Pd09-03 extracellular Vesicles: A Mechanism of Action of Bacillus Calmette-Guerin and a Potential Biomarker

Abstract

Baseline titers were not associated with response. On-treatment titers >800 were seen in 89% and 59% of responders (R) and nonresponders (NR), respectively (p[0.001). Sensitivity of this test for detecting R was 89% (negative predictive value, 78%). Ontreatment Ab fold change >8 from baseline was seen in 51% and 27% of R and NR, respectively (p[0.02). Elevated on-treatment Ab titers and fold change from baseline were noted in 47% and 18% of R and NR, respectively (p[0.004). Specificity of the combined test for detecting R was 82% (positive predictive value, 73%). These findings were also corroborated in the CISAETa/T1 subcohort.CONCLUSIONS: Secondary analysis of the prospective, multicenter phase 3 nadofaragene firadenovec trial in BCGunresponsive NMIBC indicates a role for assaying baseline and ontreatment Ab titers. A combination of Ab titer and fold-change levels can potentially predict response to this novel therapeutic in a patient population with urgent unmet clinical need.