OBJECTIVES/GOALS: Cachexia is the involuntary and irreversible loss of muscle and fat and is a major cause of morbidity and mortality in head and neck cancer (HNC). It remains a poorly understood disease diagnosed by weight loss and a confluence of symptoms. We explored the metabolic and inflammatory mechanisms of cachexia symptoms via an multiomics network algorithm. METHODS/STUDY POPULATION: Prior to chemoradiotherapy, HNC subjects completed questionnaires and donated blood for untargeted (metabolites) and targeted (lipids and cytokines) assays. Metabolites and lipids were measured by liquid chromatography mass spectrometry. Cytokines were measured by multiplex assays. We plotted a multiomics network graph by estimating partial least squares correlations amongst metabolites, lipids, cytokines, and common cachexia symptoms—max percent weight loss over 1 year, baseline BMI, fatigue, performance, albumin, hemoglobin, and white blood cell count. To interpret the network, an algorithm identified highly correlated clusters of metabolites-lipids-cytokines-symptoms representing possible biological relatedness, which were functionally annotated via metabolic enrichment analysis. RESULTS/ANTICIPATED RESULTS: In 123 subjects (59 years of age, 72% male, 84% white, avg weight loss of 13%), we analyzed 186 metabolites, 54 lipids, 7 cytokines and 7 cachexia symptoms. We required a correlation >0.25 and P-value <.05 to be included in the network graph, resulting in 323 connections and 3 identified clusters. Max weight loss and baseline BMI were in a cluster enriched by unsaturated fatty acid biosynthesis (P<.0001) and arachidonic acid (P=.01) metabolic pathways but not linked to inflammation cytokines. The five other cachexia symptoms were in a cluster with 4 cytokines (C-reactive protein, interleukin 6, IL10, IL1, Tumor necrosis factor receptor 2) and enriched by aminoacyl tRNA (P<.01) and valine biosynthesis (P=.02). We observed no meaningful differences when we stratified the analysis by human papillomavirus. DISCUSSION/SIGNIFICANCE: Cachexia symptoms in head and neck cancer may be linked to specific metabolic dysregulation—weight loss and BMI were linked to fatty acids; fatigue, anemia and others were linked to amino acids and inflammation. This information may allow for the recognition of a cachexic-metabolic subtype or provide novel targets for metabolic intervention.