CCNU (lomustine), idarubicin and dexamethasone (CIDEX): an effective oral regimen for the treatment of refractory or relapsed myeloma

Choosing treatment options for patients with relapsed/refractory multiple myeloma

Multiple myeloma (MM) is a clonal plasma cell disorder that is still incurable using conventional treatments. Over the last decade, advances in front-line therapy have led to an increase in survival, but there are still some doubts in the case of relapsed/refractory disease. We searched the PubMed database for articles on treatment options for patients with relapsed/refractory MM published between 1996 and 2013. These treatments included hematopoietic cell transplantation (HCT), rechallenges using previous chemotherapy regimens, and trials of new regimens. The introduction of new agents such as the immunomodulatory drugs (IMIDs) thalidomide and lenalidomide, and the first-in-its-class proteasome inhibitor bortezomib, has greatly improved clinical outcomes in patients with relapsed/refractory MM, but not all patients respond and those that do may eventually relapse or become refractory to treatment. The challenge is therefore to select the optimal treatment for each patient by balancing efficacy and toxicity. To do this, it is necessary to consider disease-related factors, such as the quality and duration of responses to previous therapies, and the aggressiveness of the relapse, and patient-related factors such as age, comorbidities, performance status, pre-existing toxicities and cytogenetic patterns. The message from the trials reviewed in this article is that the new agents may be used to re-treat relapsed/refractory disease, and that the sequencing of their administration should be modulated on the basis of the various disease and patient-related factors. Moreover, our understanding of the pharmacology and molecular action of the new drugs will contribute to the possibility of developing tailored treatment.

Current treatment options for myeloma

In most cases multiple myeloma is an incurable plasma cell malignancy. Despite the use of conventional therapy or high-dose chemotherapy with autologous stem cell transplantation (ASCT), patients continue to relapse at a constant rate. A small minority of patients are cured by allogeneic transplantation. Novel drugs targeting not only the myeloma cell but also its interactions with the malignant microenvironment have recently been used in patients with relapsed/refractory disease. So far, ASCT has been the treatment of choice for eligible myeloma patients. However, many questions regarding the management of myeloma patients remain unanswered. How safe is ASCT in elderly patients? Is there a role for non-myeloablative allogeneic transplantation in multiple myeloma? What is the role of novel agents, such as thalidomide, its analogues and bortezomib, in the treatment of newly diagnosed patients or as maintenance post-ASCT? This review summarises all available data for the current treatment options for myeloma providing a useful algorithm for its management.

The oral combination of thalidomide, cyclophosphamide and dexamethasone (ThaCyDex) is effective in relapsed/refractory multiple myeloma

We evaluate the efficacy of the oral combination of thalidomide, cyclophosphamide and dexamethasone (ThaCyDex) in 71 refractory/relapsed multiple myeloma patients, including a prognostic analysis to predict both response and survival. Patients received thalidomide at escalating doses (200-800 mg/day), daily cyclophosphamide (50 mg/day) and pulsed dexamethasone (40 mg/day, 4 days every 3 weeks). On an intention-to-treat basis and using the EBMT response criteria, 2% patients reached complete response (CR), 55% partial response (PR) and 26% minor response (MR) yielding a total response (CR+PR+MR) rate of 83% after 3 months of therapy. After 6 months of therapy, responses were maintained including a 10% CR. The 2-year progression free and overall survival were 57 and 66%, respectively. A favorable response was associated with beta2 microglobulin < or =4 mg/dl, platelets >80 x 10(9)/l and nonrefractory disease. Regarding survival, low beta2 microglobulin (< or =4 mg/dl), age (< or =65 years) and absence of extramedullary myelomatous lesion were associated with a longer survival. Major adverse effects included constipation (24%), somnolence (18%), fatigue (17%) and infection (13%). Only 7% of patients developed a thrombo-embolic event. ThaCyDex is an oral regimen that induces a high response rate and long remissions, particularly in relapsing patients with beta2 microglobulin < or =4 mg/dl and < or =65 years.