Busulfan

Generic Name: Busulfan

Brand Names: Busulfex, Myleran, Busulfan Fresenius Kabi

Drug Type: Small Molecule

Chemical Formula: C_₆H_₁₄O_₆S_₂

CAS Number: 55-98-1

Unique Ingredient Identifier: G1LN9045DK

Overview

Busulfan is a bifunctional alkylating agent, having a selective immunosuppressive effect on bone marrow. It is not a structural analog of the nitrogen mustards. It has been used in the palliative treatment of chronic myeloid leukemia (myeloid leukemia, chronic), but although symptomatic relief is provided, no permanent remission is brought about. According to the Fourth Annual Report on Carcinogens (NTP 85-002, 1985), busulfan is listed as a known carcinogen.

Background

Indication

For use in combination with cyclophosphamide as a conditioning regimen prior to allogeneic hematopoietic progenitor cell transplantation for chronic myelogenous (myeloid, myelocytic, granulocytic) leukemia (FDA has designated busulfan as an orphan drug for this use). It is also used as a component of pretransplant conditioning regimens in patients undergoing bone marrow transplantation for acute myeloid leukemia and nonmalignant diseases.

Associated Conditions

Chronic Myelogenous Leukemia (CML)
Essential Thrombocythemia (ET)
Polycythemia Vera (PV)

Research Report

Published: May 14, 2025

Busulfan Report

Name: Busulfan Name (English): Busulfan DrugBank ID: DB01008 Type: Small Molecule CAS Number: 55-98-1

Description: Busulfan is an alkylating agent used primarily in the treatment of chronic myelogenous leukemia and as part of conditioning regimens before hematopoietic stem cell transplantation for various hematologic malignancies and non-malignant diseases. It works by alkylating DNA, which disrupts DNA replication and RNA transcription, ultimately leading to cell death.

Pharmacodynamics: Busulfan is a bifunctional alkylating agent that forms DNA crosslinks, mainly guanine-adenine intrastrand crosslinks, interfering with DNA replication and RNA transcription. This non-specific action affects both cancerous and normal cells, particularly hematopoietic progenitor cells.

Pharmacokinetics:

Absorption: Well absorbed from the gastrointestinal tract, with an absolute bioavailability of approximately 80%. Peak plasma concentrations are reached within approximately 0.9 hours.
Distribution: Highly lipophilic and crosses the blood-brain barrier.
Metabolism: Extensively metabolized in the liver, primarily by conjugation with glutathione via glutathione S-transferases (GSTs), with GSTA1 being the primary isoform.
Elimination: Metabolites are excreted in the urine.

Indications:

Palliative treatment of chronic myelogenous leukemia.
Conditioning regimen prior to allogeneic hematopoietic progenitor cell transplantation for chronic myelogenous leukemia.
Component of pretransplant conditioning regimens in patients undergoing bone marrow transplantation for acute myeloid leukemia and nonmalignant diseases.

Contraindications: