Abstract 472P
Background
Nivolumab is conventionally used as 3 mg/kg or fixed doses of 240 mg every two weeks. Only 1-3% of patients in low and middle-income countries can access the established immunotherapy options for metastatic malignancies due to their high costs. This study assesses the effectiveness and tolerance of low-dose Nivolumab as an alternative to standard-dose treatment in managing metastatic solid tumours.
Methods
We analysed the data of all patients with metastatic solid tumours who received low dose Nivolumab of 40mg at KMC Manipal in the last 1 year. Treatment was continued until disease progression, intolerable toxicity or death. Response evaluation was done after every 8-12 weeks with CECT or PET-CT. Statistical analysis was done with chi-square test, Mann-Whitney test, and Kaplan-Meier curve.
Results
18 patients were treated with low dose Nivolumab within the age of 32- 77 years. 44.4% of patients had metastatic head and neck cancer and 33.3% had Gastric cancer, others had metastatic melanoma (2) cholangiocarcinoma and ca bladder. 50% were smokers. 77.8% were of ECOG 1 status. The mean PFS was 4.04 months (1.37- 13.5). 83.3% had progressive disease (PD) and 16.7% had stable disease (SD). During initial reassessment, patients who were started on Nivolumab after only 1 line of Chemotherapy had a statistically significant association with having a SD and those who got Nivolumab after multiple lines showed an association with having a PD (p 0.027). On further progression, we found that patients exposed to <2 lines of chemotherapy before initiation of Nivolumab, had a better PFS of 5 months compared to those patients exposed to >2 lines of chemotherapy before (4.2 months). The Kaplan-Meier survival probability estimates at 9 months were about 0.48 [95% CI (3.2-6.4) for the SD group and 0.44 [95% CI (2.2-6.6) for the PD group. 5.6% each had fatigue, neuritis, diarrhoea and thyroiditis. Most of the patients who had poor tolerance had a PD. 66.7% had no reported adverse effects.
Conclusions
Low-dose Nivolumab can be an effective option with survival benefits and considerable cost benefits in metastatic settings. Early use of low-dose Nivolumab is associated with a statistically significant event-free survival than initiating the use of Nivolumab until multiple chemotherapy options are exhausted.
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.