Pembrolizumab as first-line treatment in NSCLC with PD-L1 ≥50%: Real life results from an all-comer population

Abstract

Background: First-line therapy with pembrolizumab is the standard of care in locally advanced and metastatic non-small cell lung cancer (NSCLC) with a PD-L1 expression of ≥ 50%. However, efficacy results in patients with a PS ≥ 2, untreated brain metastases or permanent oral steroids are lacking. Methods: Patients from six certified lung cancer centers in Berlin, Germany, presenting with stage III (non resectable, not suitable for chemoradiation) and IV NSCLC, with a PD-L1 expression of ≥ 50%, diagnosed or treated between January 1st, 2017 and December 31, 2017 were included in this retrospective study. Progression-free (PFS) and overall survival (OS) were calculated using the Kaplan-Meier method. Cox regression analyses were used to identify prognostic factors for survival. Values are given as median (range). Results: During the observation period, 128 patients fulfilled the inclusion criteria. Median age was 68.6 years (39 – 85), 76 patients were male (59.4%). Histology was predominantly non-squamous (68.8%). 31 patients (24.2%) had an initial PS of ≥ 2. Oral steroids for ≥2 weeks (equivalent daily doses of ≥ 10 mg of prednisolone during therapy with pembrolizumab) were prescribed to 34 patients (26.6%). Pembrolizumab was initiated in 24 patients with previously untreated brain metastases (18.8%). Within a follow-up of 13.0 months (95% CI, 10.5 – 15.4), a median of 9 cycles (1 – 38) were administered corresponding to a duration of treatment of 6.9 months (95% CI, 4.6 – 9.2). Therapy was still ongoing in 30 patients (23.4%). PFS was 9.4 months (95% CI, 4.8 – 14.1) with a duration of response of 11.9 months (95%CI, 8.4 – 15.4). OS reached 18.9 months (95% CI, NE – NE). A PS ≥ 2 was associated with a reduced OS (HR 0.43, 95% CI, 0.25 – 0.75, p = 0.003), no effects were noted for brain metastases and steroids. Conclusions: Our data from real life practice in an all comer population demonstrate the efficacy of pembrolizumab in NSCLC with a PD-L1 expression of ≥ 50%. Despite a reduced survival in PS ≥ 2, the reached OS of 8.0 months is superior to historic cohorts with cytotoxic chemotherapy. Furthermore, OS was unchanged in case of untreated brain metastases or permanent steroids. Legal entity responsible for the study: The authors. Funding: Has not received any funding. Disclosure: All authors have declared no conflicts of interest.