71P Safety and efficacy of salvage radiotherapy after progression to checkpoint inhibitors in recurrent and/or metastatic head and neck cancer

Abstract

after ICI. Nevertheless, taxane appears to have modest effectiveness in pre-treated patients. We aimed to assess survival outcomes with taxane chemotherapies after ICI exposure and to identify prognostic and predictive factors that may influence response to those regimen. Methods:In this multicentric retrospective study, we included patients with stage IIIB or higher NSCLC who received subsequently taxane after ICI failure. Primary end points were progression-free survival on taxane (Taxane PFS) and overall survival on taxane (Taxane OS). Secondary end points were Taxane PFS to ICI PFS ratio to evaluate benefit of subsequent taxane and identification of clinical data associated with better survival on taxane.Results: We included 110 patients, mostly men (71.8 %) with a median age of 63. Patients mostly had stage IVB (65.5%) and adenocarcinoma was the predominant histologic subtype (59.1%). Docetaxel was the taxane chosen in 70% of cases. Median Taxane PFS was 3.6 months (2.7-4.8) and Taxane OS was 7.3 months (6.1-10.3). Only 36.9% of patients had a ratio Taxane PFS to ICI PFS greater than 1.3 without clinical difference in this subgroup, except for age (60.2 versus 63.9; p¼0,021). A number of 6 or above ICI cycles was an independent prognostic factor for better Taxane PFS and OS. Similarly, in multivariate model, performans status at 2 or higher (PS 2) and a 2g/dL loss of haemoglobin between the end of ICI and taxane initiation were associated with poorer Taxane OS. Only PS 2 was associated with a poorer Taxane PFS.Conclusions: Effectiveness of further treatment with taxane after ICI failure was observed only in a limited subgroup of patients. Factors associated with good health condition and a long exposure to ICI appeared to be predictive of better survival on taxanes.Legal entity responsible for the study: Institut de cancérologie de l'ouest.