Inhibitors of CDK8 and CDK19

A compound according to Formula I, or a pharmaceutically acceptable salt, solvate, tautomer or stereoisomer thereof:

• wherein:
• R1 to R4 are each independently selected from hydrogen, hydroxy, halogen, optionally substituted alkyl, optionally substituted alkoxy, and optionally substituted amino;
• R5 and R6 are each independently selected from:
• hydrogen, optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted heterocyclyl, optionally substituted alkoxy, optionally substituted aryl, and optionally substituted heteroaryl;
• —CO-(L)n-(optionally substituted alkyl), —CO-(L)n-(optionally substituted cycloalkyl), —CO-(L)n-(optionally substituted heterocyclyl), —CO-(L)n-(optionally substituted alkoxy), —CO-(L)n-(optionally substituted aryl), —CO-(L)n-(optionally substituted heteroaryl), —CO-(L)n-(optionally substituted amino), and —CO-(L)n-CO-(optionally substituted amino),
• wherein each L is independently selected from optionally substituted alkylene, (O-alkylene)w, optionally substituted heteroarylene, O and NH,
• n is selected from 0, 1 and 2, and
• w is selected from 1, 2 and 3;
• and
• —SO2-(optionally substituted alkyl), —SO2-(optionally substituted cycloalkyl), —SO2-(optionally substituted heterocyclyl), —SO2-(optionally substituted alkoxy), —SO2-optionally substituted aryl), —SO2-(optionally substituted heteroaryl), and —SO2-optionally substituted amino);
• with the proviso that the compound is not any one of the following: