Immunotherapy has revolutionized cancer treatment. Despite its success across various malignancies, a significant proportion of patients either fail to respond (primary resistance) or relapse after an initial response (acquired resistance). This review explores the different mechanisms underlying resistance to immunotherapy, including tumor-intrinsic factors such as loss of antigen presentation, genetic, and epigenetic mutations. It also examines tumor-extrinsic contributors, such as immunosuppressive cells in the tumor microenvironment, checkpoint molecule upregulation, and microbiome influences. A comprehensive understanding of resistance mechanisms is essential for improving patient selection, developing combination therapies, and ultimately enhancing the efficacy and durability of immunotherapeutic interventions.

Platelet glycoprotein IIB/IIIA antagonists are potent inhibitors of platelet aggregation. Although the incidence of thrombocytopenia following their administration is relatively low, it can sometimes lead to fatal consequences. We report a case of a 57-year-old gentleman presenting with non-ST elevation myocardial infarction complicated with tirofiban-induced profound thrombocytopenia that developed within 12 hours of administration. Given the high risk of acute-onset thrombocytopenia following treatment with glycoprotein IIb/IIIa inhibitors, platelet count monitoring is highly encouraged at frequent intervals. This case highlights the importance of early detection and treatment of thrombocytopenia.