Tocilizumab may be an effective rescue therapy to preserve vision in glucocorticoid (GC)-resistant giant cell arteritis (GCA), according to a research team who presented a review and a case series in the Journal of Neuro-Ophthalmology.
“Patients who report acute worsening of visual acuity and who would otherwise progress from functional individuals to legally blind, tocilizumab may rescue these patients,” researchers report.
The researchers reviewed 5 patients with GC-resistant GCA who were treated with tocilizumab — a recombinant humanized anti-interleukin (IL)-6 receptor monoclonal antibody — at the Royal Adelaide Hospital in Australia between 2019 and 2021. In 3 of those cases (60%), acute treatment with tocilizumab and a high-dose GC, rescued vision in at least 1 eye. These cases each involved temporal artery biopsy (TAB)-proven recalcitrant GCA and all 3 patients experienced progression of visual symptoms despite intervention.
In the first such case, an 80-year-old man with sudden vision loss of the left eye following 2 days of ipsilateral amaurosis fugax, presented with a best-corrected visual acuity (BCVA) of no light perception in the left eye and a Snellen score of 6/18 in the right eye. An examination found cilioretinal artery occlusion. He was treated with 1 g intravenous methylprednisolone (IVMP) for 3 days. His right eye’s VA deteriorated in that time to counting fingers. After 3 IVMP doses, 162 mg subcutaneous tocilizumab was administered. Following tocilizumab, VA stabilized, and the patient was discharged on a regimen of weekly tocilizumab injections. After 6 weeks, BCVA improved to counting fingers in the left eye and 6/6 in the right.
The second case involved an 85-year-old woman with age-related macular degeneration (AMD), atrial fibrillation, and hypertension who presented with vision loss in the left eye following 2 weeks of intermittent visual disturbance with malaise, headaches, and subjective fevers. Both eyes were found to have cilioretinal artery occlusions and GCA was suspected due to elevated inflammatory markers. Following 1 g IVMP, her BCVA declined from 6/9 at baseline to 6/12 in the right eye and from 6/12 to 6/60 in the left. Rescue with tocilizumab was associated with BCVA improvement to baseline levels at month 1.
The third such case was of an 83-year-old woman with metabolic syndrome, hypothyroidism, mild cognitive impairment, and amblyopia in the left eye who presented 2 days after developing blurred vision in the right eye accompanied by bitemporal headache and scalp tenderness. The patient was admitted to general medicine due to cognitive difficulties and administered 50 mg prednisone for her headache and scalp symptoms. A biopsy of the temporal artery confirmed GCA, and the patient was started on 1 g IVMP daily. At day 4 the patient’s VA decreased from 6/7.5 at baseline to hand movements in the left eye and from hand movements to light perception in the left. The patient was administered 162 mg subcutaneous tocilizumab, but no improvement to BCVA was observed at 2 weeks post-discharge.
Long-term management of GCA with the standard-of-care high-dose GC is complicated by the fact that approximately 62% of GCA patients relapse when treatment is tapered. However, when augmented with tocilizumab, patients can achieve sustained remission, according to the investigators. “Tocilizumab inhibits IL-6 signal transduction and works on the basis that elevated serum IL-6 increases the concentration of acute phase reactants such as [C-reactive protein], which correlate with increased disease severity,” the study shows.
Currently, research into tocilizumab as vision-rescue therapy for patients with GC-resistant GCA is limited to case reports, according to the investigators. They did not perform a meta-analysis due to significant heterogenicity between study groups and the variations in subgroups of GCA.
“It is possible that the observed visual recovery may represent a delayed effect of GC treatment,” the study authors explain. However, several prior reports and “our case series describing rapid improvement of GCA symptoms following tocilizumab, alongside how steroids only stabilize, not acutely improve, visual acuity and prior consensus concluding steroids uncommonly improve VA support a cause-effect relationship.”
This case series is limited by the small sample size and lack of visual field testing in some patients.
Stretton B, Tan Y, Hassall M, Simon S. The role of tocilizumab in glucocorticoid resistant giant cell arteritis: a case series and literature review. J Neuroophthalmol. Published online October 5, 2022. doi:10.1097/WNO.0000000000001645