4-amino-6-oxo-pyridazine derivatives modulating nlrp3

A compound of formula (I),

• or a pharmaceutically acceptable salt thereof, wherein:
• R1 represents:
• (i) phenyl:
• (ii) a 6-membered mono-cyclic heteroaryl group:
• or (iii) a 9- or 10-membered bicyclic heteroaryl group, all of which are optionally substituted with one or two substituent(s) selected from halo, —OH, C1-3 alkyl and —OC1-3 alkyl:
• R2 represents:
• (i) C1-3 alkyl optionally substituted with one or more substituents independently selected from halo, —OH and —OC1-3 alkyl:
• (ii) C3-6 cycloalkyl:
• or
• (iii) OC2-4 alkenyl optionally substituted with —OC1-3 alkyl:
• or
• (iv) —N(R2a)R2b.
• R2a and R2b each represent hydrogen or C1-4 alkyl, or R2a and R2b may be linked together to form a 3- to 4-membered ring optionally substituted by one or more fluoro atoms:
• one of R3a and R3b represents hydrogen or C1-6 alkyl, and the other represents:
• (i) C1-6 alkyl optionally substituted with one or more substituents independently selected from halo, —OH, —OC1-3 alkyl, —NH2, —N(H)C1-3 alkyl, —N(C1-3 alkyl)2, aryl and —C(O)N(C1-3 alkyl)2;
• (ii) C2-6 alkenyl optionally substituted with one or more substituents independently selected from halo, —OH, —OC1-3 alkyl, —NH2, —N(H)C1-3 alkyl, —N(C1-3 alkyl)2 and —C(O)N(C1-3 alkyl)2;
• (iii) aryl or heteroaryl, each of which is optionally substituted with 1 to 3 substituents independently selected from halo, —OH, —O-C1-3 alkyl, -C1-3 alkyl, haloC1-3alkyl, hydroxyC1-3 alkyl, hydroxy C1-3 alkoxy, haloC1-3alkoxy, C3-6 cycloalkyl, C3-6 cycloalkyl substituted with C1-3 alkyl:
• C1-3 alkyl substituted with C3-6 cycloalkyl and —(CH2)n1-heterocyclyl (where nl represents 0 or 1):
• (iv) -X1a-Y1a, in which Y1a represents C3-6 cycloalkyl optionally substituted with one or more substituents independently selected from halo, —OH, -C1-3 alkyl and —OC1-3 alkyl:
• or
• (v) -X1b-Y1b, in which Y1b represents heterocyclyl, optionally substituted with 1 to 3 substituents independently selected from halo, ═O, C1-3 alkyl, —OC1-3 alkyl and —C(O)O-C1-6 alkyl:
• or
• R3a and R3b are linked together to form a 3- to 10-membered cyclic group (including bridged cyclic groups, fused bicyclic groups and spiro-cyclic groups), which cyclic group may contain one or two (e.g. one) further heteroatom(s) (e.g. selected from nitrogen and oxygen) and which group may be substituted by one or more substituents selected from halo (e.g. fluoro), C1-3 alkyl, —OH, —OC1-3 alkyl, —N(C1-3 alkyl)2, hydroxyC1-3 alkyl, C1-3 alkyoxyC1-3 alkyl, halo C1-3 alkyl, -O-heteroaryl, —CH2-heteroaryl;
• and heteroaryl;
• X1a and X1b independently represent a —CH2— linker group or a direct bond (i.e. is not present):
• R4 represents:
• (i) hydrogen:
• (ii) halo:
• (iii) C1-4 alkyl optionally substituted with one or more substituents independently selected from halo, —OH and —OC1-3 alkyl;
• (iv) C3-6 cycloalkyl:
• or —OC1-3 alkyl.