procarbazine + vinblastine + bleomycin

This is a combination chemotherapy regimen consisting of three cytotoxic agents—procarbazine, vinblastine, and bleomycin. Each drug has a distinct mechanism of action: - Procarbazine is an alkylating agent that inhibits DNA, RNA, and protein synthesis by causing DNA strand breaks. - Vinblastine is a vinca alkaloid that disrupts microtubule formation during cell division by binding to tubulin, leading to mitotic arrest. - Bleomycin is an antitumor antibiotic that induces DNA strand breaks through free radical formation. This combination has been used in the treatment of Hodgkin lymphoma and other lymphomas as part of multi-agent regimens. The rationale for combining these drugs lies in their complementary mechanisms and non-overlapping toxicities, aiming to maximize cancer cell kill while minimizing resistance.