Abstract: There are cases of CD20-positive cancer where the cancer is tolerant to obinutuzumab and cases where the cancer recurs after an obinutuzumab-containing treatment. For CD20-positive cancer that is tolerant to obinutuzumab or CD20-positive cancer that has recurred following an obinutuzumab-containing treatment, a type II anti-CD20 antibody is used in combination with one or more compounds selected from the group consisting of prednisolone, doxorubicin, vincristine, and salts and prodrugs thereof. Among these compounds, prednisolone, doxorubicin, and salts and prodrugs thereof may be selected. Furthermore, among these compounds, prednisolone or a salt or prodrug thereof may be selected.

Abstract: By combining a compound having RET kinase inhibitory activity with a CDK4/6 inhibitor, the present inventors have found a drug, a combination, a pharmaceutical composition, and a preparation which are effective for treating or preventing cancer, a method for treating or preventing cancer, or a method for suppressing tumor growth.