Nivolumab combined with brentuximab vedotin for relapsed/refractory mediastinal gray zone lymphoma

TO THE EDITOR:

Mediastinal gray zone lymphoma (MGZL) is a rare non-Hodgkin lymphoma occurring predominantly in young men.¹ MGZL exhibits pathologic characteristics that are intermediate in nature between those of nodular-sclerosis classical Hodgkin lymphoma (NSCHL) and primary mediastinal large B-cell lymphoma (PMBL), and it is characteristically CD30⁺.^2,3 MGZL tumors, as in NSCHL and PMBL, harbor frequent 9p24.1 copy-number alterations and expression of programmed death-1 (PD-1) ligands 1 and (less commonly) 2.^4-7 In a small case series of relapsed/refractory (R/R) MGZL, the PD-1 inhibitor pembrolizumab induced a complete metabolic response in 2 patients.⁶ Gene expression profiling showed that MGZL clusters between NSCHL and PMBL; whole-exome sequencing supports a common cell of origin.^8,9 The 5th-edition update of the World Health Organization and the International Consensus Classification exclude cases arising outside the anterior...