The FDA has approved first-line pembrolizumab (Keytruda) for use in combination with carboplatin and either paclitaxel or nab-paclitaxel (Abraxane) for the treatment of patients with metastatic squamous non–small cell lung cancer (NSCLC).
Two-hundred seventy-eight patients were treated in the pembrolizumab cohort and 281 patients received treatment in the chemotherapy-alone arm. In the pembrolizumab arm, 121 patients remained on treatment and 157 had discontinued. The primary reasons for discontinuing were progressive disease (n = 99) and adverse events (AEs; n = 48). In the chemotherapy-alone arm, 72 patients remained on treatment, with 208 having discontinued, primarily due to progression (n = 166) and AEs (n = 25).
Patient characteristics were well balanced at baseline between the 2 arms. In the pembrolizumab arm, the median age was 65.0 years (range, 29-87), 79.1% of patients were men, 73.7% had an ECOG performance status of 1, 7.2% had stable brain metastases, and 92.1% were current/former smokers. Additionally, 60.8% received paclitaxel as their taxane, 6.1% had prior thoracic radiation, and 1.8% had prior (neo)adjuvant therapy.
PD-L1 status was measured by tumor proportion score (TPS). In the pembrolizumab arm, 34.2%, 37.1% and 26.1% had a PD-L1 TPS status of <1%, 1%-49%, and ≥50%, respectively. The corresponding rates in the placebo arm were 35.2%, 37.0%, and 26.0%, respectively.
The HR for OS was 0.61, 0.57, and 0.64 favoring the pembrolizumab arm in the TPS <1%, <1%-49%, and ≥50% subgroups, respectively. Across the same 3 subgroups, the HR for PFS favoring the pembrolizumab arm was 0.68, 0.56, and 0.37, respectively.
The median treatment duration was 6.3 months in the pembrolizumab arm compared with 4.7 months in the placebo arm. Grade 3/5 all-causes AEs occurred in 69.8% versus 68.2% of the 2 arms, respectively. Treatment-related AEs (TRAEs) led to discontinuation in 23.4% of the experimental arm versus 11.8% of the control arm. Grade 3/5 immune-mediated AEs and infusion reactions occurred in 10.8% versus 3.2% of the 2 arms respectively. Overall, TRAEs led to death in 3.6% versus 2.1% of the 2 arms, respectively.
Paz-Ares LG, Luft A, Tafreshi A, et al. Phase 3 study of carboplatin-paclitaxel/nab-paclitaxel (Chemo) with or without pembrolizumab (Pembro) for patients (Pts) with metastatic squamous (Sq) non-small cell lung cancer (NSCLC). J Clin Oncol. 2018;36 (suppl; abstr 105).
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