Combined Metronomic Chemo-immunotherapy (CMCI) in Head and Neck Cancers-An Experience from a Developing Country

Head and neck squamous cell carcinomas (HNSCC) have proven to be inherently resistant to systemic treatments as a result of histological, molecular, and etiological heterogeneity, with limited responses seen after second-line therapy and beyond. With limited treatment options after progression on systemic chemotherapy in HNSCCs, immunotherapy has a role to play with improved results. In this prospective, observational, non-randomized, open-label study, a total of 12 patients with advanced, relapsed, or metastatic HNSCC received Inj. Nivolumab weight-based dose of 3 mg per kg, intravenously every 2 weeks along with low-dose capecitabine 500 mg twice a day, was prospectively assessed. The patient's clinical, hematological, and staging characteristics were described and the clinical benefit rate (CBR) was calculated. A total of 12 patients received the combined metronomic chemo-immunotherapy (CMCI). The majority of patients were belonging to ECOG-PS 1(66%), with all patients being in stage IV disease. Six, four, and two patients received immunotherapy as the 5th, 3rd, and 4th line of therapy, respectively. Nivolumab and low-dose capecitabine were used in all 12 patients. CBR was seen in 66% (8/12) of patients, one patient died due to hepatitis and hepatic encephalopathy, another patient died due to pneumonia and respiratory complications, two patients had progressive disease, and two patients with stable disease discontinued treatment because of financial constraints and kept on capecitabine alone. The majority tolerated therapy well with no grade 3/4 immune-related adverse events (IRAEs). Two patients required supportive therapy with packed red cell transfusion and albumin infusions. Six-month overall survival (OS) and progression-free survival (PFS) in the study population were 83.3% and 66.6%, respectively. In conclusion, nivolumab along with metronomic chemotherapy with low-dose capecitabine was very well tolerated and exhibited anti-tumor activity with a CBR of 66%, 6-month OS of 83.3%, and 6-month PFS of 66.6%, in extensively pretreated patients with HNSCCs. Additional studies of nivolumab and metronomic chemotherapy and immuno-immuno combination therapy in these diseases are ongoing.