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), combined with platinum-based chemotherapy, provides a strong and lasting survival benefit. The trial focused on patients with advanced non-small cell lung cancer (NSCLC) who did not have EGFR, ALK, or ROS1 mutations. This group usually faces poor outcomes and limited options.
The combination achieved a five-year overall survival (OS) of 19.4%. This is more than double the 8.8% reported with chemotherapy alone. Patients who received Libtayo lived a median of 21.1 months, compared with 12.9 months for chemotherapy. That means a 34% lower risk of death. The benefit appeared across different subgroups, including patients with varying tumor types and PD-L1 expression levels.
Progression-free survival (PFS) also improved. The Libtayo group had a median PFS of 8.2 months versus 5.5 months in the chemotherapy group. The objective response rate (ORR) rose to 43.6% compared with 22.1% for chemotherapy alone. Complete responses occurred only in the Libtayo group, where 6.4% of patients had all detectable cancer cleared. The response also lasted longer, at 16.4 months compared with 7.3 months.
Patients with squamous cell NSCLC reached a median OS of 22.3 months, compared with 13.8 months on chemotherapy alone. For non-squamous disease, OS improved to 19.4 months versus 12.4 months. In patients with PD-L1 expression of 1% or higher, OS rose to 24 months compared with 12.1 months.
Safety outcomes matched trends seen in immunotherapy studies. In the Libtayo group, 96.5% of patients had at least one adverse event (AE), with 49% reaching Grade 3 or higher. In the chemotherapy group, AEs occurred in 95% of patients, with 33% being severe. Severe treatment-related AEs appeared in 30% of the Libtayo group, leading to discontinuation in 4.5% and death in 1%. For chemotherapy, those numbers were 18%, 1%, and 0.7%. These results highlight the need for close monitoring and personalized risk evaluation.
The EMPOWER-Lung 3 trial included patients with advanced or metastatic NSCLC. Participants were included regardless of PD-L1 expression, and some had controlled brain metastases. This broad design reflects real-world conditions. Libtayo, developed by Regeneron and Sanofi, is already approved for NSCLC in several markets. These longer-term findings support its role as a frontline choice when used with chemotherapy.
The results arrive at an important time in lung cancer care. Clinicians want treatments that extend survival while maintaining disease control. Achieving nearly 20% five-year survival is a meaningful gain in a cancer where long-term survival is uncommon. Still, many patients do not reach this milestone, so more research is essential. Future work should focus on quality of life, treatment sequences, and biomarkers that predict benefit.
These five-year results reinforce the promise of Libtayo plus chemotherapy as a first-line therapy for advanced NSCLC without driver mutations. The survival advantage is clear. Side effects remain a challenge, but the benefits may change treatment expectations and influence future guidelines. This combination offers new hope for both patients and clinicians.
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