Predictors of hematologic response and survival with stem cell transplantation in AL amyloidosis: a 25-year longitudinal study

Autologous stem cell transplantation in AL amyloidosis: Muddy waters

Immunoglobulin light chain (AL) amyloidosis is a malignant plasma cell dyscrasia causing multi-organ morbidity. High dose melphalan and autologous stem cell transplantation (ASCT) is a preferred consolidation approach and is safe with improved patient selection criteria. With the advent of bortezomib and daratumumab based induction therapy, nearly all patients can achieve deep hematological responses but follow up for daratumumab based induction is short. Consequently, the traditional approach of induction followed by ASCT is called into question. Given the multi-organ involvement of AL, endpoints beyond depth of response and hematological progression free survival (PFS) are important. Major organ dysfunction PFS (MOD-PFS) adds to PFS and is a composite endpoint of PFS, renal and cardiac organ progression, and overall survival. It is currently unknown which consolidative approach (ASCT or non-ASCT) will generate improved outcomes across the MOD-PFS spectrum a question the recently opened S2213 trial will attempt to answer.

HOVON 104, long-term follow-up of bortezomib-dexamethasone induction therapy followed by autologous stem cell transplantation in newly diagnosed AL amyloidosis patients

The HOVON 104 studied bortezomib-dexamethasone induction therapy and autologous stem cell transplantation in 50 patients, of whom 35 received an autologous stem cell transplantation (ASCT). We demonstrate a 5-year overall survival (OS) of 73% and progression-free survival (PFS) of 52% for all 50 patients with a median follow-up of 61.3 months. For the 35 transplanted patients, calculated from the date of ASCT, the 5-year OS and PFS were 91% and 68%, respectively. After ASCT, the rate of organ response improved over time but stabilized around 3 years. A complete cardiac response was seen in around 60% of patients and remained stable from 2 years onward. Reaching complete renal response was slower over time and achieved by 61% of the renal-affected patients at 5 years. We confirm the excellent outcomes after ASCT and demonstrate a 60% complete organ response with longer follow-up.

Treatment of AL amyloidosis in the era of novel immune and cellular therapies

Light chain (AL) amyloidosis is a plasma cell disorder distinguished from multiple myeloma (MM) by the degree of organ involvement due to tissue deposition of misfolded proteins. Treatments for AL amyloidosis have largely been borrowed from those developed for patients with MM. High-dose chemotherapy followed by autologous stem cell transplant (ASCT) has historically been associated with the best outcomes. The recent incorporation of daratumumab into up front therapy represents a significant advance and has changed the treatment paradigm, calling into question the role of ASCT. The development of very active novel immune and cellular therapies, specifically B cell maturation antigen (BCMA)-directed therapies, has similarly been transformative for patients with MM and is now being studied in patients with AL amyloidosis. These include chimeric antigen receptor (CAR) T cells, bispecific antibodies, and antibody drug conjugates. Although limited, preliminary data in patients with relapsed and refractory AL amyloidosis are showing promising results, and it is expected that the treatment landscape for AL amyloidosis will continue to evolve. Particular attention to safety, potential for organ recovery, and quality of life will be important when evaluating new treatments and/or treatment paradigms.

Abnormal global longitudinal strain and reduced serum inflammatory markers in cardiac AL amyloidosis patients without significant amyloid fibril deposition

Background

Cardiac dysfunction in AL amyloidosis is thought to be partly related to the direct impact of AL LCs on cardiomyocyte function, with the degree of dysfunction at diagnosis as a major determinant of clinical outcomes. Nonetheless, mechanisms underlying LC-induced myocardial toxicity are not well understood.

Methods

We identified gene expression changes correlating with human cardiac cells exposed to a cardiomyopathy-associated κAL LC. We then sought to confirm these findings in a clinical dataset by focusing on clinical parameters associated with the pathways dysregulated at the gene expression level.

Results

Upon exposure to a cardiomyopathy-associated κAL LC, cardiac cells exhibited gene expression changes related to myocardial contractile function and inflammation, leading us to hypothesize that there could be clinically detectable changes in GLS on echocardiogram and serum inflammatory markers in patients. Thus, we identified 29 patients with normal IVSd but abnormal cardiac biomarkers suggestive of LC-induced cardiac dysfunction. These patients display early cardiac biomarker staging, abnormal GLS, and significantly reduced serum inflammatory markers compared to patients with clinically evident amyloid fibril deposition.

Conclusion

Collectively, our findings highlight early molecular and functional signatures of cardiac AL amyloidosis, with potential impact for developing improved patient biomarkers and novel therapeutics.

Risk factors, treatments and outcomes of patients with light chain amyloidosis who relapse after autologous stem cell transplantation

Relapse after ASCT is an important factor affecting the long-term prognosis of patients with AL amyloidosis. However, the risk factors of relapse are unknown and there are limited studies on treatment outcomes of these patients. We retrospectively reviewed 170 patients with AL amyloidosis who underwent ASCT between 2010 and 2021. Seventy-six patients confirmed as relapse and the median time from ASCT to relapse was 39 months. On multivariate analysis of variables before and after ASCT, lambda restricted, dFLC >30 mg/L pre ASCT, reduced dose melphalan and dFLC >10 mg/L at 6 months after ASCT were independent risk factors for relapse, and achieving CR after induction therapy and renal response after ASCT were protective factors. Most relapsed patients were treated with bortezomib-based regimens (50%) followed by daratumumab-based regimens (22.2%) and other chemotherapy regimens (13.9%). The overall hematological response in evaluable patients was 68.2% with 56.8% achieving CR/VGPR. The median PFS and OS from post-transplant relapse were 25 months and 81 months, respectively. Patients receiving bortezomib or daratumumab showed a better survival compared to other chemotherapy regimens. In conclusion, this study identified independent risk factors of post-transplant relapse and demonstrated the superiority of bortezomib or daratumumab treatment for these patients. CLINICAL TRIAL REGISTRATION: NCT04210791.

Immunoglobulin light chain amyloidosis: 2024 update on diagnosis, prognosis, and treatment

DISEASE OVERVIEW

Immunoglobulin light chain amyloidosis is a clonal, nonproliferative plasma cell disorder in which fragments of immunoglobulin light or heavy chain are deposited in tissues. Clinical features depend on organs involved but can include heart failure with preserved ejection fraction, nephrotic syndrome, hepatic dysfunction, peripheral/autonomic neuropathy, and "atypical smoldering multiple myeloma or MGUS."

DIAGNOSIS

Tissue biopsy stained with Congo red demonstrating amyloid deposits with apple-green birefringence is required for the diagnosis of AL amyloidosis. Organ biopsy is not required in 85% of patients. Verification that amyloid is composed of immunoglobulin light chains is mandatory. The gold standard is laser capture mass spectroscopy.

PROGNOSIS

N-terminal pro-brain natriuretic peptide (NT-proBNP or BNP), serum troponin T(or I), and difference between involved and uninvolved immunoglobulin free light chain values are used to classify patients into four stages; 5-year survivals are 82%, 62%, 34%, and 20%, respectively.

THERAPY

All patients with a systemic amyloid syndrome require therapy to prevent deposition of amyloid in other organs and prevent progressive organ failure. Current first-line therapy with the best outcome is daratumumab, bortezomib, cyclophosphamide, and dexamethasone. The goal of therapy is a ≥VGPR. In patients failing to achieve this depth of response options for consolidation include pomalidomide, stem cell transplantation, venetoclax, and bendamustine.

FUTURE CHALLENGES

Delayed diagnosis remains a major obstacle to initiating effective therapy prior to the development of end-stage organ failure. Trials of antibodies to deplete deposited fibrils are underway.

Resolution of Cardiac Infiltration Following Autologous Stem Cell Transplantation for AL Amyloidosis

A 43-year-old man presented with severe heart failure secondary to high-risk light chain cardiac amyloidosis. He underwent chemotherapy and autologous stem cell transplantation with complete hematologic response. Serial cardiac magnetic resonance imaging post-transplant demonstrated gradual normalization of biventricular function and myocardial T1, a surrogate measure of disease burden.

Safety and Efficacy of Propylene Glycol-Free Melphalan in Patients with AL Amyloidosis Undergoing Autologous Stem Cell Transplantation: Results of a Phase II Study

Patients with systemic light chain (AL) amyloidosis undergoing treatment with high-dose melphalan and autologous stem cell transplantation (HDM/SCT) may develop renal and cardiac toxicities potentially exacerbated by the co-solvent propylene glycol in conventional melphalan formulations. We investigated the safety and efficacy of propylene glycol-free melphalan (PGF-Mel) during HDM/SCT in patients with AL amyloidosis (ClinicalTrials.gov identifier NCT02994784). The primary objective of this phase II, open-label study was evaluation for renal dysfunction, new cardiac arrhythmias, and postural hypotension related to autonomic dysfunction. Secondary objectives included time to neutrophil and platelet engraftment, treatment-related mortality (TRM), overall hematologic response, organ response, and number of peritransplantation hospitalizations. Twenty-eight patients with AL amyloidosis enrolled, of whom 27 underwent HDM/SCT. PGF-Mel at 140 to 200 mg/m2 was administered i.v. in 2 equally divided doses. Patients were monitored for up to 30 days after the last administration of PGF-Mel to assess for treatment-related toxicity. Patients were followed for 12 months from the time of treatment with HDM/SCT for evaluation of hematologic and organ responses. Kaplan-Meier analysis was used to estimate progression-free survival. Two patients (7%) developed renal dysfunction, 5 (19%) experienced new cardiac arrhythmias, and 3 (11%) developed orthostatic hypotension. All patients achieved neutrophil and platelet engraftment, at a median of 10 days and 17 days post-HDM/SCT, respectively. TRM on day +100 was 0%. Peritransplantation hospitalization was required for 23 patients (85%). The most common nonhematologic adverse events were diarrhea (93%), fatigue (82%), and nausea (74%). At 6 months post-HDM/SCT, hematologic complete response or very good partial response occurred in 66% of the patients. At 12 months post-HDM/SCT, renal response occurred in 12 of 23 (52%) patients with renal involvement, and cardiac response occurred in 3 of 11 (27%) patients with evaluable cardiac involvement. Our data indicate that PGF-Mel is safe and efficacious as a high-dose conditioning regimen for autologous SCT in patients with AL amyloidosis.

Role of autologous haematopoietic cell transplantation in the treatment of systemic light chain amyloidosis in the era of anti-CD38 monoclonal antibodies

The primary goal of the initial treatment in systemic light chain amyloidosis is to obtain a rapid and profound haematological response as safely as possible, coupled with supportive care by a multidisciplinary team. The treatment landscape has evolved with the introduction of highly effective therapies targeting the plasma cell clones, which can attain high rates of haematological complete response with minimal treatment-related morbidity and mortality. Consequently, the role of high-dose melphalan followed by autologous haematopoietic cell transplantation (HDM-AHCT) is being analysed, particularly considering the absence of randomised controlled trial data supporting its superiority over standard-dose therapies in systemic light chain amyloidosis treatment. In this Viewpoint, we will explore the role of HDM-AHCT in the management of patients with systemic light chain amyloidosis who are eligible for transplantation, and the unresolved questions surrounding HDM-AHCT use as both front-line and salvage therapy.

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.