Abstract 3162: Prognostic value of tumor mutational burden using a 409 gene NGS panel in cancer patients with advanced stage recurrent or treatment refractory disease

Tumor Mutational Burden (TMB) is a promising biomarker for prediction of response to immune checkpoint blockade (ICB). It is uncertain whether ICB has prognostic value outside of ICB therapy. The CMS400 next generation sequencing panel (NGS) is a 409 gene, 15,992 amplicon, and 1.745 Mb panel instituted during 2014-2015 and run for 556 cancer patients who had been consented for participation within a prospective molecular pathology biomarker trial (PA14-0099). All patients had advanced or recurrent solid tumor malignancies that were refractory to at least one line of systemic therapy prior to enrollment. Survival time was calculated from time of NGS-tested tissue collection. TMB was calculated by dividing reported mutations (RM) by 1.745Mb, the genetic footprint of the NGS panel. Subtraction of germline single nucleotide polymorphisms was performed for each patient. GraphPad Prism 7.03 software was used to calculate p values and to plot Kaplan-Meier survival curves. One hundred seven patients (19.2%) received ICB. When stratified by reported mutations (RM: 0, 1, 2, 3, 4-5, 6-7, 8-9, 10-18, and >19), a statistically significant decrement of overall survival was seen with increasing TMB in patients not treated with ICB (Table 1, p Median Survival Stratified by Tumor Mutational Burden and ICB Treatment StatusAll PtsAll PtsICB TreatedICB TreatedNo ICBNo ICBReported Mutations# of PtsMedian Survival (Months)# of PtsMedian Survival (Months)# of PtsMedian Survival (Months)p-value (Log-rank)Hazard Ratio of ICB Therapy95% CI of HR of ICB Therapy0 RM7150.71958.85248.50.3190.7050.368 - 1.341 RM8550.91262.07347.40.3390.6840.345 - 1.362 RM9433.91928.07533.90.8650.9510.535 - 1.693 RM8830.51951.26928.90.1890.7040.428 - 1.164-5 RM9330.81141.08230.40.5390.8150.442 - 1.506-7 RM4928.41127.33828.550.6230.8270.401 - 1.718-18 RM5623.95828.84823.10.5491.2520.553 - 2.84>19 RM2041.38102.31224.20.00230.1800.0599 - 0.543Total55635.810747.944933.40.00490.7070.567 - 0.882p-value (Log-rank) Citation Format: Richard K. Yang, Peng Wang, Fatima Z. Jelloul, Mark J. Routbort, Scott Kopetz, Kenna R. Shaw, Jack J. Lee, Jiexin Zhang, Hui Chen, Keyur P. Patel, Raja Luthra, Russell R. Broaddus. Prognostic value of tumor mutational burden using a 409 gene NGS panel in cancer patients with advanced stage recurrent or treatment refractory disease [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3162.