Abstract 438P
Background
The Checkmate 577 trial showed a disease-free survival benefit of adjuvant nivolumab after neoadjuvant chemoradiotherapy (nCRT) plus surgery for esophageal or gastroesophageal junction (GEJ) cancer. Overall survival (OS) data are not yet available. The aim of this study was to evaluate OS of patients treated with or without adjuvant nivolumab in a nationwide real-world matched comparison.
Methods
From the Netherlands Cancer Registry we selected patients with esophageal or GEJ cancer and residual pathological disease after nCRT and surgery in 2020-2023. This resulted in 333 patients treated with adjuvant nivolumab and 486 patients who received nCRT and surgery alone in the period before introduction of nivolumab. Propensity score trimming and matching were used to create to comparable groups based on patient (age, sex, performance status, comorbidity index, BMI and other malignancies), tumor (location, histology, differentiation grade, ypT, ypN) and treatment-related variables (number of chemotherapy cycles, dosage of radiotherapy, time between nCRT and resection, surgical radicality, post-operative complications, type of resection, annual hospital resection volume).
Results
Propensity score matching resulted in well-balanced groups of 311 patients per treatment group. Median follow-up time was 14.2 months and 26.6 months for patients treated with and without adjuvant nivolumab, respectively. OS was significantly better in patients treated with nivolumab compared to patients not treated with nivolumab: HR 0.71, 95% CI: 0.52-0.98; p=0.03 (Table). Table: 438P
Overall survival at 6, 12 and 18 months
| Time since start nivolumab | Adjuvant nivolumab | No adjuvant nivolumab | ||
| N at risk | OS (%) | N at risk | OS (%) | |
| 6 months | 272 | 92.8 (88.2 – 94.5) | 283 | 91.3 (88.2 – 94.5) |
| 12 months | 207 | 85.3 (81.2 – 89.5) | 247 | 80.0 (75.4 – 84.3) |
| 18 months | 106 | 77.9 (72.8 – 83.3) | 218 | 70.3 (65.4 – 75.6) |
Conclusions
In this matched real-world study OS was in favor of patients treated with nivolumab compared to patients without nivolumab. As follow-up is still limited, these analyses should be carefully updated in the forthcoming years.
Legal entity responsible for the study
Netherlands Comprehensive Cancer Organisation.
Funding
Has not received any funding.
Disclosure
R.H.A. Verhoeven: Financial Interests, Institutional, Advisory Board, Consultancy: Daiichi Sankyo; Financial Interests, Institutional, Research Grant: Bristol Myers Squibb; Non-Financial Interests, Member of Board of Directors, The Dutch Upper-GI Cancer Group is the Dutch multidisciplinary research group regarding Upper-GI cancers: Dutch Upper-GI Cancer Group; Non-Financial Interests, Member of Board of Directors: International Association of Cancer Registries. M. Slingerland: Financial Interests, Institutional, Advisory Board: Bristol Myers Squibb, AstraZeneca, Lilly. B.P.L. Wijnhoven: Financial Interests, Institutional, Research Grant: Bristol Myers Squibb; Financial Interests, Institutional, Advisory Role: Bristol Myers Squibb. M.I. van Berge Henegouwen: Financial Interests, Institutional, Advisory Role: Viatris, Johnson & Johnson, BBraun, Alesi Surgical, Stryker, Medtronic. S. Derks: Financial Interests, Institutional, Advisory Board: BMS; Financial Interests, Institutional, Invited Speaker: BMS, Servier; Financial Interests, Institutional, Funding, sponsoring investigator initiated study: Incyte. B. Mostert: Financial Interests, Institutional, Research Grant: Pfizer, Bristol Myers Squibb; Financial Interests, Institutional, Advisory Role: Lilly, Servier, Bristol Myers Squibb, AstraZeneca, Amgen. N. Haj Mohammad: Financial Interests, Institutional, Advisory Role: Servier, AstraZeneca, Bristol Myers Squibb/Pfizer, Merck/Pfizer, Lilly. H.W.M. van Laarhoven: Financial Interests, Institutional, Invited Speaker: Astellas, BeiGene, Benecke, BMS, Daiichi Sankyo, JAAP, Medtlaks, Novartis, Springer, Travel Congress Management BV, Auristone; Financial Interests, Institutional, Advisory Board: Amphera, Anocca, Astellas, AstraZeneca, BeiGene, Boehringer Ingelheim, Daiichi Sankyo, Dragonfly, MSD, Servier; Financial Interests, Institutional, Other, Advices on protocol development: Myeloid; Financial Interests, Institutional, Other, Selection of articles for Framingham: Framingham; Financial Interests, Institutional, Research Grant, LyRICX study: Servier; Financial Interests, Institutional, Research Grant, TAPESTRY study: Merck; Financial Interests, Institutional, Research Grant, AUSPICIOUS study: Incyte; Financial Interests, Institutional, Research Grant, LOAD study: ORCA; Financial Interests, Institutional, Invited Speaker, DESTINY-GASTRIC03: AstraZeneca; Non-Financial Interests, Leadership Role, Chair upper GI Faculty: ESMO; Non-Financial Interests, Institutional, Product Samples, For all clinical study mentioned, study medication is provided: See 'research funding'. All other authors have declared no conflicts of interest.