Abstract 133P
Background
Bone metastasis is frequently seen in NSCLC (non small-cell cancer )and have got poor prognosis. Bone is a hematopoietic organ and actively regulates our immune system. Nivolumab is a fully human IgG4 PD-1 ICI (immune checkpoint inhibitor) antibody, which disrupts PD-1 mediated signaling and restores antitumor immunity. We have studied the clinical outcome of Nivolumab monotherapy in NSCLC patients with bone metastasis.
Methods
All patients with NSCLC with bone metastasis treated in our institute between Jan2018 to Aug2021 were included in our study. Patients who have received immunotherapies in past were excluded. Out of total 23 patients (16 men and 7 women), with median age of 58 years, 18 had adenocarcinoma and 5 had squamous cell carcinoma. Median followup was 13months. All patients were previously treated with chemotherapies (platinum based/epidermal growth factor receptor-tyrosine kinase inhibitor), Bone modifying agents, Denosumab, Zolendronic acid. Now they are given IV infusion of Nivolumab every 2 weeks. Tumor response were defined as complete/partial response and stable/progressive disease according to RECIST1.1. Responders were classified as either CR or PR and non responders as either PD or SD. Radiological responses were assessed using the MDA (MD Anderson response classification) criteria and it divided response into 4 categories and can assess both the egression of extaskeletal lesions and osteosclerotic change (OC) on computed tomography due to the repairative process.
Results
A median of 5 doses of Nivolumab was given to patients (2-18 doses) with median treatment duration of 2.1 months (1-16months). It resulted in overall survival(OS) of 58% at 1 year and overall response rate(ORR) of 21%, and time to response(TTR) was 2.5 months, which is consistent with previous studies. Bone response was achieved in 10 lytic lesions in 8 patients. No change was seen in mixed and blastic lesions. Univariate analysis showed that the no. of bone metastasis was the only risk factor for non responders.
Conclusions
Bone metastasis impairs immunotherapy efficacy. Nivolumab monotherapy is effective for NSCLC patients with bone metastasis. Early bone response to this immunotherapy can be useful for early prediction and prognosis of such patients.
Clinical trial identification
CMCH/32/2021.
Legal entity responsible for the study
CMCH.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.