Abstract 1323P
Background
First-line pembrolizumab monotherapy in patients with PDL1-high non-small cell lung cancer significantly improves progression-free survival and overall survival continuing to demonstrate benefit with prolonged follow-up. The aim of present study is to compare outcomes in real-world oncology practice with pivotal clinical trials.
Methods
Between March 2018 and April 2020, we performed analysis of patients with metastatic NSCLC and PDL1 TPS ≥ 50% without EGFR/ALK aberrations, ECOG PS 0 and 1 who received treatment with first-line pambrolizumab.
Results
Of 246 patients median OS was 32.3 months (95% CI: 25.9-32.3) and median PFS was 22.6 months (95% CI: 13.0-25.4). CNS metastases at diagnosis were present in 21.0%. Median duration of therapy was 8.1 months (2.3-15.2). Objective response rate was 47.9% (CR 0.9%, PR 47.4%, SD 27.4%). 149/246 (60.6%) of patients were alive at 6 months. The reasons for end of therapy were death in 14.4%, disease progression in 33.3%, adverse events in 16.7% and lost to follow up in 4.5%. At data cutoff (January 26, 2021), 66/246 (26.8%) were on current treatment, of which 20 patients (8.2%) were alive more than 2 years with no disease progression. Adverse events of any cause and grade developed in 44 patients – 17.8%, leading to discontinuation of treatment, in 22 patients treatment-related grade was 3 to 5 adverse events – 8.9%, and 2.9% of patients had SAE leading to death. There was no correlation between any of the outcomes and tumor type, determination of PDL1 expression by means of the PDL1 IHC or cytology, smoking status and CNS metastases. No statistical correlation was found in patients who were long respoders (more than 2 years stabile disease) according to patient (age, sex, smoking status) and tumor characteristics (tumor type).
Conclusions
Observed outcomes in real-world study were consistent with those in pivotal clinical trials. Longer mPFS in our study can be explained with mixed radiographic response in patients permitted to stay on treatment determined by an investigator as clinical benefit. Disease progression was the most common reason for discontinuation of immunotherapy, thus suggesting adding first-line chemotherapy to some patients with PDL1 expression of ≥50%.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.