Chinese biopharmaceutical company CStone Pharmaceuticals (HKEX:2616) announced on Wednesday that it has submitted a Phase Ib clinical trial application in Australia for CS5001, its ROR1-targeting antibody-drug conjugate (ADC), in combination with first-line standard-of-care (SoC) for diffuse large B-cell lymphoma (DLBCL).

CS5001 is also being evaluated as both a monotherapy and in combination with a PD-L1 inhibitor for advanced solid tumours in an ongoing global multi-centre clinical trial.

The new study will explore CS5001 + R-CHOP, a first-line treatment for DLBCL patients who have not received prior systemic therapy; CS5001 + SoC, for patients with relapsed or refractory DLBCL; CS5001 monotherapy, targeting ROR1-expressing solid tumours; and CS5001 + sugemalimab, a combination therapy for advanced solid tumours.

The global multi-centre Phase Ib trial for CS5001 is actively enrolling patients across the United States, Australia and China. Recruitment is ongoing for monotherapy cohorts targeting aggressive and indolent advanced lymphomas, which could potentially expand into a Phase II single-arm registrational study. Additional cohorts, including the first-line DLBCL combination therapy and solid tumour monotherapy and combination therapy arms, will be initiated soon.

CS5001 is a clinical-stage ADC targeting ROR1 (receptor tyrosine kinase-like orphan receptor 1). It is designed with proprietary tumour-cleavable linker and pyrrolobenzodiazepine (PBD) prodrug.