Background: Defined as “the new kid on the blocks” in the field of medical oncology, Immunotherapy has paved the way in the armamentarium of cancer therapeutics literally in every cancer subtype. There are various biomarkers approved for considering immunotherapy, but none have been reliable. We aim to assess the response rate, PFS, OS, and clinical characteristics of patients who received immunotherapy for treatment in advanced or metastatic solid tumours. Methods: A retrospective study of all patients who were treated with immunotherapy at The Brunei Cancer Center, PJSC between December 2019 – February 2022 was included with a median follow-up of 6 months from the last dose of immunotherapy. Results: A total of 212 patients were included with Pembrolizumab 66% (n = 140), Nivolumab 24% (n = 51), Atezolizumab 8.4% (n = 18), Durvalumab 0.9% (n = 2), and Ipilimumab + Nivolumab 0.4% (n = 1). The median age was 46 years (range 31-78 years) with a female preponderance of 62%. The median number of cycles were 4.5 per patient (range 0-41). Lung cancer 29.7% (n = 63, adenoca-40, squamous-10, adenosquamous-2, SCLC-11), GI tumours 19.3 (n = 41, HCC-17, Stomach-15, MCRC-7, Pancreas-2), GU tumours 12.7% (n = 27, RCC-19, Bladder-7, Penis-1) and Head and neck tumours 9.9% (n = 21, HNSCC-13, NPC-8). On biomarker analysis for initiation of immunotherapy, PDL-1 + on IHC (either by CPS or TPS) was noted in 88 patients, TMB > 10 in 22, and MSI-H in 4 patients. The ORR in this study was 35.3% (CR-10, PR-29, and SD-36). Sixty patients received less than 3 cycles and were not included in the analysis. Disease progression (27), worsening ECOG performance status (14), and IRAEs (19) were the common reasons for discontinuation of these drugs. On ITT analysis, the ORR was 51.3%. The median duration of response is 12.5 months in responders (range 6-31 months). The Median PFS was 4.9 months (95% CI: 1.78-8.21) and the median OS was 7.1 months (95% CI: 8.14-17.85). On univariate analysis for determinants of better PFS, pretreatment NLR > 4 was associated with improved survival (p = 0.001) and presence of co-mutations, low TMB < 5 and younger age < 45 was associated with inferior survival. Conclusions: Pretreatment NLR > 4 can be used as an indicator of response to immunotherapy in the clinics. Benefits of immunotherapy are not universal, best responses were noted in NSCLC, Bladder, and RCC. Identification of novel predictive biomarkers would improve clinical outcomes in solid tumours.