Loncastuximab tesirine granted orphan drug designation in the European Union for the treatment of patients with DLBCL

On September 13, 2021, the European Commission (EC) granted orphan drug designation to loncastuximab tesirine for the treatment of patients with diffuse large B-cell lymphoma (DLBCL).¹ Loncastuximab tesirine is an antibody-drug conjugate (ADC) consisting of a CD19-directed monoclonal antibody coupled with a pyrrolobenzodiazepine (PBD) dimer cytotoxic alkylating agent. The monoclonal antibody component binds to CD19, which is expressed on the surface of B cells, and then releases the cytotoxic agent to induce apoptosis.²

This approval was based on results from the phase II, multicenter, single-arm LOTIS-2 trial. Updated results from LOTIS-2 were presented at the 9th Society of Hematologic Oncology (SOHO) Annual Meeting in an oral presentation by Brad S. Kahl.³ Patients enrolled in LOTIS-2 had pathologically defined relapsed or refractory (R/R) DLBCL following at least two prior systemic therapies. Updated safety and efficacy data (≥17 months since first dose of loncastuximab tesirine) demonstrated an overall response rate of 48.3% (70/145 patients), with 24.1% of patients having a complete response (CR). The median duration of response in this most recent update was 13.4 months for all responders, and was not yet reached in patients with a CR.³

On April 23, 2021, the U.S. Food and Drug Administration (FDA) issued an accelerated approval for loncastuximab tesirine for the treatment of adult patients with R/R DLBCL who have had at least two prior lines of therapy, which was previously reported on the Lymphoma Hub.