Tumor PD-L1 IHC relates moderately with treatment outcome following anti-PD1 therapy in pts with NSCLC and single biopsies do not account for tumor heterogeneity. Aim: 1. Assess safety of the PET procedures. 2. Quantify 89Zirconium-labeled nivolumab (89Zr-nivo) and 18F-labeled BMS-986192 (18F-PD-L1) uptake. 3. Assess tracer uptake heterogeneity. 4. Correlate tracer uptake with PD-1/PD-L1 IHC in tumor, stroma and with treatment outcome.
NSCLC pts eligible for treatment with nivolumab were included. Pts received whole body 18F-PD-L1 and 89Zr-nivo PET scans. Baseline tumor biopsy was required to assess PD-(L)1 IHC status (28.8 assay). SUVpeak was calculated for delineable lesions and correlated to PD-(L)1 IHC and response after 12 wks of nivolumab treatment.
10 pts (3 ≥50%, 5 ≥1%, 5 negative by PD-L1 IHC) were enrolled and 37 lesions analysed. No toxicity related to radiotracer was observed. Tumor uptake of both tracers was visualized in all pts, but not in all lesions. Tracer uptake varied among pts with mean 18F-PD-L1 SUVpeak 4.6, range 0.5 - 14.4 and mean 89Zr-nivo SUVpeak 5.0, range 1.6 – 11 (p = 0.03) and within pts with mean SUVpeak difference 3.6-fold (±2.1) and 2.4-fold (±0.77) between lesions for 18F-PD-L1 and 89Zr-nivo, respectively. For lesions with ≥50% PD-L1 IHC, mean 18F-PD-L1 SUVpeak was 8.0 (±4.7) as compared to 3.5 (±1.6) for lesions with
1. PET-imaging with both tracers is safe and feasible, with good tumor-to-normal tissue contrast. 2. Tumor uptake showed heterogeneity among pts and among tumors within pts. 3. Pts with ≥50% tumor PD-L1 expression showed higher 18F-PD-L1 uptake. 4. Pts with high PD-1 expression showed higher 89Zr-nivo uptake, and pts with PR demonstrated higher 18F-PD-L1 and 89Zr-nivo tracer uptake than pts with PD/SD, although these are without statistical significance which may be due to the small dataset.
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Joop de Langen
E. Smit: Has an advisory role at Lilly. Received research funding from Company: Boehringer Ingelheim, Bayer, Roche/Genentech and AstraZeneca (paid to institution). D.K. Leung, R.A. Smith, L.M. Wilson, W. Hayes: Is employed at BMS and owns stock and/or other ownership interests in BMS. All other authors have declared no conflicts of interest.