ADC Therapeutics SA, an NYSE listed company advancing next-generation antibody-drug conjugates (ADCs) using highly potent and targeted pyrrolobenzodiazepine (PBD) dimer technology, announced the approval of ZYNLONTA by the U.S. Food and Drug Administration (FDA). The single-agent treatment was approved for adult patients with relapsed or refractory (r/r) large B-cell lymphoma after two or more lines of systemic therapy, including high-grade B-cell lymphoma, diffuse large B-cell lymphoma (DLBCL) not otherwise specified (NOS), and DLBCL arising from low-grade lymphoma. ZYNLONTA is the first and only CD19-targeted antibody-drug conjugate (ADC) as a single-agent treatment for adult patients with this indication. It was granted accelerated approval by the FDA based on its overall response rate observed from its LOTIS-2 trial, with contingent approval underway post a confirmatory test.
The FDA approval based on data from its Phase II Clinical Trial, LOTIS-2, is a multinational, single-arm clinical trial with 145 adult patients having r/r DLBCL following two or more prior lines of systemic therapy. The results demonstrated an overall response rate (ORR) of 48.3% (70/145 patients), including a complete response (CR) rate of 24.1% (35/145 patients) along with a partial response (PR) rate of 24.1% (35/145 patients). Patients showed a median time to response of 1.3 months, with the 70 responders demonstrating a median duration of response (mDoR) of 10.3 months.
ZYNLONTA (loncastuximab tesirine-lpyl) will soon be commercially available in the United States, addressing wherein more than 40% of first-line DLBCL treatments fail, followed by poor prognosis worsening with each line of therapy. Additionally, DLBCL is the most common type of non-Hodgkin lymphoma in the United States and a rapidly progressing, aggressive disease that is heterogeneous with multiple subtypes. This indicates a broad population with a possibility of relapse and failure in therapy that will now be benefitted from Zynlonta.
ADC Therapeutics has also launched the Advancing Patient Support Program, a comprehensive patient support program that offers financial assistance, ongoing education, and other resources to eligible patients prescribed with it. ADC is also working on various pyrrolobenzodiazepine (PBD)-based antibody-drug conjugates (ADCs) to develop a solid hematologic and solid tumors franchise. Its second lead candidate, Camidanlumab tesirine (ADCT-301), targeting CD25/regulatory T cells, is in its Phase II trial to treat Hodgkin’s lymphoma. With its current approval and its pipeline drugs, ADC Therapeutics plans to address the broad population of cancer patients with a significant unmet need.