Outcomes for patients with systemic light chain amyloidosis and Mayo stage 3B disease

Etiological Treatment of Cardiac Amyloidosis: Standard of Care and Future Directions

PURPOSE OF REVIEW

Cardiac amyloidosis (CA) is a condition caused by interstitial infiltration of misfolded proteins structured into amyloid fibrils. Transthyretin (ATTR) and immunoglobulin light chain (AL) amyloidosis represent the most common forms of CA. CA was traditionally perceived as a rare and incurable disease, but diagnostic and therapeutic advances have undermined the conventional paradigm.

RECENT FINDINGS

The standard of care for ATTR-CA include agents capable of selectively stabilizing the precursor protein (e.g., tafamidis), whereas the plasma cell clone is the main target of chemotherapy for AL-CA. For long, tafamidis represented the only drug approved for patients with ATTR-CA. Recent data from ATTRibute-CM led to the approval of acoramidis, whereas patisiran received refusal based on the APOLLO-B trial. Novel CRISPR-Cas9-based drugs (i.e., NTLA-2001) hold great potential in the setting of ATTR-CA. Several hematological regimens are available to treat AL-CA. The main limit of current therapies is their inability to trigger removal of amyloid from tissues. However, the investigation of monoclonal antibodies targeting misfolded ATTR (e.g., PRX004, NI301A) or AL (e.g., birtamimab, anselamimab) has led to encouraging results. Various cutting-edge strategies are being tested for treatment of CA and may change the prognostic landscape of this condition in the next years.

The Real-World Data on Patients With Cardiac Stage IIIb AL Amyloidosis

BACKGROUND

Morbidity and mortality of patients with immunoglobulin light chain (AL) amyloidosis are strongly associated with the severity of cardiac involvement, especial in patients with cardiac stage IIIb, but the real-world data on these patients is still limited.

PATIENTS AND METHODS

A retrospective analysis was conducted on 77 patients diagnosed with cardiac stage IIIb AL amyloidosis at our center. We analyzed the clinical characteristics, treatment and outcome of the patients.

RESULTS

The median age of patients was 57 years and 49.4% were male. Median serum N-terminal pro-brain natriuretic peptide (NT-proBNP) and cardiac troponin T (cTnT) were 13,384 ng/L and 0.166 ug/L, and 42 (54.5%) patients had heart failure at diagnosis. Fifty-seven (74.0%) patients received antiplasma cell treatment, and the main treatment options include bortezomib or thalidomide combined with dexamethasone. The hematologic overall response rate was 70% (28/40), and at 6-month landmark analysis, patients with hematologic responses had a higher survival rate. Cardiac and renal responses were achieved in 14 (37.8%) and 13 (32.5%) patients, respectively. After a median follow-up of 10 months (range 1-115 months), median overall survival (OS) was 18 months, and the estimated survival rates at 3, 6, and 12 months were 79.9%, 75.6%, and 54.5%, respectively. In Cox regression models, age, hypotension and cTnT were independently predictive of mortality after adjusting for heart failure.

CONCLUSION

The hematologic, cardiac and renal responses were relative lower in patients with cardiac stage IIIb AL amyloidosis. The overall prognosis of patients was poor, and age, hypotension, and cTnT can be used to predict mortality.

A real-life study of daratumumab combinations in newly diagnosed patients with light chain (AL) amyloidosis

Daratumumab-based regimens are the new standard of care for newly diagnosed patients with AL amyloidosis based on the results of the ANDROMEDA study. However, real-world data on daratumumab efficacy in upfront therapy in unselected patients are scanty. In the framework of a prospective observational study, we investigated the efficacy and safety of daratumumab in 88 newly diagnosed patients, including subjects with IIIb cardiac stage (26%) or myeloma defining events (29%). Daratumumab was administered with bortezomib in 50 (56%) patients, lenalidomide in 31 (35%), and monotherapy in 7 (8%). The rate of serious adverse events was low (16%). The overall hematologic response rate was 75% with 52 (59%) patients attaining at least a very good partial response (VGPR) at six months. Amongst patients evaluable for organ response, the rate of cardiac and renal responses at 6 months was 31% and 21%, respectively. Comparing stage IIIb patients with the remaining ones, the rate of profound hematologic response was not significantly different (≥VGPR 57% vs. 59%, p 0.955) likewise the rate of cardiac (33% vs. 30%, p 0.340) and renal (40% vs. 16%, p 0.908) responses. Daratumumab-based regimens demonstrated to be safe and effective in treatment-naïve AL amyloidosis even in advanced stage disease.

Monoclonal Gammopathy of Undetermined Cardiovascular Significance; Current Evidence and Novel Insights

Monoclonal gammopathy of undetermined significance (MGUS) is a premalignant condition characterized by the presence of low levels of a monoclonal protein in the serum and a low percentage of clonal plasma cells in the bone marrow. MGUS may progress to multiple myeloma or other plasma cell disorders at a rate of 1% annually. However, MGUS may also have adverse effects on the cardiovascular system independent of its malignant potential. Emerging data have shown that MGUS is associated with cardiovascular disease. The mechanisms underlying this association are not fully understood but may involve genetic abnormalities, vascular calcification, cryoglobulinemia, cold agglutinin disease, autoantibodies and the direct or indirect effects of the monoclonal protein on the vascular endothelium. Herein, we review current evidence in this field and we suggest that patients with MGUS may benefit from regular cardiovascular risk assessment to prevent severe cardiovascular complications, in parallel with close hematological follow-up to monitor potential disease progression.