Tofacitinib is the first Janus kinase (JAK) inhibitor commercially approved for the treatment of rheumatoid arthritis. This compound and a number of other JAK inhibitors are currently being tested in phase II and III trials for the treatment of a variety of autoimmune inflammatory diseases. Whereas a characteristic safety profile is emerging for some JAK inhibitors, differences between individual agents might emerge on the basis of distinct potency against their molecular targets. Similarly to biological therapy, JAK inhibition can lead to serious and opportunistic infections, and viral infections seem to be particularly frequent. Although no malignancy signals have been identified to date, long-term follow-up and further research are needed to understand the risk of malignancy associated with these compounds. As is the case for biologic agents, vaccination is important to mitigate the risks of these emerging therapies.

The emerging safety profile of JAK inhibitors in rheumatic disease

Objectives: Tofacitinib is an oral Janus kinase inhibitor for the treatment of rheumatoid arthritis (RA). We report an integrated safety summary of tofacitinib from two phase I, nine phase II, six phase III and two long-term extension studies in adult patients with active RA. Methods: Data were pooled for all tofacitinib-treated patients (data cut-off: 31 March 2015). Incidence rates (IRs; patients with event/100 patient-years) and 95% CIs are reported for adverse events (AEs) of interest. Results: 6194 patients received tofacitinib for a total 19 406 patient-years' exposure; median exposure was 3.4 patient-years. IR (95% CI) for serious AEs was 9.4 (9.0 to 9.9); IR for serious infections was 2.7 (2.5 to 3.0). IR for (all) herpes zoster was 3.9 (3.6 to 4.2); IR for disseminated or multidermatomal herpes zoster was 0.3 (0.2 to 0.4). IR for opportunistic infections (excluding tuberculosis) was 0.3 (0.2 to 0.4) and was 0.2 (0.1 to 0.3) for tuberculosis. IR for malignancies (excluding non-melanoma skin cancer (NMSC)) was 0.9 (0.8 to 1.0); NMSC IR was 0.6 (0.5 to 0.7). IR for gastrointestinal perforations was 0.1 (0.1 to 0.2). Analysis of IR for serious infections, herpes zoster and malignancies by 6-month intervals did not reveal any notable increase in IR with longer-duration tofacitinib exposure. Conclusion: This analysis of tofacitinib exposure up to 8.5 years allowed estimation of safety events with improved precision versus previous tofacitinib reports. AEs were generally stable over time; no new safety signals were observed compared with previous tofacitinib reports.

https://ard.bmj.com/content/annrheumdis/76/7/1253.full.pdf

Long-term safety of tofacitinib for the treatment of rheumatoid arthritis up to 8.5 years: integrated analysis of data from the global clinical trials

Objective Baricitinib is an oral, once-daily selective Janus kinase (JAK1/JAK2) inhibitor for adults with moderately to severely active rheumatoid arthritis (RA) We evaluated baricitinib’s safety profile through 288 weeks (up to September 1, 2016) with an integrated database [8 phase III/II/Ib trials, 1 longterm extension (LTE)] Methods The “all-bari-RA” group included patients who received any baricitinib dose Placebo comparison was based on the 6 studies with 4 mg and placebo up to Week 24 (“placebo-4 mg” dataset) Dose response assessment was based on 4 studies with 2 mg and 4 mg including LTE data (“2 mg-4 mg–extended”) The uncommon events description used the non-controlled all-bari-RA Results There were 3492 patients who received baricitinib for 6637 total patient-years (PY) of exposure (median 21 yrs, maximum 55 yrs) No differences in rates of death, adverse events leading to drug discontinuation, malignancies, major adverse cardiovascular event (MACE), or serious infections were seen for 4 mg versus placebo or for 4 mg versus 2 mg Infections including herpes zoster were significantly more frequent for 4 mg versus placebo Deep vein thrombosis/pulmonary embolism were reported with 4 mg but not placebo [all-bari-RA incidence rate (IR) 05/100 PY]; the IR did not differ between doses (05 vs 06/100 PY, 2 mg vs 4 mg, respectively) or compared to published RA rates All-bari-RA had 6 cases of lymphoma (IR 009/100 PY), 3 gastrointestinal perforations (005/100 PY), 10 cases of tuberculosis (all in endemic areas; 015/100 PY), and 22 all-cause deaths (033/100 PY) IR for malignancies (08/100 PY) and MACE (05/100 PY) were low and did not increase with prolonged exposure Conclusion In this integrated analysis of patients with moderate to severe active RA with exposure up to 55 years, baricitinib has an acceptable safety profile in the context of demonstrated efficacy Trial registration numbers: NCT01185353, NCT00902486, NCT01469013, NCT01710358, NCT01721044, NCT01721057, NCT01711359, and NCT01885078 at clinicaltrialsgov

https://www.jrheum.org/content/jrheum/46/1/7.full.pdf

Safety Profile of Baricitinib in Patients with Active Rheumatoid Arthritis with over 2 Years Median Time in Treatment

Background Mepolizumab has demonstrated favorable safety and efficacy profiles in placebo-controlled trials of 12 months' duration or less; however, long-term data are lacking. Objective We sought to evaluate the long-term safety and efficacy of mepolizumab in patients with severe eosinophilic asthma (SEA). Methods COLUMBA (Open-label Long Term Extension Safety Study of Mepolizumab in Asthmatic Subjects, NCT01691859 ) was an open-label extension study in patients with SEA previously enrolled in DREAM (Dose Ranging Efficacy And Safety With Mepolizumab in Severe Asthma, NCT01000506 ). Patients received 100 mg of subcutaneous mepolizumab every 4 weeks plus standard of care until a protocol-defined stopping criterion was met. Safety end points included frequency of adverse events (AEs), serious AEs, and AEs of special interest. Efficacy end points included annualized exacerbation rates, changes from baseline in Asthma Control Questionnaire 5 scores, and blood eosinophil counts. Immunogenicity was also assessed. Results Overall, 347 patients were enrolled for an average of 3.5 years (maximum, 4.5 years; total exposure, 1201 patient-years). On-treatment AEs were reported in 94% of patients (exposure-adjusted rate, 3688 events/1000 patient-years). The most frequently reported on-treatment AEs were respiratory tract infection, headache, bronchitis, and asthma worsening. Seventy-nine (23%) patients experienced 1 or more on-treatment serious AEs; there were 6 deaths, none of which were assessed as related to mepolizumab. For patients with 156 weeks or greater enrollment, the exacerbation rate was 0.74 events/y (weeks 0–156), a 56% reduction from the off-treatment period between DREAM and COLUMBA. For all patients, at the first postbaseline assessment, the mean Asthma Control Questionnaire 5 score was reduced by 0.47 points, and blood eosinophil counts were reduced by 78%, with similar improvements maintained throughout the study. The immunogenicity profile (8% anti-drug antibodies) was consistent with previous studies. Conclusion These data support the long-term safety and efficacy of mepolizumab in patients with SEA.

Assessment of the long-term safety of mepolizumab and durability of clinical response in patients with severe eosinophilic asthma.

Objectives To evaluate the risk of serious infection (SI) and herpes zoster (HZ) in rheumatoid arthritis patients receiving JAK inhibitors. Methods We conducted a systematic literature review and meta-analysis of phase II and III randomized controlled trials of tofacitinib (5 mg bid), baricitinib (4 mg od) and upadacitinib (15 mg od). Patient-exposure years were calculated. A per-protocol analysis was applied, incorporating follow-up time from patients randomized to placebo who cross into the treatment arm. Pooled incidence rates per 100 person-years of SI and HZ were calculated. Incidence rate ratios (IRRs) of drug vs placebo were compared using a meta-synthesis approach. Results Twenty-one studies were included in the meta-analysis; 11 tofacitinib (5888 patients), six baricitinib (3520 patients) and four upadacitinib studies (1736 patients). For SI, the incidence rates were 1.97 (95% CI: 1.41, 2.68), 3.16 (95% CI: 2.07, 4.63) and 3.02 (95% CI: 0.98, 7.04), respectively. The IRRs comparing treatment arm to placebo were statistically non-significant: 1.22 (95% CI: 0.60, 2.45), 0.80 (95% CI: 0.46, 1.38) and 1.14 (95% CI: 0.24, 5.43), respectively. For HZ, the incidence rates were 2.51 (95% CI: 1.87, 3.30), 3.16 (95% CI: 2.07, 4.63) and 2.41 (95% CI: 0.66, 6.18), respectively. The IRR of HZ comparing baricitinib with placebo was 2.86 (95% CI: 1.26, 6.50). Non-significant IRRs were seen with tofacitinib and upadacitinib: 1.38 (95% CI: 0.66, 2.88) and 0.78 (95% CI: 0.19, 3.22), respectively. Indicator opportunistic infections excluding HZ were too rare to provide meaningful incidence rates. Conclusion The absolute SI rates were low. However across the JAK inhibitors, the incidence of HZ is higher than expected for the population (3.23 per 100 patient-years). While the risk was numerically greatest with baricitinib, indirect comparisons between the drugs did not demonstrate any significant difference in risk. Systematic review registration number Prospero 2017 CRD4201707879.

A systematic review and meta-analysis of infection risk with small molecule JAK inhibitors in rheumatoid arthritis

No consensus has previously been formed regarding the types and presentations of infectious pathogens to be considered as 'opportunistic infections' (OIs) within the setting of biologic therapy. We systematically reviewed published literature reporting OIs in the setting of biologic therapy for inflammatory diseases. The review sought to describe the OI definitions used within these studies and the types of OIs reported. These findings informed a consensus committee (infectious diseases and rheumatology specialists) in deliberations regarding the development of a candidate list of infections that should be considered as OIs in the setting of biologic therapy. We reviewed 368 clinical trials (randomised controlled/long-term extension), 195 observational studies and numerous case reports/series. Only 11 observational studies defined OIs within their methods; no consistent OI definition was identified across studies. Across all study formats, the most numerous OIs reported were granulomatous infections. The consensus group developed a working definition for OIs as 'indicator' infections, defined as specific pathogens or presentations of pathogens that 'indicate' the likelihood of an alteration in host immunity in the setting of biologic therapy. Using this framework, consensus was reached upon a list of OIs and case-definitions for their reporting during clinical trials and other studies. Prior studies of OIs in the setting of biologic therapy have used inconsistent definitions. The consensus committee reached agreement upon an OI definition, developed case definitions for reporting of each pathogen, and recommended these be used in future studies to facilitate comparison of infection risk between biologic therapies.

https://ard.bmj.com/content/annrheumdis/74/12/2107.full.pdf?with-ds=yes

Opportunistic infections and biologic therapies in immune-mediated inflammatory diseases: consensus recommendations for infection reporting during clinical trials and postmarketing surveillance

F Bartalesi

Papers

Opportunistic infections and biologic therapies in immune-mediated inflammatory diseases: consensus recommendations for infection reporting during clinical trials and postmarketing surveillance