Systemic anaplastic large-cell lymphoma (ALCL) is an aggressive subtype of T-cell lymphoma characterized by the uniform expression of CD30. The antibody-drug conjugate brentuximab vedotin delivers the potent antimicrotubule agent monomethylauristatin E to CD30-positive malignant cells. A phase II multicenter trial was conducted to evaluate the efficacy and safety of brentuximab vedotin in patients with relapsed or refractory systemic ALCL. Patients with systemic ALCL and recurrent disease after at least one prior therapy received brentuximab vedotin 1.8 mg/kg intravenously every 3 weeks over 30 minutes as an outpatient infusion. The primary end point of the study was overall objective response rate as assessed by independent central review. Of 58 patients treated in the study, 50 patients (86%) achieved an objective response, 33 patients (57%) achieved a complete remission (CR), and 17 patients (29%) achieved a partial remission. The median durations of overall response and CR were 12.6 and 13.2 months, respectively. Grade 3 or 4 adverse events in ≥ 10% of patients were neutropenia (21%), thrombocytopenia (14%), and peripheral sensory neuropathy (12%). Brentuximab vedotin induced objective responses in the majority of patients and CRs in more than half of patients with recurrent systemic ALCL. Targeted therapy with this CD30-directed antibody-drug conjugate may be an effective treatment for relapsed or refractory systemic ALCL and warrants further studies in front-line therapy.