Satraplatin Demonstrates High Cytotoxic Activity Against Genetically Defined Lymphoid Malignancies

Satraplatin is an oral platinum analog with proven clinical efficacy and a more favorable toxicity profile, although with increased hematotoxicity, when compared to cisplatin. Hence, we carried out a systematic biomarker analysis to identify hematological malignancies with high susceptibility to satraplatin.

Half-maximal inhibitory concentrations (IC₅₀) for satraplatin and cisplatin were determined for 66 different cancer cell lines by CTG Luminescent Cell Viability Assay. In a second step, whole transcriptome RNA sequencing and whole-exome DNA sequencing technology followed by unbiased analysis of gene expression, gene mutation and copy number levels were performed and correlated with drug efficacy.

Satraplatin was significantly more active against hematological malignancies compared to solid organ cancer. In addition, satraplatin showed a significantly more potent antiproliferative activity compared to cisplatin in most lymphoma cell lines achieving sub micromolar IC₅₀ values. Single BCL2 apoptosis regulator (BCL2) gene mutation and 9p21 copy-number deletions including S-methyl-5'-thioadenosine phosphorylase (MTAP) deficiency were identified as key characteristics for high sensitivity to satraplatin.

Satraplatin demonstrated a high cytotoxic activity in genetically well-defined hematological malignancies which is distinct from that of cisplatin. MTAP deficiency was identified as biomarker of enhanced satraplatin efficacy in hematological cancer-derived cell lines. These data in combination with the lipophilicity of satraplatin provide the rationale for targeting specific lymphatic entities such as primary central nervous system lymphoma and cutaneous T-cell lymphoma to improve clinical outcome.