941P - Risk factors for progressive disease after immune checkpoint inhibitors (ICIs) in advanced head and neck squamous cell carcinoma (HNSCC): Who might not be candidate for ICI?

Background

Immune checkpoint inhibitors (ICI) do not always show favorable outcomes in patients with advanced head and neck squamous cell carcinoma (HNSCC)). Once progressive disease (PD) occurs, the patient becomes deteriorated and ineligible for subsequent cytotoxic chemotherapy. Therefore, avoiding PD prior to ICI treatment is crucial. The purpose of this study is to identify the clinical features in patients who developed PD after ICI therapy.

Methods

We conducted a retrospective analysis of 125 patients with recurrent and/or metastatic (R/M) HNSCC treated with ICI between January 2013 and December 2018 at 11 medical centers in the Republic of Korea. We evaluated best response by RECIST1.1, progression-free survival and overall survival (OS). The associations between these outcomes and various clinical factors were analyzed.

Results

The median age was 57 years. 41.6% of the patients received ICIs as a third or later line of palliative chemotherapy. The complete response rate was 3.2%, partial response rate was 12.0%, stable disease rate was 25.6%, and the rate of PD was 54.4%. Hyper PD, defined as tumor growth kinetics ratio >2, was observed in 14.4%. The median PFS and OS were 2.3 months and 6.6 months, respectively. In univariate analysis, a neutrophil-to-lymphocyte ratio (NLR) >4, a sum of the target lesions >40 mm, and prior chemotherapy lines ≥2 were significant predictors of PD (P=0.014, 0.031, and 0.042, respectively). Multivariate logistic analysis showed high NLR, large tumor size, prior line of chemotherapy, type of ICI were independent predictors for PD. Furthermore, NLR >4 (HR 2.80, p<0.001), a poor performance status (ECOG≥2) (HR 4.76, p<0.001), and a sum of the target lesions >40mm (HR 1.70, p=0.048) were independently associated with poor OS. Patients who experienced PD had significantly shorter median OS (7.4 vs. 18.4 months, p<0.0071).

Conclusions

Our study identified clinical features that were associated with PD to ICIs in patients with R/M HNSCC. NLR, tumor size, and number of prior chemotherapy lines can serve as clinical predictors for the likelihood of PD for ICI. Clinicians can utilize these findings to personalize treatment plans and enhance patient outcomes.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

Bhumsuk Keam.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.