6-mercaptopurine + methotrexate + prednisolone + vincristine

The combination of 6-mercaptopurine, methotrexate, prednisolone (or prednisone), and vincristine—commonly referred to as the "POMP" regimen—is a multi-agent chemotherapy protocol primarily used in the treatment of acute lymphoblastic leukemia (ALL) and sometimes acute myeloid leukemia (AML). Each component has a distinct mechanism of action:

• 6-mercaptopurine is an antimetabolite that inhibits purine synthesis.
• Methotrexate is an antimetabolite that inhibits dihydrofolate reductase, blocking DNA synthesis.
• Prednisolone is a synthetic glucocorticoid with lympholytic effects.
• Vincristine is a vinca alkaloid that disrupts microtubule formation during cell division.

This combination can be used for induction or maintenance therapy. It has been shown to induce remission in both pediatric and adult patients with ALL and AML. The regimen's efficacy depends on patient factors such as age and prior therapy. Toxicities include myelosuppression, liver function abnormalities, gastrointestinal intolerance, neuropathy from vincristine, and increased risk of infection.