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Feasibility, safety, and biodistribution of 18F-BMS-986229 PET in patients with esophagogastric (EG) cancer
Background
The addition of programmed cell death protein 1 (PD-1) blockade to combination cytotoxic chemotherapy improves overall survival among patients with EG cancer in the frontline metastatic setting. However, due to tumor heterogeneity, PD-L1 expression based on single site biopsies is inadequate to identify those who will derive benefit from the addition of checkpoint blockade, and better biomarkers are needed. We developed PD-L1 specific positron emission tomography (PET) imaging using 18F-BMS-986229 in patients with EG cancer for non-invasive assessment of tumor PD-L1 status.
Methods
Patients with EG cancer who had a PD-L1 combined positive score (CPS) >1 by immunohistochemistry received one injection of 18F-BMS-986229 (370 MBq), a PD-L1 targeted tracer, and then underwent a whole-body PET/CT (80 mA) 60 minutes post-injection.
Results
Ten patients underwent imaging with 18F-BMS-986229 PET, with a median age of 65 years (37 - 81), nine of whom were male and eight of whom had de novo stage IV disease. All 10 patients had adenocarcinoma; four were gastroesophageal junction tumors, three were esophageal, and three were gastric. Median qualifying PD-L1 CPS was 10 (5 - 70). The maximum tumor standardized uptake value (SUV) on 18F-fluorodeoxyglucose (18F-FDG) PET at the time of 18F-BMS-986229 PET ranged from 3.4 to 24.9. Median number of lines of therapy at the time of imaging was one. All ten patients received treatment with PD-1 blockade during their treatment course (seven with pembrolizumab, three with nivolumab). Two patients had received treatment with PD-1 blockade prior to enrollment and one was actively receiving treatment with PD-1 blockade at the time of undergoing the scan. Seven out of 10 (70%) of patients had at least mild tracer uptake at the primary lesion on 18F-BMS-986229 PET and one patient (1/10, 10%) had an adrenal metastasis with uptake on 18F-BMS-986229 PET. Complete results of 18F-BMS-986229 PET findings, including comparison with 18F-FDG PET, will be presented. No clinically significant toxicities or adverse events were observed.
Conclusions
PET imaging with a PD-L1 targeted tracer 18F-BMS-986229 is safe and feasible. PD-L1 PET may be an adjunct to discrete biopsies in evaluating EG cancer PD-L1 positivity. Correlation with tumor PD-L1expression and PET uptake is underway and will be presented.
Clinical trial identification
NCT04161781: A Study of PET Scans With the Radioactive Tracer 18F-BMS-986229 in Patients With Esophageal, Stomach, or Gastroesophageal Junction Cancer.
Legal entity responsible for the study
The authors.
Funding
Department of Defense Congressionally Directed Medical Research Program (CA 150646 to Y.Y.J.).
Disclosures
Y. Janjigian: Advisory / Consultancy: Bristol-Myers Squibb, Merck Serono, RGENIX, Eli Lilly, Daiichi-Sankyo, Pfizer, Bayer, Imugene, Merck, Zymeworks, Seagen, Basilea Pharmaceutica, AstraZeneca, Michael J. Hennessy Associates, Paradigm Medical Communications; Research grant / Funding (institution): NCI, Department of Defense, Cycle for Survival, Fred's Team, RGENIX, Bayer, Genetech/Roche, Bristol-Myers Squibb, Eli Lilly, Merck; Shareholder / Stockholder / Stock options: RGENIX. All other authors have declared no conflicts of interest.
