Abstract: The invention relates to methods of (i) treating a subject for a disease, (ii) amelioration of decline of forced vital capacity in a subject in need thereof, (iii) modulating ?V?6 integrin, ?V?1 integrin, or both ?V?6 integrin and ?V?1 integrin in a subject in need thereof, (iv) increasing the expression of one or more genes in a subject in need thereof, (v) decreasing the expression of one or more genes in a subject in need thereof, and (vi) modulating the activity of at least one gene affecting fibrotic activity in a subject in need thereof, comprising administration of compounds of Formula (A), Formula (I), Formula (II), or (S)-4-((2-methoxyethyl)(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)amino)-2-(quinazolin-4-ylamino)butanoic acid, or a pharmaceutically acceptable salt thereof as described herein; and administering to the subject at least a second drug selected from pirfenidone and nintedanib, or a salt thereof.