ABSTRACT
Classical Hodgkin lymphoma (cHL) is a highly curable disease, but the prognosis for relapsed/refractory cHL is grave. Pembrolizumab has recently shown impressive effects in patients with relapsed/refractory cHL in a phase Ib study (KEYNOTE-013). This report presents a case of a 17-year-old male with refractory cHL who received multiple chemotherapy regimens and radiotherapies, including brentuximab vedotin. Following both the second and fourth cycles of intravenous pembrolizumab 100 mg (2 mg/kg), positron emission tomography/computed tomography (PET/CT) scan showed progression. However, because performance status and fever improved, treatment was continued, and complete remission was confirmed by PET/CT after eight cycles of pembrolizumab. This case suggests that clinicians need to be aware of the potential for pseudoprogression in patients treated with pembrolizumab.