Stability Analysis and Numerical simulations of a Tumor-immune Interaction Model with Constant Chemotherapy Infusion

Abstract

 Considering the effect of constant chemotherapy infusion, a mathematical model of tumor–immune interaction is formulated and analyzed. Building upon the framework of de Pillis-type models, the present work incorporates immune response, tumor dynamics, and steady drug infusion. We establish the positivity and boundedness of solutions to ensure biological feasibility. Local and global stability analyses of equilibrium points are carried out, with special emphasis on tumor-free and coexistence equilibria. Numerical simulations are presented to validate the analytic findings and illustrate the impact of chemotherapy on tumor suppression. The results indicate that constant chemotherapy infusion can effectively stabilize the tumor-free equilibrium under suitable dosing conditions, highlighting its potential in controlling tumor growth and improving treatment outcomes.