Method for predicting the response to CDK4/6 inhibitor therapy in cancer patients

A method for predicting a response or resistance to and/or a benefit from treatment with an inhibitor of cyclin-dependent kinases 4 optionally CDK4/6 inhibitor in a subject suffering from a neoplastic disease comprising:

• determining in a sample obtained from said subject the expression level of at least one marker selected from the group consisting of Desmoglein 3 (DSG3), Intraflagellar Transport Protein 52 (IFT52), genes associated with multidrug resistance, and genes associated with SUMOylation,
• wherein the neoplastic disease is hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer,
• wherein the genes associated with multidrug resistance are selected from the group consisting of ATP-binding Cassette Sub-Family B Member 6, mitochondrial (ABCB6), Multidrug resistance-associated protein 1 (ABCC1), ATP-binding Cassette Sub-family A Member 5 (ABCA5), ATP-binding Cassette Sub-family C Member 6 (ABCC6) and ATP-binding Cassette transporter Sub-family C Member 11 (ABCC11), ATP Binding Cassette Subfamily C Member 12 (ABCC12), and/or wherein the genes associated with SUMOylation are selected from the group consisting of Protein Inhibitor of Activated STAT 2 (PIAS2), Dual specificity mitogen-activated protein kinase kinase 6 (MAP2K6), Conserved Helix-Loop-Helix Ubiquitous Kinase (CHUK), Small ubiquitin-related modifier 1 (SUMO1), G/T mismatch-specific thymine DNA glycosylase (TDG), Inhibitor of Nuclear Factor Kappa-B Kinase Subunit gamma (IKBKG) and Xeroderma pigmentosum, complementation group C (XPC),
• wherein the expression level of the at least one marker is indicative for predicting the response or resistance to and/or the benefit from the treatment with the CDK4/6 inhibitor in said subject.