Considerations for Use of Immune Checkpoint Inhibitors in Cancer Therapy for Patients with Co-existing Thyroid Eye Disease

Abstract

Immune checkpoint inhibitors (ICIs) have revolutionised the field of oncology. Whilst mostly well-tolerated, severe and fatal adverse events have been documented. These immune-related adverse events (irAE) likely relate to the strengthened immunity harnessed by ICIs against tumours. Endocrinopathies are one of the commonest irAEs, with both hypothyroidism and hyperthyroidism encountered after ICI use. As such, patients with pre-existing autoimmune conditions, such as Graves’ disease (GD) with clinically active thyroid eye disease (TED), are excluded from most clinical trials studying ICIs due to concerns of exacerbating pre-existing autoimmune conditions or the potential of irAEs developing. The scarce information regarding the safety and efficacy of ICIs in this population poses a clinical challenge for oncologists. The objective of this commentary aims to highlight the challenges and provide recommendations pertaining to two specific cohorts of patients with GD: (1) GD patients with minimal eye complications, (2) GD patients with previous TED who underwent radiotherapy, surgery or pulse methylprednisolone (PMP) and are now quiescent, and (3) patients potentially with subclinical autoimmune thyroid disease.