Disclosed is the use of (a) a compound of formula A which includes compounds such as (S)-5-fluoro-3-phenyl-2-[1-(9H-purin-6-ylamino)-propyl]-3H-quinazolin-4-one and 6-fluoro-3-phenyl-2-[1-(9H-purin-6-ylamino)-ethyl]-3H-quinazolin-4-one, wherein R is selected from the group consisting of H, halo, and alkyl； R&rsquo； is alkyl； or a pharmaceutically acceptable salt thereof； and optionally a pharmaceutically acceptable excipient, and (b) at least one additional therapeutic agent, wherein the at least one additional therapeutic agent is rituximab, ofatumumab, or a combination thereof； in the manufacture of a medicament for the treatment of a condition in a subject, wherein the condition is cancer； and wherein the subject is refractory to at least two standard or experimental chemotherapy treatments, resistant to chemotherapy treatment or in relapse after treatment with chemotherapy, and wherein the medicament is formulated for separate, sequential or simultaneous administration of (a) and (b).
