Retlirafusp alfa shows sustained 3-year survival benefits in unresectable Stage III NSCLC, especially with surgery.
Background
Unresectable Stage III non-small cell lung cancer (NSCLC) presents a significant therapeutic challenge, often requiring multimodal treatment. Current standard-of-care, while improving, still leaves a substantial gap in long-term survival for many patients. The PD-L1 pathway is a key immune checkpoint target, and TGF-β signaling is known to promote immunosuppression and tumor progression. Combining PD-L1 blockade with TGF-β inhibition offers a promising strategy to overcome resistance mechanisms and enhance anti-tumor immunity in this aggressive disease.
Study Design
The phase 2 TRAILBLAZER trial (NCT04580498) investigated neoadjuvant retlirafusp alfa in 107 patients with unresectable Stage III NSCLC without EGFR or ALK alterations. Patients without high PD-L1 expression received retlirafusp alfa plus chemotherapy (arm A; n=88). Patients with high PD-L1 were randomized 1:1 to retlirafusp alfa plus chemotherapy (arm B; n=9) or retlirafusp alfa monotherapy (arm C; n=10). Treatment involved induction followed by surgery or radiotherapy, then consolidation retlirafusp alfa. The primary endpoints included event-free survival (EFS) and overall survival (OS) at 3 years.
Results
With a median follow-up of 39.4 months, retlirafusp alfa regimens demonstrated sustained survival benefits. The 3-year event-free survival (EFS) rate was 50.5% (95% CI 39.0-61.0) in the combined arm A+B (retlirafusp alfa + chemotherapy) and significantly higher at 77.1% (95% CI 34.5-93.9) in arm C (monotherapy). The corresponding 3-year overall survival (OS) rates were 68.3% (95% CI 57.5-77.0) for arm A+B and 87.5% (95% CI 38.7-98.1) for arm C. Notably, among the 27 patients who underwent surgery after induction treatment:
The 3-year EFS and OS rates were 69.5% (95% CI 48.1-83.5%) and 84.9% (95% CI 64.5-94.0%), respectively. These rates were superior to those in radiotherapy-treated patients, who showed 3-year EFS of 50.8% (36.5-63.4%) and OS of 70.4% (56.7-80.5%). Safety data remained consistent with prior reports, showing no new signals.
Key Findings
- Retlirafusp alfa showed a 3-year EFS rate of 50.5% (arm A+B) and 77.1% (arm C) in unresectable Stage III NSCLC.
- The 3-year OS rate was 68.3% (arm A+B) and 87.5% (arm C).
- Patients undergoing surgery after induction achieved superior 3-year EFS (69.5%) and OS (84.9%) compared to radiotherapy-treated patients.
- Safety profile remained consistent with previous reports, with no new signals over 39.4 months of follow-up.
Why It Matters
This updated analysis suggests that neoadjuvant retlirafusp alfa, particularly when combined with a response-adapted surgical strategy, offers a promising new approach for unresectable Stage III NSCLC. For clinicians and patients, this could mean improved long-term survival outcomes, especially if surgery becomes feasible after induction therapy. While specific dosing protocols for retlirafusp alfa are not detailed here, the sustained benefits observed over 3 years highlight the potential of bifunctional immune checkpoint inhibitors. Further research in larger trials is needed to refine patient selection and treatment sequencing, but these results support integrating such agents into future NSCLC treatment paradigms.
retlirafusp-alfa
nsclc
lung-cancer
neoadjuvant
pd-l1-inhibitor
tgf-beta-inhibitor