• Efficient sec. amine–Pt-nitrile addition was used to generate platinum–acridine hybrid agents. • Cytotoxicity levels (IC 50) in non-small cell lung cancer cell lines span two orders of magnitude. • The most hydrophilic compound shows the highest level of accumulation and low-nanomolar activity. • The data support an active, transporter-mediated uptake mechanism. Three new derivatives of a platinum–acridine hybrid anticancer agent were synthesized using nitrile–amine coupling (amidination) chemistry. In the new structures, the nonleaving group propane-1,3-diamine (pn) of a previously optimized analogue (hybrid 1) was replaced with 2,2-dimethylpropane-1,3-diamine (Me 2 pn, hybrid 2), (1 R ,2 R)-1,2-diaminocyclohexane (R , R -dach, hybrid 3), or (1 S ,2 S)-1,2-diaminocyclohexane (S , S -dach, hybrid 4). The cytotoxicity of the four compounds was determined in two non-small cell lung cancer (NSCLC) cell lines, NCI-H460 and A549. The IC 50 values extracted from cell proliferation assays span a range of two orders of magnitude, with the highest activity established for compound 1 in NCI-H460 (8 nM) and the lowest for compound 4 in A549 (825 nM). Partitioning coefficients (log D , based on compound distribution in 1-octanol/saline) and levels of cellular accumulation (by inductively coupled plasma mass spectrometry, ICP-MS) were determined for the hybrids. The results suggest that efficient cellular uptake by an active transport mechanism, which depends on the nature of the nonleaving group, is a modulator of chemosensitivity and a prerequisite for the high nanomolar cytotoxicity observed for the most active platinum–acridines. [ABSTRACT FROM AUTHOR]