ABSTRACT
Immunoglobin light chain (AL) amyloidosis is a rare disease characterized by organ deposition of amyloid fibrils, most commonly in the heart and kidney. Disease heterogeneity necessitates organ-specific assessment to determine prognosis and response or progression. To facilitate development of new therapies, the Amyloidosis Forum (a public-private partnership between the US Food and Drug Administration and the nonprofit Amyloidosis Research Consortium) held a series of meetings and formed multiple working groups to identify clinical trial end points and analytic strategies. This report summarizes the recommendations of Renal Working Group. Estimated glomerular filtration rate (eGFR) and proteinuria were selected to evaluate eligibility, response, and/or progression in the context of investigational clinical trials for patients with AL amyloidosis. Accurate response assessments at the earliest possible time point were emphasized. The context of use, specific patient population, and the investigational therapeutic mechanism should ultimately drive selection of appropriate end points to evaluate renal response/progression in AL amyloidosis clinical trials.
ABSTRACT
BACKGROUND: Therapeutic plasma exchange (TPE) removes both pathologic and protective immunoglobulins (Ig). SARS-CoV-2 immunity is partially mediated by anti-SARS-CoV-2 spike antibodies (SAb), which impair viral host-cell invasion. Nonetheless, the systematic effect of TPE on SAb concentration and SARS-CoV-2 immunity is unknown. METHODS: Paired plasma waste specimens from the first (first-TPE) and last (last-TPE) TPE treatment were collected from 9 patients between July 21, 2021 and March 1, 2022. The effects of TPE on Ig levels were assessed by quantitatively comparing the SAb, total IgG, and total IgM levels first-/last-TPE treatment. Complementary qualitative assessment for these changes was achieved via protein electrophoresis (PEP) and immunofixation (IFE). A retrospective review was performed to investigate the incidence of new SARS-CoV-2 infections following TPE v. other treatment at the same outpatient apheresis/infusion center during the same time frame. RESULTS: Median SAb levels between the first- and last-TPE waste specimens decreased significantly from 424.6 AU/mL to 17.0 AU/mL (P = 0.004). Concordantly, PEP and IFE analysis demonstrated broad Ig decreases. Cumulative incidence of subsequent COVID-19 diagnosis at 30, 90, and 180 days post-procedure did not differ between the TPE v. other treatment groups (n = 709 total patients). CONCLUSIONS: TPE significantly reduced SAb levels, a marker of SARS-CoV-2 immunity, but did not appear to provoke increased incidence of COVID-19 infections. Further investigation of the kinetics of TPE-mediated SAb decrease and post-TPE recovery are warranted.
Subject(s)
COVID-19 , Plasma Exchange , Humans , Incidence , COVID-19 Testing , COVID-19/epidemiology , COVID-19/therapy , SARS-CoV-2 , Immunoglobulin G , Antibodies, ViralABSTRACT
Amyloid light-chain (AL) amyloidosis is a rare, typically fatal disease characterized by the accumulation of misfolded immunoglobulin light chains (LCs). Birtamimab is an investigational humanized monoclonal antibody designed to neutralize toxic LC aggregates and deplete insoluble organ-deposited amyloid via macrophage-induced phagocytosis. VITAL was a phase 3 randomized, double-blind, placebo-controlled clinical trial assessing the efficacy and safety of birtamimab + standard of care (SOC) in 260 newly diagnosed, treatment-naive patients with AL amyloidosis. Patients received 24 mg/kg IV birtamimab + SOC or placebo + SOC every 28 days. The primary composite end point was the time to all-cause mortality (ACM) or centrally adjudicated cardiac hospitalization ≥91 days after the first study drug infusion. The trial was terminated early after an interim futility analysis; there was no significant difference in the primary composite end point (hazard ratio [HR], 0.826; 95% confidence interval [CI], 0.574-1.189; log-rank P = .303). A post hoc analysis of patients with Mayo stage IV AL amyloidosis, those at the highest risk of early mortality, showed significant improvement in the time to ACM with birtamimab at month 9 (HR, 0.413; 95% CI, 0.191-0.895; log-rank P = .021). At month 9, 74% of patients with Mayo stage IV AL amyloidosis treated with birtamimab and 49% of those given placebo survived. Overall, the rates of treatment-emergent adverse events (TEAEs) and serious TEAEs were generally similar between treatment arms. A confirmatory phase 3 randomized, double-blind, placebo-controlled clinical trial of birtamimab in patients with Mayo stage IV AL amyloidosis (AFFIRM-AL; NCT04973137) is currently enrolling. The VITAL trial was registered at www.clinicaltrials.gov as #NCT02312206.
Subject(s)
Amyloidosis , Immunoglobulin Light-chain Amyloidosis , Humans , Immunoglobulin Light-chain Amyloidosis/drug therapy , Standard of Care , Antibodies, Monoclonal, Humanized/adverse effects , Double-Blind Method , Treatment OutcomeABSTRACT
Subcutaneous daratumumab plus bortezomib/cyclophosphamide/dexamethasone (VCd; D-VCd) improved outcomes versus VCd for patients with newly diagnosed immunoglobulin light-chain (AL) amyloidosis in the phase 3 ANDROMEDA study. We report a subgroup analysis of Asian patients (Japan; Korea; China) from ANDROMEDA. Among 388 randomized patients, 60 were Asian (D-VCd, n = 29; VCd, n = 31). At a median follow-up of 11.4 months, the overall hematologic complete response rate was higher for D-VCd versus VCd (58.6% vs. 9.7%; odds ratio, 13.2; 95% confidence interval [CI], 3.3-53.7; P < 0.0001). Six-month cardiac and renal response rates were higher with D-VCd versus VCd (cardiac, 46.7% vs. 4.8%; P = 0.0036; renal, 57.1% vs. 37.5%; P = 0.4684). Major organ deterioration progression-free survival (MOD-PFS) and major organ deterioration event-free survival (MOD-EFS) were improved with D-VCd versus VCd (MOD-PFS: hazard ratio [HR], 0.21; 95% CI, 0.06-0.75; P = 0.0079; MOD-EFS: HR, 0.16; 95% CI, 0.05-0.54; P = 0.0007). Twelve deaths occurred (D-VCd, n = 3; VCd, n = 9). Twenty-two patients had baseline serologies indicating prior hepatitis B virus (HBV) exposure; no patient experienced HBV reactivation. Although grade 3/4 cytopenia rates were higher than in the global safety population, the safety profile of D-VCd in Asian patients was generally consistent with the global study population, regardless of body weight. These results support D-VCd use in Asian patients with newly diagnosed AL amyloidosis. ClinicalTrials.gov Identifier: NCT03201965.
Subject(s)
Immunoglobulin Light-chain Amyloidosis , Multiple Myeloma , Humans , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Bortezomib/adverse effects , Cyclophosphamide/adverse effects , Dexamethasone/adverse effects , Immunoglobulin Light-chain Amyloidosis/drug therapy , Immunoglobulin Light-chain Amyloidosis/etiology , Multiple Myeloma/drug therapyABSTRACT
BACKGROUND: Cytogenetic abnormalities are common in patients with amyloid light-chain (AL) amyloidosis; some are associated with poorer outcomes. This post hoc analysis of ANDROMEDA evaluated the impact of certain cytogenetic abnormalities on outcomes in this patient population. METHODS: Patients with newly diagnosed AL amyloidosis were randomised 1:1 to daratumumab, bortezomib, cyclophosphamide, and dexamethasone (D-VCd) or VCd. Outcomes were evaluated in the intent-to-treat (ITT) population and in patients with t(11;14), amp1q21, del13q14, and del17p13. RESULTS: Overall, 321 patients had cytogenetic testing (D-VCd, n = 155; VCd, n = 166); most common abnormalities were t(11;14) and amp1q21. At a median follow-up of 20.3 months, haematologic complete response rates were higher with D-VCd vs VCd across all cytogenetic subgroups and organ response rates were numerically higher with D-VCd vs VCd across most subgroups. Point estimates for hazard ratio of major organ deterioration-PFS and -EFS favoured D-VCd over VCd for all cytogenetic subgroups. Deep haematologic responses (involved minus uninvolved free light chains [FLC] <10 mg/L or involved FLC ≤20 mg/L) were seen in more patients with D-VCd than VCd in all ITT and t(11;14) cohorts. CONCLUSIONS: These results support the use of D-VCd as standard of care in patients with newly diagnosed AL amyloidosis regardless of cytogenetic abnormalities.
Subject(s)
Immunoglobulin Light-chain Amyloidosis , Humans , Immunoglobulin Light-chain Amyloidosis/drug therapy , Immunoglobulin Light-chain Amyloidosis/genetics , Treatment Outcome , Bortezomib/therapeutic use , Chromosome Aberrations , Cyclophosphamide/therapeutic use , Immunoglobulin Light Chains/genetics , Dexamethasone/therapeutic useABSTRACT
Multiple myeloma remains an incurable disease with the usual disease course requiring induction therapy, autologous stem cell transplantation for eligible patients, and long-term maintenance. Risk stratification tools and cytogenetic alterations help inform individualized therapeutic choices for patients in hopes of achieving long-term remissions with preserved quality of life. Unfortunately, relapses occur at different stages of the course of the disease owing to the biological heterogeneity of the disease. Addressing relapse can be complex and challenging as there are both therapy- and patient-related factors to consider. In this broad scoping review of available therapies in relapsed/refractory multiple myeloma (RRMM), we cover the pharmacologic mechanisms underlying active therapies such as immunomodulatory agents (IMiDs), proteasome inhibitors (PIs), monoclonal antibodies (mAbs), traditional chemotherapy, and Venetoclax. We then review the clinical data supporting the use of these therapies, organized based on drug resistance/refractoriness, and the role of autologous stem cell transplant (ASCT). Approaches to special situations during relapse such as renal impairment and extramedullary disease are also covered. Lastly, we look towards the future by briefly reviewing the clinical data supporting the use of chimeric antigen receptor (CAR-T) therapy, bispecific T cell engagers (BITE), and Cereblon E3 Ligase Modulators (CELMoDs).
Subject(s)
Hematopoietic Stem Cell Transplantation , Multiple Myeloma , Humans , Multiple Myeloma/therapy , Quality of Life , Transplantation, Autologous , Neoplasm Recurrence, LocalABSTRACT
Patient-reported outcomes in AL amyloidosis have not been well-studied. We analyzed health-related quality of life (HRQOL) and AL amyloidosis symptoms data from the phase 3 TOURMALINE-AL1 trial (NCT01659658) (ixazomib-dexamethasone, n = 85; physician's choice of chemotherapy [PC], n = 83). HRQOL and symptom burden were measured with the SF-36v2, Functional Assessment of Cancer Therapy/Gynecologic Oncology Group Neurotoxicity subscale (FACT/GOG-Ntx), and an amyloidosis symptom questionnaire (ASQ). Score changes during treatment were analyzed descriptively and using repeated-measures linear mixed models; analyses were not adjusted for multiplicity. Least-squares (LS) mean changes from baseline were significantly higher (better HRQOL) for ixazomib-dexamethasone at several cycles for SF-36v2 Role Physical and Vitality subscales (p < .05); no subscales demonstrated significant differences favoring PC. For FACT/GOG-Ntx, small but significant differences in LS mean changes favored ixazomib-dexamethasone over PC at multiple cycles for seven items and both summary scores; significant differences favored PC for one item (trouble hearing) at multiple cycles. ASQ total score trended downward (lower burden) in both arms; significant LS mean differences favored ixazomib-dexamethasone over PC at some cycles (p < .05). Patients with relapsed/refractory AL amyloidosis treated with ixazomib-dexamethasone experienced HRQOL and symptoms that were similar to or trended better than patients treated with PC despite longer duration of therapy.
Subject(s)
Amyloidosis , Immunoglobulin Light-chain Amyloidosis , Multiple Myeloma , Physicians , Female , Humans , Amyloidosis/drug therapy , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Dexamethasone/adverse effects , Immunoglobulin Light-chain Amyloidosis/drug therapy , Immunoglobulin Light-chain Amyloidosis/etiology , Multiple Myeloma/drug therapy , Quality of LifeABSTRACT
Background: Patients with amyloid light chain amyloidosis and severe cardiac dysfunction have a poor prognosis. Treatment options that induce rapid and deep hematologic and organ responses, irrespective of cardiac involvement, are needed. Objectives: The aim of this study was to evaluate the impact of baseline cardiac stage on efficacy and safety outcomes in the phase 3 ANDROMEDA trial. Methods: Rates of overall complete hematologic response and cardiac and renal response at 6 months and median major organ deterioration-progression-free survival and major organ deterioration-event-free survival were compared across cardiac stages (I, II, or IIIA) and treatments (daratumumab, bortezomib, cyclophosphamide, and dexamethasone [D-VCd] or bortezomib, cyclophosphamide, and dexamethasone [VCd]). Rates of adverse events (AEs) were summarized for patients with and without baseline cardiac involvement and by cardiac stage. Results: Median follow-up duration was 15.7 months. The proportions of stage I, II, and IIIA patients were 23.2%, 40.2%, and 36.6%. Across cardiac stages, hematologic and organ response rates were higher and major organ deterioration-progression-free survival and major organ deterioration-event-free survival were longer with D-VCd than VCd. AE rates were similar between treatments and by cardiac stage; serious AE rates were higher in patients with cardiac involvement and increased with increasing cardiac stage. The incidence of cardiac events was numerically greater with D-VCd vs VCd, but the rate of grade 3 or 4 events was similar. The exposure-adjusted incidence rate for cardiac events was lower with D-VCd than VCd (median exposure 13.4 and 5.3 months, respectively). Conclusions: These findings demonstrate the efficacy of D-VCd over VCd in patients with newly diagnosed amyloid light chain amyloidosis across cardiac stages, thus supporting its use in patients with cardiac involvement. (NCT03201965).
ABSTRACT
Cardiac transthyretin amyloidosis (ATTR) is an often underdiagnosed disease that can lead to significant morbidity and mortality for patients. In recent years, technetium-99m pyrophosphate scintigraphy (PYP) imaging has become a standard of care diagnostic tool to help clinicians identify this disease. With newly emerging therapies for ATTR cardiomyopathy, it is critical to identify patients who are eligible for therapy as early as possible. At our institution, we sought to describe the frequency of PYP scanning and how it has impacted the management of a patient suspected to have amyloid cardiomyopathy. Between 1 January 2017 and 31 December 2020, we identified 273 patients who completed PYP scanning for evaluation of cardiac amyloidosis at Tufts Medical Center, a tertiary care centre. We reviewed pertinent clinical data for all study subjects. A PYP scan was considered positive when the heart to contralateral lung ratio was greater than or equal to 1.5, with a visual grade of 2 or 3, and confirmation with single-photon emission computerised tomography (SPECT) imaging. In total there were 55 positive, 202 negative, and 16 equivocal PYP scans. Endomyocardial biopsies were rarely performed following PYP results. Of the seven patients with a positive PYP scan who underwent biopsy, five were positive for ATTR amyloid; of the patients with a negative scan who were biopsied, none were positive for ATTR amyloidosis and two were positive for amyloid light-chain (AL) amyloidosis. The biomarkers troponin I, B-type naturietic peptide (BNP), and N-terminal pro-BNP (NT-proBNP), as well as the interventricular septal end-diastolic thickness (IVSd) seen on echocardiogram, were all found to be statistically higher in the PYP positive cohort than in the PYP negative cohort using Mann-Whitney U statistical analysis. In total, 27 out of the 55 patients with a positive PYP scan underwent therapy specific for cardiac amyloid. In conclusion, this study reinforces the clinical significance of the PYP scan in the diagnosis and management of cardiac amyloidosis. A positive scan allowed physicians to implement early amyloid-directed treatment while a negative scan encouraged physicians to pursue an alternative diagnosis.
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Over the past two decades, significant progress has been made in the diagnosis, risk assessment and treatment of patients with multiple myeloma, translating into remarkable improvements in survival outcomes. Yet, cure remains elusive, and almost all patients eventually experience relapse, particularly those with high-risk and refractory disease. Immune-based approaches have emerged as highly effective therapeutic options that have heralded a new era in the treatment of multiple myeloma. Idecabtagene vicleucel (ide-cel) is one such therapy that employs the use of genetically modified autologous T-cells to redirect immune activation in a tumor-directed fashion. It has yielded impressive responses even in patients with poor-risk disease and is the first chimeric antigen receptor (CAR) T-cell therapy to be approved for treatment in relapsed or refractory multiple myeloma. In this review, we examine the design and pharmacokinetics of ide-cel, audit evidence that led to its incorporation into the current treatment paradigm and provide insight into its clinical utilization with a focus on real-life intricacies.
ABSTRACT
Although upfront autologous stem cell transplantation (ASCT) generally improves progression-free survival (PFS) in newly diagnosed multiple myeloma (NDMM), the overall survival (OS) benefit and optimal timing of ASCT are not well established. Patients with early response may be able to safely continue induction and avoid ASCT without compromised outcomes. We report an extended follow-up analysis of a phase 2 trial that randomized transplant-eligible patients with NDMM who responded to induction (50/65 patients) to continued induction or ASCT; median follow-up was 8.0 years. Patients had similar 8-year PFS (55% vs. 43%), 8-year OS (83% vs. 72%), and rates of at least very good partial response (72% vs. 84%) whether continuing induction of lenalidomide and dexamethasone (Ld arm) or receiving ASCT (Ld + ASCT arm) (p = 0.5). Notably, over 50% of patients receiving continuous Ld had PFS of 5-10 years. These results suggest the need for prospective trials incorporating response-adapted therapeutic approaches to NDMM.STATEMENT OF PRIOR PRESENTATIONPresented in abstract form (interim analysis) at the 56th annual meeting of the American Society of Hematology (San Francisco, CA, 6 December 2014) and at the 57th annual meeting of the American Society of Hematology (Orlando, FL, 3 December 2015).
Subject(s)
Hematopoietic Stem Cell Transplantation , Multiple Myeloma , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Bortezomib/therapeutic use , Dexamethasone/therapeutic use , Hematopoietic Stem Cell Transplantation/methods , Humans , Lenalidomide/therapeutic use , Multiple Myeloma/drug therapy , Multiple Myeloma/therapy , Prospective Studies , Stem Cell Transplantation , Transplantation, AutologousABSTRACT
OPINION STATEMENT: Light-chain amyloidosis is a rare disorder where a small clone of plasma cells is producing excess toxic light chains that deposit in various organs and cause dysfunction. Cardiac involvement is a major determinant of survival and rapid reduction of light chain is critical for recovery of organ function and overall survival. Immunotherapy targeting the clonal plasma cells and amyloid fibrils has emerged as a promising candidate. Daratumumab, both alone and in combinations with other anti-myeloma agents, is able to achieve deep hematologic responses and has greatly improved outcomes. Isatuximab, elotuzumab, and CAEL101 have also shown promising results and further studies are ongoing in the frontline as well as the relapsed/refractory setting. The frailty of AL patients and the relapsing/remitting nature of the disease present unique challenges, and the low toxicity of monoclonal antibodies makes them well-suited for these patients. Other immunotherapy agents including chimeric antigen receptor T cells, bispecific antibodies, and antibody-drug conjugates have altered the landscape in treatment of multiple myeloma, and are in the early phase of evaluation in patients with AL amyloidosis with results eagerly awaited.
Subject(s)
Immunoglobulin Light-chain Amyloidosis , Multiple Myeloma , Humans , Immunoglobulin Light-chain Amyloidosis/diagnosis , Immunoglobulin Light-chain Amyloidosis/etiology , Immunoglobulin Light-chain Amyloidosis/therapy , Immunologic Factors/therapeutic use , Immunotherapy/adverse effects , Immunotherapy/methods , Multiple Myeloma/drug therapy , Neoplasm Recurrence, LocalABSTRACT
In the phase 3 ANDROMEDA trial, patients treated with daratumumab, bortezomib, cyclophosphamide, and dexamethasone (D-VCd) had significantly higher rates of organ and hematologic response compared with patients who received VCd alone. Here, we present patient-reported outcomes (PROs) from the ANDROMEDA trial. PROs were assessed through cycle 6 using three standardized questionnaires. Treatment effect through cycle 6 was measured by a repeated-measures, mixed-effects model. The magnitude of changes in PROs versus baseline was generally low, but between-group differences favored the D-VCd group. Results were generally consistent irrespective of hematologic, cardiac, or renal responses. More patients in the D-VCd group experienced meaningful improvements in PROs; median time to improvement was more rapid in the D-VCd group versus the VCd group. After cycle 6, patients in the D-VCd group received daratumumab monotherapy and their PRO assessments continued, with improvements in health-related quality of life (HRQoL) reported through cycle 19. PROs of subgroups with renal and cardiac involvement were consistent with those of the intent-to-treat population. These results demonstrate that the previously reported clinical benefits of D-VCd were achieved without decrement to patients' HRQoL and provide support of D-VCd in patients with AL amyloidosis.
Subject(s)
Amyloidosis , Immunoglobulin Light-chain Amyloidosis , Multiple Myeloma , Amyloidosis/drug therapy , Antibodies, Monoclonal , Antineoplastic Combined Chemotherapy Protocols , Bortezomib , Cyclophosphamide , Dexamethasone , Humans , Immunoglobulin Light-chain Amyloidosis/drug therapy , Immunoglobulin Light-chain Amyloidosis/etiology , Multiple Myeloma/drug therapy , Quality of Life , Treatment OutcomeABSTRACT
BACKGROUND: Amyloidosis is a protein misfolding disorder that leads to the deposition of beta-pleated sheets of a fibrillar derivative of various protein precursors. Identification of the type of precursor protein is integral in treatment decision-making. The presence of two different types of amyloid in the same patient is unusually rare, and there are no previous reports of two different types of amyloid deposition in the ligamentum flavum (LF) in the same patient. CASE DESCRIPTION: Here, we describe two patients with spinal stenosis who underwent laminectomies and were found to have AL and ATTR amyloid deposits in the LF. CONCLUSION: As the spine is becoming recognized as a site for ATTRwt amyloid deposition, patients undergoing spinal decompression surgery may potentially benefit from evaluation for amyloidosis in the LF.
Subject(s)
Amyloidosis , Immunoglobulin Light-chain Amyloidosis , Multiple Myeloma , Amyloidosis/diagnosis , Amyloidosis/drug therapy , Antibodies, Monoclonal/therapeutic use , Humans , Immunoglobulin Light-chain Amyloidosis/diagnosis , Immunoglobulin Light-chain Amyloidosis/drug therapy , Treatment OutcomeABSTRACT
Chromosome 1q gain/amplification (1q +) has been reported to be associated with inferior outcomes in multiple myeloma (MM) patients. Big therapeutic advances have shifted the treatment landscape by introducing monoclonal antibodies. There is a relative lack of data on outcomes in patients harboring this alteration in the era of monoclonal antibodies. Baseline characteristics and therapy-related data from newly diagnosed MM patients harboring 1q + detected by fluorescence in situ hybridization (FISH) were collected in a single institution. Among 34 identified subjects, the presence of elevated LDH was found to be associated with shorter overall survival (OS), and increased bone marrow plasma cell percentage (≥ 60%) was associated with worse progression-free survival (PFS). 1q + copy number more than three was associated with both shorter OS and PFS. Additionally, the administration of lenalidomide was associated with superior OS. The use of autologous stem cell transplantation, bortezomib, or daratumumab, was found to have no prognostic benefits in our sample. Lenalidomide may be an optimal therapeutic choice for this population, and future larger studies are warranted to confirm this benefit and further investigate the role of monoclonal antibodies in this subpopulation.
Subject(s)
Chromosome Duplication , Chromosomes, Human, Pair 1 , Multiple Myeloma/genetics , Aged , Disease Management , Female , Humans , Male , Middle Aged , Multiple Myeloma/epidemiology , Multiple Myeloma/therapy , Retrospective Studies , Survival AnalysisABSTRACT
Smoldering multiple myeloma (SMM) routinely precedes the development of multiple myeloma. While some patients experience aggressive disease, others have more indolent courses akin to those with monoclonal gammopathy of undetermined significance. Much effort has been made to understand the pathobiological basis of this heterogeneity. Scientific advancements have led to the emergence of various clinical and genomic markers of relevance, translating into evolution of disease definitions over time. More recently, the interest in manipulation of biological pathways has intensified in a bid to stall or halt disease progression. Studies with lenalidomide have exemplified the promise of early intervention, whereas numerous therapeutic approaches remain the subject of ongoing clinical investigation. This review summarizes the historic progress made in defining SMM as a distinct clinicopathologic entity, provides a critical appraisal of the evidence guiding risk assessment, and suggests a pragmatic approach to its modern-day management. Finally, an overview of developments on the horizon is also provided.
Subject(s)
Monoclonal Gammopathy of Undetermined Significance , Multiple Myeloma , Smoldering Multiple Myeloma , Disease Progression , Humans , Monoclonal Gammopathy of Undetermined Significance/etiology , Monoclonal Gammopathy of Undetermined Significance/genetics , Multiple Myeloma/etiology , Multiple Myeloma/genetics , Risk Assessment , Risk Factors , Smoldering Multiple Myeloma/etiology , Smoldering Multiple Myeloma/geneticsABSTRACT
The purpose of this study is to characterize the population pharmacokinetics (popPK) of subcutaneous (SC) daratumumab in combination with bortezomib, cyclophosphamide, and dexamethasone and explore the relationship between daratumumab systemic exposure and selected efficacy and safety end points in patients with newly diagnosed systemic amyloid light-chain amyloidosis. The popPK analysis included pharmacokinetic and immunogenicity data from patients receiving daratumumab SC in combination with bortezomib, cyclophosphamide, and dexamethasone in the ANDROMEDA study (AMY3001; safety run-in, n = 28; randomized phase, n = 183). Nonlinear mixed-effects modeling was used to characterize the popPK and quantify the impact of potential covariates. The exposure-response (E-R) analysis included data from all patients in the randomized phase of ANDROMEDA (n = 388). Logistic regression and survival analysis were used to evaluate the relationships between daratumumab systemic exposure and efficacy end points. The E-R analysis on safety was conducted using quartile comparison and logistic regression analysis. The observed concentration-time data of daratumumab SC were well described by a 1-compartment popPK model with first-order absorption and parallel linear and nonlinear Michaelis-Menten elimination pathways. None of the investigated covariates were determined to be clinically meaningful. Daratumumab systemic exposure was generally similar across subgroups that achieved different levels of hematologic response, and there was no apparent relationship between daratumumab systemic exposure and the investigated safety end points. In conclusion, the popPK and E-R analyses supported the selected 1800-mg flat dose of daratumumab SC in combination with the bortezomib, cyclophosphamide, and dexamethasone regimen for the treatment of light-chain amyloidosis. No dose adjustment was recommended for investigated covariates.