An EGFR inhibitor for use in a method for treating or suppressing a cancer, reducing its severity, lowering its risk or inhibiting its metastasis in an individual, comprising administering to the individual a therapeutically effective amount of an ALK inhibitor of formula I or II, or a pharmaceutically acceptable salt or solvate thereof: wherein: R 1a and R 1b are independently selected from the group consisting of hydrogen, C 1-6 alkyl, and C 3-8 cycloalkyl; R 2a and R 2b are independently selected from the group consisting of hydrogen, C 1-6 alkyl, and C 3-8 cycloalkyl; R 3 is selected from the group consisting of hydrogen, C 1-6 alkyl, C 3-6 cycloalkyl, and 4- to 8-membered heterocyclyl, R 4 is selected from the group consisting of C 1-4 alkyl and C 3-6 cycloalkyl; R 5 is halo; R 6 is selected from the group consisting of C 1-4 alkyl and C 3-6 cycloalkyl; and R 7 is selected from the group consisting of hydrogen, C 1-4 alkyl, and C 3-6 cycloalkyl, with proviso that when R 1a, R 1b, R 2a, and R 2b are each hydrogen, then R 3 is selected from the group consisting of C 3-6 cycloalkyl and 4- to 8-membered heterocyclyl; wherein: R 1a and R 1b are independently selected from the group consisting of hydrogen, C 1-4 alkyl, and C 3-6 cycloalkyl; R 2a and R 2b are independently selected from the group consisting of hydrogen, C 1-4 alkyl, and C 3-6 cycloalkyl; and R 3 is selected from the group consisting of hydrogen, C 1-4 alkyl, C 3-6 cycloalkyl, and 4- to 8-membered heterocyclyl; and a therapeutically effective amount of the EGFR inhibitor; wherein the EGFR inhibitor is afatinib, osimertinib or Avitinib; and wherein the cancer is non-small cell lung cancer carrying an EGFR T790M mutation. R 1a and R 1b are independently selected from the group consisting of hydrogen, C 1-6 alkyl, and C 3-8 cycloalkyl; R 2a and R 2b are independently selected from the group consisting of hydrogen, C 1-6 alkyl, and C 3-8 cycloalkyl; R 3 is selected from the group consisting of hydrogen, C 1-6 alkyl, C 3-6 cycloalkyl, and 4- to 8-membered heterocyclyl, R 4 is selected from the group consisting of C 1-4 alkyl and C 3-6 cycloalkyl; R 5 is halo; R 6 is selected from the group consisting of C 1-4 alkyl and C 3-6 cycloalkyl; and R 7 is selected from the group consisting of hydrogen, C 1-4 alkyl, and C 3-6 cycloalkyl, with proviso that when R 1a, R 1b, R 2a, and R 2b are each hydrogen, then R 3 is selected from the group consisting of C 3-6 cycloalkyl and 4- to 8-membered heterocyclyl; wherein: R 1a and R 1b are independently selected from the group consisting of hydrogen, C 1-4 alkyl, and C 3-6 cycloalkyl; R 2a and R 2b are independently selected from the group consisting of hydrogen, C 1-4 alkyl, and C 3-6 cycloalkyl; and R 3 is selected from the group consisting of hydrogen, C 1-4 alkyl, C 3-6 cycloalkyl, and 4- to 8-membered heterocyclyl; and a therapeutically effective amount of the EGFR inhibitor; wherein the EGFR inhibitor is afatinib, osimertinib or Avitinib; and wherein the cancer is non-small cell lung cancer carrying an EGFR T790M mutation. R 1a and R 1b are independently selected from the group consisting of hydrogen, C 1-4 alkyl, and C 3-6 cycloalkyl; R 2a and R 2b are independently selected from the group consisting of hydrogen, C 1-4 alkyl, and C 3-6 cycloalkyl; and R 3 is selected from the group consisting of hydrogen, C 1-4 alkyl, C 3-6 cycloalkyl, and 4- to 8-membered heterocyclyl; and a therapeutically effective amount of the EGFR inhibitor; wherein the EGFR inhibitor is afatinib, osimertinib or Avitinib; and wherein the cancer is non-small cell lung cancer carrying an EGFR T790M mutation.