Cyanopyrrolidine derivatives as inhibitors for DUBs

A compound of formula (I):

• or a pharmaceutically acceptable salt of said compound, wherein:
• R1a, R1b, R1c and R1d each independently represent hydrogen or C1-C6 alkyl, or R1a is linked to R1b to form a 3 to 6-membered cycloalkyl ring, or R1d is linked to R1c or R1e to form a 3 to 6-membered cycloalkyl ring;
• R1e and R1f each independently represent hydrogen, fluorine, cyano, hydroxyl, amino, C1-C6 alkyl, C1-C6 alkoxy or a 5 or 6-membered heteroaryl or aryl ring, or R1e and R1f together form a 3 to 6-membered cycloalkyl ring, or R1e is linked to R1d to form a 3 to 6-membered cycloalkyl ring;
• A is a 5 to 10-membered heteroaryl or aryl ring;
• wherein ring A is optionally substituted with one to four —Q1(R2)n, wherein each occurrence of —Q1(R2)n is the same or different, wherein:
• n is 0 or 1;
• Q1 represents halogen, cyano, oxo, nitro, —OR3, —SR3, —NR3R4, —CONR3R4, —NR3COR4, —NR3CONR4R5, —COR3, —C(O)OR3, —SO2R3, —SO2NR3R4, —NR3SO2R4, —NR3SO2NR4R5, —NR3C(O)OR4, —C1-C6 alkyl, —C1-C6 alkoxy, —C2-C6 alkenyl, a covalent bond, an oxygen atom, a sulphur atom, —SO—, —SO2—, —CO—, —C(O)O—, —CONR3—, —NR3—, —NR3CO—, —NR3CONR4—, —SO2NR3—, -NR4SO2—, —NR3SO2NR4—, —NR3C(O)O—, —NR3C(O)OR4—, C1-C6 alkylene, or —C2-C6 alkenylene;
• R3, R4 and R5 each independently represent hydrogen, C1-C6 alkyl or C1-C6 alkylene;
• wherein R2 represents a 3 to 10-membered heterocyclyl, heteroaryl, aryl or cycloalkyl ring, which is unsubstituted or substituted with one to four substituents selected from halogen, cyano, oxo, nitro, —OR6, —SR6, —NR6R7, —CONR6R7, —NR6COR7, —NR6CONR7R8, —COR6, —C(O)OR6, —SO2R6, —SO2NR6R7, —NR6SO2R7, —NR6SO2NR7R8, —NR6C(O)OR7, C1-C6 alkyl, C1-C6 alkoxy, C2-C6 alkenyl, C2-C6 alkynyl, Q2-R6, —Q2-NR6CONR7R8, —Q2-NR6R7, —Q2-COR6, —Q2-NR6COR7, —Q2-NR6C(O)OR7, —Q2-SO2R6, Q2-CONR6R7, —Q2-CO2R6, —Q2-SO2NR6R7, —Q2-NR6SO2R7 and —Q2-NR6SO2NR7R8;
• Q2 represents a covalent bond, an oxygen atom, a sulphur atom, —SO—, —SO2—, —CO—, C1-C6 alkylene, or C2-C6 alkenylene;
• and
• R6, R7, R8 each independently represent hydrogen, C1-C6 alkyl, 3 to 10-membered heterocyclyl ring, 5 to 10-membered heteroaryl ring, 5 to 10-membered aryl ring, or 3 to 10-membered cycloalkyl ring;
• wherein said C1-C6 alkyl, C1-C6 alkoxy, C2-C6 alkenyl, C2-C6 alkynyl, C1-C6 alkylene and C2-C6 alkenylene, are each independently optionally substituted with one to four substituents, each independently selected from halogen, hydroxyl, thiol, cyano, amino, nitro, and SF5.