Overland ADCT BioPharma, a joint venture created by Overland Pharmaceuticals (“Overland”) and ADC Therapeutics SA, announced the first patient has been dosed in China with ZYNLONTA® in combination with rituximab compared to standard immunochemotherapy in the LOTIS-5 confirmatory Phase 3 global clinical trial in second-line or later, transplant ineligible patients with diffuse large B-cell lymphoma (DLBCL). In April 2021, ZYNLONTA was granted accelerated approval by the U.S. Food and Drug Administration (FDA) as the first and only CD19-targeted antibody drug conjugate (ADC) as a single-agent treatment for adult patients with relapsed or refractory DLBCL after two or more lines of systemic therapy. The joint venture has now joined the LOTIS-5 global confirmatory Phase 3 clinical trial of ZYNLONTA, which is intended to support a supplemental Biologics License Application (sBLA) for ZYNLONTA in the U.S. and China in second-line, transplant-ineligible patients.

ZYNLONTA, Overland ADCT BioPharma's lead product candidate, is an ADC composed of a humanized monoclonal antibody directed against human CD19 and conjugated to a pyrrolobenzodiazepine (PBD) dimer cytotoxin. In clinical trials, ZYNLONTA has demonstrated significant single-agent clinical activity across a broad population of patients with r/r DLBCL, mantle cell lymphoma and follicular lymphoma. ZYNLONTA® is a CD19-directed antibody drug conjugate (ADC).

Once bound to a CD19-expressing cell, ZYNLONTA is internalized by the cell, where enzymes release a pyrrolobenzodiazepine (PBD) payload. The potent payload binds to DNA minor groove with little distortion, remaining less visible to DNA repair mechanisms. This ultimately results in cell cycle arrest and tumor cell death. The U.S. Food and Drug Administration (FDA) has approved ZYNLONTA (loncastuximab tesirine-lpyl) for the treatment of adult patients with relapsed or refractory (r/r) large B-cell lymphoma after two or more lines of systemic therapy, including diffuse large B-cell lymphoma (DLBCL) not otherwise specified (NOS), DLBCL arising from low-grade lymphoma and also high-grade B-cell lymphoma.

The trial included a broad spectrum of heavily pre-treated patients (median three prior lines of therapy) with difficult-to-treat disease, including patients who did not respond to first-line therapy, patients refractory to all prior lines of therapy, patients with double/triple hit genetics and patients who had stem cell transplant and CAR-T therapy prior to their treatment with ZYNLONTA. This indication is approved by the FDA under accelerated approval based on overall response rate and continued approval for this indication may be contingent upon verification and description of clinical benefit in a confirmatory trial.