Thyroid dysfunction induced by nivolumab: searching for disease patterns and outcomes.

Purpose: Nivolumab is a monoclonal antibody that blocks the activation of programmed death-1 receptor, promoting T-cell activation against cancer cells. Thyroid dysfunction (TD) is a common immune-related adverse event (irAE) induced by nivolumab. We report the prevalence, patterns and outcomes of nivolumab-induced TD among cancer patients in our center.

Methods: All patients treated with nivolumab during 2016 were included. We assessed thyroid function tests, thyroid autoimmunity, thyroid imaging, and clinical outcome during nivolumab therapy as well as overall survival (OS).

Results: Seventy-three patients (55 with non-small-cell lung cancer [NSCLC], 9 with melanoma and 9 with Hodgkin lymphoma) were included. Median of follow up: 390.5 days. Seventeen patients (23.3%) developed TD during treatment. Thyrotoxicosis was reported in seven patients. Serum thyroid-stimulating hormone (TSH) nadir occurred after a median of 51 days (95% CI: 35-71). Thyroid antibodies were positive in three of the seven patients. Five of the seven hyperthyroid patients became hypothyroid later, and four of them required levothyroxine treatment. Primary hypothyroidism occurred in ten patients. Serum TSH peak occurred after a median of 110 days [95% CI: 85.2-197]. Thyroid autoimmunity was positive in one patient. In patients with NSCLC, TD was associated with better OS (HR = 0.4 [95% CI: 0.17-0.94]; p = 0.035).

Conclusions: TD induced by nivolumab is a common and heterogeneous irAE. Thyrotoxicosis develops earlier than hypothyroidism. A pattern consistent with a transient thyroiditis followed by hypothyroidism was observed in one-third of patients. Our results suggest that patients with NSCLC and nivolumab-induced TD might have better survival.