Autologous Stem Cell Transplant for Immunoglobulin Light Chain Amyloidosis Patients Aged 70 to 75

Systemic AL amyloidosis: current approach and future direction

Systemic Light chain (AL) amyloidosis is a monoclonal plasma cell proliferative disorder characterized by deposition of amyloidogenic monoclonal light chain fragments causing organ dysfunction. It is a fatal disease and if not diagnosed and treated early can lead to organ failure and potentially death. The renal system along with the cardiovascular system are the most common organs involved but other organs such as gut and liver can be involved as well. The initial evaluation of patients requires confirming the diagnosis with tissue biopsy and staining with Congo red followed by confirmatory typing with mass spectrometry of the Congo red positive tissue. Then establishing the extent of the organs involvement by various staging and biomarkers testing. The treatment options and the tolerability of therapy depend on the disease staging, frailty, and co-morbidities. The autologous hematopoietic cell transplantation (HCT) after high dose melphalan therapy is an effective strategy which is usually done after initial bortezomib induction therapy. Unfortunately, most systemic AL amyloidosis patients are not candidate for HCT due to frailty, old age, multi-organ involvement, renal and heart failure at the time of diagnosis. While it is widely accepted that the patients need to be treated until they achieve complete hematologic response, the maintenance therapy after HCT is not well established in AL amyloidosis. In this review, we report the literature on the latest treatment updates of AL amyloidosis and the ongoing clinical trials highlighting the future treatments.

AL amyloidosis clonal plasma cells are regulated by microRNAs and dependent on anti-apoptotic BCL2 family members

BACKGROUND

Noncoding RNAs such as microRNAs (miRNAs) have attracted attention as biological pathway regulators, which differ from chromosomal translocations and gene point mutations. Their involvement in the molecular mechanisms underlying light chain (AL) amyloidosis pathogenesis is yet to be elucidated.

AIMS

To decipher specific miRNA expression profile in AL-amyloidosis and to examine how miRNAs are involved in AL pathogenesis.

METHODS

The expression profile of miRNAs and mRNA from bone marrow (BM)-derived CD138+ cells were determined using the NanoString nCounter assay and RNA-Seq, respectively. The effect of aberrantly expressed miRNAs on potential molecular targets was analyzed by qRT-PCR, Western blot, Mito-potential assay, and Annexin-PI staining.

RESULTS

Genes which were significantly differentially expressed between AL-amyloidosis and MM, were found to be involved in cell growth and apoptotic mechanisms. Specifically, BCL2L1, MCL1, and BCL2 were upregulated in AL-amyloidosis compared with MM and controls. The levels of miR-181a-5p and miR-9-5p, which regulate the above-mentioned genes, were lower in BM samples from AL-amyloidosis compared with controls, providing a mechanism for BCL2 family gene upregulation. When miR-9-5p and miR-181a-5p were overexpressed in ALMC1 cells, BCL2L1, MCL1, and BCL2 were downregulated and induced apoptosis. Treatment of ALMC-1 cells with venetoclax, (BCL-2 inhibitor), resulted in the upregulation of those miRNAs, the downregulation of BCL2, MCL1, and BCL2L1 mRNA and protein levels, and subsequent apoptosis.

CONCLUSION

Our findings suggest that miR-9-5p and miR-181a-5p act as tumor-suppressors whose downregulation induces anti-apoptotic mechanisms underlying the pathogenesis of AL-amyloidosis. The study highlights the post-transcriptional regulation in AL-amyloidosis and provides pathogenetic evidence for the potential use of BCL-2 inhibitors in this disease.

Single Center Experience of Autologous Stem Cell Transplantation in Patients with Systemic Light Chain Amyloidosis in Korea

BACKGROUND

Systemic light chains is the most common systemic amyloidosis. In patients with AL amyloidosis, the prognosis is influenced by the extent of organ damage, especially cardiac involvement. Autologous stem cell transplantation (ASCT) is a highly effective treatment for AL amyloidosis for selective patient METHODS: One hundred patients treated with ASCT for AL amyloidosis were reviewed in the Samsung Medical Center amyloidosis cohort. The cardiac, renal, and hematologic response was analyzed, and survival results compared based on organ involvement and hematologic response.

RESULTS

The most common involved organ was kidney (n = 62) followed by heart (n = 50). The organ response rate was 44.0% and 37.1% in the patients with cardiac and renal involvement, respectively. In hematologic response, overall response rate (ORR) was 79.0%, including 48.0% complete response (CR). Median overall survival (OS) in patients with and without hematologic CR were not reached and 64.2 months (95% CI, 19.5 to 109.0), respectively (P < .001). The survival rate was not significantly different between patients with or without cardiac or renal involvement. Treatment-related mortality (TRM) in 30 days and 100 days was 2.0% and 3.0%, respectively.

CONCLUSIONS

ASCT is an effective treatment option for eligible patients with AL amyloidosis. Achieving hematologic CR is essential for long-term survival.

A safety review of drug treatments for patients with systemic immunoglobulin light chain (AL) amyloidosis

INTRODUCTION

In AL amyloidosis, a usually small plasma cell clone secretes unstable, amyloid-forming light chains, causing cytotoxicity and progressive (multi)organ function deterioration. Treatment aims at reducing/eradicating the underlying clone, to reduce/zero the supply of the amyloidogenic protein and halt the amyloidogenic cascade.

AREAS COVERED

Safety data of alkylating agents, proteasome inhibitors, immunomodulatory drugs, and monoclonal antibodies from clinical trials are reviewed.

EXPERT OPINION

Drugs used to treat AL amyloidosis are derived from experience with multiple myeloma or other B cell malignancies. However, treating AL amyloidosis is particularly challenging, as it implies delivering anti-neoplastic therapy to a hematologic malignancy directly causing (multi)organ function deterioration, often in elderly subjects with other comorbidities and polypharmacotherapy. This unique combination translates in increased patients' frailty and higher sensitivity toward treatment-related toxicities. Therefore, dose/schedule adjustments and special precautions are needed when translating treatment experience from multiple myeloma or other B cell malignancies to AL amyloidosis. Treatment of patients with AL amyloidosis should be risk adapted, tailored to individual patients' risk profile, considering the type and extent of organ involvement, and eventual comorbidity. As several classes of effective anti-plasma cell or B cell drugs are available, therapeutic choices are also influenced by individual drug's safety profile.

Treatment of AL amyloidosis

AL amyloidosis is caused by the conversion of monoclonal immunoglobulin light chains into amyloid fibrillar aggregates that deposit in tissue and lead to organ dysfunction. Diagnosis is histological and relies primarily on non-invasive biopsies, showing Congo red-positive amorphous deposits containing immunoglobulin light chains, most commonly of lambda isotype. The clinical presentation is extremely polymorphous, due to the large number of organs that can be affected by the disease. The kidneys and the heart are most frequently involved organs, in about two thirds of patients each, responsible for nephrotic syndrome and restrictive cardiomyopathy. Treatment is based on chemotherapy aimed at eliminating the medullary clone producing the pathogenic monoclonal light chains. It is guided by risk assessment, based on the serum levels of cardiac biomarkers. Its effectiveness must be regularly assessed by the serum free light chain assay. Current reference regimens combine an alkylating agent, with high doses of dexamethasone and most often a proteasome inhibitor. They are effective in the majority of patients. The overall prognosis depends on the importance of the initial severity of organ involvement, particularly the heart, and is strongly influenced by the haematological response. The treatment must be rapidly modified in non-responders, especially in those with severe cardiac disease, with the introduction of immunomodulatory drugs and antibodies targeting plasma cells. However, effective therapies for patients with the more severe amyloid cardiopathy are an unmet need. Strategies directly accelerating the removal of amyloid deposits, despite disappointing preliminary results, could further improve the prognosis of this disease.