Daratumumab Treatment Research Articles

Commentary: Case report: Daratumumab treatment in pre-transplant alloimmunization and severe hemolytic anemia.

Pereda et al. recently reported three cases in which daratumumab was utilized to reduce the 36 burden of red blood cell (RBC) and human leukocyte antigen (HLA) alloantibodies (1). These 37 cases support the need for further investigation into the potential use of daratumumab and related 38 plasma cell depletion therapies for patients with significant alloimmunization. However, the 39 authors' cases, particularly cases 1 and 2 in which the authors describe patients with sickle cell 40 disease (SCD) and multiple RBC antibodies, lack sufficient immunohematology and transfusion 41 details to reliably conclude the effectiveness and safety of daratumumab to reduce and existing alloantibodies can persist despite daratumumab treatment (3-6). Secondly, the 80 authors fail to acknowledge the possibility that the alloantibodies may have disappeared naturally 81 through the phenomenon of evanescence. Numerous studies have shown that many patients' 82 RBC alloantibodies will decline in titer to levels below a detectable threshold without further 83 exposure (7-9). Though the loss of all antibodies due to evanescence may be less likely, not 84 accounting for this potential mechanism of a waning antibody is concerning. 85 86 Furthermore, literature demonstrates that even if these antibodies have become undetectable, 87 these patients may still be at risk for DHTRs (10-13).

Predictive role of absolute lymphocyte count in daratumumab-treated patients with relapsed/ refractory multiple myeloma.

Daratumumab has shown an encouraging antitumor effect in patients with multiple myeloma (MM), and was known to alter the immune properties by off-targeting immunosuppressive cells. Here, we aimed to evaluate the change in absolute lymphocyte count (ALC) as a surrogate marker for predicting survival outcomes of patients treated with daratumumab. Between 2018 and 2021, the medical records of patients with relapsed/refractory MM (RRMM) treated with daratumumab monotherapy at 10 centers in South Korea were reviewed. We collected the ALC data at pre-infusion (D0), day 2 after the first infusion (D2), and prior to the third cycle of daratumumab therapy (D56). Fifty patients who were administered at least two cycles of daratumumab were included. Overall response rate was 54.0% after two cycles of daratumumab treatment. On D2, almost all patients experienced a marked reduction in ALC. However, an increase in ALC on D56 (ALCD56) was observed in patients with non-progressive disease, whereas failure of ALC recovery was noted in those with progressive disease. Patients with ALCD56 > 700/μL (n = 39, 78.0%) had prolonged progression- free survival (PFS) and overall survival (OS) than those with ALCD56 ≤ 700/μL (median PFS: 5.8 months vs. 2.6 months, p = 0.025; median OS: 24.1 months vs. 6.1 months, p = 0.004). In addition, ALCD56 >700/μL was a significant favorable prognostic factor for PFS (hazard ratio [HR], 0.22; p = 0.003) and OS (HR, 0.23; p = 0.012). Increase in ALC during daratumumab treatment was significantly associated with prolonged survival outcomes in patients with RRMM. The ALC value can predict clinical outcomes in patients treated with daratumumab.

HSD42 Modelling Time and Costs Associated With Daratumumab Treatment Delivery in the Home Care Setting Versus the Hospital in Spain to Understand Potential Benefits to Patients and Hospitals

Subcutaneous (SC) formulations of daratumumab replace the previous need for intravenous infusion, potentially enabling treatment to be provided at alternative sites of care. This research aims to evaluate if daratumumab SC injection for multiple myeloma in the home care setting can provide value to patients and hospitals in terms of time spent on treatment and associated costs, versus receiving treatment in the Spanish hospital setting.

EZH2 Targeting Induces CD38 Upregulation and Response to Anti-CD38 Antibodies in Multiple Myeloma

Multiple myeloma (MM) is the second most common hematological malignancy characterized by the accumulation of tumor plasma cells within the bone marrow. MM is characterized by high molecular and clinical heterogeneity. During the last 10 years new therapeutic classes including targeted immunotherapies significantly improved the overall survival of MM patients. However, drug resistance and relapse remain major challenges in MM. In MM, marked reduction of CD38 expression via exocytosis, endocytosis, degradation of the antigen-antibody complex and trogocytosis has been associated with resistance to CD38 targeted immunotherapies. Our group previously described a link and a negative correlation between CD38 and EZH2 (Enhancer of Zeste homolog 2) expression during normal B to plasma cell differentiation in association with a transcriptional control of CD38 expression involving the polycomb PRC2 complex (Herviou et al. Leukemia. 2019). Here we identified a significant negative correlation between CD38 expression and EZH2 expression in 2 independent cohorts of MM patients (p<0.05; Montpellier cohort n=198; Compass cohort n=631). Thus, we hypothesized that PRC2 targeting using EZH2 inhibitor could result in CD38 re-expression to overcome daratumumab resistance. We first characterized the membrane CD38 expression by calculating the Antibody Binding Capacity in our unique panel of 40 Human Myeloma Cell lines (HMCL) representative of MM heterogeneity. We observed a heterogeneous expression of the membrane CD38 expression on MM cell lines with cell lines demonstrating no membrane expression and cell lines demonstrating high membrane expression. Next, we selected 3 HMCLs with low (JJN3), intermediate (XG2), and high (XG7) CD38 expression, and treated these cell lines with sublethal concentration of EZH2 inhibitor (EPZ-6438) for 9 days. CD38 membrane expression was characterized at Day 3, Day 6 and Day 9. Interestingly, EZP-6438 treatment induced upregulation of cell surface CD38 expression on all the HMCLs tested with the highest effect measured at day 9. Similar re-expression pattern was observed by western blot at these timing in the JJN3 CD38low cell line. Remarkably, ChIPseq analyses underlined a significant association of H3K27me3 mark at CD38 promoter in CD38neg and CD38low cell lines compared to CD38highcells. In addition, we investigated the efficiency of CD38 monoclonal antibodies (Daratumumab and Isatuximab) lysis through ADCC (Antibody dependent cellular cytotoxicity) assay after 9 days of EPZ-6438 pretreatment. Using JJN3 CD38low HMCL, EPZ-6438 pretreatment significantly improved the ADCC lysis induced by low doses of Daratumumab and Isatuximab treatment, in presence of purified Natural Killer (NK) from healthy donor, together with CD38 re-expression (p<0.05; n=3). Finally, we searched to validate these results using primary MM cells from patients at relapse after Daratumumab treatment. EPZ-6438 pretreatment resulted in a significant CD38 membrane expression upregulation with a 2 fold difference compared to the control condition together with improved ADCC toxicity of anti-CD38 antibodies in vitro. Altogether we demonstrated that treatment of MM cells with EZH2 inhibitor leads to significant upregulation of membrane CD38 expression in cell lines and primary MM cells from patients. CD38 re-expression was linked to an improvement of Daratumumab and Isatuximab ADCC efficiency. Thus, EZH2 targeting may be of therapeutic interest to overcome resistance to anti-CD38 targeted immunotherapies in Multiple Myeloma.

Evaluation of the Path to Diagnosis and Time to Treatment in Patients with Light-Chain Amyloidosis Using the Komodo Claims Database

Background: Light-chain (AL) amyloidosis is a rare, progressive, systemic disease caused by plasma cell dyscrasia (PCD) and results in significant morbidity and mortality. Delays in diagnosis have been reported mainly due to nonspecific symptoms and heterogeneity in patients' clinical presentation. Anti-PCD therapy should be initiated immediately upon diagnosis to achieve a favorable hematologic response and deep organ response to improve overall survival. The goal of this analysis was to understand the path to diagnosis and the treatment patterns around the time of diagnosis using real-world data in a current population with AL amyloidosis. Methods: A retrospective cohort study of adults (age ≥18 years) with AL amyloidosis was conducted using Komodo Health US claims data (January 2015-January 2021). Patients with ≥24 months' continuous coverage from the first claim of any condition to the date of first diagnosis of AL amyloidosis (index date; ICD-10: E85.81) and follow-up ≥6 months postdiagnosis were included. Results are reported using descriptive statistics. Patients were grouped according to organ in which the symptoms were primarily experienced. Results: A total of 2621 patients were identified (56% male; mean age, 65.6 years) who met the inclusion criteria. More than 91% of patients reported experiencing cardiac symptoms prior to diagnosis and the median time to diagnosis for this group was 32 months, the longest of any patient group (Table). Diagnoses of AL amyloidosis on the index date were most frequently made by internal medicine (20%) or a hematologist/oncologist (19%). The specialties most frequently diagnosing AL amyloidosis as the primary diagnosis on the index date were hematology/oncology (22%) and oncology/medical (20%). Hematology/oncology was the most common specialty visited by patients on the index date and within 1- and 3-months prior to diagnosis but was not one of the top 6 specialties visited within 6- and 12-months prior to diagnosis. The top 6 specialties for which services were rendered within 6- and 12-months prior to the index date were Internal Medicine, Diagnostic Radiology, Cardiology, Pathology, Emergency Medicine, and Family Practice. Despite the prevalence of cardiac symptoms, only 10% of patients had AL amyloidosis diagnosed by cardiologists. Anti-PCD treatment was initiated on the same date as diagnosis for 254 (9.7%) patients and within 30 days of diagnosis for 1128 (43%) patients (Figure). Cyclophosphamide-bortezomib-dexamethasone (CyBorD) was the most common treatment on the index date, and within 7-, 14-, and 30-days of diagnosis. Higher proportions of patients with cardiac symptoms received CyBorD, prednisone, and doxycycline than those without cardiac symptoms, whereas higher proportions of patients without cardiac symptoms received daratumumab than those with cardiac symptoms. The median time from index date to first daratumumab treatment was 131 days, and the median duration of daratumumab treatment was 168 days. The proportion of patients receiving daratumumab increased and the time from index date to daratumumab treatment initiation decreased each successive year. Conclusions: These data suggest a need for greater awareness and understanding of presenting symptoms to facilitate earlier diagnosis of AL amyloidosis. Anti-PCD treatment was initiated for almost half the patients within 1 month of the index date (first diagnosis of AL amyloidosis). The time from diagnosis to initiation of daratumumab treatment is decreasing over time, most likely due to approval of daratumumab and increased awareness of AL amyloidosis. There is still a lag time between diagnosis and initiation of treatment. It is essential that treatment is started as quickly as possible. Therapies under development that decrease amyloid burden may contribute to improving patient survival and outcomes. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Outcomes of Patients with AL Amyloidosis after Failure of Daratumumab-Based Therapy

Daratumumab (DARA) has shown efficacy in patients (pts) with AL amyloidosis inducing rapid and deep hematologic and organ responses. DARA with VCd is an approved treatment for newly diagnosed pts with AL amyloidosis, while DARA-based therapies are a major salvage option for pts with relapsed or refractory AL amyloidosis. However, with the increasing use of DARA, there is a growing number of pts who either relapse or are refractory to DARA-based therapy. The data on the management of these pts are scarce and treatment options may be limited. In the current analysis, we aim to describe the outcomes of pts with AL amyloidosis who failed on DARA treatment and received further salvage therapy. The analysis included consecutive pts with AL amyloidosis treated in the Department of Clinical Therapeutics, Athens Greece, who received DARA-based therapy, at any time during the course of their disease. Overall, 116 pts with AL amyloidosis received therapy with DARA and the analysis focused on 31 (26.7%) that either relapsed after DARA discontinuation or were refractory to DARA or had non-satisfactory response requiring further therapy. The characteristic of these 31 pts at the time of initial diagnosis, included cardiac involvement in 27 (87%), renal in 15 (48%), liver in 4 (13%), PNS in 5 (16%) and 9 (29%) had soft tissue involvement. Baseline Mayo stage was 3% / 45% / 48% for stages 1 / 2 / 3 [6 (19%) were Mayo 3b] and renal stage distribution was 55% / 32% / 10% for stages 1 / 2 / 3. Translocation (11;14) (in 29%), and +1q21 (in 26%) of pts were the most common cytogenetic abnormalities. At DARA index therapy, 23 (74.2%) pts had received DARA monotherapy and 8 (25.8%) in combinations (mainly with bortezomib); in 13 (42%) pts as first line and in 18 (58%) as salvage therapy; the median number of treatments prior to DARA index therapy was 1 (range 0-4). DARA was given as salvage therapy in 11 (61.1%) pts due to inadequate hematologic response to prior therapy, in 6 (33.3%) due to hematologic relapse or progression and in 1 (5.6%) due to organ progression. Median duration of DARA therapy was 2.8 months (range 0.5-31.7 months) and on ITT the hematologic response rate at index DARA therapy was 61.3% [CR/VGPR: 10 (32.3%), PR: 9 (29%)]. DARA failure was due to hematologic relapse in 18 (58%) pts, inadequate hematologic response in 11 (32%) and in 2 (6.5%) due to organ progression; the median time to "failure" during or after therapy with DARA was 13.6 months (0.5-43.6); at the time of DARA failure, 8 (26%) pts had had an organ response and 5 (16%) organ progression. At the time of DARA failure, 26 pts (84%) were exposed to bortezomib, 15 (48%) to lenalidomide and 3 (10%) to melphalan. Treatments post DARA failure included re-treatment with DARA combinations (with bortezomib or IMiDs) in 9 (29%) pts, venetoclax in 3 (9.7%) pts, belantamab mafodotin in 4 (12.9%) pts, bortezomib-based regimens in 6 (19.4%) pts, lenalidomide-based in 3 (9.7%) pts, pomalidomide in 3 (9.7%) pts, ixazomib in 2 patient (6.4%) and alkylating agent in 1 patient (3.2%). Median NTproBNP at start of post DARA therapy was 3936 ng/L and median dFLC was 123 mg/L. Hematologic response rate was 55% [VGPR/CR: 14 pts (45%), PR: 3 pts (10%)]; organ responses were observed in 9 pts (29%) and organ progression in 16 pts (51.6%). Among the 9 pts retreated with DARA-based regimens, 2 (22.2%) achieved VGPR and for non-DARA regimens hematologic response rate was 68.1% [CR/VGPR: 12 (54.5%), PR: 3 (13.6%)]. Ten pts (32.3%) have died; 1- and 2-year survival rate from the start of post DARA therapy was 64% and 55%. In univariate analysis, factors that were associated with inferior survival post DARA were NTproBNP (p=0.002), ALP (p<0.001) and dFLC (p=0.025) levels. Pts that failed DARA due to inadequate hematologic response had inferior survival than those that started therapy due to hematologic relapse, but the difference was not statistically significant (p=0.279) (Fig 1). In conclusion, treatment of pts with AL amyloidosis who have failed DARA therapy is feasible, based on the use of non-cross resistant drugs or other targeted therapies. Hematologic responses in 55% and a 2-year survival of 55% in this difficult to treat population are respectful and set the benchmark for the evaluation of new therapies in this setting. Re-treatment with DARA may not be the best option, but more data are needed. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Avoiding Daratumumab Interference with Blood Typing

Background Daratumumab is an IgG monoclonal antibody that binds CD38 on hematopoietic cells and induces apoptosis. It is FDA approved for upfront treatment of systemic light chain amyloidosis as well as treatment of frontline and relapsed/refractory multiple myeloma. Daratumumab, similar to other CD38 monoclonal antibodies, interferes with blood compatibility testing by causing panagglunination on the Indirect Antiglobulin Test (IAT) leading to false positive results and delays in blood availability for transfusion. This panagglutination can persist up to 6 months after the last Daratumumab infusion. Additionally, attempts to overcome this may mask the presence of a clinically significant antibody resulting in acute or delayed hemolytic transfusion reactions. Several laboratory techniques like RBC genotyping, phenotyping, and the use of Dithiothretol (DTT) treatment of serum are used to overcome this laboratory abnormality. These are either technically time consuming or not widely available in all healthcare institutions. DTT, though readily available, requires prior notification of the blood bank when a patient who is being treated with Daratumumab needs a transfusion. This labor intensive and time consuming process may result in delays in patient care adverse outcomes. By far, the most cost effective way is to obtain blood type and antibody screen (IAT) prior to the initial Daratumumab administration. However, this requires institutional strategy (policy, procedure and pathway) for all potential patients starting anti CD38 monoclonal antibodies in general and daratumumab in particular, to allow timely typing and screening of blood in preparation for future transfusion needs. This quality improvement project was instituted to obtain a type and screen (T&S) prior to patients starting Daratumumab in order to champion high value healthcare which balances clinical benefit with costs and harms with the ultimate goal of improving patient outcomes. Methods and Results We retrospectively identified 32 patients who received their first Daratumumab infusion or subcutaneous injection from 11/1/2017 to 5/31/2020 at Community Medical Centers and Community Cancer Institute in Clovis, California and Fresno, California. 13 patients did not have a T&S done within 30 days prior to initiation of Daratumumab, which translates to 40.6%. We conducted manual chart of all patients prior to the intervention and found 6 patients without prior T&S who required transfusions after starting Daratumumab. Each transfusion was regarded as an event regardless of the units of blood received. We calculated the time from T&S order to receipt of transfusion. In total, there were 15 events which amounts to 1,5990 cumulative minute, with the average time to transfusion (TTT) being 1066 minutes. There were also 6 patients with T&S performed prior to Daratumumab initiation who had a total of 22 transfusion events that took 20417 minutes. The average TTT for this group is 928 minutes. The difference in average TTT between patients who had T&S and those that did not have T&S is 138 minutes, which can be clinically significant. We implemented a T&S as part of "Day 0" in our chemotherapy orders in December 2020. 17 patients received their first Daratumumab from January 2021 to January 2022. 15 patients (88%) had T&S performed and 2 patients did not as they were patients from out of network providers. Conclusion We are continuing to gather additional data to see if this improvement results in a decrease in average TTT post implementation. This is quality improvement project represents a major step in reducing delays in blood compatibility testing due to Daratumumab. There are no significant changes in resource utilization since patients who need transfusions will require a T&S to be done regardless. Ensuring that a T&S is performed antecedent to the first Daratumumab treatment will reduce delays in obtaining matched blood products for our myeloma patients. This supports timely transfusions to lower adverse outcomes associated with anemia due to chemotherapy and multiple myeloma.

Cytomegalovirus and Epstein-Barr Virus Infection during Daratumumab Treatment in Patients with Multiple Myeloma

Cytomegalovirus and Epstein-Barr Virus Infection during Daratumumab Treatment in Patients with Multiple Myeloma

Efficacy and Safety of Belantamab Mafodotin Monotherapy in Patients with Relapsed or Refractory Light Chain Amyloidosis: A Phase 2 Study By the European Myeloma Network

Introduction. Currently, no established treatments exist for relapsed/refractory (RR) light chain (AL) amyloidosis especially for daratumumab & bortezomib exposed patients (pts). Belantamab mafodotin (belamaf), a multi-modal antibody-drug conjugate targeting BCMA, has shown efficacy and tolerability in heavily pretreated pts with RR multiple myeloma (MM), including those refractory to daratumumab. Clonal plasma cells in AL and MM are phenotypically similar, expressing BCMA; thus, belamaf could be a novel treatment option in RRAL amyloidosis. This study evaluates the efficacy and safety of belamaf monotherapy in pts with RRAL amyloidosis. Methods. The ongoing prospective, open-label, multinational, phase 2, EMN27 study (NCT04617925) aims to enroll 36 RRAL amyloidosis pts who require therapy. Pts at Mayo cardiac stage 3B are excluded. Belamaf monotherapy at 2.5 mg/kg is administered every 6 weeks for up to 8 cycles; dosing can be reduced to 1.92 mg/kg for toxicity. Per study design, an interim safety analysis (after 6 pts received ≥1 treatment cycle) and an efficacy analysis (after 13 pts are enrolled) were planned. The safety analysis revealed no new safety signals, and the efficacy analysis was conducted in 13 pts; with at least 3 pts achieving very good partial response (VGPR). Enrolment is continuing to include all planned pts. This descriptive analysis included pts initiating treatment ≥3 months before the cut-off date (31 May 2022). Results. Seventeen pts were included in this analysis (median age: 65 years [range: 46.0-80.0]; 12 male [70.6%]). At baseline, 5 (29.4%) and 12 (70.6%) pts had New York Heart Association class I and II symptoms respectively; the median N-terminal pro-brain natriuretic peptide, high-sensitivity troponin T, and dFLC were 1,588.0 ng/L (range 190.0-7,270.0), 46.2 ng/L (range 11.0-115.6), and 145 mg/L (range 39-2791), respectively. Except for the heart, commonly involved organs were the peripheral nerves (8 pts, 47.1%), kidneys (4 pts, 23.5%); liver, soft tissue, and gastrointestinal tract involvement was seen in 3 (17.7%) pts, each. Median number of prior lines was 3 (range 1-7). Ten (58.8%) pts had previously received daratumumab treatment and 15 pts (88.2%) had previous bortezomib exposure. At data cut-off, 4 (23.5%) pts were continuing treatment and 13 (76.5%) discontinued due to disease progression (7, 41.2%), adverse event (AE; 3, 17.7%), death (2, 11.8%) and physician decision (1, 5.9%). AEs leading to discontinuation were renal failure (1pt) and keratopathy (2pts). Median duration of belamaf therapy was 1.5 months (range <0.1-8.8). At a median follow up of 8.4 months (range 3.4-14.5), best hematologic response rate for all pts was 52.9% (9 pts - VGPR: 23.5% [4 pts], partial response [PR]: 29.4% [5 pts]). At 1 and 3 months, the respective best hematologic response rates were 52.9% (9 pts; VGPR: 17.6% [3 pts], PR: 35.3% [6 pts]) and 52.9% (9 pts; VGPR: 23.5% [4 pts], PR: 29.4% [5 pts]). The subgroup of pts previously exposed to daratumumab had a best hematologic response rate of 40.0% (4 pts; VGPR and PR: 20.0% [2 pts] each response) during follow-up. For all pts, median time to first hematologic response was 9.0 days (range 7.0-28.0) and to VGPR or better 22.0 days (range 15.0-85.0); the corresponding median times for pts previously exposed to daratumumab were 15.0 days (range 8.0-28.0) and 22.0 days (range 15.0-29.0). For all pts, any organ response rate at 3 months was 29.4% (5 pts; heart: 17.6% [3 pts], kidney: 11.8% [2 pts]). All pts on the study experienced >1 treatment-emergent adverse event (TEAE), with 16 pts (94.1%) experiencing eye disorders, 7 pts (41.2%) experienced blood and lymphatic system disorders, and cardiac disorders occurred in 2 (11.8%) pts. Two (11.8%) pts had a fatal SAE, both unrelated to study treatment. Out of 16 pts with ocular adverse events, 13 pts (76.5%) were reported to have visual acuity reduced, while 11 pts (64.7%) were reported to have keratopathy (all non-serious AEs) and 2 pts (11.8%) with visual impairment, both serious AEs (SAE) (Table 1). Conclusions. In heavily pretreated RR pts with AL amyloidosis, belamaf monotherapy induced rapid, clinically meaningful responses with a convenient delivery scheme and manageable safety profile. Longer dosing intervals (compared to myeloma) show reduced severity of ocular events. The results suggest that belamaf may represent a valid new treatment option for this difficult to treat patient population. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Single Cell Gene Expression Predicts Plasma Cell Leukemia Patient Response to Daratumumab

The promise of precision medicine is to identify the ideal treatment for each patient, eliminating failed treatment cycles and reducing treatment burdens on patients and payors. While gene sequencing can predict effective treatment options in some cases, studies have estimated that only 10-15% of cancer patients are treated with genotype matched drugs. Gene expression is theoretically an attractive alternative to predicting therapeutic response because, it provides a direct readout of dysregulated cellular activities including druggable pathways. However, the use of bulk gene expression to predict therapeutic response is hampered by tumor heterogeneity; that is, a biopsied tumor contains multiple cells types and different tumor clones and a bulk analysis only generates an average gene expression signal across all of the cells, leading to a decreased sensitivity for identifying biomarkers found only in specific cell subgroups. More recently, single-cell gene expression analysis has shown promise in improving precision medicine through a focused look into the biology of the tumor cells themselves. For example, we previously showed (Scolnick, et al ASCO 2022) that a model trained on single-cell gene expression data collected from 17 Multiple Myeloma (MM) patient's plasma cells (PCs) could be used to predict the therapeutic response of seven independent MM patient samples at 100% accuracy. Here we combine single-cell gene expression analysis with Singleron Biotechnology's MapResponse™ machine learning algorithms to extend our predictions to data from peripheral blood mononuclear cells (PBMCs) of plasma cell leukemia patients who were treated with daratumumab. Our model accurately predicted the response to daratumumab treatment for both patients based on the PCs collected from blood samples. These early findings point to the potential value of combining single-cell RNA sequencing with machine learning methods such as MapResponse™ to bring precision medicine to more patients based on minimal invasive assessment of PBMCs.

Cyclophosphamide-Bortezomib-Dexamethasone (CyBorD) +/- Daratumumab Treatment Results in Sustained Hematologic Response in Patients with AL Amyloidosis: A Retrospective Analysis of Patients at Mayo Clinic

Introduction Light chain (AL) amyloidosis is a rare plasma cell disorder characterized by amyloid fibril deposition in various organs leading to progressive organ damage. The standard of care therapy has been cyclophosphamide-bortezomib-dexamethasone (CyBorD) until January 2021 when daratumumab was approved by the FDA for use after data from the Phase 3 ANDROMEDA trial revealed improved outcomes with the quadruplet regimen. Here, we retrospectively evaluated the outcomes of patients with newly diagnosed AL amyloidosis treated with CyBorD +/- daratumumab as first line therapy at the Mayo Clinic from 2009 to 2022. Methods The study was approved by the Mayo Clinic Institutional Review Board. We performed a retrospective analysis of patients diagnosed with AL amyloidosis between 2009 and 2022 who received CyBorD +/- daratumumab as first line therapy. The regimen consisted of subcutaneous bortezomib (1.3 mg/m2 or 1.5mg/m2 on days 1, 4, 8, and 11 every 28 days), cyclophosphamide (300mg/m2 orally or IV weekly), and dexamethasone (20-40mg orally or IV weekly). In patients who also received daratumumab, dosing was 1,800 mg weekly for cycles 1 and 2, every 2 weeks for cycles 3-6, followed by weekly for any additional cycles. Data extracted from the medical record included patient characteristics, subsequent therapies, labs, rates of relapse, and outcomes. Results There were 164 patients available who met criteria for inclusion of newly diagnosed AL amyloidosis. Of the 164, 30 (18.3%) received CyBorD with daratumumab. Mean age at diagnosis was 63.8 years (range, 35-81 years). Most frequent organ involvement included cardiac in 73.8% and kidney in 61.0% patients. Eighty-one percent of patients achieved a hematologic response (defined as complete response in 38% or very good partial response, VGPR, in 43%). No patients were considered eligible for transplant at diagnosis, however after CyBorD +/- daratumumab therapy, 62 (37.8%) received an autologous stem cell transplant (ASCT). Over half of patients received maintenance therapy after initial treatment (53.7%), with daratumumab being the most common maintenance therapy prescribed (62.5%). The most frequent treatment related adverse event included peripheral neuropathy (40.7%), although no patients experienced grade 4 peripheral neuropathy. Forty-five percent of patients experienced cytopenias during treatment, however only <1% required transfusions. There was no difference in treatment related adverse effects with the addition of daratumumab. At 1-year, overall survival was 94% (95% CI 0.90-0.98) and at 5 years, overall survival was 77% (95% CI 0.67-0.87). Conclusions In our retrospective analysis, CyBorD +/- daratumumab produced a durable hematologic response in newly diagnosed patients with AL amyloidosis. Although 18% of patients received daratumumab, outcomes were still excellent, with nearly 40% of patients eligible for ASCT after treatment and 5-year overall survival of 77%.

Efficacy and safety of daratumumab in patients with relapsed/refractory multiple myeloma

Objective: To investigate the efficacy and safety of daratumumab in relapsed/refractory multiple myeloma (RRMM) patients. Methods: Fifty-two RRMM patients treated with daratumumab from September 2019 to November 2021 in West China Hospital were retrospectively enrolled, including 31 males and 21 females. The mean age of these patients at the first diagnosis of multiple myeloma was (58±10) years. According to the dosage of daratumumab, patients were divided into low dosage group (n=10) and high dosage group (n=42). Overall response rate (ORR), progression-free survival (PFS), overall survival (OS), and adverse event rates were investigated. Univariate and multivariate analysis of potential factors were conducted. Results: Of the 52 patients, 8 received daratumumab monotherapy, 27 received daratumumab plus immuno-modulatory drug (IMiD) treatment, 4 received daratumumab plus proteosome inhibitor (PI) treatment, and 11 received daratumumab plus dexamethasone treatment. The diagnosis age of high dosage group patients was (57±9) years, which was significantly younger than that of low dosage group [(66±10) years] (P=0.009). The baseline creatinine level of high dosage group patients [M (Q1, Q3)] was 91 (68, 196) μmol/L, which was significantly higher than that of low dosage group [66 (51, 76) μmol/L] (P=0.021). There was no significant difference in other baseline clinical characteristics, previous treatment regimens, previous lines of treatment, and regimen and cycles of daratumumab between the high dosage group and low dosage group (all P>0.05). The ORR for the 52 patients was 71.2% (37/52). The ORR for daratumumab plus IMiD group was 81.5% (22/27), which was significantly higher than that in monotherapy or dexamethasone group [ORR: 52.6% (10/19), P=0.036). With a median follow-up [M (Q1, Q3)] of 7 (5, 26) months, the median PFS for overall cohort was 17 (95%CI: 9.6-24.4) months. The median PFS for daratumumab plus IMiD group was 26 (95%CI: 6.0-46.0) months, which was significantly better than that in monotherapy or dexamethasone group [12 (95%CI: 3.5-20.5) months] (HR=0.231, 95%CI: 0.075-0.715, P=0.011). Higher diagnosis age was the risk factor of progression (HR=1.085, 95%CI: 1.016-1.158, P=0.014), while more cycles of daratumumab treatment was the protective factor of progression (HR=0.669, 95%CI: 0.495-0.904, P=0.009). There was no significant influence of daratumumab dosage on progression (high dosage vs low dosage, HR=1.016, 95%CI: 0.221-4.668, P=0.984). The median OS for overall cohort was 26 (95%CI: 13.1-38.9) months. Higher serum calcium was the independent risk factor of death (HR=12.190, 95%CI: 1.170-127.048, P=0.037). There was no significant influence of daratumumab dosage on death (high dosage vs low dosage, HR=0.818, 95%CI: 0.171-3.917, P=0.802). Adverse events included infections (43.2%, 16/37), infusion-associated reactions (29.7%, 11/37), and thrombocytopenia (27.0%, 10/37). Conclusions: Daratumumab is effective to treat RRMM. The dosage of daratumumab has no significant influence on prognosis when used in combined treatment. The incidence of adverse events is relatively low, with a favorable safety profile.

Molecular Determinants Underlying the Anti-Cancer Efficacy of CD38 Monoclonal Antibodies in Hematological Malignancies

CD38 was first discovered as a T-cell antigen and has since been found ubiquitously expressed in various hematopoietic cells, including plasma cells, NK cells, B cells, and granulocytes. More importantly, CD38 expression levels on malignant hematopoietic cells are significantly higher than counterpart healthy cells, thus presenting itself as a promising therapeutic target. In fact, for many aggressive hematological cancers, including CLL, DLBCL, T-ALL, and NKTL, CD38 expression is significantly associated with poorer prognosis and a hyperproliferative or metastatic phenotype. Studies have shown that, beyond being a biomarker, CD38 functionally mediates dysregulated survival, adhesion, and migration signaling pathways, as well as promotes an immunosuppressive microenvironment conducive for tumors to thrive. Thus, targeting CD38 is a rational approach to overcoming these malignancies. However, clinical trials have surprisingly shown that daratumumab monotherapy has not been very effective in these other blood malignancies. Furthermore, extensive use of daratumumab in MM is giving rise to a subset of patients now refractory to daratumumab treatment. Thus, it is important to consider factors modulating the determinants of response to CD38 targeting across different blood malignancies, encompassing both the transcriptional and post-transcriptional levels so that we can diversify the strategy to enhance daratumumab therapeutic efficacy, which can ultimately improve patient outcomes.

CAR-T cells derived from multiple myeloma patients at diagnosis have improved cytotoxic functions compared to those produced at relapse or following daratumumab treatment.

Chimeric antigen receptor T cells (CAR‐T) have provided promising results in multiple myeloma (MM). However, many patients still relapse, pointing toward the need of improving this therapy. Here, we analyzed peripheral blood T cells from MM patients at different stages of the disease and investigated their phenotype and capacity to generate functional CAR‐T directed against CS1 or B Cell Maturation antigen. We found a decrease in naive T cells and elevated frequencies of exhaustion markers in T cells from treated MM patients. Interestingly, individuals treated with daratumumab display elevated ratios of central memory T cells. CAR‐T derived from patients at relapse show reduced in vitro expansion and cytotoxic capacities in response to MM cells compared to those produced at diagnosis. Of note, CAR‐T from daratumumab treated patients display intermediate defects. Reduced anti‐myeloma activity of CAR T cells from treated patients was also observed in a mouse model. Our findings suggest that T cell defects in MM patients, specifically during relapse, have a major impact on their capacity to generate efficient therapeutic CAR‐T. Selecting naive or central memory T cell subsets to generate therapeutic T cells could improve the CAR‐T therapy for MM.

Abstract 5141: Using single cell gene expression to develop treatment response predictions in multiple myeloma

Abstract The promise of precision medicine in oncology is to identify the ideal treatment for each patient, eliminating failed treatment cycles and reducing treatment burdens on patients and payors. While gene sequencing can predict effective treatment options in some cases, studies have estimated that only 10-15% of cancer patients are treated with genotype matched drugs. Additional treatment selection tools for predicting patient response thus remains a critical clinical need. While gene sequencing has clear utility in predicting therapeutic response, gene expression is less commonly used in clinical tests to guide treatment selection. Gene expression is theoretically attractive to predicting therapeutic response because, unlike mutational analysis, it provides a direct readout of the dysregulated biochemical activities in the cells which may be targeted by particular therapies. One of the major problems with conventional approaches to using gene expression to predict therapeutic response is tumor heterogeneity; that is, a biopsied tumor contains multiple cells types and even different tumor clones that can confound a conventional bulk gene expression analysis. More recently, single-cell RNA expression analysis technologies have grown in popularity. These technologies enable the fine characterization of tumors and their cellular makeup and hold the promise of increasing the power of gene expression measurements for identifying therapy response prediction tools. Here we show the application of single cell gene expression analysis with Proteona’s MapResponse™ machine-learning algorithms to developing a predictive classifier for patient response to Daratumumab treatment in multiple myeloma. Starting with publicly available data (Cohen et al. Nat. Medicine 2021), we developed a classifier that accurately predicted the response of 94% of subjects in the published study. This classifier was able to accurately predict response in an independent cohort of Daratumumab-treated patients. In contrast, the classifier performed poorly in a cohort of patients who did not receive Daratumumab. Together these data suggest the classifier has specificity to predicting response to Daratumumab and is not a general prognostic signature. These early findings point to the potential value of combining single-cell RNA sequencing with machine-learning methods such as MapResponse™ to bring precision medicine to more patients. Citation Format: Jonathan Scolnick, Stacy Xu, Sanjay de Mel, Cinnie Yentia Soekojo, Wee Joo Chng. Using single cell gene expression to develop treatment response predictions in multiple myeloma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5141.

Abstract 3436: Novel multifunctional tetravalent CD38 NKp46 FLEX NK࣪ engagers actively target and kill multiple myeloma cells

Abstract Given that CD38 is a clinically validated target for NK cell mediated cytotoxicity in multiple myeloma, we sought to leverage our FLEX NKTrademark platform to create a NK engager antibody targeting CD38. FLEX NKTrademark is a proprietary platform for production of tetravalent multifunctional NK engager antibodies with a novel FLEX linker to allow for simultaneous binding of both the targeted cancer cells and NK cells. NK engagement and activation is mediated through a binder directed against the natural cytotoxicity receptor NKp46. With the FLEX NKTrademark scaffold, we created two novel tetravalent NK cell engagers targeting CD38, one with a wild type (WT) Fc and one with a mutant null Fc. Both CD38 NKp46 engagers showed dose dependent binding to CD38 expressing multiple myeloma cell lines MM1S and KMS11 and no binding to a CD38 knock out MM.1S cell line. Both engagers also bound multiple myeloma cell lines with ~ 2-fold higher mean fluorescence intensity than anti-CD38 monoclonal antibody (mAb)or daratumumab alone. Epitope mapping studies for our anti-CD38 mAb using alanine scanning mutagenesis showed that amino acid S274 on CD38, critical for binding to daratumumab, is not important for our anti-CD38 antibody binding to CD38, suggesting a distinct epitope detected by our antibody. Interestingly, the NKp46 monoclonal antibody alone without a functional Fc induced peripheral blood NK cell cytolysis of the multiple myeloma cells, consistent with a prior report that NKp46 plays a key role in NK-cell mediated killing of myeloma cells. Both CD38 NKp46 engagers showed further enhanced dose dependent NK cell redirected cytolysis and degranulation against multiple myeloma cells compared to anti-NKp46 monoclonal antibody. The CD38 NKp46 engagers demonstrated higher cytotoxicity than the anti-CD38 binder mAb or daratumumab alone. The CD38 NKp46 engager with the WT Fc is more potent in induction of TNF-α and IFN-ɣ production compared to daratumumab and the engager with the mutant Fc. No IL-1β or IL-6 was induced by the engagers or daratumumab. Daratumumab treatment resulted in NK cell fratricide, while no fratricide was observed with the CD38-NKp46 NK engager with the mutant Fc. In peripheral blood mononuclear cell hemato-toxicity studies depletion of monocytes and NK cells were observed with daratumumab but no depletion was observed with the CD38 NKp46 engager with the mutant Fc. These results suggest that the CD38 NKp46 engagers have a favorable NK cell engager profile for targeting CD38 expressing multiple myeloma that’s distinct from daratumumab. Citation Format: Liang Lin, Hao-Ming Chang, Cecilia Nakid, Stanley Frankel, Dennis Wu, Jean Kadouche, Daniel Teper, Ofer Mandelboim, Jean-Christophe Bories, Antonio Arulanandam, Wei Li. Novel multifunctional tetravalent CD38 NKp46 FLEX NK࣪ engagers actively target and kill multiple myeloma cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3436.

99mTc-CD3813: A Nanobody-Based Single Photon Emission Computed Tomography Radiotracer with Clinical Potential for Myeloma Imaging and Evaluation of CD38 Expression.

Daratumumab (DARA) is an anti-CD38 monoclonal antibody for the treatment of multiple myeloma (MM). The tumor CD38 expression level is one of the important factors in determining the efficacy of DARA treatment. Therefore, there is an urgent clinical need for a noninvasive tool to evaluate the CD38 levels in cancer patients before, during, and after DARA treatment. In this study, we prepared a new molecular imaging probe 99mTc-CD3813, the 99mTc-labeled nanobody CD3813, for noninvasive imaging of CD38 expression by single photon emission computed tomography (SPECT). We evaluated 99mTc-CD3813 for its CD38 affinity and specificity and its capacity to image the CD38 expression in the MM and lymphoma xenografts models. 99mTc-CD3813 SPECT/CT is able to visualize subcutaneous/orthotopic myeloma lesions in animal models and has advantages over 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography. Excess DARA has less impact on its tumor uptake (3.14 ± 0.83 vs 2.29 ± 0.91 %ID/g, n.s.), strongly suggesting that there is no competition between 99mTc-CD3813 and DARA in binding to CD38. 99mTc-CD3813 SPECT/CT revealed significant reduction in CD38 expression in the Ramos-bearing mice under DARA treatment, as evidenced by their reduced tumor uptake (3.04 ± 0.70 vs 1.07 ± 0.28 %ID/cc, P < 0.001). 99mTc-CD3813 SPECT/CT was also able to detect the increased tumor uptake (0.79 ± 0.29 vs 2.12 ± 0.12 %ID/cc, P < 0.001) due to the upregulation of CD38 levels caused by all-trans retinoic acid infection. 99mTc-CD3813 is a promising SPECT radiotracer for imaging the CD38-positive tumors and has clinical potential as a molecular imaging tool for evaluation of the CD38 expression level in patients before, during, and after DARA treatment.

CD38: A target in relapsed/refractory acute lymphoblastic leukemia-Limitations in treatment and diagnostics.

Daratumumab, an anti-CD38 antibody, is used experimentally in the treatment of relapsed acute lymphoblastic leukemia (ALL). We treated five patients suffering from relapsed ALL with daratumumab. Four patients had T ALL, three of whom achieved complete remission (CR) after treatment and underwent stem cell transplant (SCT). Two of them had a second relapse and died 6 and 8 months after SCT, respectively. One transplanted T ALL patient remained in CR2 15 months after relapse. In the remaining T-ALL patient, the disease progressed under daratumumab treatment, and the patient died early after the first relapse. The B-cell precursor ALL patient with a second CD19-negative relapse, whose disease turned out to be resistant to the combination of daratumumab with chemotherapy, later achieved CR3 with inotuzumab ozogamicin, underwent SCT and remained in CR3. Leukemia burden should be monitored after daratumumab, and care should be taken not to misclassify leukemic cells with false negativity of surface CD38; using an antibody reacting with nondaratumumab epitopes is advantageous.

Programmed Cell Death-1 and Its Ligands as Targets for Therapy of Multiple Myeloma Patients.

PurposeAmong hematological malignancies, the expression profile of programmed cell death-1 (PD-1) and its ligands in multiple myeloma (MM) is still debated by numerous research groups. In current study, we characterized the expression of PD-1 and its ligands both on RNA and protein levels in MM patients. We have also attempted to analyze whether daratumumab therapy might overcome CD38-mediated immunosuppression that inhibits in particular CD8+ T-cell function.Patients and MethodsThis study included 149 newly diagnosed MM patients and 15 relapsed/refractory MM patients before and after daratumumab treatment. The mRNA levels of PDCD1, PDCD1LG1, PDCD1LG2 and their splicing variants was assessed by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). Flow cytometry was used to characterize the surface expression of PD-1 and its ligands on plasma cells, B and T cells. The surface expression of PD-1 on T cells was assessed by flow cytometry before and after daratumumab treatment.ResultsThe mRNA expression of PDCD1LG1, PDCD1LG2 and their splicing variants were higher in plasma cells as compared to bone marrow mononuclear cells (BMMCs). Our results show that the percentage of plasma cells expressing PD-L1 was significantly higher than plasma cells expressing PD-L2 (p<0.0001) in bone marrow (BM) of MM patients. There was no significant difference between the percentage of plasma cells expressing PD-1 and B cells expressing PD-1 in BM of MM patients (11.19% vs 8.91%). We also found that the percentage of CD8+PD-1+ T cells was significantly higher than CD4+PD-1+T cells in BM (p<0.0001) of MM patients. Here, we observed no change in PD-1 expression on CD4+ and CD8+ T cells after the daratumumab treatment.ConclusionThe PD-1 and its ligands might represent an interesting target for MM immunotherapy, as one would target both malignant plasma cells as well as the immune cells that play a key role in tumor escape mechanisms.

Practical Considerations for the Daratumumab Management in Portuguese Routine Clinical Practice: Recommendations From an Expert Panel of Hematologists.

The recent therapeutic progress in multiple myeloma (MM) has led to the introduction of novel and highly potent drug classes. Daratumumab was the first CD38-targeting antibody showing to be effective and safe in MM patients as monotherapy and in combination regimens, which led to its rapid implementation in clinical practice. Considering that treatment discontinuation for drug-related adverse events can impact patients’ quality of life and outcomes, the treatment decision should consider different factors and be weighted for each patient individually. Here, we aimed to guide clinicians using daratumumab treatment for MM by addressing practical real-world considerations based on an expert panel of Portuguese hematologists. Carefully following the recommendations mentioned in daratumumab’s SmPC, and of those from other drugs used in combination regimens, along with ensuring a good communication with all healthcare professionals involved, is critical to prevent any complications arising from treatment. The risk of infection should be assessed for all patients under treatment with daratumumab and patients should be educated on the potential adverse events. Recommendations on prophylaxis and vaccination should be considered to avoid infections, and delays in the planned therapeutic schedule may be required to prevent adverse consequences of hematological toxicity. Daratumumab treatment is effective and feasible in patients with renal impairment, although careful patient monitoring and a frequent communication with the Nephrology department are of the utmost importance. Sharing clinical practice plays an important role in medical education by allowing to maximize treatment efficacy and minimize its safety risks.