Amorphous solid dispersions and pharmaceutical compositions of the protein kinase inhibitor dasatinib. The pharmaceutical compositions may be used in methods of treating a proliferative disorder such as cancer, or in methods of delivering dasatinib to patients without regard to whether the patient is concurrently administered a gastric acid-reducing agent, or without regard to whether the patient has an elevated gastric pH. The compositions may be particularly suitable for patients afflicted by achlorhydria or hypochlorhydria, or