932P - Survival in patients with relapsed/metastatic head and neck squamous cell carcinoma (HNSCC) treated with pembrolizumab or cetuximab-based therapy: A real-worlddata study with the TriNetX platform

Background

Pembrolizumab alone or with platinum-based chemotherapy is a standard first-line systemic treatment for recurent/metastatic (R/M) HNSCC in Europe, based on results of KEYNOTE-048 phase III trial. Real-world data (RWD) are scarce since aprpoval by EMA in 2019. We present real-world data (RWD) of overall survival (OS) of three cohorts of R/M HNSCC patients: cohort 1 (pembrolizumab plus chemotherapy, P+CT), cohort 2 (pembrolizumab alone, P), and cohort 3 (cetuximab plus chemotherapy, C+CT). Data were extracted from TriNetX, the global federated health research network that includes several hospitals in Europe and America.

Methods

The TriNetX network was used to search and analyze clinical anonymized information. The analysis process included two main steps: 1) Defining the cohorts through query criteria: R/M HNSCC, no prior systemic therapy, survival information available, P or P+CT or C+CT. 2) Setting up and running the analysis. Research was done in in a time window of 3 years. Index event was defined as the diagnosis of metastasis. Kaplan-Meier analysis was used to estimate survivals and comparison between cohort 1 vs 3 and cohort 2 vs 3.

Results

Number of patients matching the search criteria were: cohort 1 (P+CT) N=2965, cohort 2 P) N=2138, cohort 3 (C+CT) N=3947. Median age was 61.8, 65.6, and 62.7 yr for cohort 1, 2, and 3, respectively. Male percentage was 74.8%, 72.8%, and 78.3%, respectively. Primary tumor in oropharynx was present in 37.4%, 16.2% and 54.2%, respectively. Unspecified or ill-defined primary tumor location was present in 32.5%, 23.4%, and 43.1%, respectively. Information about PD-L1 status was not available. Median OS for cohort 1 and 2 were not reached; it was 951 days for cohort 3. Log-rank comparison was significantly different for cohort 1 vs 3 (p<0.001), and for 2 vs 3 (p<0.001), demonstrating superiority for either of the anti-PD1 cohorts.

Conclusions

OS with pembrolizumab-based therapy is superior compared to cetuximab plus CT in these RWD cohorts of first-line treatment for R/M HNSCC. An unexpected high median overall survival was found in all cohorts. The TriNetX system has limitations that must be detected and improved.

Clinical trial identification

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

L. Ugidos De La Varga: Financial Interests, Personal, Advisory Board: AstraZeneca; Financial Interests, Personal, Invited Speaker: MSD, BMS, Merck. All other authors have declared no conflicts of interest.