Dynamic changes in full blood count (FBC) occurring in patients treated with immune checkpoint inhibitors (ICIs) to predict responses in patients with metastatic renal cell carcinoma (mRCC).

Abstract

e17110 Background: ICI transformed the treatment of 1L mRCC, yet early clinical predictors of response are still unknown. Methods: Retrospective database analysis from Barts Cancer Institute, London was carried out. Patients with treatment naïve mRCC were identified and grouped according to their 1L treatment: 1: VEGF inhibitor 2: IO/IO 3: IO/VEGF Data on hemoglobin, neutrophil-to-lymphocyte ratio (NLR), platelet–lymphocyte ratio (PLR) at baseline, 6weeks and 12weeks after treatment initiation was correlated with outcome. Results: Between Jan 2014 - Dec 2019; 28, 29 and 21 patients received 1L VEGF, IO/IO or IO/VEGF respectively. Patient receiving 1L VEGF inhibitors showed a decrease in Hb levels both in responding and non-responding groups (significant group effect: F(1,6) = 6.6, p = 0.04); significant time effect:F(2,12) = 12.4, p = 0.001). Group x time interaction was not significant. NLR levels decreased both in responding and non-responding groups over time (significant time effect: F(2,12) = 16.7, p = 0.001. PLR levels in non-responders increased over time, whereas in responding group, PLR levels steadily decreased over 6 and 12 weeks (significant time effect: F(2,12) = 0.3, 0.044). Patients receiving IO/IO combination therapy; within the non-responder group, Hb levels didn’t change significantly whereas in the responding group Hb levels increased significantly and overtook Hb levels of non-responding group (P = 0.001). NLR levels significantly decreased in the responding group (0.041) and a similar trend was observed at 12 weeks with a decrease in PLR among non-responders, with a significant group affect (F(1,5) = 0.18, 0.035). In patient treated with 1L IO/VEGF, among non-responders Hb levels increased slightly, only to return to baseline levels again at 12 weeks after treatment initiation. Whereas, Hb levels in the responding group increased significantly in both 6weeks and 12weeks after starting therapy. Significant time effect:F(2,20) = 3.65, p = 0.044. NLR levels in the responding group presented a steady decrease over time with a significant group and time effect. Both responders and non-responders experienced an increase in PLR over time. However, while PLR decreased at 12 weeks among responders, it continued to increase among non responders (significant time effect: F(2,20) = 0.3, 0.03), (significant group effect: F(1,10) = 0.05, 0.005) and significant interaction: F(2,20) = 0.1, 0.01) Conclusions: Close monitoring of FBC changes may predict response to ICI.