Abstract 940P
Background
Treatment of resected, early-stage NSCLC is rapidly evolving, with four Phase 3 trials evaluating adjuvant immunotherapies targeting the PD1/PDL1 pathway. This study characterized real-world PDL1 expression prevalence and outcomes.
Methods
This retrospective cohort study included adult patients (pts) with resected stage IB-IIIA NSCLC diagnosed in 2016–2019 at three Canadian centers (that conducted reflex PDL1 testing) using pan-Canadian Lung Cancer Observational Study (PALEOS) data. Pts receiving neoadjuvant therapy were excluded. Outcomes included: PDL1 prevalence, epidermal growth factor receptor mutation (EGFRm) status, and treatment patterns, survival, and disease recurrence, which were only analyzed for PDL1-positive (PDL1+) patients.
Results
Among 539 pts with PDL1 status reported, 51.6% were female, 76.6% had non-squamous histology, and among those tested (n=390), 21% were EGFRm-positive. 222 (41.2%) pts were PDL1 negative (PDL1-) and 317 (58.8%) were PDL1+ (expression ≥1%); 43.2% of PDL1+ pts had expression ≥50%. Of stage IB, II, and IIIA patients, 53.3%, 60.3%, and 65.8% were PDL1+, respectively. Among PDL1+ pts, mean age at diagnosis was 70.2 years. Most pts (58.7%) had undergone resection alone (32.2% (IB), 18.3% (II), 8.2% (IIIA)); 41.3% had received resection + adjuvant therapy (3.2% (IB), 21.5% (II), and 16.7% (IIIA)). Median follow-up was 22.6 months. See table for survival data. 31.9% of pts had disease recurrence, of which 70.3% was metastatic. First recurrence was most common in the lung and brain (16.8% each). Table: 940P
Survival outcomes in PDL1+ pts
| All PDL1+ PtsN=317 | PDL1+ ≥50%N=137 | ||
| Overall survival | Median, mo (95% CI) | NR (NR-NR) | NR (NR-NR) |
| Probability, % (95% CI) | |||
| 2-yr4-yr | 81 (77-86)65 (57-75) | 77 (70-86)64 (54-77) | |
| Disease-free survival | Median, mo (95% CI) | 40.0 (30.0-NR) | 40.0 (22.5-NR) |
| Probability, % (95% CI) | |||
| 2-yr4-yr | 61 (55-67)44 (36-54) | 56 (47-66)43 (30-61) |
CI = confidence interval; mo = month(s); NR = not reached; yr = year.
Conclusions
PDL1 prevalence in this study population was similar to that in metastatic NSCLC. Clinical outcomes by stage and treatment modality will be presented. This study gives context to emerging clinical trials—new therapeutic options are needed.
Clinical trial identification
Editorial acknowledgement
The authors wish to thank Dana L. Anger of WRITRIX Medical Communications Inc. for editorial assistance.
Legal entity responsible for the study
AstraZeneca Canada.
Funding
AstraZeneca Canada.
Disclosure
P.K. Cheema: Financial Interests, Institutional, Invited Speaker: AstraZeneca Canada, Amgen; Financial Interests, Institutional, Advisory Role: AstraZeneca Canada, Amgen, BMS, Merck, Novartis, F.Hoffman-La Roche, Pfizer, Janssen, BeiGene, Sanofi, Bayer, EMD Serono. I. Syed: Financial Interests, Institutional, Full or part-time Employment: AstraZeneca Canada; Financial Interests, Institutional, Stocks/Shares: AstraZeneca Canada. F. Gwadry-Sridhar: Financial Interests, Institutional, Full or part-time Employment: Pulse Infoframe Inc.; Financial Interests, Institutional, Stocks/Shares: Pulse Infoframe Inc.; Financial Interests, Institutional, Leadership Role: Pulse Infoframe Inc. M. Rakibuz-Zaman: Financial Interests, Institutional, Full or part-time Employment: Pulse Infoframe Inc. B. Sheffield: Financial Interests, Institutional, Advisory Role: Amgen, AstraZeneca, Bayer, Biocartis, Boehringer Ingelheim, Cell Marque, Elevation Oncology, Eli Lilly, EMD Serono, Incyte, Janssen, Merck, Novartis, Pfizer, Roche, Thermo Fisher, Turning Point Therapeutics. D. Moldaver: Financial Interests, Institutional, Full or part-time Employment: AstraZeneca Canada; Financial Interests, Institutional, Stocks/Shares: AstraZeneca Canada. M.K. Shanahan: Financial Interests, Institutional, Full or part-time Employment: AstraZeneca Canada; Financial Interests, Institutional, Stocks/Shares: AstraZeneca Canada. G. Liu: Financial Interests, Institutional, Advisory Role: AstraZeneca, Takeda, Merck, BMS, Roche, EMD Serono, Jazz Pharmaceuticals, Pfizer, Novartis; Financial Interests, Institutional, Research Grant: AstraZeneca, Takeda. M.S. Kuruvilla: Financial Interests, Institutional, Advisory Board: AstraZeneca Canada, BMS, Merck. All other authors have declared no conflicts of interest.