Association of CD8 + T cells expressing nivolumab-free PD-1 with clinical status in a patient with relapsed refractory classical Hodgkin lymphoma

A 37-year-old man with refractory classical Hodgkin lymphoma (cHL) underwent PD-1 blockade therapy with nivolumab, which resulted in a partial response. However, treatment was discontinued due to immune-related adverse events (irAEs), including myasthenia gravis and myositis. Retreatment with nivolumab resulted in a complete metabolic response and hepatic irAE. Subsequently, nivolumab was administered at extended dosing intervals. Intermittent infusion of ten doses of nivolumab for a total dose of 2400 mg/body helped control the relapsed/refractory cHL over three years. During nivolumab treatment, disease progression and emergence of irAEs were associated with the proportion of CD8 + T cells expressing nivolumab-free PD-1 relative to the total number of CD8 + T cells. The findings in this nivolumab-sensitive patient highlight the clinical utility of monitoring immune cells expressing nivolumab-free PD-1 in patients with cHL who have been treated with nivolumab and have experienced irAEs.