Improvement in long-term outcomes with successive Total Therapy trials for multiple myeloma: are patients now being cured?

Key Points• RARa2 activates Wnt and hedgehog pathways in maintaining myeloma stem cell features and drug resistance.We previously demonstrated that RARa2 expression is increased in CD138 selected plasma cells of relapsed multiple myelomas (MMs), and increased expression was linked to poor prognosis in newly diagnosed MM patients. In the present study, we demonstrate that increased RARa2 confers myeloma stem cell features. Higher expression of RARa2 was identified in the multiple myeloma stem cell (MMSC) fraction. Overexpression of RARa2 in bulk MM cell lines resulted in: 1) increased drug resistance; 2) increased clonogenic potential; 3) activation of both Wnt and Hedgehog (Hh) pathways; 4) increased side population and aldehyde dehydrogenase levels; and 5) increased expression of embryonic stem cell genes. The opposite effects were seen with RARa2 knockdown. We demonstrate that RARa2 induces drug resistance by activating the drug efflux pump gene ABCC3 and anti-apoptotic Bcl-2 family members. Inhibition of Wnt signaling or ABCC3 function could overcome drug resistance in RARa2 overexpressing MM cells. We also showed that in the 5TGM1 mouse model, targeting of the Wnt and Hh pathways using CAY10404, cyclopamine, or itraconazole significantly reduced the myeloma tumor burden and increased survival. Targeting RARa2 or its downstream signaling pathways provides a potential strategy to eliminate

Section: Discussionmentioning

confidence: 99%

RARα2 expression confers myeloma stem cell features

Yang

Shi

Tolomelli

et al. 2013

“…80 In Total Therapy 3, 5-year PFS is now 67%. 81 In the Hovon-65/GMMG-HD4 trial, tandem transplantation was an independent predictor of overall survival, with a hazard ratio of 0.75.…”

Section: Plerixafor Dosingmentioning

confidence: 99%

How we manage autologous stem cell transplantation for patients with multiple myeloma

Gertz¹,

Dingli

2014

An estimated 22 350 patients had multiple myeloma diagnosed in 2013, representing 1.3% of all new cancers; 10 710 deaths are projected, representing 1.8% of cancer deaths. Approximately 0.7% of US men and women will have a myeloma diagnosis in their lifetime, and with advances in therapy, 77 600 US patients are living with myeloma. The 5-year survival rate was 25.6% in 1989 and was 44.9% in 2005. The median age at diagnosis is 69 years, with 62.4% of patients aged 65 or older at diagnosis. Median age at death is 75 years. The rate of new myeloma cases has been rising 0.7% per year during the past decade. The most common indication for autologous stem cell transplantation in the United States is multiple myeloma, and this article is designed to provide the specifics of organizing a transplant program for multiple myeloma. We review the data justifying use of stem cell transplantation as initial management in myeloma patients. We provide selection criteria that minimize the risks of transplantation. Specific guidelines on mobilization and supportive care through the transplant course, as done at Mayo Clinic, are given. A review of the data on tandem vs sequential autologous transplants is provided.

“…Abnormal karyotype had an unfavorable impact in the Total Therapy programs. 5 Because more sensitive techniques reveal CA in nearly all MM, karyotyping is not a routine test.…”

Section: Diagnostic Techniques For Camentioning

confidence: 99%

Treatment of multiple myeloma with high-risk cytogenetics: a consensus of the International Myeloma Working Group

Sonneveld

Avet-Loiseau

Lonial

et al. 2016

728

601

The International Myeloma Working Group consensus updates the definition for high-risk (HR) multiple myeloma based on cytogenetics Several cytogenetic abnormalities such as t(4;14), del(17/17p), t(14;16), t(14;20), nonhyperdiploidy, and gain(1q) were identified that confer poor prognosis. The prognosis of patients showing these abnormalities may vary with the choice of therapy. Treatment strategies have shown promise for HR cytogenetic diseases, such as proteasome inhibition in combination with lenalidomide/pomalidomide, double autologous stem cell transplant plus bortezomib, or combination of immunotherapy with lenalidomide or pomalidomide. Careful analysis of cytogenetic subgroups in trials comparing different treatments remains an important goal. Cross-trial comparisons may provide insight into the effect of new drugs in patients with cytogenetic abnormalities. However, to achieve this, consensus on definitions of analytical techniques, proportion of abnormal cells, and treatment regimens is needed. Based on data available today, bortezomib and carfilzomib treatment appear to improve complete response, progression-free survival, and overall survival in t(4;14) and del(17/17p), whereas lenalidomide may be associated with improved progression-free survival in t(4;14) and del(17/17p). Patients with multiple adverse cytogenetic abnormalities do not benefit from these agents. FISH data are implemented in the revised International Staging System for risk stratification.