Rituximab in the treatment of Graves' orbitopathy: latest updates and perspectives

Efficacy of rituximab in treating steroid-resistant Graves' orbitopathy in active moderate-to-severe and sight-threatening forms: A retrospective observation from China

Background and objectives

The efficacy of rituximab (RTX) in treating steroid-resistant Graves' orbitopathy (GO) has been limitedly studied in Asians. Moreover, RTX has been considered even less for patients with steroid-resistant dysthyroid optic neuropathy (DON) who failed to undergo orbital decompression surgery for physical or financial reasons, or who responded poorly to the procedure. This study aimed to investigate the efficacy of RTX in treating steroid-resistant active moderate-to-severe and sight-threatening GO in a Chinese population.

Methods

Data from 28 patients with steroid-resistant GO prescribed a single dose of 500 mg RTX were retrospectively retrieved. Treatment responses and contributing factors were analyzed.

Results

The median follow-up time was 22 (8-34) weeks. 23 (82.1 %) patients had a positive objective outcome recommended by the European Group on Graves' Orbitopathy (EUGOGO), while 25 (92.6 %) had a decrease in 7-item clinical activity score (CAS) by at least 2. Diplopia, visual dysfunction, and MRI-detected T2 relaxation time of the involved extraocular muscles improved significantly at the last follow-up compared to baseline (81.0 % vs. 47.6 %, 38.9 % vs. 16.7 %, and 87.8 (8.64) vs. 75.8 (10.9) ms, respectively; all p values < 0.05). No significant improvement was seen in terms of proptosis and eye muscle duction. Notably, a higher baseline IgG4 to IgG ratio was a predictor for RTX-induced positive EUGOGO outcomes. After RTX treatment, all 8 patients with DON demonstrated inactivation, and 4 improved in visual acuity by ≥ 1 line. No patient with DON experienced obvious deterioration.

Conclusion

A single dose of 500 mg RTX seemed to be an effective and tolerable treatment for steroid-resistant GO. However, larger-scale studies with a control group are required for a more solid conclusion. The role of RTX in steroid-resistant DON management where surgery is unavailable or ineffective should be further explored.

A Randomized Clinical Trial of Intravenous Methylprednisolone With 2 Protocols in Patients With Graves Orbitopathy

CONTEXT

Intravenous glucocorticoid (IVGC) is an accessible and affordable treatment for Graves orbitopathy (GO); the 4.5-g protocol is well studied, but many details of treatment protocols need to be clarified.

OBJECTIVE

To compare the efficacy and safety of weekly and monthly protocol of IVGC in GO.

METHODS

A prospective, randomized, observer-masked, single-center clinical trial, followed up to week 24, at the third affiliated hospital of Southern Medical University; 58 patients with active and moderate to severe GO, aged 18-60 years old, who had not received relevant treatment were included. The intervention was weekly protocol or monthly protocol of IVGC; both received a cumulative dose of methylprednisolone 4.5 g and had a duration of 12 weeks. The overall effective rate, improvement of quality of life (QOL) and signal intensity ratio (SIR) were measured.

RESULTS

There was no significant difference in the effective rate between the 2 groups at week 12 and week 24 (86.21% vs 72.41%, P = .195; 86.21% vs 82.61%, P = .441), there was no significant difference in the improvement of clinical activity score, exophthalmos, soft tissue involvement, diplopia, and QOL. At week 24, the mean SIR and maximum SIR of the 2 groups were lower than those before treatment, and there were no statistically significant difference between the 2 groups. There was no significant difference in the incidence of adverse events between the 2 groups (31.03% vs 27.59%, P = .773).

CONCLUSION

The efficacy and safety of the 2 protocols are comparable; the monthly protocol could be used as an alternative to the weekly protocol.

Methotrexate is associated with decreased total thyroxine in patients with rheumatoid arthritis

BACKGROUND

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease characterized by joint swelling, pain, and deformation. RA patients have an increased risk of thyroid dysfunction, and drugs of RA treatment may have potential effects on thyroid function.

METHODS

This is a single-center cross-sectional study including 281 inpatients with RA in the First Affiliated Hospital of Guangzhou University of Chinese Medicine. The purpose of this study is to explore the correlation between RA therapeutic drugs and thyroid function. The medical records of 281 inpatients with RA were collected, including general data, laboratory examination, complications, and RA treatment. Spearman correlation analysis was used to explore the association of independent variables with thyroid function and antibodies in RA patients. Multinomial logistics and binary logistic regression were used for multivariate analysis. The statistically significance level was set as P < 0.05. SPSS 22.0 was used for statistical analysis.

RESULTS

Patients taking methotrexate (OR = 0.067, 95%CI: 0.008-0.588, P = 0.015) had lower levels of total thyroxine (TT4) (TT4 < 78.38 nmol/L). There was a negative correlation between glucocorticoids (r = - 0.153, P = 0.010) and total triiodothyronine (TT3) level (TT3 ≥ 1.34 nmol/L), but it was not significant in the multivariate regression model of TT3, although the regression model was statistically significant (P = 0.001).

CONCLUSION

Methotrexate is associated with decreased TT4 levels in RA patients, and glucocorticoids is associated with decreased TT3 levels. Drugs of RA treatment may affect the thyroid function of patients while treating RA, which may be one of the causes of secondary thyroid diseases in RA patients.

Efficacy and Safety of intravenous monoclonal antibodies in patients with moderate-to-severe active Graves'ophthalmopathy: a systematic review and meta-analysis

Backgrounds

The effects of various treatments on Graves' ophthalmopathy (GO) have been studied. As monoclonal antibodies (mAbs) have been proposed for the treatment of moderate to severe GO, direct comparisons between different mAbs are lacking.We therefore conducted this meta-analysis to objectively compare the efficacy and safety of intravenous mAbs.

Methods

To identify eligible trials, references published before September 2022 were electronically searched in PubMed, Web of Science, Pubmed, Embase,Cochrane Library, CBM, CNKI,Wan-Fang and ICTRP databases.The Newcastle-Ottawa scale (NOS) and the Cochrane Risk of Bias Assessment Tool were used to assess the risk of bias of the original studies.The primary and secondary outcomes were the response and inactivation rates, with the secondary outcomes being the clinical activity score (CAS),the improvement of proptosis and diplopia improvement,and the adverse event rate. Publication bias was evaluated, along with subgroup and sensitivity analyses.

Results

A total of 12 trials with 448 patients were included. The meta-analysis showed that TCZ (tocilizumab) was most likely to be the best treatment in terms of response according to indirect contrast, followed by TMB (teprotumumab) and RTX (rituximab).TCZ, followed by TMB and RTX, was also most likely to be the best treatment in terms of reducing proptosis. In terms of improving diplopia, TMB was most likely to be the best treatment, followed by TCZ and RTX.TCZ was the highest probability of safety, followed by RTX and TMB.

Conclusions

Based on the best available evidence,TCZ should be the preferred treatment for moderate to severe GO.In the absence of head-to-head trials,indirect comparisons of treatments are routinely used to estimate the effectiveness of the treatments of interest. In addition,the optimal dose and potential mechanism of action of monoclonal antibodies remain to be established,and it is encouraging that the treatment paradigm for GO may change in the future.This study was designed in accordance with the Preferred Reporting Items for conducting Systematic Reviews and Meta-Analyses (PRISMA)(27).

Systematic Review Registration

http://www.crd.york.ac.uk/prospero, identifier CRD42023398170.