Emerging combination treatment strategies containing novel agents in newly diagnosed multiple myeloma

Treatment strategies for multiple myeloma have changed substantially over the past 10 years following the introduction of bortezomib and the immunomodulatory drugs thalidomide and lenalidomide. In the front-line setting, combination regimens incorporating these novel agents are demonstrating substantial activity, which is translating into improved outcomes compared with previous standards of care. Response rates and depth of response that were previously only seen with high-dose therapy plus stem-cell transplantation (HDT-SCT) can now be achieved with new induction regimens utilizing these novel agents. This has raised the need for trials that will determine the clinical benefit of early SCT in patients that have already achieved a high quality of response. Here, we review the improvements in response and outcome that are seen with these novel-agent regimens, both as induction therapy prior to HDT-SCT and in non-transplant patients, and highlight the latest data from key studies of various novel combinations, including regimens featuring bortezomib plus thalidomide or lenalidomide. We also review data on response and outcomes in patients with poor prognostic characteristics that indicate that the adverse impact typically seen with these factors may be overcome using novel-agent therapy.

Targeting the proteasome as a therapeutic strategy against haematological malignancies

The ubiquitin-proteasome pathway is responsible for the vast majority of regulated eukaryotic intracellular proteolysis. Inhibition of the proteasome induces beneficial antitumour effects by blocking cell-cycle progression, inducing apoptosis and suppressing angiogenesis. Bortezomib is the first proteasome inhibitor to reach the clinical arena, where Phase I - III trials verified its activity against relapsed/refractory multiple myeloma. Testing is ongoing to determine bortezomib's role in front-line therapy of this plasma cell dyscrasia, as well as in non-Hodgkin's lymphoma, in which encouraging single-agent activity has been seen. Proteasome inhibition is also a rational strategy to overcome chemoresistance and induce chemosensitisation. Combinations of bortezomib and other agents have enhanced efficacy, and additional studies are probing the activity of several regimens in lymphoid and myeloid malignancies. The current state of knowledge about the activity of bortezomib, both alone and in combination with standard chemotherapeutics, as part of the emerging armamentarium against haematological malignancies is reviewed.