WCLC 2019 – Pembrolizumab monotherapy in previously untreated NSCLC: very first results in Chinese patients


  • Cristina Ferrario — Agenzia Zoe
  • Univadis
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Takeaway

  • Immunotherapy with pembrolizumab as single-agent leads to improved overall survival (OS) compared to platinum-based chemotherapy in treatment-naïve Chinese patients with locally advanced/metastatic non-small cell lung cancer (NSCLC).
  • The immunotherapy safety profile is favourable.
  • Findings refer to patients with PD-L1 tumour proportion score (TPS) ≥1% and are consistent with primary endpoints from the global study.

Why this matters

  • Patients from Asia are under-represented in clinical trials.
  • Pembrolizumab has been shown to improve OS vs chemotherapy in the same disease setting in the global study.
  • Data on Chinese population are lacking.

Study design

  • The study design was the same for the global, open-label, phase 3 study and the Chinese extension.
  • Included patients were randomized to up to 35 cycles of pembrolizumab 200 mg q3w or up to 6 cycles of paclitaxel/pemetrexed + carboplatin, with optional pemetrexed maintenance for non-squamous tumours.
  • Patients were stratified by performance status (ECOG PS 0/1), histology (squamous/non-squamous histology), and PD-L1 TPS (≥50%/1‒49%).
  • OS in patients with PD-L1 TPS ≥50%, ≥20%, and ≥1% was the primary endpoint.
  • Consistency across outcomes in Chinese patients was assessed in the study extension.

Key results

  • At the cutoff date, 262 patients PD-L1–positive (TPS ≥1%) and without targetable EGFR/ALK aberrations were enrolled in the Chinese extension and randomized to pembrolizumab (n=128) or chemotherapy (n=128).
  • PD-L1 TPS ≥50% and ≥20% was observed in 55.7% and 77.9% of patients, respectively.
  • Median OS (mOS) was higher in patients treated with immunotherapy compared with chemotherapy: 20.0 vs 14.0 months (HR 0.62), respectively, with PD-L1 TPS ≥50% and 20.0 vs 13.7 months for both PD-L1 TPS ≥20% and ≥1%.
  • In the pembrolizumab group, objective response rates (ORR) (RECIST v1.1, blinded independent central review) for TPS ≥50%, ≥20% and ≥1% were 41.7%, 37.5% and 32.8%, respectively.
  • Corresponding rates in the chemotherapy group were 24.3%, 24.3% and 24.6%, respectively.
  • Incidence of grade 3-5 treatment-related adverse events was about 4 fold higher with chemotherapy (68%) vs pembrolizumab (17%).

Funding

  • MSD.

Expert commentary

“This is the first study showing the same efficacy for pembrolizumab monotherapy in Chinese patients as in the global study. As chemotherapy toxicity is different in patients from Asia, more data on immune-chemo therapy combination is needed”. Lizza Hendriks. Maastricht UMC+, The Netherlands.