The present invention relates inter alia to a compound of formula (I) wherein R.sub.1, R.sub.2 and R.sub.3, are as defined in the specification and to compositions comprising the same and to the use of the compounds and to compositions of the compounds in treatment, for example in the treatment of fibrotic diseases or interstitial lung diseases, in particular idiopathic pulmonary fibrosis.

The present invention relates inter alia to a compound of formula (I) wherein R.sub.1, R.sub.2 and R.sub.3, are as defined in the specification and to compositions comprising the same and to the use of the compounds and to compositions of the compounds in treatment, for example in the treatment of fibrotic diseases or interstitial lung diseases, in particular idiopathic pulmonary fibrosis.

This invention is in the area of improved compounds, compositions and methods of transiently protecting healthy cells, and in particular hematopoietic stem and progenitor cells (HSPC) as well as renal cells, from damage associated with DNA damaging chemotherapeutic agents. In one aspect, improved protection of healthy cells is disclosed using disclosed compounds that act as highly selective and short, transiently-acting cyclin-dependent kinase 4/6 (CDK 4/6) inhibitors when administered to subjects undergoing DNA damaging chemotherapeutic regimens for the treatment of proliferative disorders.

This invention is in the area of improved compounds, compositions and methods of transiently protecting healthy cells, and in particular hematopoietic stem and progenitor cells (HSPC) as well as renal cells, from damage associated with DNA damaging chemotherapeutic agents. In one aspect, improved protection of healthy cells is disclosed using disclosed compounds that act as highly selective and short, transiently-acting cyclin-dependent kinase 4/6 (CDK 4/6) inhibitors when administered to subjects undergoing DNA damaging chemotherapeutic regimens for the treatment of proliferative disorders.

The invention is fused heterocyclic compounds of formula (I), and salts thereof, compositions thereof, and methods of use therefor. In particular, disclosed herein are certain fused heterocyclic compounds that can be useful for inhibiting protein kinase, including Bruton's tyrosine kinase (Btk), and for treating disorders mediated thereby.

##STR00001##

The invention is fused heterocyclic compounds of formula (I), and salts thereof, compositions thereof, and methods of use therefor. In particular, disclosed herein are certain fused heterocyclic compounds that can be useful for inhibiting protein kinase, including Bruton's tyrosine kinase (Btk), and for treating disorders mediated thereby.

##STR00001##

The invention is fused heterocyclic compounds of formula (I), and salts thereof, compositions thereof, and methods of use therefor. In particular, disclosed herein are certain fused heterocyclic compounds that can be useful for inhibiting protein kinase, including Bruton's tyrosine kinase (Btk), and for treating disorders mediated thereby. ##STR00001##

The invention is fused heterocyclic compounds of formula (I), and salts thereof, compositions thereof, and methods of use therefor. In particular, disclosed herein are certain fused heterocyclic compounds that can be useful for inhibiting protein kinase, including Bruton's tyrosine kinase (Btk), and for treating disorders mediated thereby. ##STR00001##

Compounds of Formulae I, II or III, and pharmaceutically acceptable salts thereof, are useful as CDK inhibitors.

Compounds of Formulae I, II or III, and pharmaceutically acceptable salts thereof, are useful as CDK inhibitors.