Use of pembrolizumab in patients with PS2 NSCLC

Clinical trials assessing the efficacy of pembrolizumab have previously enrolled patients with performance status (PS) 0–1. However, almost a fifth of patients with non-small cell lung cancer (NSCLC) are PS2, leaving questions over the efficacy and safety of pembrolizumab in these patients.

Results reported from the ‘pembrolizumab in patients with non-small cell lung cancer of performance status 2’ (PePS2) study (NCT02733159) show that pembrolizumab can be safety administered to this patient group, with no increase in immune-related or other toxicities.1

As reported in The Lancet Respiratory Medicine, PePS2 is a multi-center, single-arm, open-label, phase II trial conducted in ten hospitals in the UK in which patients with NSCLC of PS2 were given pembrolizumab 200mg every three weeks. Over a 13-month period (Jan 17–Feb 18), 60 patients were recruited and deemed evaluable. Treatment evaluations were stratified by tumor proportion score (TPS) and line of therapy, with co-primary outcomes of durable clinical benefit (DCB) and toxicity.

In first-line patients (n=24), the incidence of DCB was 38% (95% CI 21–57), and in subsequent-line patients (n=36) it was 36% (95% CI 22–52). In patients with a TPS <1% (n=27), 1–49% (n=15), and ≥50% (n=15) the incidence of DCB was 22% (95% CI 11–41), 47% (95% CI 25–70) and 53% (95% CI 30–75), respectively. Toxicity was observed in 28% (95% CI 19–41) of patients.

The efficacy data reported from this study are comparable to that reported for patients with PS0–1 NSCLC, and the publication concludes that data from this study ‘provides clinicians with the confidence to incorporate pembrolizumab into the treatment pathway of patients with NSCLC of PS2’.


  1. Middleton G, Brock K, Savage J, et al. Pembrolizumab in patients with non-small-cell lung cancer of performance status 2 (PePS2: a single arm, phase 2 trial. Lancet Respir Med. 2020 Mar 19. doi: 10.1016/S2213-2600(20)30033-3 [Epub ahead of print].