Cancer Cachexia Syndrome In The Prediction Of Outcome In Patients With Metastatic Non-Small Cell Lung Cancer (Nsclc) Treated With Immune Checkpoint Inhibitors (Icis): Results From A Single-Institution, Prospective, Observational Study.

e21644 Background: Cancer cachexia syndrome (CCS) is a multifactorial inflammatory syndrome affecting a large subset of patients (pts) with NSCLC which in preclinical models negatively impairs antitumor immunity. We conducted a prospective, observational study to investigate the effect of CCS and sarcopenia on the efficacy of ICIs in NSCLC. Methods: CCS was defined as weight loss of > 5% in the last 6 months or any degree of weight loss > 2% in combination with BMI < 20% or baseline skeletal muscle index at the level of the 3rd lumbar vertebra consistent with sarcopenia. Skeletal muscle index was calculated using slice-o-matic tomovision software in the abdominal CT scan before starting ICIs. Results: 83 pts were included in the analysis. Median follow up was 9.5 months. Median age was 66 years, 61.4% had non-squamous histology, 20.5% received ICIs as first and the remaining as second-line therapy. 20.5% of pts experienced partial response (PR), 31% had stable disease (SD) and 48.2% had disease progression (PD). Median progression-free survival (PFS) was 4.4 months and median overall survival (OS) was 10.33 months. 43.4% of the whole group were categorized as having CCS, whereas 63.3% of 30 pts evaluated using tomovision had sarcopenia. CCS negatively affected response rates (p = 0.003) but not response duration (p = 0.266). CCS was associated with reduced PFS (2.46 vs 5.77 months, p = 0.006) and OS (4.8 vs 14.53 months, p = 0.001). In the multivariate analysis, CCS independently predicted for shorter OS (HR = 2.01; CI: 1,14-3,54; p = 0.014). Sarcopenia was also associated with reduced OS (5.4 vs 17.9 months, p = 0.012). Analysis on the whole pt population will be presented at the conference. Conclusions: CCS is associated with lower response rates and independently predicts for shorter OS in pts with NSCLC treated with ICIs. Further research on CCS could better define its role as a potential biomarker and a research platform for maximizing immunotherapy efficacy.