A multicenter phase II study of darinaparsin in relapsed or refractory Hodgkin's and non-Hodgkin's lymphoma

Darinaparsin is a novel organic arsenic compound that is being developed to improve the efficacy and therapeutic index of arsenic as an antineoplastic agent. It has activity in preclinical models of hematological malignancies and we set out to test it in patients with refractory lymphoma. In this multicenter, Phase II trial, patients with relapsed or refractory Hodgkin (HL) and non-Hodgkin lymphoma (NHL) were treated with darinaparsin 300 mg/m ² intravenously daily for five consecutive days every 28 days, for up to six cycles. The primary endpoint was the overall response rate. Twenty-nine heavily pretreated patients with lymphoma (22 with NHL and 7 with HL) were enrolled. There was one complete response (CR), one unconfirmed CR (CRu), three partial responses (PRs), and four with stable disease (SD), with an overall response rate of 17% (95% confidence interval (CI) 6-36%). Among the seven patients with peripheral T-cell lymphoma (PTCL), there was one CR, one CRu, and two with prolonged SD. The most common toxicities were fatigue, nausea, diarrhea, and anemia. Darinaparsin was safe and showed preliminary activity in this heavily pretreated population of relapsed/refractory lymphoma patients. Encouraging responses were seen in PTCL and further study in this subtype is planned.