Efficacy and Safety of Low-Dose Nivolumab in Treatment of Advanced Solid Tumors: A Retrospective Audit from Resource-Constrained Settings

Abstract

Background Immunotherapy has improved outcomes in many advanced solid tumors. In resource-constrained settings, less than 2% of patients can afford standard dose immunotherapy. A recent phase II study showed the efficacy of low-dose immunotherapy in this setting. We used low-dose immunotherapy on a compassionate basis in patients who had progressed on available standard treatment options and standard dose immunotherapy was not feasible. Patients and Methods We retrospectively collected data from the medical oncology department for consecutive patients who had initially received standard lines of therapy followed by low-dose immunotherapy (nivolumab 40 mg) on a compassionate basis. The demographic details, histology, prior treatment, clinical and radiological response, date of disease progression, date of death, and toxicity data were collected. Results A total of 54 consecutive patients, who received low-dose immunotherapy with nivolumab from January 1, 2018 to February 14, 2020, were included in this analysis; 4 patients were not radiologically evaluable. The median age was 50.4 years (range 35–74 years), male:female ratio was 6:1. The most common comorbidities were hypertension and diabetes seen in 12 (22.2%) and 6 (11.1%) patients, respectively. The majority of the patients (70.4%) were of head and neck cancer. The median follow-up was 4.5 months (range 0.5–11.7). Clinical benefit was observed in 18 (33.3%) patients. Partial response and stable disease were achieved in 9 (16.7%) and 5 (9.3%) patients, respectively. Median survival was not reached for these patients. Six months progression-free survival and overall survival were 100 versus 8.7% (hazard ratio [HR] 0.05, 95% confidence interval [CI]: 0.01–0.36; p = 0.003) and 100 versus 29.7% (HR 0.03, 95% CI: 0.00–0.95; p = 0.047), respectively, for responders and nonresponders. The side effects were manageable. Conclusion In resource-constrained settings, low-dose immunotherapy with nivolumab seems to be an effective treatment option. Further studies are warranted to evaluate this approach.