FRI0123 SAFETY PROFILE OF BARICITINIB FOR THE TREATMENT OF RHEUMATOID ARTHRITIS UP TO 8.4 YEARS: AN UPDATED INTEGRATED SAFETY ANALYSIS

JAK-STAT Signaling and Beyond in the Pathogenesis of Spondyloarthritis and Their Clinical Significance

PURPOSE OF REVIEW

Janus kinase-signal transducers and activators of transcription cell signaling proteins (JAK-STATs) play a key regulatory role in functioning of several inflammatory cytokines. JAK-STAT signaling proteins are the key regulators of the cytokine/cytokine receptor system involved in the pathogenesis of various autoimmune disease including spondyloarthritis (SpA). This article mainly highlights the JAK-STAT signaling system, its association with the relevant cytokine/cytokine-receptor system, and its regulatory role in pathogenesis of SpA. Also, we have briefly addressed the principle for the use JAKi in SpA and the current status of use of JAK inhibitors (JAKi) in SpA.

RECENT FINDINGS

Recent developments with newer JAK molecules as well as other molecules beyond JAK inhibitors are now an exciting field for the development of novel therapies for autoimmune diseases and various malignant conditions. In this article, we have provided a special emphasis on how various cell signaling systems beyond JAK/STAT pathway are relevant to SpA and have provided a comprehensive review on this upcoming field in respect to the novel TYK2 inhibitors, RORγT inhibitors, mTOR inhibitors, NGF inhibitors, and various STAT kinase inhibitors. SpA are a group of autoimmune diseases with multifactorial etiologies. SpA is linked with genetic predisposition, environmental risk factors, and the immune system-mediated systemic inflammation. Here, we have provided the regulatory role of JAK/STAT pathway and other intracellular signaling system in the pathogenesis of SpA and its therapeutic relevance.

Safety of baricitinib for the treatment of rheumatoid arthritis over a median of 4.6 and up to 9.3 years of treatment: final results from long-term extension study and integrated database

OBJECTIVE

To report long-term safety from the completed extension trial of baricitinib, an oral selective Janus kinase inhibitor, in patients with active rheumatoid arthritis (RA).

METHODS

Treatment-emergent adverse events are summarised from an integrated database (9 phase III/II/Ib and 1 long-term extension) of patients who received any baricitinib dose (All-bari-RA). Standardised incidence ratio (SIR) for malignancy (excluding non-melanoma skin cancer (NMSC)) and standardised mortality ratio (SMR) were estimated. Additional analysis was done in a subset of patients who had ever taken 2 mg or 4 mg baricitinib.

RESULTS

3770 patients received baricitinib (14 744 patient-years of exposure (PYE)). All-bari-RA incidence rates (IRs) per 100 patient-years at risk were 2.6, 3.0 and 0.5 for serious infections, herpes zoster and major adverse cardiovascular events (MACE), respectively. In patients aged ≥50 with ≥1 cardiovascular risk factor, the IR for MACE was 0.77 (95% CI 0.56 to 1.04). The IR for malignancy (excluding NMSC) during the first 48 weeks was 0.6 and remained stable thereafter (IR 1.0). The SIR for malignancies excluding NMSC was 1.07 (95% CI 0.90 to 1.26) and the SMR was 0.74 (95% CI 0.59 to 0.92). All-bari-RA IRs for deep vein thrombosis (DVT)/pulmonary embolism (PE), DVT and PE were 0.5 (95% CI 0.38 to 0.61), 0.4 (95% CI 0.26 to 0.45) and 0.3 (95% CI 0.18 to 0.35), respectively. No clear dose differences were noted for exposure-adjusted IRs (per 100 PYE) for deaths, serious infections, DVT/PE and MACE.

CONCLUSIONS

In this integrated analysis including long-term data of baricitinib from 3770 patients (median 4.6 years, up to 9.3 years) with active RA, baricitinib maintained a similar safety profile to earlier analyses. No new safety signals were identified.

TRIAL REGISTRATION NUMBER

NCT01185353, NCT00902486, NCT01469013, NCT01710358, NCT02265705, NCT01721044, NCT01721057, NCT01711359 and NCT01885078.

A Decade of JAK Inhibitors: What Have We Learned and What May Be the Future?

The discovery of cytokines and their role in immune and inflammatory disease led to the development of a plethora of targeted biologic therapies. Later, efforts to understand mechanisms of cytokine signal transduction led to the discovery of JAKs, which themselves were quickly identified as therapeutic targets. It has been a decade since the first JAK inhibitors (jakinibs) were approved, and there are now 9 jakinibs approved for the treatment of rheumatic, dermatologic, hematologic, and gastrointestinal indications, along with emergency authorization for COVID-19. In this review, we will summarize relevant discoveries that led to first-generation jakinibs and review their efficacy and safety as demonstrated in pivotal clinical studies. We will discuss the next generation of more selective jakinibs, along with agents that target kinase families beyond JAKs. Finally, we will reflect on both the opportunities and challenges ahead as we enter the second decade of the clinical use of jakinibs.

Long-term safety of tofacitinib up to 9.5 years: a comprehensive integrated analysis of the rheumatoid arthritis clinical development programme

Objective

Tofacitinib is an oral Janus kinase (JAK) inhibitor for the treatment of rheumatoid arthritis (RA). We report the largest integrated safety analysis of tofacitinib, as of March 2017, using data from phase I, II, III, IIIb/IV and long-term extension studies in adult patients with RA.

Methods

Data were pooled for patients with RA who received ≥1 tofacitinib dose. Incidence rates (IRs; patients with events/100 patient-years [PY]; 95% CIs) of first-time occurrences were obtained for adverse events (AEs) of interest.

Results

7061 patients received tofacitinib (total exposure: 22 875 PY; median [range] exposure: 3.1 [0 to 9.6] years). IRs (95% CI) for serious AEs, serious infections, herpes zoster (all), opportunistic infections (excluding tuberculosis [TB]) and TB were 9.0 (8.6 to 9.4), 2.5 (2.3 to 2.7), 3.6 (3.4 to 3.9), 0.4 (0.3 to 0.5) and 0.2 (0.1 to 0.2), respectively. IRs (95% CI) for malignancies (excluding non-melanoma skin cancer [NMSC]), NMSC and lymphomas were 0.8 (0.7 to 0.9), 0.6 (0.5 to 0.7) and 0.1 (0.0 to 0.1), respectively. IRs (95% CI) for gastrointestinal perforations, deep vein thrombosis, pulmonary embolism, venous thromboembolism, arterial thromboembolism and major adverse cardiovascular events were 0.1 (0.1 to 0.2), 0.2 (0.1 to 0.2), 0.1 (0.1 to 0.2), 0.3 (0.2 to 0.3), 0.4 (0.3 to 0.5) and 0.4 (0.3 to 0.5), respectively. IR (95% CI) for mortality was 0.3 (0.2 to 0.3). IRs generally remained consistent across 6-month intervals to >78 months.

Conclusion

This represents the largest clinical dataset for a JAK inhibitor in RA to date. IRs remained consistent with previous reports from the tofacitinib RA clinical development programme, and stable over time.

Trial registration numbers

NCT01262118; NCT01484561; NCT00147498; NCT00413660; NCT00550446; NCT00603512; NCT00687193; NCT01164579; NCT00976599; NCT01059864; NCT01359150; NCT02147587; NCT00960440; NCT00847613; NCT00814307; NCT00856544; NCT00853385; NCT01039688; NCT02187055; NCT00413699; NCT00661661.

For summary of phase I, phase II, phase III, phase IIIb/IV and LTE studies included in the integrated safety analysis, see online supplemental table 1.

Impact of Janus Kinase Inhibition on the Treatment of Axial Spondyloarthropathies

Many immune cells and effector molecules (e.g. cytokines, Interferons, growth factors) utilize different combinations of Janus kinase (JAK) and signal transducer and activator of transcription (STAT) molecules to transduce signals from the cell surface to the nucleus, where they regulate transcription. This pathway is basically involved in almost all inflammatory diseases and also in the interleukin (IL)-23/IL-17 cascade, which is an essential part of the pathogenesis of spondyloarthropathies (SpA). Upon evidence from in vitro and in vivo experiments indicating disease-modifying effects of JAK inhibition in inflammatory joint disease, numerous inhibitors of the JAK/STAT pathway (= JAKinibs) with different selectivity against the four members of the JAK family [JAK1, JAK2, JAK3, and tyrosine kinase 2 (TYK2)] were developed. Trials in rheumatoid arthritis were successful with respect to efficacy and safety, and currently, three JAKinibs are approved for the treatment of rheumatoid arthritis in the European Union. Although new treatment options (anti-IL-23, anti-IL-17, and phosphodiesterase 4 inhibitors) have become available for spondyloarthritis and especially psoriatic arthritis (PsA) within the last years, most of them are biologics and do not address all disease manifestations equally. Therefore, multiple trials were initiated to evaluate JAKinibs in PsA and axial spondyloarthritis (axSpA). A trial of Tofacitinib (OPAL) was successful in PsA and has led to the inclusion of JAKinibs into the treatment algorithm. Currently many trials with JAKinibs are ongoing for PsA and axSpA, with one phase III trial of upadacitinib (selective JAK1 inhibitor) showing good therapeutic response in active radiographic axSpA.