Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. (the "Company") announced that the Company received marketing authorization in China from National Medical Products Administration (NMPA) for the programmed cell death ligand 1(PD-L1)-directed innovative humanized monoclonal antibody ("mAb") tagitanlimab (formerly KL-A167) used in combination with cisplatin and gemcitabine for the first-line treatment of patients with recurrent or metastatic nasopharyngeal cancer (NPC).

The approval is based on a randomized, double-blinded, placebo controlled, multi-center, phase III clinical study evaluates the efficacy and safety results of tagitanlimab in combination with cisplatin and gemcitabine versus placebo in combination with cisplatin and gemcitabine for the treatment of recurrent or metastatic NPC, which was led by Professor Shi Yuankai of the Cancer Hospital Chinese Academy of Medical Sciences as the principal investigator.

According to the study results, tagitanlimab used in combination with cisplatin and gemcitabine for the first-line treatment for recurrent or metastatic NPC could have better progression-free survival (PFS), higher objective response rate (ORR) and extended duration of response (DoR) compared with chemotherapy, where all the patients could benefit regardless of the PD-L1 expression. The median PFS for tagitanlimab in combination with chemotherapy is not reached compared to 7.9 months for placebo in combination with chemotherapy (HR=0.47, 95% CI: 0.33-0.66, p<0.0001), and the risk of disease progression and death is reduced by 53%; ORR is 81.7% vs 74.5%; median DoR is 11.7 vs 5.8 months (HR=0.48, 95% CI: 0.32-0.70), which has nearly doubled compared to placebo arm; currently the median overall survival (OS) is still not mature, however the beneficial trend for OS of tagitanlimab in combination with chemotherapy has already been observed (HR=0.62, 95％CI: 0.32-1.22), and its risk of death is reduced by 38%^[1]. Tagitanlimab also showed a manageable safety profile.

This is the second indication approved for tagitanlimab. Previously, NMPA has approved the marketing in China of tagitanlimab monotherapy for the treatment of patients with recurrent or metastatic NPC who have failed after prior 2L+ chemotherapy.

Dr. Micheal Ge, CEO of Kelun-Biotech said, "We are pleased that the second indication of our self-developed PD-L1 monoclonal antibody was successfully approved for marketing and demonstrated statistically significant and clinically meaningful improvements in PFS. For domestic NPC patients, Tagitanlimab has realized a breakthrough in therapeutic coverage and innovation from the backline to the frontline, which once again strongly validates the excellent strength of Kelun-Biotech's new drug research and development. In the future, the company will always be based on unmet clinical needs, source innovation, and explore more and more excellent clinical therapeutic solutions to benefit more patients."