Retrospective study assessing the use of angiotensin converting enzyme inhibitors or angiotensin receptor blockers to reduce toxicity from tyrosine kinase inhibitors in metastatic renal cell carcinoma.

Abstract

411 Background: The main toxicities associated with tyrosine-kinase inhibitors (TKIs) in the treatment of renal cell carcinoma (RCC) are proteinuria and hypertension. Angiotensin converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) have established reno-protective and anti-hypertensive effects and can help with toxicity in mRCC. We hypothesize that use of ACEIs/ARBs is an effective method to decrease the degree of proteinuria and hypertension in patients treated with TKIs for metastatic/advanced renal cell carcinoma (mRCC). Methods: Single Institution retrospective study; mRCC patients (pts) who received TKI and ACEIs/ARBs and had urine protein measurements available at baseline and at 4-6 wk follow up post ACEs/ARBs were included in the analysis. Primary endpoints included improvement in grade of proteinuria and BP in mRCC pts on TKI treatment at baseline and with addition of ACEIs/ARBs. Secondary endpoints included number of dose interruptions (DI), BUN and creatinine changes. Paired statistical tests were used to compare the selected outcome variables between baseline and post ACE/ARB measures: for example, nonparametric Wilcoxon Signed-rank test for paired quantitative data and McNemar test for paired binary data. Results: Out of 71 screened patients between 2020-2023, N of 22 mRCC (N=22, 72.7% male, 77.3% white; 9% Hispanic; N=14 for TKI+ immunotherapy; N=8 TKI alone) pts were selected. ACEIs/ARBs treatment was associated with significantly reduced levels of proteinuria at 4–6wk follow-up. At baseline vs. follow-up, pts were found to have significantly lower proteinuria overall after ACEI/ARBs (p=0.0147), and 45.4% of pts had clinically insignificant proteinuria vs. 22.7% at baseline. Additionally, DI rates for TKI were significantly lower for pts placed on ACEIs/ARBs, with an 81% chance that pts with prior DI would not experience similar event in the follow-up period (p=0.003). Reductions in BP, creatinine, and TKI dosing were seen but not statistically significant (p>0.05 for all measures). Conclusions: In our small study, degree of proteinuria was notably reduced with administration of ACEIs/ARBs. Further findings show fewer DI of TKIs with ACEIs/ARBs use. Our findings suggest a potential role for ACEIs/ARBs in managing toxicity in patients undergoing TKI based therapy for mRCC. Future studies are needed to evaluate the use of ACE/ARB from the time of initiation of TKI based therapy to reduce the toxicities and improve the adherence to mRCC treatment which may result in better outcomes.