Class: Alkylating agent (Nitrogen mustard derivative) with purine-like properties.
- Structure: Contains a nitrogen mustard group (alkylator) and a benzimidazole ring (purine analog feature) → gives it dual mechanism.
Mechanism of Action
- Alkylates DNA → intra- and inter-strand cross-links → inhibits DNA replication and transcription.
- Purine analog–like activity → interferes with DNA synthesis and repair.
- Leads to apoptosis and mitotic catastrophe.
Clinical Uses
- Chronic lymphocytic leukemia (CLL).
- Indolent non-Hodgkin’s lymphomas (NHL), including rituximab-refractory disease.
- Off-label: mantle cell lymphoma, multiple myeloma, HL.
Dosing
- IV:
- CLL: 100 mg/m² IV on days 1 and 2 of a 28-day cycle × 6 cycles.
- NHL: 120 mg/m² IV on days 1 and 2 of a 21-day cycle × 6–8 cycles.
- Premedicate with antiemetics; hydration recommended.
Toxicities
- Myelosuppression (dose-limiting; neutropenia, thrombocytopenia, anemia).
- Infections (opportunistic, reactivation of hepatitis B, CMV, PCP).
- Infusion-related reactions.
- Nausea, vomiting, fatigue, fever.
- Dermatologic: rash, rare Stevens–Johnson syndrome (SJS)/TEN.
- Secondary malignancies (MDS, AML with prolonged use).
Monitoring
- CBC before and during cycles.
- Hepatitis B screening (risk of reactivation).
- Monitor for opportunistic infections (consider prophylaxis).
- Renal and hepatic function tests.
- Watch for infusion-related reactions and skin toxicity.
In summary:
Bendamustine is a hybrid alkylator with purine-like activity, widely used in CLL and indolent NHL. Its hallmark is myelosuppression and immunosuppression, with risk of infections and secondary malignancies, making infection prophylaxis and monitoring critical.