605P - Prognostic role of blood cell count-based immuno-inflammatory parameters in the Valentino trial

Abstract

BackgroundWe aimed to investigate the association between blood cell count-based immuno-inflammatory parameters, clinico-pathological characteristics and clinical outcomes in patients (pts) with RAS wt, metastatic colorectal cancer (mCRC) randomized to panitumumab (pani) plus FOLFOX4 induction followed by maintenance with pani +/- 5FU/LV in the phase 2 Valentino study. MethodsPts in the intention-to-treat population (n=229) were screened for the availability of pre-treatment complete blood cell count. We focused on neutrophil-to-lymphocyte ratio (NLR), absolute monocyte count (AMC) and platelet count (PC). NLR and AMC were defined high if≥4 and 900/mcl, respectively, based on literature data. PC was defined high if > of the median value of the study population. The Kaplan-Meier method and Cox proportional hazards regression model were used for survival analyses. ResultsA total of 215 pts were included. NLR and AMC were significantly associated with ECOG PS. AMC and PC were associated with the presence of synchronous metastases and primary tumor resection. After a median follow-up of 26.7 months, high NLR was associated with worse progression-free survival [PFS] (HR 1.51, p=0.015) and overall survival [OS] (HR 2.18, p<0.001), as well as high AMC (HR for PFS 1.85, p=0.003; HR for OS 2.49, p<0.001) and high PC (HR for PFS 1.65, p=0.001; HR for OS 1.85, p=0.003). In the multivariable models, only PC confirmed its independent association with both clinical outcomes (HR for PFS 1.71, p<0.001; HR for OS 1.70, p=0.01), while AMC was only independently associated with PFS (HR 2.44, p=0.03) and NLR did not demonstrate any significant association. The PFS benefit of adding 5-FU/LV to pani in the maintenance setting was independent from NLR and AMC (interaction p=0.15 and p=0.48, respectively), but was retained only in the subgroup with low PC (interaction p=0.04). No significantly association with response or disease control was observed. ConclusionsIn pts with RAS wt, mCRC randomized in the Valentino study, baseline PC showed and independent association with OS and PFS and baseline AMC was independently associated with PFS. Pts with high PC did not derive any PFS benefit from the addiction of 5-FU/LV to pani in the maintenance setting. Clinical trial identificationNCT02476045. Legal entity responsible for the studyThe authors. FundingFondazione IRCCS Istituto Nazionale dei Tumori di Milano, Amgen. DisclosureS. Lonardi: Honoraria (self): Roche; Honoraria (self): Amgen; Honoraria (self): Bayer; Honoraria (self): Merck-Serono; Honoraria (self): Servier; Honoraria (self): Bristol-Myers Squibb. L. Rimassa: Honoraria (self): AstraZeneca; Honoraria (self): AbbVie; Honoraria (self): Lilly; Honoraria (self): Bayer; Honoraria (self): Sirtex Medical; Honoraria (self): Italfarmaco; Honoraria (self): Sanofi; Honoraria (self): ArQule; Honoraria (self): Baxter; Honoraria (self): Ipsen; Honoraria (self): Exelixis; Honoraria (self): Amgen; Honoraria (self): Incyte; Honoraria (self): Celgene. A. Zaniboni: Honoraria (self): Sanofi; Honoraria (self): Amgen; Honoraria (self): Bayer; Honoraria (self): Merck-Serono; Honoraria (self): Roche. A. Sartore-Bianchi: Honoraria (self): Sanofi; Honoraria (self): Amgen; Honoraria (self): Bayer; Honoraria (self): Merck-Serono; Honoraria (self): Roche. M. Di Bartolomeo: Honoraria (self): Amgen; Honoraria (self): Roche; Honoraria (self): Lilly; Honoraria (self): Servier; Honoraria (self): Incyte; Honoraria (self): Celgene. F.G.M. De Braud: Honoraria (self): Amgen; Honoraria (self): Roche; Honoraria (self): Novartis. F. Pietrantonio: Honoraria (self): Sanofi; Honoraria (self): Amgen; Honoraria (self): Bayer; Honoraria (self): Merck-Serono; Honoraria (self): Roche; Honoraria (self): Servier. All other authors have declared no conflicts of interest.