Pune, India | September 12, 2025
Regeneron Pharmaceuticals has shared five-year follow-up results from its Phase 3 EMPOWER-Lung 3 trial. The findings show that Libtayo (cemiplimab), when used with platinum-based chemotherapy, offers a strong and lasting survival benefit. The trial included patients with advanced non-small cell lung cancer (NSCLC) who lacked EGFR, ALK, or ROS1 mutations. This group often has poor outcomes and limited treatment options.
The combination therapy delivered a five-year overall survival (OS) rate of 19.4%. This is more than double the 8.8% seen in the chemotherapy-only group. Median OS was 21.1 months for the Libtayo combination, compared to 12.9 months for chemotherapy alone. This reflects a 34% reduction in the risk of death. The benefit was consistent across different tumor types and PD-L1 expression levels.
Progression-free survival (PFS) also improved with the combination. Median PFS reached 8.2 months, compared to 5.5 months with chemotherapy alone. The objective response rate (ORR) rose to 43.6%, while it was only 22.1% in the chemotherapy group. Complete responses occurred only in the Libtayo arm, where 6.4% of patients had no detectable cancer after treatment. The duration of response was also longer—16.4 months versus 7.3 months—indicating better long-term control.
Patients with squamous cell carcinoma saw strong benefits. Their median OS was 22.3 months with the combination, compared to 13.8 months for chemotherapy alone. Those with non-squamous tumors also improved, reaching 19.4 months versus 12.4 months. Among patients with PD-L1 expression of 1% or more, OS rose to 24 months, up from 12.1 months with chemotherapy alone.
Safety remains an important factor. In the Libtayo group, 96.5% of patients had at least one adverse event (AE), and 49% were Grade 3 or worse. In the chemotherapy group, 95% experienced AEs, with 33% being severe. Treatment-related severe AEs affected 30% of Libtayo patients. This led to treatment discontinuation in 4.5% and death in 1%. In the chemo group, the respective rates were 18%, 1%, and 0.7%. These figures align with past immunotherapy studies. They underline the need for careful monitoring and personalized care.
The EMPOWER-Lung 3 trial enrolled patients with advanced or metastatic NSCLC. It included individuals regardless of PD-L1 levels and allowed those with stable brain metastases. This design reflects real-world patient populations. Libtayo, co-developed by Regeneron and Sanofi, is already approved for NSCLC in several markets. These results strengthen its use as a first-line therapy when combined with chemotherapy.
This data comes at a critical time in lung cancer treatment. The goal is to extend life while keeping the disease under control. A five-year survival rate near 20% is a notable achievement in this field. Still, most patients do not reach that milestone. Ongoing research is needed. Future studies should look at long-term quality of life, treatment timing, and biomarkers that predict success.
The five-year results from EMPOWER-Lung 3 offer new hope to patients and clinicians. Libtayo with chemotherapy shows clear survival gains for advanced NSCLC without targetable mutations. Though side effects must be managed, the benefits could shift treatment expectations and guide future standards. This combination therapy is a promising step toward better long-term outcomes.
