Shandong Boan Biotechnology Co., Ltd. (Boan Biotech) has received clearance from China’s Center for Drug Evaluation under the National Medical Products Administration to initiate a Phase II clinical study evaluating its proprietary anti-CD25 antibody BA1106 in combination with PD-1 inhibitor BA1104 (a nivolumab biosimilar) for first- or second-line treatment of non-small cell lung cancer (NSCLC).

The upcoming multicenter, single-arm, open-label trial will assess efficacy, safety and pharmacokinetics in patients with driver gene-negative NSCLC—a subgroup representing an estimated 40%–50% of all NSCLC cases. These patients face limited therapeutic options as resistance to existing immune checkpoint inhibitors (ICIs) remains common.

BA1106 is the first investigational non-IL-2-blocking anti-CD25 antibody in China to enter clinical development for solid tumors. Engineered with “moderate” antibody-dependent cellular cytotoxicity and a distinct binding epitope, the molecule is designed to selectively deplete regulatory T cells (Tregs) while preserving IL-2 signaling and expanding effector T-cell populations, potentially strengthening anti-tumor immune responses.

Phase I results showed encouraging anti-tumor activity for the BA1106 and BA1104 combination in lung adenocarcinoma, squamous cell lung cancer and gastric cancer patients who had progressed on prior ICIs. Safety outcomes were favorable: most treatment-related adverse events were Grade 1–2, no dose-limiting toxicities emerged, and the maximum tolerated dose was not reached up to 1.2 mg/kg.

With Phase II now authorized, Boan Biotech plans to evaluate the regimen in both immunotherapy-naïve NSCLC patients and those with disease progression after prior immunotherapy, while also exploring applicability to other solid tumors such as gastric cancer.