Daratumumab-Based Treatment for Immunoglobulin Light-Chain Amyloidosis.

BACKGROUND: Systemic immunoglobulin light-chain (AL) amyloidosis is characterized by deposition of amyloid fibrils of light chains produced by clonal CD38+ plasma cells. Daratumumab, a human CD38-targeting antibody, may improve outcomes for this disease. METHODS: We randomly assigned patients with newly diagnosed AL amyloidosis to receive six cycles of bortezomib, cyclophosphamide, and dexamethasone either alone (control group) or with subcutaneous daratumumab followed by single-agent daratumumab every 4 weeks for up to 24 cycles (daratumumab group). The primary end point was a hematologic complete response. RESULTS: A total of 388 patients underwent randomization. The median follow-up was 11.4 months. The percentage of patients who had a hematologic complete response was significantly higher in the daratumumab group than in the control group (53.3% vs. 18.1%) (relative risk ratio, 2.9; 95% confidence interval [CI], 2.1 to 4.1; P<0.001). Survival free from major organ deterioration or hematologic progression favored the daratumumab group (hazard ratio for major organ deterioration, hematologic progression, or death, 0.58; 95% CI, 0.36 to 0.93; P = 0.02). At 6 months, more cardiac and renal responses occurred in the daratumumab group than in the control group (41.5% vs. 22.2% and 53.0% vs. 23.9%, respectively). The four most common grade 3 or 4 adverse events were lymphopenia (13.0% in the daratumumab group and 10.1% in the control group), pneumonia (7.8% and 4.3%, respectively), cardiac failure (6.2% and 4.8%), and diarrhea (5.7% and 3.7%). Systemic administration-related reactions to daratumumab occurred in 7.3% of the patients. A total of 56 patients died (27 in the daratumumab group and 29 in the control group), most due to amyloidosis-related cardiomyopathy. CONCLUSIONS: Among patients with newly diagnosed AL amyloidosis, the addition of daratumumab to bortezomib, cyclophosphamide, and dexamethasone was associated with higher frequencies of hematologic complete response and survival free from major organ deterioration or hematologic progression. (Funded by Janssen Research and Development; ANDROMEDA ClinicalTrials.gov number, NCT03201965.).

Cytomegalovirus seropositivity is associated with improved responses to CD38 monoclonal antibody therapies in multiple myeloma: A single-centre retrospective study.

The CD38-targeting monoclonal antibodies (CD38 mAbs) are well-established therapies in multiple myeloma (MM), but responses to treatment are not always deep or durable. Natural killer (NK) cells deficient in Fc epsilon receptor gamma subunits, known as g-NK cells, are found in higher numbers among individuals exposed to cytomegalovirus (CMV) and are able to potentiate the efficacy of daratumumab in vivo. Here, we present a single-centre, retrospective analysis of 136 patients with MM with known CMV serostatus who received a regimen containing a CD38 mAb (93.4% daratumumab and 6.6% isatuximab). CMV seropositivity was associated with an increased overall response rate to treatment regimens containing a CD38 mAb (odds ratio 2.65, 95% confidence interval [CI] 1.17-6.02). However, CMV serostatus was associated with shorter time to treatment failure in a multivariate Cox model (7.8 vs. 8.8 months in the CMV-seropositive vs. CMV-seronegative groups respectively, log-rank p = 0.18, hazard ratio 1.98, 95% CI 1.25-3.12). Our data suggest that CMV seropositivity may predict better response to CD38 mAbs, although this did not correspond to longer time to treatment failure. Larger studies directly quantitating g-NK cells are required to fully understand their effect on CD38 mAb efficacy in MM.

Antibody and T-cell responses by ultra-deep T-cell receptor immunosequencing after COVID-19 vaccination in patients with plasma cell dyscrasias.

We investigated antibody and coronavirus disease 2019 (COVID-19)-specific T-cell mediated responses via ultra-deep immunosequencing of the T-cell receptor (TCR) repertoire in patients with plasma cell dyscrasias (PCD). We identified 364 patients with PCD who underwent spike antibody testing using commercially available spike-receptor binding domain immunoglobulin G antibodies ≥2 weeks after completion of the initial two doses of mRNA vaccines or one dose of JNJ-78436735. A total of 56 patients underwent TCR immunosequencing after vaccination. Overall, 86% tested within 6 months of vaccination had detectable spike antibodies. Increasing age, use of anti-CD38 or anti-B-cell maturation antigen therapy, and receipt of BNT162b2 (vs. mRNA-1273) were associated with lower antibody titres. We observed an increased proportion of TCRs associated with surface glycoprotein regions of the COVID-19 genome after vaccination, consistent with spike-specific T-cell responses. The median spike-specific T-cell breadth was 3.11 × 10-5 , comparable to those in healthy populations after vaccination. Although spike-specific T-cell breadth correlated with antibody titres, patients without antibody responses also demonstrated spike-specific T-cell responses. Patients receiving mRNA-1273 had higher median spike-specific T-cell breadth than those receiving BNT162b2 (p = 0.01). Although patients with PCD are often immunocompromised due to underlying disease and treatments, COVID-19 vaccination can still elicit humoral and T-cell responses and remain an important intervention in this patient population.

Health-related quality of life in patients with light chain amyloidosis treated with bortezomib, cyclophosphamide, and dexamethasone ± daratumumab: Results from the ANDROMEDA study.

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.

Outcomes of kidney transplant recipients with ESKD due to plasma cell dyscrasia: A case series.

Transplant centers have historically been reluctant to proceed with kidney transplantation in individuals with plasma cell dyscrasias (PCDs) due to concern for high rates of PCD recurrence and PCD-related mortality. As novel therapies for PCDs have improved hematologic outcomes, strategies to optimize kidney transplantation in individuals with PCD-mediated kidney disease are needed. In this single-center case series we discuss our protocol for the transplantation of individuals with ESKD attributed to PCD as well as the hematologic and allograft outcomes of 12 kidney transplant recipients with ESKD attributed to PCD. Median follow-up time after kidney transplantation was 44 months (IQR 36, 84). All patients had a functioning allograft 1 year after kidney transplantation. 9/12 patients were alive and had a functioning allograft 5 years after kidney transplantation. Five patients experienced relapse of PCD (of whom three responded well to subsequent therapies) and four patients developed secondary malignancies, including three patients with urologic malignancies. This case series demonstrates that patients with kidney disease attributed to PCD have favorable outcomes with kidney transplantation. Transplant evaluation in patients with PCDs should involve a multidisciplinary team of transplant nephrologists and oncologists to select appropriate candidates. Providers should consider screening for urologic malignancies pre- and post-transplantation.

Evaluation of subcutaneous daratumumab injections in the ambulatory care setting.

INTRODUCTION: Subcutaneous daratumumab is non-inferior to intravenous daratumumab for the treatment of multiple myeloma and significantly reduced incidence of systemic reactions. However, manufacturer for subcutaneous daratumumab has not provided guidance regarding optimal methods for monitoring for hypersensitivity reactions following subcutaneous daratumumab administration. METHODS: A retrospective analysis was performed in two cohorts of patients who received at least two doses of subcutaneous daratumumab for the treatment of plasma cell disorders: patients with previous exposure to intravenous daratumumab (dara-exposed) and patients without history of intravenous daratumumab (dara-naïve). The primary outcome was incidence of systemic and injection-site reactions following first dose of subcutaneous daratumumab. Secondary analysis included time to systemic and injection-site reactions, grading of adverse reaction, and incidence of second systemic reaction. RESULTS: Thirty-one patients were dara-naïve and 49 patients were dara-exposed. Differences in incidence of systemic (dara-naïve: 9.7% vs dara-exposed: 6.1%, p = 0.67) and injection-site reactions (dara-naïve: 12.9% vs dara-exposed: 14.3%, p = 0.99) did not reach statistical significance. Difference in median time to systemic reaction (dara-naïve: 3 h vs dara-exposed: 12 h, p = 0.18) was clinically important but did not reach statistical significance. Median time to injection-site reactions (dara-naïve: 6 h vs dara-exposed: 24 h, p = 0.03) was shorter in the dara-naïve cohort. No clinically meaningful difference was observed for incidence of second systemic reaction. CONCLUSION: Most reactions were mild and did not require medical intervention. Following first subcutaneous daratumumab dose, monitoring for 3 h for dara-naïve patients and no monitoring time for dara-exposed patients for hypersensitivity reactions may be a safe and reasonable practice.

Phase 1b trial of isatuximab, an anti-CD38 monoclonal antibody, in combination with carfilzomib as treatment of relapsed/refractory multiple myeloma.

BACKGROUND: Isatuximab (Isa), an anti-CD38 monoclonal antibody, and carfilzomib (K), a next-generation proteasome inhibitor (PI), both have potent single-agent activity in relapsed and refractory multiple myeloma (RRMM). METHODS: This phase 1b study evaluated the combination of Isa and K in 33 patients with RRMM. Isa was administered by intravenous infusion in 3 dosing cohorts: dose level 1 (Isa at 10 mg/kg biweekly), dose level 2 (DL2; Isa at 10 mg/kg weekly for 4 doses and then biweekly), and dose level 3 (Isa at 20 mg/kg weekly for 4 doses and then biweekly) and all patients received K (20 mg/m2 intravenously for cycle 1, days 1 and 2, and then 27 mg/m2 for all subsequent doses). A standard 3+3 dose-escalation design was used, no dose-limiting toxicity was observed, and the maximum tolerated dose was not reached. An expansion cohort of 18 patients was enrolled at DL2 to further evaluate safety and efficacy. Responses were assessed with the International Myeloma Working Group response criteria, and patients continued treatment until disease progression or unacceptable toxicity. RESULTS: With a median follow-up of 26.7 months, in this heavily pretreated population with a median of 3 prior lines (refractory to PIs and immunomodulatory drugs, 76%; refractory to K, 27%), the overall response rate was 70% (stringent complete response/complete response, 4; very good partial response, 8; partial response, 11). The median progression-free survival was 10.1 months, and the 2-year survival probability was 76%. The most common treatment-related adverse events (grade 2 or higher) were anemia, leukopenia, neutropenia, thrombocytopenia, hypertension, and infection. Infusion reactions were common (55%) but did not limit dosing. CONCLUSIONS: Treatment with Isa plus K was well tolerated with no unexpected toxicity. The combination was effective despite the enrollment of heavily pretreated patients with RRMM. LAY SUMMARY: This phase 1b study was designed to assess the safety, pharmacokinetics, and preliminary efficacy of isatuximab and carfilzomib in patients with relapsed and refractory multiple myeloma. Thirty-three patients were treated: 15 in dose escalation and 18 in dose expansion. Patients received an average of 10 cycles. The treatment was safe and effective. No unexpected toxicity or drug-drug interactions were noted. Seventy percent of the subjects responded to therapy, and the progression-free survival was 10.1 months.

Impact of Plerixafor Use at Different Peripheral Blood CD34+ Thresholds on Autologous Stem Cell Collection in Patients with Multiple Myeloma.

Patients with multiple myeloma (MM) scheduled for autologous stem cell transplantation must undergo autologous stem cell mobilization; unfortunately, however, many do not obtain an adequate collection yield. Despite the availability of plerixafor, its widespread and uniform use is limited by its cost, and consequently, many institutions have adopted various risk-adapted algorithms. We report our mobilization experience as we have modified our plerixafor algorithm to a more liberal one, with the expectation of greater collection efficiency and mobilization success with higher plerixafor use. A total of 344 mobilization attempts were analyzed over 3 time periods and using 3 different peripheral blood CD34+ cell counts to guide plerixafor use: <15/µL (n = 66), <20/µL (n = 130), and <40/µL (n = 148). The primary endpoints were evaluation of changes in mean plerixafor utilization and apheresis days and assessment of the impact on overall mobilization costs. Secondary endpoints were a description of the impact of lenalidomide use on mobilization and evaluation of the rate of mobilization failure. We found that mean plerixafor use increased from 1.32 to 1.65 to 1.74 doses per mobilization (P = .026) and the mean days of apheresis decreased from 2.15 to 2.17 to 1.89 days per mobilization for the <15/µL, <20/µL, and <40/µL cohorts, respectively (P = .011). The combined cost of plerixafor and apheresis procedures at a threshold of 40/µL is close to that at a threshold of 15/µL, while saving 26 apheresis days per 100 patients. In general, there were low rates of mobilization failure across all thresholds. Patients who received more than 6 cycles of lenalidomide demonstrated impaired mobilization and required more apheresis sessions (P < .013) and greater plerixafor use (P < .001) to achieve target stem cell yields. Overall, using plerixafor in patients with MM, with a day 4 pCD34 count of <40/µL is a reasonable and cost-effective strategy to optimize apheresis utilization.

Updates on Hematologic Malignancies in the Older Adult: Focus on Acute Myeloid Leukemia, Chronic Lymphocytic Leukemia, and Multiple Myeloma.

PURPOSE OF REVIEW: Hematologic malignancies are common and difficult to treat in older adults. In this review, we focus on recent updates in diseases with several novel agents relevant to older adults-acute myeloid leukemia (AML), chronic lymphocytic leukemia (CLL), and multiple myeloma (MM). RECENT FINDINGS: In AML, CPX-351 offers a new induction chemotherapy for secondary AML that prolongs survival, and venetoclax and IDH inhibitors are efficacious and well tolerated. In CLL, chemoimmunotherapy is being replaced by monoclonal antibodies and small molecule inhibitors that are more effective and better tolerated. In MM, new immunomodulatory drugs, proteasome inhibitors, and monoclonal antibodies have expanded treatment options for older patients. The introduction of novel agents has dramatically shifted the landscape of therapeutic options for older adults with hematologic malignancies. Clinical trials in older adults are needed to expand treatment options for these patients.

Zoledronic acid-induced orbital inflammation in a patient with multiple myeloma.

Multiple myeloma is a cancer of malignant plasma cells which stimulates osteoclasts and is associated with increased bone turnover and osteolysis. Bisphosphonates including zolendronic acid are used to prevent skeletal complications in patients with multiple myeloma. Orbital inflammation is a rare but serious complication following use of bisphosphonates. The diagnosis is made by excluding other possible causes in patients with myeloma and rapid initiation of therapy is required. Corticosteroids are the mainstay of therapy but the ideal treatment course has not been delineated. This report describes a case of this rare complication and provides a review of the literature.

Beyond the plasma cell: emerging therapies for immunoglobulin light chain amyloidosis.

Systemic immunoglobulin light chain (LC) amyloidosis (AL) is a potentially fatal disease caused by immunoglobulin LC produced by clonal plasma cells. These LC form both toxic oligomers and amyloid deposits disrupting vital organ function. Despite reduction of LC by chemotherapy, the restoration of organ function is highly variable and often incomplete. Organ damage remains the major source of mortality and morbidity in AL. This review focuses on the challenges posed by emerging therapies that may limit the toxicity of LC and improve organ function by accelerating the resorption of amyloid deposits.

Repurposing tofacitinib as an anti-myeloma therapeutic to reverse growth-promoting effects of the bone marrow microenvironment.

The myeloma bone marrow microenvironment promotes proliferation of malignant plasma cells and resistance to therapy. Activation of JAK/STAT signaling is thought to be a central component of these microenvironment-induced phenotypes. In a prior drug repurposing screen, we identified tofacitinib, a pan-JAK inhibitor Food and Drug Administration (FDA) approved for rheumatoid arthritis, as an agent that may reverse the tumor-stimulating effects of bone marrow mesenchymal stromal cells. Herein, we validated in vitro, in stromal-responsive human myeloma cell lines, and in vivo, in orthotopic disseminated xenograft models of myeloma, that tofacitinib showed efficacy in myeloma models. Furthermore, tofacitinib strongly synergized with venetoclax in coculture with bone marrow stromal cells but not in monoculture. Surprisingly, we found that ruxolitinib, an FDA approved agent targeting JAK1 and JAK2, did not lead to the same anti-myeloma effects. Combination with a novel irreversible JAK3-selective inhibitor also did not enhance ruxolitinib effects. Transcriptome analysis and unbiased phosphoproteomics revealed that bone marrow stromal cells stimulate a JAK/STAT-mediated proliferative program in myeloma cells, and tofacitinib reversed the large majority of these pro-growth signals. Taken together, our results suggest that tofacitinib reverses the growth-promoting effects of the tumor microenvironment. As tofacitinib is already FDA approved, these results can be rapidly translated into potential clinical benefits for myeloma patients.

Optimizing the CAR T-Cell Therapy Experience in Multiple Myeloma: Clinical Pearls From an Expert Roundtable.

Chimeric antigen receptor T-cell (CAR-T) therapies offer substantial advancement in the treatment of multiple myeloma (MM). However, the CAR-T therapy process involves complex decision-making that is informed by many variables. This review aims to provide an overview of the patient selection and administration process for CAR-T therapy for MM from the perspective of experienced healthcare providers (HCPs), including considerations for each step in the CAR-T therapy process. Referring HCPs should initiate conversations with HCPs at CAR-T capable centers earlier in the treatment journey, even before patients are eligible for CAR-T therapy, particularly for patients from underserved populations and patients with high-risk disease, to ensure adequate time for logistical planning and patient education. Patient selection for CAR-T therapy may be guided by factors such as performance status, rate of disease progression, and logistical considerations. Some anticancer therapies may affect T-cell fitness and therefore impact CAR-T manufacturing and patient outcomes; however, additional research is needed to confirm this in MM. Bridging therapies should be tailored to the needs of the patient and ideally halted 1 week or longer before CAR-T infusion, contingent upon the agent(s) used. Lymphodepletion regimens may need to be modified for patients with renal insufficiency. Collaboration with HCPs at both the treating and referring centers is important to optimize coordinated care of patients. Collaboration with and guidance from experienced HCPs throughout patient selection, referral, and CAR-T administration is instrumental in optimizing patient outcomes as access to CAR-T therapies expands.

Salvage therapies including retreatment with BCMA-directed approaches after BCMA CAR-T relapses for multiple myeloma.

ABSTRACT: For patients with relapsed/refractory multiple myeloma with a relapse after B-cell maturation antigen (BCMA)-directed chimeric antigen receptor T-cell therapy (CAR-T), optimal salvage treatment strategies remain unclear. BCMA-directed CAR-T and bispecific antibodies (BsAbs) are now commercially available, and the outcomes for retreatment with BCMA-directed approaches are not well studied. We performed a retrospective analysis of 68 patients with relapsed disease after BCMA-directed CAR-T to evaluate outcomes and responses to salvage therapies. With a median follow-up of 13.5 months, median overall survival from time of relapse until death was 18 months (95% confidence interval [CI], 13.2 to not reached [NR]). Fifty-eight patients received subsequent myeloma-directed therapies, with a total of 265 lines of therapy (LOTs). The overall response rate for firstline salvage therapy was 41% (95% CI, 28-55). Among all LOTs, high response rates were observed among those receiving another BCMA-directed CAR-T (89%), BCMA-directed BsAbs (60%), CD38-directed combinations (80% when combined with BsAb; 50% when combined with immunomodulatory drugs and/or proteasome inhibitors), and alkylator-combinations (50% overall; 69% with high-dose alkylators). Thirty-four patients received at least 1 line of salvage BCMA-directed therapy; median progression-free survival was 8.3 months (95% CI, 7.9 to NR), 3.6 months (95% CI, 1.4 to NR), and 1 month (95% CI, 0.9 to NR) with median duration of response (DOR) of 8 months, 4.4 months, and 2.8 months for subsequent BCMA-directed CAR-T, BsAb, and belantamab mafadotin, respectively. Retreatment with BCMA-directed CAR-T and BsAbs can be effective salvage options after BCMA-directed CAR-T relapse; however, DORs appear limited, and further studies with new combinations and alternative targets are warranted.

CD4+ CAR-T cell exhaustion associated with early relapse of multiple myeloma after BCMA CAR-T cell therapy.

Multiple myeloma is characterized by frequent clinical relapses following conventional therapy. Recently, chimeric antigen receptor T (CAR-T) cells targeting B-cell maturation antigen (BCMA) has been established as a treatment option for patients with relapsed or refractory disease. However, while >70% of patients initially respond to this treatment, clinical relapse and disease progression occur in most cases. Recent studies showed persistent expression of BCMA at the time of relapse, indicating that immune intrinsic mechanisms may contribute to this resistance. While there were no pre-existing T cell features associated with clinical outcomes, we found that patients with a durable response to CAR-T cell treatment had greater persistence of their CAR-T cells compared to patients with transient clinical responses. They also possessed a significantly higher proportion of CD8+ T effector memory cells. In contrast, patients with short-lived responses to treatment have increased frequencies of cytotoxic CD4+ CAR-T cells. These cells expand in vivo early after infusion but express exhaustion markers (HAVCR2 and TIGIT) and remain polyclonal. Finally, we demonstrate that non-classical monocytes are enriched in the myeloma niche and may induce CAR-T cell dysfunction through mechanisms that include TGFß. These findings shed new light on the role of cytotoxic CD4+ T cells in disease progression after CAR-T cell therapy.

CD46-Targeted Theranostics for PET and 225Ac-Radiopharmaceutical Therapy of Multiple Myeloma.

PURPOSE: Multiple myeloma is a plasma cell malignancy with an unmet clinical need for improved imaging methods and therapeutics. Recently, we identified CD46 as an overexpressed therapeutic target in multiple myeloma and developed the antibody YS5, which targets a cancer-specific epitope on this protein. We further developed the CD46-targeting PET probe [89Zr]Zr-DFO-YS5 for imaging and [225Ac]Ac-DOTA-YS5 for radiopharmaceutical therapy of prostate cancer. These prior studies suggested the feasibility of the CD46 antigen as a theranostic target in multiple myeloma. Herein, we validate [89Zr]Zr-DFO-YS5 for immunoPET imaging and [225Ac]Ac-DOTA-YS5 for radiopharmaceutical therapy of multiple myeloma in murine models. EXPERIMENTAL DESIGN: In vitro saturation binding was performed using the CD46 expressing MM.1S multiple myeloma cell line. ImmunoPET imaging using [89Zr]Zr-DFO-YS5 was performed in immunodeficient (NSG) mice bearing subcutaneous and systemic multiple myeloma xenografts. For radioligand therapy, [225Ac]Ac-DOTA-YS5 was prepared, and both dose escalation and fractionated dose treatment studies were performed in mice bearing MM1.S-Luc systemic xenografts. Tumor burden was analyzed using BLI, and body weight and overall survival were recorded to assess antitumor effect and toxicity. RESULTS: [89Zr]Zr-DFO-YS5 demonstrated high affinity for CD46 expressing MM.1S multiple myeloma cells (Kd = 16.3 nmol/L). In vitro assays in multiple myeloma cell lines demonstrated high binding, and bioinformatics analysis of human multiple myeloma samples revealed high CD46 expression. [89Zr]Zr-DFO-YS5 PET/CT specifically detected multiple myeloma lesions in a variety of models, with low uptake in controls, including CD46 knockout (KO) mice or multiple myeloma mice using a nontargeted antibody. In the MM.1S systemic model, localization of uptake on PET imaging correlated well with the luciferase expression from tumor cells. A treatment study using [225Ac]Ac-DOTA-YS5 in the MM.1S systemic model demonstrated a clear tumor volume and survival benefit in the treated groups. CONCLUSIONS: Our study showed that the CD46-targeted probe [89Zr]Zr-DFO-YS5 can successfully image CD46-expressing multiple myeloma xenografts in murine models, and [225Ac]Ac-DOTA-YS5 can effectively inhibit the growth of multiple myeloma. These results demonstrate that CD46 is a promising theranostic target for multiple myeloma, with the potential for clinical translation.

Intensity of Cyclophosphamide-Based Bridging Therapy Before Chimeric Antigen Receptor T Cell Therapy in Myeloma.

Patients receiving autologous chimeric antigen receptor T cell (CAR-T) therapy for multiple myeloma (MM) may require bridging therapy (BT) before CAR-T infusion to maintain some level of disease control. Alkylators, such as cyclophosphamide (Cy), are often used in regimens, either in high-intensity regimens, such as modified hyperCVAD (cyclophosphamide, vincristine, doxorubicin, and dexamethasone), or once-weekly regimens, such as KCd (carfilzomib, cyclophosphamide, and dexamethasone). However, there is no consensus regarding the optimal BT alkylator dose intensity in MM. We performed a single-center analysis of all instances of BT before planned autologous CAR-T for MM during a 5-year period ending in April 2022. We classified bridging regimens into 3 cohorts: (1) hyperfractionated Cy (HyperCy) with inpatient Cy every 12 to 24 hours or as a continuous i.v. infusion; (2) less intensive Cy dosing (WeeklyCy), such as KCd; and (3) NonCy, in which no alkylators were used in BT. Demographic, disease-related, and treatment-related characteristics were collected for all patients. The 3 BT cohorts were compared using the Fisher exact test, Kruskal-Wallis test, and log-rank test, as appropriate. We identified 70 discrete BT instances among 64 unique patients, including 29 (41%) with HyperCy, 23 (33%) with WeeklyCy, and 18 (26%) with NonCy. The median total Cy dosing during BT in the 3 groups were 2100 mg/m2, 615 mg/m2, and 0 mg/m2, respectively. Age, number of prior lines of therapy, triple-class refractory status, presence of high-risk cytogenetics, extramedullary disease, bone marrow plasma cell burden, involved free light chain (iFLC) kinetics before collection, and other measures of disease aggressiveness were comparable across the 3 cohorts. iFLC levels rose ≥25% and ≥100 mg/L during BT (approximating progressive disease) in comparable proportions (P = .25) among the cohorts: 52% for HyperCy, 39% for WeeklyCy, and 28% for NonCy. All BT instances without subsequent CAR-T were due to manufacturing failures. Among 61 instances of BT followed by CAR-T, vein-to-vein times were slightly longer (P = .03) with HyperCy (45 days) compared with WeeklyCy (39 days) and NonCy (46.5 days). Neutrophil recovery times were similar in the 3 cohorts, but platelet recovery took longer with HyperCy (64 days) compared with WeeklyCy (42 days) and NonCy (12 days). Progression-free survival was comparable among the cohorts, but median overall survival (OS) was not: 15.3 months with HyperCy, versus 30.0 months with WeeklyCy and not reached with NonCy. In our retrospective analysis of BT before CAR-T therapy in MM, HyperCy did not result in superior disease control than WeeklyCy despite a 3-fold higher dose of Cy. In contrast, HyperCy was associated with longer post-CAR-T platelet recovery and worse OS despite comparable measurements of disease aggressiveness and tumor burden. Study limitations include our small sample size, as well as confounding from gestalt markers of MM aggressiveness that might have led to poorer outcomes as well as physicians' decision to prescribe HyperCy. Given the rarity of objective disease responses to chemotherapy in relapsed/refractory MM, our analysis suggests that hyperfractionated Cy regimens do not outperform once-weekly Cy regimens for most patients who require BT before CAR-T therapy.

Significance of the pee-value: relevance of 24-hour urine studies for patients with myeloma.

International Myeloma Working Group (IMWG) response criteria require refrigerated 24-hour urine specimens for most patients. However, given that serum free light chain testing has been shown to outperform 24-hour urine immunofixation as a prognostic marker, the importance of maintaining urine testing options or requirements within each level of IMWG response criteria has not been investigated. We analyzed responses to induction therapy for all transplant-eligible patients with multiple myeloma at our institution over a 3-year period using traditional versus 'urine-free' IMWG response criteria (where references to urine were removed from the descriptions for every depth of response). Of 281 evaluable patients, responses changed for only 4% of patients (95% confidence interval 2-7%) using urine-free criteria. Our results call into question the continued requirement for 24-hour urine measurements as part of IMWG response assessments for all patients. Research into the prognostic performance of urine-free IMWG criteria is ongoing.

Safety and Efficacy of BCMA CAR-T Cell Therapy in Older Patients With Multiple Myeloma.

Risks of B-cell maturation antigen (BCMA) chimeric antigen receptor T-cell (CAR-T) therapy for patients with multiple myeloma (MM) include cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), cytopenias, and infections. The efficacy and safety of BCMA CAR-T therapy in the geriatric setting, including complications such as falls and delirium, which may be more prevalent in older patients, have not been fully analyzed. We wanted to analyze the efficacy and safety of BCMA CAR-T therapy among older patients (age ≥70 at infusion) versus younger patients with MM. We analyzed all patients with MM who received any autologous BCMA CAR-T therapy over a 5-year period at our institution. Key endpoints included CRS, ICANS incidence, days to absolute neutrophil count (ANC) recovery, incidence of hypogammaglobulinemia (IgG < 400 mg/dL), infections within 6 months, progression-free survival (PFS), and overall survival (OS). Of 83 analyzed patients (age range 33-77), 22 (27%) were aged ≥70 at infusion. The older cohort had lower creatinine clearances (median 67.3 versus 91.9 mL/min, P < .001) and a higher proportion of patients with performance status ≥1 (59% versus 30%, P = .02) but were otherwise similar. Rates of any-grade CRS, any-grade ICANS, and days to ANC recovery were similar between groups. Rates of baseline hypogammaglobulinemia were 36% in older patients and 30% in younger patients (P = .60), whereas post-infusion hypogammaglobulinemia occurred in 82% versus 72%, respectively (P = .57). Infections occurred in 36% (n = 8) of the older cohort versus 52% (n = 32) of the younger cohort (P = .22). There were no statistically significant differences between the older and younger cohorts in terms of documented falls (9% versus 15%, P = .72) or non-ICANS delirium (5% versus 7%, P = 1.0). Median PFS was 13.1 months in older patients (95% confidence interval [CI], 9.2-not reached [NR]) versus 12.5 months in younger patients (95% CI 11.3-22.5, P = .42. Median OS was not reached in the older cohort (95% CI, NR-NR) versus 31.4 months in the younger cohort (95% CI, 24.8-NR) with P = .04. However, age ≥70 was not a significant predictor of OS after adjusting for high-risk cytogenetics, triple-class refractoriness, extramedullary disease, and bone marrow plasma cell burden. Although limited by small sample size and unmeasured confounders, our retrospective analysis did not demonstrate significant increases in CAR-T toxicity among older patients. This included toxicities associated with geriatric populations such as falls and delirium. Our paradoxical finding of borderline better OS among patients aged ≥70, which was not significant in regression modeling, may have been due to selection bias in favor of disproportionately healthy CAR-T candidates in the geriatric population. Overall, BCMA CAR-T remains a safe and effective option for older patients with MM.

Daratumumab Plus Bortezomib and Dexamethasone in Newly Diagnosed Systemic Light Chain Amyloidosis.

Light chain amyloidosis (AL) is a plasma cell dyscrasia characterized by organ dysfunction, morbidity, and early mortality. Daratumumab in combination with cyclophosphamide, bortezomib, and dexamethasone is now standard frontline AL therapy; however, not all patients are candidates for this intensive regimen. Given the potency of Daratumumab, we evaluated an alternative frontline regimen: daratumumab, bortezomib, and limited-duration dexamethasone (Dara-Vd). Over a 3 year period, we treated 21 patients with Dara-Vd. At baseline, all patients had cardiac and/or renal dysfunction, including 30% of patients with Mayo stage IIIB cardiac disease. Nineteen of 21 patients (90%) achieved a hematologic response with 38% achieving a complete response. The median time to response was 11 days. Ten of 15 (67%) evaluable patients achieved a cardiac response and 7 of 9 (78%) achieved a renal response. The 1-year overall survival was 76%. In untreated systemic AL amyloidosis, Dara-Vd produces rapid and deep hematologic and organ responses. Dara-Vd was well-tolerated and efficacious, even among patients with extensive cardiac dysfunction.