Bortezomib: the evidence of its clinical impact in multiple myeloma

Multiple myeloma is a relatively common and incurable form of hematologic malignancy for which there is currently no single standard therapy. Bortezomib inhibits the 20S proteasome involved in the degradation of intracellular proteins, induces apoptosis, reverses drug resistance in multiple myeloma cells, and influences their microenvironment by blocking cytokine circuits, cell adhesion and angiogenesis in vivo. Aims: The objective of this review is to evaluate the evidence for the use of bortezomib in the treatment of multiple myeloma. Evidence review: In patients with relapsed multiple myeloma bortezomib significantly prolongs overall survival and time to progression, and improves response rates, duration of response, and quality of life compared with oral high-dose dexamethasone. Although the incidence of grade 4 adverse events was similar, grade 3 events and herpes zoster infections occur more frequently in patients treated with bortezomib than with high-dose dexamethasone. Evidence from a pharmacoeconomic study indicates that the benefits of bortezomib compared to thalidomide plus best standard care may be achieved at a reasonable cost. Clinical value: Bortezomib is a valuable treatment option in the management of relapsed multiple myeloma that improves survival and delays disease progression compared with oral high-dose dexamethasone treatment, albeit with an increased incidence of some adverse events such as grade 3 thrombocytopenia and neutropenia.