Despite their unique advantages and vast potential, nanomaterials employed in cancer therapy still encounter challenges such as uneven biodistribution, unintended drug leakage, and especially potential tissue damage caused by off-target toxicity. Bioinert nanomaterials, known for their excellent chemical stability, and minimal biological reactivity, can exert localized tumoricidal effects in response to specific external stimuli. However, the lack of precise control or poor penetration depth largely limits the therapeutic efficacy, necessitating the development of innovative stimuli-responsive therapeutic strategies. This study presents an alternative drug-responsive cancer therapeutic approach based on nickel-iron layered double hydroxide (NiFe-LDH), which exhibited negligible toxicity to both normal cells and cancer cells. By conjugating a platelet-derived growth factor receptor (PDGFR)-β-targeting cyclic peptide, NiFe-LDH achieved high specificity for prostate cancer cells, significantly enhancing tumor targeting and accumulation. Upon administration of deferoxamine mesylate (DFOM), an FDA-approved iron chelator, NiFe-LDH transitioned from a "bioinert" state to a "bioactive" nanotherapeutic through structural disassembly and robust release of nickel ions (Ni²⁺). The released ions disrupted mitochondrial function, upregulated insulin-like growth factor binding protein 3 (IGFBP3), and further inhibited the PI3K/AKT/mTOR signaling pathway, consequently leading to potent and selective induction of apoptosis in prostate cancer cells. Unlike conventional therapies, which often cause varying degrees of toxicity in non-target organs, this stimuli-responsive nanoplatform could minimize off-target effects and systemic toxicity by combining the non-toxic LDH with the clinically used DFOM. Our findings demonstrate that DFOM-responsive NiFe-LDH can effectively inhibit tumor growth in both cultured cells and tumor xenografts, suggesting a rational and clinically translatable platform for precision cancer therapy.