tofacitinib received U.S. marketing approval, through December 2017. Data came from RA patients in the registry who began treatment during November 2012–June 2017 with either tofacitinib (1,544 patients) or a biologic agent (7,083 patients). The safety assessment focused on four outcomes: the combined rate of major adverse cardiovascular events (including MI, strokes, and fatal events); the incidence of serious infection; the incidence of any herpes zoster regardless of severity; and VTE. These outcomes were numerous enough to allow for propensity-score matching of patients from the tofacitinib and biologic subgroups to adjust for baseline differences between patients in these two categories, but as of the end of 2017, the cumulative number of VTEs was not high enough to allow for propensity-score adjustment, Dr. Kremer said, so instead he reported the unadjusted numbers. Further data collection should allow an adjusted analysis of VTE within another couple of years, he added. The currently available VTE data were “underpowered” for more rigorous statistical analysis, Dr. Kremer said.
After adjustment, the patients treated with tofacitinib had a 42% lower rate of major cardiovascular events, compared with patients who received a biologic drug, but the difference was not statistically significant, and the two subgroups had virtually identical rates of all serious infections. The incidence of herpes zoster was 2.26-fold more frequent among tofacitinib-treated patients than among those on other biologic agents, a statistically significant difference. The unadjusted VTE analysis showed a rate of 0.19/100 patient-years with tofacitinib treatment, and 0.33/100 patient-years with other biological agents, a difference that was not statistically significant, Dr. Kremer reported. Comparison of the rates of pulmonary embolism and deep vein thrombosis were each not statistically different between the two treatment subgroups.
Concern about possibly increased rates of VTE with the use of tofacitinib or other JAK inhibitors arose recently primarily because of two reports. In February 2019, the Food and Drug Administration released a safety announcement that data from an ongoing, postmarketing study of tofacitinib showed an elevated rate of RA patients with pulmonary embolism when they received an off-label, 10-mg twice-daily dosage of the drug, twice the labeled maximum dosage for this population. (The labeling for tofacitinib allows for a maximum dosage of 10 mg twice daily for patients treated for ulcerative colitis.) In addition, a recent report on another JAK inhibitor approved for U.S. marketing for RA treatment, baricitinib (Olumiant), documented a possible excess of VTE events among patients treated with this drug, compared with those who received placebo (Arthritis Rheumatol. 2019 Jan 21. doi: 10.1002/art.40841).
Regarding the now well-described excess of herpes zoster with tofacitinib treatment, Dr. Kremer said that perhaps the best way to address this in a patient who seems to be at risk is to prophylactically vaccinate the patient with the recombinant, adjuvanted zoster vaccine (Shingrix). However, this means withdrawing disease-modifying treatment from the RA patient for 3 weeks at the time of each of two vaccinations, with the possibility of flare induced by the adjuvant, he explained in an interview. The risks and benefits of this approach have not been investigated, he noted, and the Corrona data he studied came almost entirely from the period before Shingrix came onto the U.S. market following its approval in late 2017.
Dr. Kremer has been a consultant to and has received research funding from Pfizer, the company that markets tofacitinib. He has been a consultant to AbbVie, Amgen, Bristol-Myers Squibb, Genentech, and Regeneron/Sanofi, and has received research funding from AbbVie, Eli Lilly, Genentech, and Novartis. One of the coauthors on the report is a Pfizer employee.
SOURCE: Kremer JM et al. Ann Rheum Dis. Jun 2019;78(Suppl 2):82-3; Abstract OP0028. doi: 10.1136/annrheumdis-2019-eular.621.