Abstract 456P
Background
Immune checkpoint inhibitor (ICI) therapies such as nivolumab and pembrolizumab show considerable efficacy by targeting PD-1/PD-L1 interactions. ICI therapies have emerged as a promising treatment modality for various cancers, including head and neck cancer. Real-world evidences on their efficacy are limited.
Methods
This is a retrospective, single centre study of 70 patients. Eligible patients from 1st April 2022 to 29th February 2024 who had histologically confirmed, recurrent and metastatic squamous cell carcinoma of the head and neck region, who had received nivolumab, pembrolizumab alone or in combination with chemotherapy were included in the analysis. Patient demographics, response rates, progression-free survival (PFS), toxicity and overall survival were analyzed.
Results
Out of 70 total patients, 44 (63%) received nivolumab, and 26 (37%) received pembrolizumab. Amongst 44 patients who received Nivolumab, 21 received it at standard dose (3mg/kg once every 2 weekly) while, 23 patients received it at low dose (40 mg flat dose once every 2 weekly). Pembrolizumab was administered at 200mg flat dose once every 3 weekly. Amongst 70 patients, 43 received ICI in first line. The Overall response rate (ORR) of the entire study was 48.57% and disease control rate was 60%. ORR of standard dose and low dose nivolumab group was similar (52%). Out of 70 patients, 54 (77%) received a combination of ICI with chemotherapy. The chemotherapy regimens included Taxane plus platinum in 12 patients and Methotrexate (either single agent or in combination with gefitinib and celecoxib) in 42 patients. The ORR of the chemo-ICI group was 54%, while it was 31% in ICI monotherapy group. The median PFS and OS for the entire study group was 3 and 5 months respectively. The median number of cycles administered was 5 (range: 1-28). 8 (11%) patients experienced immune-related adverse events (irAE) which were all G1/G2 in severity.
Conclusions
We observed similar ORR with using either low or standard dose of nivolumab. Combination of chemo-ICI leads to improved ORR than ICI alone. We can hypothesize that in platinum refractory head and neck cancer cases, adding methotrexate to ICI leads to improvement in ORR which needs to be confirmed in larger studies.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.