DNA repair blood test for predicting response of lung cancer patients to immunotherapy

A method of treating a subject having cancer, the method comprising:

• (a) determining a level of catalytic activity of the DNA repair enzymes N-methylpurine DNA glycosylase (MPG), apurinic/apyrimidinic endonuclease 1 (APE1), 8-oxoguanine DNA glycosylase 1 (OGG1) in a biological sample of the subject;
• and
• (b) [i] administering to a subject having a statistically significant different level of catalytic activity of said DNA repair enzymes as compared to the catalytic activity of said DNA repair enzyme in a biological sample of a healthy subject, a therapeutically effective amount of an immune checkpoint regulator;
• or
• [ii] administering to a subject having a non-statistically significant different level of catalytic activity of said DNA repair enzymes as compared to the catalytic activity of said DNA repair enzyme in a biological sample of a healthy subject, a therapeutically effective amount of an anti-cancer agent other than said immune checkpoint regulator, thereby treating the cancer;
• wherein determining said MPG catalytic activity is effected using a double stranded oligonucleotide substrate having a hypoxanthine lesion (Hx),
• wherein determining said MPG catalytic activity is effected using an oligonucleotide substrate having an N6-ethenoadenine lesion (eA),
• wherein determining said APE1 catalytic activity is effected using an oligonucleotide substrate having a furanyl abasic site lesion (AP) or
• wherein determining said OGG1 catalytic activity is effected using an oligonucleotide substrate having an 8-oxoguanine lesion.