Bagot M, et al. - In this clinical trial with dose-escalation and cohort-expansion parts, researchers tested IPH4102 (a first-in-class monoclonal antibody targeting KIR3DL2, a cell surface protein that is expressed in cutaneous T-cell lymphoma) in patients with cutaneous T-cell lymphoma, focusing on its safety and activity. The study was run in five academic hospitals in the US, France, the UK, and the Netherlands. Dose limiting toxicity was not seen in the dose-escalation part, and a flat dose of 750 mg was advised by the trial's safety committee for the cohort-expansion, corresponding to the maximum administered dose. Of grade 1–2 adverse events, peripheral edema and fatigue were documented as the most common. During a median follow-up of 14.1 months, 16 of 44 patients were seen to achieve a confirmed global overall response; 15 responses were observed in 35 patients with Sézary syndrome. In patients with relapsed or refractory cutaneous T-cell lymphoma, especially those with Sézary syndrome, the safety as well as encouraging clinical activity of IPH4102 was evident in this study.