ABSTRACT
Circulating tumor DNA (ctDNA) is emerging as a potential biomarker in early-stage urothelial cancer but its utility in metastatic disease remains unknown. In the phase 3 KEYNOTE-361 study, pembrolizumab with and without chemotherapy was compared with chemotherapy alone in patients with metastatic urothelial cancer. The study did not meet prespecified efficacy thresholds for statistical significance. To identify potential biomarkers of response, we retrospectively evaluated association of pre- and post-treatment ctDNA with clinical outcomes in a subset of patients who received pembrolizumab (n = 130) or chemotherapy (n = 130) in KEYNOTE-361. Baseline ctDNA were associated with best overall response (BOR;P = 0.009), progression-free survival (PFS;P < 0.001), and overall survival (OS;P < 0.001) for pembrolizumab, but not chemotherapy (all, P > 0.05). Chemotherapy induced larger ctDNA decreases from baseline to treatment cycle 2 than pembrolizumab; however, change with pembrolizumab (n = 87) were more associated with BOR (P = 4.39 × 10-5) and OS (P = 7.07 × 10-5) versus chemotherapy (n = 102; BOR: P = 1.01 × 10-4; OS: P = 0.018). Tumor tissue-informed versions of ctDNA change metrics were most associated with clinical outcomes but did not show statistically significant independent value for explaining OS beyond radiographic change by RECIST v1.1 when jointly modeled (pembrolizumab P = 0.364; chemotherapy P = 0.823). These results suggest distinct patterns in early ctDNA changes with immunotherapy and chemotherapy and differences in their association with long-term outcomes, which provide preliminary insights on the utility of liquid biopsies for treatment monitoring in metastatic urothelial cancer. Clinical trial registration: NCT02853305.
ABSTRACT
PURPOSE: Vandetanib is a once-daily, oral inhibitor of vascular endothelial growth factor receptor and epidermal growth factor receptor signaling. The antitumor activity of vandetanib monotherapy or vandetanib with paclitaxel and carboplatin (VPC) was compared with paclitaxel and carboplatin (PC) in previously untreated patients with non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: All NSCLC histologies and previously treated CNS metastases were permitted in this partially blinded, placebo-controlled, randomized phase II study. Patients were randomly assigned 2:1:1 to receive vandetanib, VPC, or PC. Progression-free survival (PFS) was the primary end point, and the study was powered to detect a reduced risk of progression with VPC versus PC (hazard ratio = 0.70; one-sided P < .2) and to demonstrate noninferiority for vandetanib versus PC. Overall survival was a secondary assessment. RESULTS: The risk of progression was reduced for patients receiving VPC (n = 56) versus PC (n = 52; hazard ratio = 0.76, one-sided P = .098); median PFS was 24 weeks (VPC) and 23 weeks (PC). The vandetanib monotherapy arm (n = 73) was discontinued after a planned interim PFS analysis met the criterion for discontinuation (hazard ratio > 1.33 v PC). Overall survival was not significantly different between patients receiving VPC or PC. Rash, diarrhea, and hypertension were common adverse events; no pulmonary or CNS hemorrhage events required intervention. CONCLUSION: VPC could be safely administered to patients with NSCLC, including those with squamous cell histology and treated brain metastases. Compared with the PC control arm, patients receiving VPC had longer PFS, meeting the prespecified study end point, whereas those receiving vandetanib monotherapy had shorter PFS.
