Outcomes during and after long-term tocilizumab treatment in patients with giant cell arteritis

Effectiveness of janus kinase inhibitors in relapsing giant cell arteritis in real-world clinical practice and review of the literature

BACKGROUND

A substantial proportion of patients with giant cell arteritis (GCA) relapse despite standard therapy with glucocorticoids, methotrexate and tocilizumab. The Janus kinase/signal transducer and activator of transcription (JAK/STAT) signalling pathway is involved in the pathogenesis of GCA and JAK inhibitors (JAKi) could be a therapeutic alternative. We evaluated the effectiveness of JAKi in relapsing GCA patients in a real-world setting and reviewed available literature.

METHODS

Retrospective analysis of GCA patients treated with JAKi for relapsing disease at thirteen centers in Spain and one center in United States (01/2017-12/2022). Outcomes assessed included clinical remission, complete remission and safety. Clinical remission was defined as the absence of GCA signs and symptoms regardless of the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) values. Complete remission was defined as the absence of GCA signs and symptoms along with normal ESR and CRP values. A systematic literature search for other JAKi-treated GCA cases was conducted.

RESULTS

Thirty-five patients (86% females, mean age 72.3) with relapsing GCA received JAKi therapy (baricitinib, n = 15; tofacitinib, n = 10; upadacitinib, n = 10). Before JAKi therapy, 22 (63%) patients had received conventional synthetic immunosuppressants (e.g., methotrexate), and 30 (86%) biologics (e.g., tocilizumab). After a median (IQR) follow-up of 11 (6-15.5) months, 20 (57%) patients achieved and maintained clinical remission, 16 (46%) patients achieved and maintained complete remission, and 15 (43%) patients discontinued the initial JAKi due to relapse (n = 11 [31%]) or serious adverse events (n = 4 [11%]). A literature search identified another 36 JAKi-treated GCA cases with clinical improvement reported for the majority of them.

CONCLUSIONS

This real-world analysis and literature review suggest that JAKi could be effective in GCA, including in patients failing established glucocorticoid-sparing therapies such as tocilizumab and methotrexate. A phase III randomized controlled trial of upadacitinib is currently ongoing (ClinicalTrials.gov ID NCT03725202).

Giant Cell Arteritis

Giant cell arteritis (GCA) is the most common primary vasculitis and is associated with potential bilateral blindness. Neither clinical nor laboratory evidence is simple and unequivocal for this disease, which usually requires rapid and reliable diagnosis and therapy. The ophthalmologist should consider GCA with the following ocular symptoms: visual loss or visual field defects, transient visual disturbances (amaurosis fugax), diplopia, eye pain, or new onset head or jaw claudication. An immediate ophthalmological examination with slit lamp, ophthalmoscopy, and visual field, as well as color duplex ultrasound of the temporal artery should be performed. If there is sufficient clinical suspicion of GCA, corticosteroid therapy should be initiated immediately, with prompt referral to a rheumatologist/internist and, if necessary, temporal artery biopsy should be arranged. Numerous developments in modern imaging with colour duplex ultrasonography, MRI, and PET-CT have the potential to compete with the classical, well-established biopsy of a temporal artery. Early determination of ESR and CRP may support RZA diagnosis. Therapeutically, steroid-sparing immunosuppression with IL-6 blockade or methotrexate can be considered. These developments have led to a revision of both the classification criteria and the diagnostic and therapeutic recommendations of the American College of Rheumatologists and the European League against Rheumatism, which are summarised here for ophthalmology.

Treatment for giant cell arteritis with 8 weeks of prednisone in combination with tocilizumab: a single-arm, open-label, proof-of-concept study

BACKGROUND

Even after the approval of tocilizumab, substantial glucocorticoid exposure (usually ≥6 months) and toxicity continue to be important problems for patients with giant cell arteritis. We aimed to assess the outcomes of a group of patients with giant cell arteritis treated with tocilizumab in combination with 8 weeks of prednisone.

METHODS

This prospective, single arm, proof-of-concept study was conducted at Massachusetts General Hospital (Boston, MA, USA). Individuals aged 50 years or older who had new-onset or relapsing giant cell arteritis with active disease were eligible for inclusion. Participants received 12 months of tocilizumab 162 mg weekly subcutaneously in combination with 8 weeks of prednisone. The primary endpoint was sustained prednisone-free remission at week 52. Adverse events were also evaluated. This trial is registered with ClinicalTrials.gov (NCT03726749), and is complete.

FINDINGS

Between Nov 28, 2018, and Nov 2, 2020, we enrolled 30 patients (mean age 73·7 years [SD 8·1], 18 [60%] women and 12 [40%] men, 30 [100%] White race, 15 [50%] new-onset disease, 23 [77%] temporal artery biopsy-proven, 14 [47%] imaging-proven). The initial prednisone doses were 60 mg (n=7), 50 mg (n=1), 40 mg (n=7), 30 mg (n=6), and 20 mg (n=9). All patients entered remission within 4 weeks from baseline. 23 (77%) of 30 patients were in sustained prednisone-free remission at week 52 and seven (23%) patients relapsed, with a mean time to relapse of 15·8 weeks (SD 14·7). Overall, four (13%) participants developed a serious adverse event, including one related or probably related to prednisone exclusively, two related or probably related to tocilizumab exclusively, and one related or probably related to prednisone, tocilizumab, or both. Two of the non-responder patients stopped tocilizumab and withdrew from the study prematurely after having a second disease relapse. No cases of giant cell arteritis-related permanent vision loss occurred during the study.

INTERPRETATION

These results suggest that 12 months of tocilizumab in combination with 8 weeks of prednisone could induce and maintain remission in patients with giant cell arteritis. Confirmation of these findings in a randomised controlled trial is required.

FUNDING

Genentech.

Relapse after cessation of weekly tocilizumab for giant cell arteritis: a multicentre service evaluation in England

OBJECTIVES

The National Health Service in England funds 12 months of weekly subcutaneous tocilizumab (qwTCZ) for patients with relapsing or refractory giant cell arteritis (GCA). During the COVID-19 pandemic, some patients were allowed longer treatment. We sought to describe what happened to patients after cessation of qwTCZ.

METHODS

Multicentre service evaluation of relapse after stopping qwTCZ for GCA. The log-rank test was used to identify significant differences in time to relapse.

RESULTS

336 GCA patients were analysed from 40 centres, treated with qwTCZ for a median (interquartile range, IQR) of 12 (12-17) months. At time of stopping qwTCZ, median (IQR) prednisolone dose was 2 (0-5) mg/day. By 6, 12 and 24 months after stopping qwTCZ, 21.4%, 35.4% and 48.6% respectively had relapsed, requiring an increase in prednisolone dose to a median (IQR) of 20 (10-40) mg/day. 33.6% of relapsers had a major relapse as defined by EULAR. Time to relapse was shorter in those that had previously also relapsed during qwTCZ treatment (P = 0.0017); in those not in remission at qwTCZ cessation (P = 0.0036); and in those with large vessel involvement on imaging (P = 0.0296). Age ≥65, gender, GCA-related sight loss, qwTCZ treatment duration, TCZ taper, prednisolone dosing, and conventional synthetic DMARD use were not associated with time to relapse.

CONCLUSION

Up to half our patients with GCA relapsed after stopping qwTCZ, often requiring a substantial increase in prednisolone dose. One third of relapsers had a major relapse. Extended use of TCZ or repeat treatment for relapse should be considered for these patients.