Before revision:  Both the single-drug and combination therapy policies obtained in training exhibit a 100\% success rate at suppressing simulated heterogeneous harmful cell growth and responding to diverse system fluctuations and perturbations within the alloted time and using conservative dosing. The policies obtained were found to be highly robust to model parameter changes and fluctuations not introduced during training .
After revision:  Both the single-drug and combination therapy policies obtained in training exhibit a 100\% success rate at suppressing simulated heterogeneous harmful cell growth and responding to diverse system perturbations while establishing low-dose no-event baselines. These policies were found to be highly robust to model parameter changes and fluctuations not introduced during training .