The disclosure herein includes 5-(5-(2-(3-aminopropoxy)-6-methoxyphenyl)-1H- pyrazol-3-ylamino)pyrazine-2-carbonitrile (S)-lactate monohydrate that inhibits Chk1/2 and is useful in the treatment of cancer.L'invention concerne un monohydrate de 5-(5-(2- (3-aminopropoxy)-6-méthoxyphényl)-1H-pyrazol-3-ylamino) pyrazine-2-carbonitrile (S)-lactate qui inhibe Chk1/2 et est utile dans le traitement du cancer.