Mechanisms of the escape phase of myeloma

Multiple myeloma and persistence of drug resistance in the age of novel drugs (Review)

Multiple myeloma (MM) is a mature B cell neoplasm that results in multi-organ failure. The median age of onset, diverse clinical manifestations, heterogeneous survival rate, clonal evolution, intrinsic and acquired drug resistance have impact on the therapeutic management of the disease. Specifically, the emergence of multidrug resistance (MDR) during the course of treatment contributes significantly to treatment failure. The introduction of the immunomodulatory agents and proteasome inhibitors has seen an increase in overall patient survival, however, for the majority of patients, relapse remains inevitable with evidence that these agents, like the conventional chemotherapeutics are also subject to the development of MDR. Clinical management of patients with MM is currently compromised by lack of a suitable procedure to monitor the development of clinical drug resistance in individual patients. The current MM prognostic measures fail to pick the clonotypic tumor cells overexpressing drug efflux pumps, and invasive biopsy is insufficient in detecting sporadic tumors in the skeletal system. This review summarizes the challenges associated with treating the complex disease spectrum of myeloma, with an emphasis on the role of deleterious multidrug resistant clones orchestrating relapse.

'Light-chain escape-multiple myeloma'-an escape phenomenon from plateau phase: report of the largest patient series using LC-monitoring

PURPOSE

More intensive and novel therapy options in multiple myeloma (MM) hold the promise to improve treatment outcome. However, disease evolution, induced with long disease duration and extensive pretreatment, has resulted in changes in the biological behaviour of MM and unusual relapse emergence, such as of extramedullary (EM) disease or a shift in secretion from intact immunoglobulin (Ig) to free-light chains (FLCs) only.

METHODS

We studied ten patients since 2004, thoroughly assessed relevant patient characteristics, prominent similarities, SFLC-changes, therapy response, mode and speed of progression, and the incidence of light-chain escape (LCE)-MM within our entire myeloma patient cohort. Serum FLCs (SFLCs) were determined via Freelite-assay (Dade-Behringer Nephelometer).

RESULTS

This report summarizes the to date largest series of ten patients, whose MM appeared stable, as judged by conventional monitoring of intact Ig levels, but developed severe organ dysfunction as a consequence of initially undetected LC-progression. Median number of anti-MM cycles before LCE occurrence was six, including autologous and/or allogeneic stem cell transplants and novel drugs, predominantly thalidomide, in 4/10. Classic diagnostics, such as electrophoresis and quantitative Ig measurement proved futile to detect LC-progression, whereas SFLCs were reliable markers. The LCE-MM prevalence within 407 MM patients treated in our institution between 2004 and 2007 was 2.46%.

CONCLUSIONS

Our report suggests that early detection of LCE-MM by means of serial SFLC measurements may prevent unnecessary complications, allows to detect unusual relapse manifestations in the era of intensive and biological therapy options and possibly also permits to improve treatment results in LCE-MM.

OPP-EBV-CAD regimen as salvage treatment in advanced refractory or resistant multiple myeloma

With the aim of developing an effective therapy for heavily pretreated refractory MM outpatients, we evaluated the OPPEBVCAD regimen, a Hodgkin's disease-derived protocol that includes many drugs effective in MM administered in a sequential schedule. Twenty-two pts aged 42-72 years, with symptomatic highly-pretreated refractory (18 cases), or primary resistant MM (four cases. including two pts with plasma cell leukemia-PCL) received this therapy every 28 days (2-4 cycles, followed by a maintenance program). Therapeutic response (Chronic Leukemia-Myeloma Task Force criteria) and performance status (PS) and pain (W.H.O.) were evaluated. All of the pts were evaluable for response. There were 9 (40%) objective responses (OR: stabilization of blood counts and bone lesions, serum calcium normalization, 50% or more reduction in the concentration of serum monoclonal component (MC), 90% reduction in Bence-Jones proteinuria), 8 (36%) partial responses (PR: 25-50% reduction in serum MC), 1 no response or stable disease (NR), and 4 (18%) cases of progressive disease (PD). OR plus PR were 77%. Of the 4 primary resistant tumors (2 PCL and 2 MM), 2 achieved PR, 1 OR (a PCL case) and 1 progressed. Median survival was 15 months for responding pts (OR plus PR) and 4.5 months for non-responders (NR plus PD). PS and pain improved in 15 pts and did not change in 9. The most frequent side effects were cytopenias, with one drug related infective death. The OPPEBVCAD regimen proved to be an effective therapy for refractory relapsing or primary resistant MM: in responders (two-thirds of the pts), survival was prolonged by about 10 months. Its efficacy in anthracycline-treated pts, as well as the feasibility of using it on an outpatient basis without any continuous drug infusions, make this regimen a promising third line salvage therapy.

Multiple myeloma

OBJECTIVES

To review the epidemiology, pathogenesis, clinical features, diagnosis, treatment, and nursing management of multiple myeloma.

DATA SOURCES

Review articles, research studies, and book chapters related to multiple myeloma.

CONCLUSIONS

Despite insights into the immunobiology of multiple myeloma and the advances in intensive therapy and supportive care, multiple myeloma remains an incurable disease. Patients will experience chronic and acute symptomatic episodes throughout the course of their disease.

IMPLICATIONS FOR NURSING PRACTICE

Oncology nurses can assist patients with multiple myeloma and their families to manage both the disease and treatment related symptoms and to improve their overall quality of life. Specific nursing assessments can provide early recognition of complications, such as hypercalcemia and spinal cord compression.

The role of haematopoietic stem cell-supported myeloablative therapy for the management of multiple myeloma

Haematopoietic stem cell-supported myeloablative therapy appears to be a promising treatment modality for MM. It yields increased overall response and CR rates when compared with conventional chemotherapy, and seems to prolong the duration of survival. These conclusions, while encouraging, have mostly been drawn from uncontrolled studies carried out in select groups of patients and, obviously, need to be confirmed in controlled clinical trials. While the results of these studies are still awaited, the wider application of BMT should probably be encouraged. As in other malignancies, the best candidates appear to be those less heavily pre-treated, with chemosensitive disease, low tumour cell mass and other favourable prognostic features, for example low beta 2-microglobulin levels. Under these conditions, the chance of entering CR following BMT, be it autologous or allogeneic, is currently estimated to be of at least 50%, and the long-term probability of survival averages approximately 30%. However, while it appears that a plateau for progression-free survival cannot be ascertained following a single ABMT, reported observations of patients with continued disease-free survivals up to and beyond 10 years after allografting suggest that this latter procedure may be curative. It seems likely therefore that the higher mortality related to allogeneic BMT (which in recent years decreased from 50% to approximately 30% as the results of a better selection of patients and increasing experience in their management) may be offset by more durable control of the disease and cure in a certain proportion of patients. Recurrence of underlying malignant disease remains, however, a major problem and is the most common cause of treatment failure following BMT. For this reason, attempts to improve the impact of transplantation are warranted. Options currently under investigation include the development of more effective conditioning regimens, as applied in double auto-transplant or with targeted therapy using antibody-radionuclide conjugates, as well as post-transplant immunomodulation with either IFN-alpha, interleukin-2 or idiotype vaccines. In addition, many other problems regarding BMT for MM are still unresolved and could be properly addressed only in future clinical trials. The most important of these issues include the choice of the best conditioning regimen and the optimal source of haematopoietic stem cells, the nature of relapse after autografting, the need to purge or not to purge the autologous marrow, the existence of a 'graft-versus-myeloma' effect and its role in prolonging the duration of disease control and, finally, the likelihood of cure, especially for patients with molecularly-defined CR.

Allogeneic bone marrow transplantation for the treatment of multiple myeloma. An overview of published reports

Allogeneic bone marrow transplantation (BMT) was first explored for the treatment of multiple myeloma (MM) in the mid 1980s. Since then, there has been a rapidly growing clinical demand for the use of this modality of treatment, so that the number of patients receiving worldwide transplants from HLA-identical siblings is actually estimated to be at least several hundreds. Although it is difficult to compare results between different centers because of differences in patient characteristics, selection criteria for transplantation and conditioning regimens, a certain number of conclusions have emerged from these experiences. There is evidence that allogeneic BMT performed in different phases of MM and with different conditioning regimens yields a high frequency of complete remissions (CR), in the range of 50% to 60%, and long-term survival and remission rates, both averaging approximately 20%. Although a toxic-related mortality rate of 40% has been consistently reported for many years, the outcome of patients in whom BMT was performed as consolidation of remission has recently improved. Prior responsiveness to conventional chemotherapy, also the presence of low tumor cell mass (both at diagnosis and before transplant) predicts for increased CR rate (up to 70% or more), as well as long-term survival and remission rates (both averaging approximately 50%). The continued relapse-free survival, up to and beyond ten years, reported for some of these patients provides strong evidence that allogeneic BMT has the potential ability to cure MM, probably as the result of an immunologic effect of the infused donor's marrow T lymphocytes against residual myeloma cells (graft-versus-myeloma).(ABSTRACT TRUNCATED AT 250 WORDS)