Daratumumab is effective in the relapsed or refractory systemic light‐chain amyloidosis but associated with high infection burden in a frail real‐life population

A Review of Cardiac amyloidosis: Presentation, Diagnosis, and Treatment

Amyloidosis is a group of disorders that can affect almost any organ due to the misfolding of proteins with their subsequent deposition in various tissues, leading to various disease manifestations based on the location. When the heart is involved, amyloidosis can manifest with a multitude of presentations such as heart failure, arrhythmias, orthostatic hypotension, syncope, and pre-syncope. Diagnosis of cardiac amyloidosis can be difficult due to the non-specific nature of symptoms and the relative rarity of the disease. Amyloidosis can remain undiagnosed for years, leading to its high morbidity and mortality due to this delay in diagnosis. Newer imaging modalities, such as cardiac magnetic resonance imaging, advanced echocardiography, and biomarkers, make a timely cardiac amyloidosis diagnosis more feasible. Many treatment options are available, which have provided new hope for this patient population. This manuscript will review the pathology, diagnosis, and treatment options available for cardiac amyloidosis and provide a comprehensive overview of this complicated disease process.

Efficacy and safety of intravenous daratumumab-based treatments for AL amyloidosis: a systematic review and meta-analysis

BACKGROUND

Intravenous daratumumab (DARA IV) has been increasingly used in the treatment of amyloid light-chain (AL) amyloidosis. However, the outcomes for patients administered with DARA IV have not been aggregated. The objective of this systematic review and meta-analysis was to investigate the efficacy and safety of DARA IV for AL amyloidosis.

METHODS

We searched Medline, EMBASE, Cochrane Library and Web of Science up to 17 June 2021. Response rates and survival rates, and the corresponding 95% confidence intervals (CIs) were pooled and calculated using a fixed-effects model.

RESULTS

Thirty studies (5 cohort studies and 25 single-arm studies) with 997 patients were included. In patients receiving DARA IV-based treatments, very good partial response or better response rate, complete response rate, very good partial response rate, partial response rate and overall response rate were 66% (95% CI, 62-69%), 30% (95% CI, 23-36%), 40% (95% CI, 33-46%), 17% (95% CI, 14-21%), and 77% (95% CI, 73-80%), respectively. Cardiac and renal responses were 41% (95% CI, 34-49%) and 43% (95% CI, 32-54%), respectively. 58% (95% CI, 49-66%) of patients achieved PFS one year or longer. 2.5% (range, 1-10.0%) of patients experienced grade 3 or 4 adverse events, of which the most common adverse event was lymphocytopenia (range, 13.6-25.0%).

CONCLUSION

This study supports the efficacy and safety of DARA IV for the treatment of patients with AL amyloidosis.

Molecular Mechanism of Pathogenesis and Treatment Strategies for AL Amyloidosis

In amyloid light-chain (AL) amyloidosis, small B-cell clones (mostly plasma cell clones) present in the bone marrow proliferate and secrete unstable monoclonal free light chains (FLCs), which form amyloid fibrils that deposit in the interstitial tissue, resulting in organ injury and dysfunction. AL amyloidosis progresses much faster than other types of amyloidosis, with a slight delay in diagnosis leading to a marked exacerbation of cardiomyopathy. In some cases, the resulting heart failure is so severe that chemotherapy cannot be administered, and death sometimes occurs within a few months. To date, many clinical studies have focused on therapeutics, especially chemotherapy, to treat this disease. Because it is necessary to promptly lower FLC, the causative protein of amyloid, to achieve a hematological response, various anticancer agents targeting neoplastic plasma cells are used for the treatment of this disease. In addition, many basic studies using human specimens to elucidate the pathophysiology of AL have been conducted. Gene mutations associated with AL, the characteristics of amyloidogenic LC, and the structural specificity of amyloid fibrils have been clarified. Regarding the mechanism of cellular and tissue damage, the mass effect due to amyloid deposition, as well as the toxicity of pre-fibrillar LC, is gradually being elucidated. This review outlines the pathogenesis and treatment strategies for AL amyloidosis with respect to its molecular mechanisms.

Efficacy and Safety of Daratumumab-based Regimens in Pretreated Light Chain (AL) Amyloidosis: A Systematic Review

With recent advances in novel chemotherapeutic agents and increasing use of autologous hematopoietic stem cell transplant, there has been a significant improvement in outcomes for patients with AL Amyloidosis. Daratumumab, with its excellent safety and efficacy profile, appears to be an ideal treatment option for patients with newly diagnosed as well as relapsed refractory AL amyloidosis. In this systematic review, we analyzed the published literature on the role of Daratumumab in pretreated relapsed and refractory AL-amyloidosis patients using PubMed, Embase, Cochrane, and clinicaltrials.gov databases. A total of 16 studies evaluated the role of Daratumumab as monotherapy (DMT) or in combination with other chemotherapeutic agents (DCT). DMT and DCT were associated with promising efficacy with hematologic and organ responses (cardiac/renal) seen in 50%-90% and 50%-80% of the patients, respectively. Daratumumab appeared to be well tolerated with no significant treatment-related adverse events as DMT or DCT.

Daratumumab in AL Amyloidosis: A Real-Life Experience of the “RTM” (Regional Tuscan Myeloma Network)

Systemic amyloidosis arises from monoclonal CD38+ plasma cells that produce misfolded immunoglobulin light chains, which form amyloid fibrils that are deposited into different tissues, leading to organ damage. Daratumumab is a human IgG/k monoclonal antibody that targets CD38, a glycoprotein uniformly expressed on human plasma cells. Daratumumab has been utilized in recent years with unprecedented responses in multiple myeloma. In patients with relapsed or refractory AL amyloidosis, daratumumab has shown promising efficacy in terms of hematologic responses and improvement in organ function. Here, we report real-life treatment with Daratumumab in 33 AL amyloidosis patients treated within the Regional Tuscan Myeloma network at 5 centers with associated MGUS or SMM (n = 15) or symptomatic MM (n = 18). Patients were treated at relapsed/refractory disease stages (n = 29) with a median of one previous line of therapy or at diagnosis (n = 4). Daratumumab showed good efficacy, representing 60% of good hematological responses and 50% of organ responses in a real-life population of patients with an acceptable toxicity profile.

Predictive factors of outcomes in patients with AL amyloidosis treated with daratumumab

Daratumumab as a single agent (sDARA) or in combination with chemotherapies (cDARA) leads to impressive hematologic and organ responses in AL amyloidosis. However, predictive factors associated with outcomes, and optimal duration of therapy remain unclear. We analyzed 107 patients with AL amyloidosis treated with daratumumab between 2017 and 2020. The median overall survival (OS) was not reached while the median major organ deterioration progression free survival (MOD-PFS) was 36 months in the sDARA cohort and not reached in the cDARA cohort, respectively. Hematologic response > VGPR was achieved in 81% of patients receiving sDARA and 86% of patients treated with cDARA. Several predictive factors were identified on a univariate analysis, including NTproBNP >8500 pg/mL but only achievement of at least VGPR and presence of 1q21 gain were independently associated with MOD-PFS and OS on a multivariate analysis. Finally, patients receiving > 12 cycles had significantly longer MOD-PFS (30 vs.13 months; (p = .0018) and OS (NR vs. 15 months; p < .0001). NTproBNP > 8500 pg/mL, presence of 1q21 gain and shorter duration of therapy (≤ 12 cycles) are strong negative predictive factors for outcomes with daratumumab therapy in AL amyloidosis.

Progress in research: Daratumumab improves treatment outcomes of patients with AL amyloidosis

Outcomes for patients with systemic light-chain (AL) amyloidosis have improved over the last two decades with timely diagnosis, use of novel chemotherapeutic agents, risk stratification and better patient selection criteria before hematopoietic autologous stem cell transplant (ASCT). However, majority of patients have advanced stage disease at initial presentation and at relapse rendering them ineligible for intensive cytotoxic chemotherapy or ASCT. Daratumumab (Dara) with or without standard chemotherapy appears to be an excellent treatment option for newly diagnosed and relapsed refractory AL amyloidosis. This is largely due to its tolerable safety and remarkable efficacy as seen in multiple retrospective, small phase II studies as well as a phase III randomized controlled trial. Here we review published clinical trials and retrospective data of Dara in AL amyloidosis that explore its role as a valuable addition to the treatment armamentarium for this challenging disease.

Daratumumab in combination with proteasome inhibitors, rapidly decreases polyclonal immunoglobulins and increases infection risk among relapsed multiple myeloma patients: a single center retrospective study

Background

Daratumumab (Dara) is generally well tolerated, but is associated with increased risk of infection.

Methods

We investigated hypogammaglobinemia occurrence in different Dara-based regimens. Multiple myeloma (MM) patients were treated with ⩾2 cycles of Dara-based therapy during 2016-2020, mainly for relapsed/refractory disease. Data on patient characteristics, treatment regimens, polyclonal IgG (poly-IgG) and uninvolved free light chain (Un-FLC) levels during treatment, as well as predictors for hypogammaglobinemia and predictors for infections, were evaluated retrospectively.

Results

A total of 84 patients, median age 67.2 years, were included. Dara, mainly as ⩾2 line therapy (88.1%, n = 74), was combined with immunomodulating drugs (IMiDs) (53%), proteasome inhibitors (PIs) (15%), IMiDs-PIs (11%), or dexamethasone only (21%). Median treatment duration was 13 months. Median Poly-IgG levels at 0, 2, and 4 months were 7.1 g/l, 4.5 g/l, and 4 g/l, respectively, and remained low throughout treatment. Lower poly-IgG pre-Dara (p = 0.001) and Dara-PIs (±IMiDs) regimen were associated with lower poly-IgG levels at 4 months (p = 0.03). Only patients treated with Dara monotherapy had partial immune reconstitution, reflected by resumption of IgM levels. Most (85%) patients developed ⩾1 infections, mostly grade 1-2 respiratory (76%). A lower poly-IgG level post Dara (RR = 1.137 p = 0.026) predicted increased risk of any infection. Intravenous immunoglobulin (IVIG) was associated with a significant decrease in all infections.

Conclusion

Relapsed MM patients treated with Dara, often experience persistent hypogammaglobinemia, irrespective of responsiveness to treatment. Infections, especially respiratory, are frequent and apparently related to low Poly-IgG levels. IVIG should be considered for reducing infections in these patients.

Daratumumab: Beyond Multiple Myeloma

Daratumumab (DARA) is the biological name of an Immunoglobulin G1k human monoclonal antibody. DARA the first-in-class therapy targeting CD38 expressing- plasma cells (PC) and plasma blasts. It has been approved for the treatment of multiple myeloma. It is also being examined in the setting of other hematologic malignancies. As DARA targets PCs, it could potentially be used to treat many other disease processes that are antibody mediated. In fact, several case reports and case series report experiences of using DARA to treat a variety of antibody-mediated disorderss. The aim of this review is to present a summary of the literature thus far regarding the application of DARA beyond its uses in multiple myeloma and other hematologic diseases. Specifically, we address uses of DARA as an immunologic modulator in various antibody mediated processes.

Treatment of AL Amyloidosis: Mayo Stratification of Myeloma and Risk-Adapted Therapy (mSMART) Consensus Statement 2020 Update

Immunoglobulin light chain (AL) amyloidosis is a clonal plasma cell disorder leading to progressive and life-threatening organ failure. The heart and the kidneys are the most commonly involved organs, but almost any organ can be involved. Because of the nonspecific presentation, diagnosis delay is common, and many patients are diagnosed with advanced organ failure. In the era of effective therapies and improved outcomes for patients with AL amyloidosis, the importance of early recognition is further enhanced as the ability to reverse organ dysfunction is limited in those with a profound organ failure. As AL amyloidosis is an uncommon disorder and given patients' frailty and high early death rate, management of this complex condition is challenging. The treatment of AL amyloidosis is based on various anti-plasma cell therapies. These therapies are borrowed and customized from the treatment of multiple myeloma, a more common disorder. However, a growing number of phase 2/3 studies dedicated to the AL amyloidosis population are being performed, making treatment decisions more evidence-based. Supportive care is an integral part of management of AL amyloidosis because of the inherent organ dysfunction, limiting the delivery of effective therapy. This extensive review brings an updated summary on the management of AL amyloidosis, sectioned into the 3 pillars for survival improvement: early disease recognition, anti-plasma cell therapy, and supportive care.

Comprehensive Review of AL amyloidosis: some practical recommendations

Amyloid light chain (AL) amyloidosis is among the more common and more severe of the amyloidoses usually involving the slow proliferation of a bone-marrow-residing plasma cell (PC) clone and the secretion of unstable immunoglobulin-free light chains (FLC) that infiltrate peripheral tissues and result in detrimental end-organ damage. Disease presentation is rather vague, and the hallmark of treatment is early diagnosis before irreversible end-organ damage. Once diagnosed, treatment decision is transplant-driven whereby ~20% of patients are eligible for autologous stem cell transplantation (ASCT) with or without bortezomib-based induction. In the setting of ASCT-ineligibility, bortezomib plays a central role in upfront treatment with the recent addition of daratumumab to the current emerging standard of care. In general, management of AL amyloidosis is aimed at achieving deep, durable responses with very close monitoring for early detection of relapse/refractory disease. This article provides a comprehensive review of the management of patients with AL amyloidosis including goals of therapy, current treatment guidelines in the setting of both ASCT-eligibility and ineligibility, treatment response monitoring recommendations, toxicity management, and treatment of relapse/refractory disease.

Daratumumab in the Treatment of Light-Chain (AL) Amyloidosis

Systemic light-chain (AL) amyloidosis is caused by a small B cell, most commonly a plasma cell (PC), clone that produces toxic light chains (LC) that cause organ dysfunction and deposits in tissues. Due to the production of amyloidogenic, misfolded LC, AL PCs display peculiar biologic features. The small, indolent plasma cell clone is an ideal target for anti-CD38 immunotherapy. A recent phase III randomized study showed that in newly diagnosed patients, the addition of daratumumab to the standard of care increased the rate and depth of the hematologic response and granted more frequent organ responses. In the relapsed/refractory setting, daratumumab alone or as part of combination regimens gave very promising results. It is likely that daratumumab-based regimens will become new standards of care in AL amyloidosis. Another anti-CD38 monoclonal antibody, isatuximab, is at an earlier stage of development as a treatment for AL amyloidosis. The ability to target CD38 on the amyloid PC offers new powerful tools to treat AL amyloidosis. Future studies should define the preferable agents to combine with daratumumab upfront and in the rescue setting and assess the role of maintenance. In this review, we summarize the rationale for using anti-CD38 antibodies in the treatment of AL amyloidosis.

A prospective phase 2 trial of daratumumab in patients with previously treated systemic light-chain amyloidosis

Daratumumab is a human monoclonal antibody targeting CD38, an antigen uniformly expressed by plasma cells in multiple myeloma and light-chain amyloidosis (AL). We report the results of a prospective multicenter phase 2 study of daratumumab monotherapy in AL (NCT02816476). Forty previously treated AL patients with a difference between involved and uninvolved free light chains (dFLC) >50 mg/L were included in 15 centers between September of 2016 and April of 2018. Patients received 6 28-day cycles of IV daratumumab, every week for cycles 1 and 2 and every 2 weeks for cycles 3 through 6. Median age was 69 years (range, 45-83). Twenty-six patients had ≥2 organs involved, with heart in 24 and kidney in 26. Median time from diagnosis to enrollment was 23 months (interquartile range, 4-122), with a median of 3 prior therapies (range, 1-5). At data cutoff (September of 2019), all patients discontinued therapy; 33 received the planned 6 cycles. Overall, 22 patients had hematological response, and 19 patients (47.5%) achieved very good partial response (dFLC <40 mg/L) or better. Median time to hematological response was 1 week. Patients with no response after 4 doses were unlikely to respond further. Renal and cardiac responses occurred in 8 and 7 patients, respectively. Daratumumab was well tolerated, with no unexpected adverse events. With a median follow-up of 26 months, the 2-year overall survival rate was 74% (95% confidence interval, 62-81). Daratumumab monotherapy is associated with deep and rapid hematological responses in previously treated AL patients, with a good safety profile. Further studies of daratumumab in combination regimens are warranted.

Updates in the Diagnosis and Management of AL Amyloidosis

PURPOSE OF REVIEW

Light chain (AL) amyloidosis is an insidious progressive disease which results in significant morbidity and inevitable mortality if not diagnosed and treated promptly. This review will highlight recent developments and summarize critical clinical points and updated practice changes for the clinician in 2020.

RECENT FINDINGS

Comparative analyses of staging systems, updated prognostic tools, and treatment response criteria now allow for improved patient stratification and treatment decisions; the role of minimal residual disease in response assessment is still being assessed. Clinical and genetic predictors for long-term survivors have been highlighted. Standard-of-care front-line bortezomib and the integration of anti-CD38 monoclonal antibodies in the relapsed disease have transformed treatment approach in recent years. Various clinical trials in the pipeline include novel anti-plasma cell therapies and therapies directed against amyloid deposits which promise to further advance the treatment landscape. Diagnosis, response assessment, and treatment paradigms for AL amyloidosis have evolved significantly in the past 15 years, translating into superior outcomes and increased chances of long-term survival for AL amyloidosis.

Daratumumab for relapsed AL amyloidosis-When cumulative real-world data precedes clinical trials: A multisite study and systematic literature review

OBJECTIVES

Patients with relapsed/refractory AL amyloidosis (RRAL) have poor prognosis, but emerging data shows promising results with the use daratumumab. We evaluated daratumumab treatment in RRAL in real-world setting.

METHODS

A retrospective multisite study of RRAL patients treated with daratumumab alone and in combinations.

RESULTS

Forty-nine patients, diagnosed between 1.1.2008 and 1.2.2018 were included; 27% also had multiple myeloma (MM). Revised Mayo score was ≥ 3 in 67%. Hematologic overall response rate was 81%, 64% achieved very good partial response (VGPR) or better. Concurrent active MM was associated with lower rates of VGPR (OR 0.19, 95% CI 0.04-0.81; P = .03) in a multi-variate analysis. Cardiac and renal responses were 74% and 73%, respectively. Median progression-free survival (PFS) was 28.4 months and median overall survival (OS) was not reached; 2-year PFS and OS were 68.6 ± 7.5% and 90.4 ± 4.6%, respectively. Hematologic response correlated with prolonged PFS and OS. Daratumumab was safe and well tolerated, no patients discontinued therapy due to toxicity. Our data was aligned with outcomes from a systematic literature review, which identified 10 case series (n = 517) and 2 clinical trials (n = 62) meeting prespecified criteria.

CONCLUSIONS

Our data support favorable safety tolerability and efficacy of daratumumab among non-selective RRAL patients in a real-world setting.

Treatment with daratumumab in patients with relapsed/refractory AL amyloidosis: a multicentric retrospective study and review of the literature

Management of patients with relapsed or refractory (R/R) AL amyloidosis is complex. Some initial reports have shown positive results with daratumumab in heavily pre-treated AL amyloidosis patients. In this retrospective multicentric study, 38 patients (mean age 64 ± 9 years) with R/R AL amyloidosis treated with daratumumab were included. Cardiac and renal involvement was present in 76 and 74% of patients, and 42% had ≥3 organs involved. Median number of previous lines of therapy was 2 (range 1-8). Overall hematological response was 72%, including 28% complete responses. The median time to first hematological response was 2 weeks. A high-quality response (≥very good partial response) was obtained in 65% of patients who had never achieved such depth of response previously. Hematological responses were more frequent among patients receiving daratumumab as second-line therapy compared to subsequent therapies (92 vs. 61%). Cardiac and renal organ response rates were 37 and 59%. At 12 months, overall and progression-free survival were 59% (95%CI: 0.36-0.77) and 52% (95%CI: 0.29-0.70), respectively. Daratumumab is a safe and effective drug in the treatment of R/R AL amyloidosis and should be considered early in the course of the disease.

Daratumumab for systemic AL amyloidosis: prognostic factors and adverse outcome with nephrotic-range albuminuria

Daratumumab has shown promising first results in systemic amyloid light-chain (AL) amyloidosis. We analyzed a consecutive series of 168 patients with advanced AL receiving either daratumumab/dexamethasone (DD, n = 106) or daratumumab/bortezomib/dexamethasone (DVD, n = 62). DD achieved a remission rate (RR) of 64% and a very good hematologic remission (VGHR) rate of 48% after 3 months. Median hematologic event-free survival (hemEFS) was 11.8 months and median overall survival (OS) was 25.6 months. DVD achieved a 66% RR and a 55% VGHR rate. Median hemEFS was 19.1 months and median OS had not been reached. Cardiac organ responses were noted in 22% with DD and 26% with DVD after 6 months. Infectious complications were common (Common Terminology Criteria [CTC] grade 3/4: DD 16%, DVD 18%) and likely related to a high rate of lymphocytopenia (CTC grade 3/4: DD 20%, DVD 17%). On univariable analysis, hyperdiploidy and gain 1q21 conferred an adverse factor for OS and hemEFS with DD, whereas translocation t(11;14) was associated with a better hemEFS. N-terminal prohormone of brain natriuretic peptide &gt;8500 ng/L could not be overcome for survival with each regimen. Multivariable Cox regression analysis revealed plasma cell dyscrasia (difference between serum free light chains [dFLC]) &gt;180 mg/L as an overall strong negative prognostic factor. Additionally, nephrotic-range albuminuria with an albumin-to-creatinine-ratio (ACR) &gt;220 mg/mmol was a significantly adverse factor for hemEFS (hazard ratio, 2.1 and 3.1) with DD and DVD. Daratumumab salvage therapy produced good results and remission rates challenging any therapy in advanced AL. Outcome is adversely influenced by the activity of the underlying plasma cell dyscrasia (dFLC) and nephrotic-range albuminuria (ACR).

Roles of CD38 in the Immune Response to Infection

CD38 is a multifunctional protein widely expressed in cells from the immune system and as a soluble form in biological fluids. CD38 expression is up-regulated by an array of inflammatory mediators, and it is frequently used as a cell activation marker. Studies in animal models indicate that CD38 functional expression confers protection against infection by several bacterial and parasitic pathogens. In addition, infectious complications are associated with anti-CD38 immunotherapy. Although CD38 displays receptor and enzymatic activities that contribute to the establishment of an effective immune response, recent work raises the possibility that CD38 might also enhance the immunosuppressive potential of regulatory leukocytes. This review integrates the current knowledge on the diversity of functions mediated by CD38 in the host defense to infection.