Head and neck squamous cell carcinoma (HNSCC) arises from the mucosal lining of the oral cavity, pharynx, and larynx. With approximately 64,000 new cases in the US in 2024, HNSCC continues to grow as a significant health concern. Oral and laryngeal cancers are mainly linked to tobacco and alcohol use, while pharyngeal cancers are increasingly driven by HPV, particularly HPV-16. HNSCC is classified as HPV-positive or HPV-negative. Although it progresses histologically from dysplasia to invasive disease, most cases are diagnosed at an advanced stage without detectable pre-malignant signs.

Kelun-Biotech presented data from phase III study (KL167-Ⅲ-08, NCT05294172) comparing tagitanlimab plus gemcitabine and cisplatin (GP) versus placebo plus GP in recurrent or metastatic NPC patients who had received no prior treatment in the recurrent or metastatic (R/M) setting. 

At the pre-specified interim analysis, progression-free survival (PFS) per blinded independent central review (BICR) showed a 53% reduction in the risk of progression or death with tagitanlimab plus GP (hazard ratio [HR], 0.47; 95% CI, 0.33–0.66; one-sided p < 0.0001). Median PFS was not reached (95% CI, 10.9–NE) in the tagitanlimab arm vs. 7.9 months (95% CI, 6.9–8.3) in the placebo arm. The 12-month PFS rates were 56.7% and 26.7%, respectively. The objective response rate (ORR) per BICR was 81.7% (95% CI, 75.6–86.9) for tagitanlimab plus GP vs. 74.5% (95% CI, 64.7–82.8) for placebo plus GP. Median duration of response (DoR) was 11.7 months (95% CI, 8.2–NE) vs. 5.8 months (95% CI, 5.6–6.9; HR 0.48, 95% CI, 0.32–0.70). Overall survival (OS) favored tagitanlimab plus GP, although median OS was not reached in either arm (HR, 0.62; 95% CI, 0.32–1.22).

The most common grade ≥3 treatment-related adverse events were decreased neutrophil count (57.9% vs. 49.0%), decreased white blood cell count (52.8% vs. 46.9%), and anemia (38.6% vs. 40.8%).

KOL insights: 

“For domestic [patients with] NPC, 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.” – Expert Opinion

Conclusion:

In patients with R/M NPC, Tagitanlimab, a PD-L1 inhibitor from Kelun-Biotech, has demonstrated a notable improvement in PFS and durable response rates when used in combination with chemotherapy. The data indicate a favorable survival trend with tagitanlimab, even though median OS has not yet been reached. With its approval in December 2024 by China's  National Medical Products Administration (NMPA) for patients who have failed after prior 2L+ systematic therapies, and its manageable safety profile, tagitanlimab is gaining traction as a possible new first-line standard of therapy for R/M NPC.