Comparison of biosimilar filgrastim and originator filgrastim for peripheral blood stem cell mobilization for allogeneic hematopoietic stem cell transplantation.

BACKGROUND: Nivestym, a biosimilar granulocyte colony-stimulating factor (G-CSF) to the originator filgrastim (Neupogen), is now being used for the mobilization of peripheral blood stem cells (PBSC) in allogeneic hematopoietic stem cell transplantation (allo-HSCT). We aim to compare the efficacy of Nivestym and Neupogen for PBSC mobilization in healthy allogeneic donors. METHODS: We conducted a retrospective single-center study including 541 adult allo-HSCT donors receiving Nivestym (January 2013-July 2020), or Neupogen (July 2020-June 2023) for donor PBSC mobilization. Bivariate analysis was conducted using SPSS version 28. Statistical significance was determined at a p-value <.05. RESULTS: Our study included 541 allo-HSCT donors who received Neupogen (n = 345, 64%) or Nivestym (n = 196, 36%) for PBSC mobilization. The median age was 47 years (range 17-76). The median donor weight was 86 kg (95% confidence interval [CI]: 87-91). Donors receiving Neupogen had similar pre-G-CSF white blood cell count, CD34+ percentages, and circulating CD34+ count compared with donors receiving Nivestym. The Neupogen group had similar median PBSC product total neutrophil count, CD34+ percentage, absolute CD34+ count, and infused CD34+ dose compared with the Nivestym group. For donors aged 35 years or younger, the median CD34+ dose was higher in donors who received Neupogen compared with Nivestym (6.9 vs. 6.3 million cells/kg, p = .044). CONCLUSIONS: Nivestym demonstrated similar efficacy for PBSC mobilization compared with Neupogen among allo-HSCT donors. In donors aged 35 years or younger, a slightly lower PBSC product CD34+ count was noted with Nivestym compared with Neupogen.

Impact of Extraosseous Extramedullary Disease on Outcomes of Patients with Relapsed-Refractory Multiple Myeloma receiving Standard-of-Care Chimeric Antigen Receptor T-Cell Therapy.

The presence of extramedullary disease (EMD) has been associated with poor outcomes in patients with relapsed-refractory multiple myeloma (RRMM). Herein, we report the outcomes of RRMM patients who were treated with standard-of-care (SOC) chimeric antigen receptor (CAR) T-cell therapy and had active extraosseous EMD before the infusion. Data were retrospectively collected from patients at three US institutions with the intent to receive SOC CAR T. Responses were assessed per the International Myeloma Working Group criteria. A total of 152 patients proceeded with infusion, of whom 47 (31%) had EMD (EMD group) and 105 (69%) did not (non-EMD group). Baseline patient characteristics were comparable between the two groups. The EMD group had a higher incidence of high-grade CRS, steroid and anakinra use, and thrombocytopenia on day +30 compared to the non-EMD group. In addition, the EMD group had an inferior overall response rate (58% vs 96%, p < 0.00001), median progression-free survival (PFS) (5.1 vs 12.4 months; p < 0.0001), and overall survival (OS) (12.2 vs 27.5 months; p = 0.00058) compared to the non-EMD group. We further subdivided the non-EMD patients into those with paramedullary disease (PMD-only group, n = 26 [17%]) and those with neither EMD nor PMD (bone marrow-contained group or BM-only group, n = 79 [52%]). Patients with PMD-only had similar median PFS (11.2 vs 13.6 months, p = 0.3798) and OS (not reached [NR] vs 27.5 months, p = 0.6446) compared to patients with BM-only disease. However, patients with EMD exhibited inferior median PFS (5.1 vs 13.6 months, p < 0.0001) and OS (12.2 vs 27.5, p = 0.0008) compared to patients in the BM-only group. Treatment with SOC CAR T yielded meaningful clinical outcomes in real-world RRMM patients with extraosseous EMD, though responses and survival outcomes were suboptimal compared to patients without EMD. The presence of only EMD but not PMD was associated with significantly worse survival outcomes following the CAR T infusion.

TACTUM: Trends in Access to Cellular Therapies in Multiple Myeloma, Perspectives of Treating Versus Referring Physicians.

Chimeric antigen receptor T cell therapy (CAR-T) and bispecific T cell engagers (TCE) for multiple myeloma (MM) are readily available at many large US medical centers. However, many potentially eligible patients may not be referred to the specialized centers administering these therapies. Perspectives regarding potential barriers for MM cellular therapy from referring-center oncologists (ROs) versus treating-center oncologists (TOs) have not been reported previously. We conducted TACTUM-23, a survey of US oncologists who treat MM, to identify perceived barriers to these cellular therapies. This 24-question survey, which focused on demographics and perceived barriers to CAR-T and TCE, was conducted between June and August 2023. Of 247 oncologists, 37 (15%) completed the survey including 26 (70%) TOs who prescribed both CAR-T and TCEs, 4 (11%) TOs who only prescribed TCEs, and 7 (19%) ROs who referred patients. The top RO-stated barrier to CAR-T was financial toxicity, while the top TO-stated barrier to CAR-T was leukapheresis/ manufacturing slot availability. The top RO-stated barrier to TCE was financial toxicity, while the top TO-stated barrier to TCE was the hospitalization requirement. In conclusion, financial concerns are perceived by ROs to be the top barrier to both CAR-T and TCEs in myeloma. In contrast, TOs perceive logistical concerns to be the top barrier. Interventions to lower financial toxicity during these therapies, and outreach to raise awareness of such interventions among ROs, are needed alongside strategies to streamline manufacturing (for CAR-T) and monitoring.

Managing Infection Complications in the Setting of Chimeric Antigen Receptor T cell (CAR-T) Therapy.

Chimeric antigen receptor T-cell (CAR T-cell) therapy has changed the paradigm of management of non-Hodgkin's lymphoma (NHL) and Multiple Myeloma. Infection complications have emerged as a concern that can arise in the setting of therapy and lead to morbidity and mortality. In this review, we classified infection complications into three categories, pre-infusion phase from the time pre- lymphodepletion (LD) up to day zero, early phase from day of infusion to day 30 post-infusion, and late phase after day 30 onwards. Infections arising in the pre-infusion phase are closely related to previous chemotherapy and bridging therapy. Infections arising in the early phase are more likely related to LD chemo and the expected brief period of grade 3-4 neutropenia. Infections arising in the late phase are particularly worrisome because they are associated with adverse risk features including prolonged neutropenia, dysregulation of humoral and adaptive immunity with lymphopenia, hypogammaglobinemia, and B cell aplasia. Bacterial, respiratory and other viral infections, protozoal and fungal infections can occur during this time . We recommend enhanced supportive care including prompt recognition and treatment of neutropenia with growth factor support, surveillance testing for specific viruses in the appropriate instance, management of hypogammaglobulinemia with repletion as appropriate and extended antimicrobial prophylaxis in those at higher risk (e.g. high dose steroid use and prolonged cytopenia). Finally, we recommend re-immunizing patients post CAR-T based on CDC and transplant guidelines.

Outpatient CAR T-Cell Therapy as Standard of Care: Current Perspectives and Considerations.

Chimeric antigen receptor T-cell therapy (CAR-T) has altered the treatment landscape of several hematologic malignancies. Until recently, most CAR-T infusions have been administered in the inpatient setting, due to their toxicity profile. However, the advent of new product constructs, as well as improved detection and management of adverse effects, have greatly increased the safety in administering these therapies. CAR-T indications continue to expand, and inpatient administration is associated with increased healthcare resource utilization and overall cost. Therefore, transitioning CAR-T administration to the outpatient setting has been of great interest in an effort to improve access, reduce financial burden, and improve patient satisfaction. Establishment of a successful outpatient CAR-T requires several components, including a multidisciplinary cellular therapy team and an outpatient center with appropriate clinical space and personnel. Additionally, clear criteria for outpatient administration eligibility and for inpatient admission with pathways for prompt toxicity evaluation and admission, and toxicity management guidelines should be implemented. Education about CAR-T therapy and its associated toxicities is imperative for all clinical staff, as well as patients and their caregivers. Finally, rigorous financial planning and close collaboration with payers to ensure equitable access, while effectively managing cost, are essential to program success and sustainability. This review provides a summary of currently published experiences, as well as expert opinion regarding implementation of an outpatient CAR-T program.

Administration of teclistamab in four patients with multiple myeloma requiring hemodialysis.

OBJECTIVE: Relapsed/refractory multiple myeloma (MM) has poor outcomes, especially in heavily pretreated patients. Limited data exists on the use of novel therapies in MM patients with renal dysfunction. This case series describes the successful initiation of teclistamab in four patients with heavily pre-treated MM on hemodialysis (HD). DATA SOURCES: The medical records of four adult MM patients on HD who received teclistamab were retrospectively reviewed. DATA SUMMARY: All patients completed teclistamab step-up dosing and received at least one full dose. HD runs were administered irrespective of teclistamab initiation. Patients tolerated therapy well, with only one patient experiencing grade 1 CRS, which was managed with supportive care. CONCLUSIONS: Due to the complexity of this patient population, close monitoring and multidisciplinary care are crucial. This approach is essential for effectively managing MM patients with renal dysfunction and for exploring novel treatment options.

Safety and Efficacy of Teclistamab in Patients with Relapsed/Refractory Multiple Myeloma: A Real-World Experience.

Teclistamab is a B cell maturation antigen (BCMA)-directed bispecific antibody approved for relapsed/refractory multiple myeloma (RRMM) on the basis of the phase I/II MajesTEC-1 trial. Here we report clinical outcomes with standard-of-care teclistamab in a real-world RRMM population. A total of 106 patients from 5 academic centers who received teclistamab from August 2022 to August 2023 were included in this retrospective analysis, 83% of whom would have been considered ineligible for the MajesTEC-1 trial. All patients were triple-class exposed, 64% were penta-class refractory, and 53% had received prior BCMA-directed therapy. Cytokine release syndrome was observed in 64% of patients, and only 1 event was grade ≥3, whereas immune effector cell-associated neurotoxicity syndrome was observed in 14% of patients (3 events were grade 3 or 4). One-third (31%) of patients experienced at least 1 infection, with nearly half of these infections graded as severe (grade ≥3). The overall response rate (ORR) was 66%, and the complete or better response rate was 29%. The ORR was 47% for patients with extramedullary disease (EMD), 59% for patients with prior BCMA-directed therapy exposure, and 68% for patients with penta-refractory disease. At a median follow-up of 3.8 months, the median progression-free survival (PFS) was 5.4 months (95% CI, 3.4 months to not reached), while median overall survival was not reached. Patients with Eastern Cooperative Oncology Group Performance Status ≥2, EMD, and age ≤70 years had inferior PFS on multivariable analysis. Our study demonstrates reasonable safety and good efficacy of teclistamab in patients with RRMM treated in a real-world setting.

Exploring the High-Grade and Refractory Neurotoxicity of Teclistamab: An Underreported Entity.

T-cell re-directing bispecific antibodies targeting B-cell maturation antigens have recently entered real-world use in relapsed/refractory multiple myeloma. While no head-to-head comparison has been done, they have generally been observed to have lower-grade toxicities compared with their chimeric antigen receptor T-cell (CAR-T) counterparts. However, in our real-world, single-institution experience, we have encountered two patients receiving teclistamab who experienced high-grade and refractory immune effector cell-associated neurotoxicity syndrome (ICANS) that did not respond to traditional toxicity mitigation strategies of high-dose corticosteroids or other immunosuppressive therapies. As we increase our use of these novel and vital agents, caution must be warranted.

Efficacy and Safety of Daratumumab, Pomalidomide, and Dexamethasone (DPd) Compared to Daratumumab, Bortezomib, and Dexamethasone (DVd) in Daratumumab-Naïve Relapsed Multiple Myeloma.

Daratumumab-based combinations with pomalidomide/dexamethasone (DPd), or bortezomib/dexamethasone (DVd), have shown activity in relapsed/refractory multiple myeloma (RRMM) patients. However, no direct comparisons of safety or efficacy of the two regimens have been published to date. We conducted a retrospective study to compare the safety and efficacy of DPd and DVd in daratumumab-naïve RRMM patients. We included 140 daratumumab-naïve patients who had received DPd or DVd for RRMM. Overall, the DPd group had a greater number of patients who had high-risk disease characteristics. Although response was deeper in the DPd group, the median progression-free survival (PFS) and overall survival (OS) were similar between the two groups. The DPd group exhibited a higher incidence of hematologic toxicities, whereas the DVd group had a higher incidence of peripheral neuropathy. The study results showed that while DPd may provide a deeper response, there was no significant difference in PFS or OS compared to DVd. For the high proportion of difficult-to-treat patients, duration of treatment may have contributed to these results, indicating that patient and disease characteristics should be considered when selecting salvage treatments.

The story of the development of generic lenalidomide: How one company thwarted the Hatch-Waxman Act to generate billions of dollars in revenue.

Lenalidomide (Revlimid®) was originally approved by the Food and Drug Administration (FDA) in 2005, however, a generic version was not available until 2022. In that time, the price of lenalidomide has increased more than 20 times, and in 2021 alone, it accounted for >$5.8 billion dollars in Medicare Part D spending. This was a direct consequence of legal tactics employed by the manufacturer to thwart development of generic formulations of lenalidomide. In this report, we review the clinical development of lenalidomide, provide background on generic drug manufacturing in the United States (US), describe the steps that the manufacturer took to prevent entry of generic lenalidomide into the US market, and advocate for legislative reform of the FDA approval process and patent law protections in the US.

Outcomes of Penta-Refractory Multiple Myeloma Patients Treated with or without BCMA-Directed Therapy.

Despite advances in treatment, outcomes remain poor for patients with penta-relapsed refractory multiple myeloma (RRMM). In this retrospective analysis, we evaluated the survival outcomes of penta-RRMM patients treated with (BCMA)- directed therapy (BDT). We identified 78 patients with penta-RRMM. Median age was 65 years, 29 (37%) had R-ISS stage III disease, 63 (81%) had high-risk cytogenetics, and 45 (58%) had extra-medullary disease. Median LOT prior to penta-refractory state was 5 (3-12). Amongst penta-RRMM, 43 (55%) were treated with BDT, 35 (45%) were not treated with BDT. Type of BDT received included belantamab mafadotin 15 (35%), Chimeric Antigen Receptor T-cell therapy 9 (21%), BCMA monoclonal antibody 6 (14%), and Bispecific T-cell engager 2 (5%). Eleven (25%) patients received more than one BDT. No significant differences were identified between baseline characteristics for the two groups. Patients treated with a BDT had better median overall survival, 17 vs. 6 months, HR 0.3 p-value < 0.001. Poor performance status, white race, and high-risk cytogenetics were associated with worse outcomes, whereas using a BDT was associated with better outcomes. Patients with penta-refractory MM have poor outcomes. Our retrospective analysis showed a significant survival benefit using BDT when compared to non-BDT for patients with penta-RRMM.

Hematopoietic stem cell transplantation-associated thrombotic microangiopathy and the role of advanced practice providers and pharmacists.

Hematopoietic stem cell transplantation-associated thrombotic microangiopathy (HSCT-TMA) is a severe and potentially life-threatening complication. HSCT-TMA is often underdiagnosed due to multifactorial pathophysiology and a historic lack of standard diagnostic criteria. Identification of the multi-hit hypothesis and the key role of the complement system, particularly the lectin pathway of complement, has led to development of treatments targeting the underlying pathogenesis of HSCT-TMA. Additional research is ongoing to investigate the efficacy and safety of these targeted therapies in patients with HSCT-TMA. Advanced practice providers (APPs; nurse practitioners and physician assistants) and pharmacists are critical members of the multidisciplinary HSCT team and ensure management of patients throughout the continuum of care. Additionally, pharmacists and APPs can improve patient care through medication management of complex regimens; transplant education for patients, staff, and trainees; evidence-based protocol and clinical guideline development; assessment and reporting of transplant-related outcomes; and quality improvement initiatives to improve outcomes. Understanding the presentation, prognosis, pathophysiology, and treatment options for HSCT-TMA can improve each of these efforts. Collaborative practice model for monitoring and care of HSCT-TMA. Advanced practice providers and pharmacists contribute to many aspects of patient care in transplant centers, including medication management for complex regimens; transplant education for patients, staff, and trainees; evidence-based protocol and clinical guideline development; assessment and reporting of transplant-related outcomes; and quality improvement initiatives. HSCT-TMA is a severe and potentially life-threatening complication that is often underdiagnosed. The collaboration of a multidisciplinary team of advanced practice providers, pharmacists, and physicians can optimize recognition, diagnosis, management, and monitoring of patients with HSCT-TMA, thereby improving outcomes for these patients.

Incidence of breakthrough fungal infections on isavuconazole prophylaxis compared to posaconazole and voriconazole.

BACKGROUND: Invasive fungal infections (IFIs) are a common infectious complication during the treatment of acute myeloid leukemia (AML), high-risk myelodysplastic syndrome (MDS) or post hematopoietic cell transplantation (HCT). For these patients, the National Comprehensive Cancer Network recommends posaconazole or voriconazole for IFI prophylaxis. In clinical practice, however, there has been increased use of isavuconazole due to favorable pharmacokinetic and pharmacodynamic parameters despite limited data for this indication. The comparative prophylactic efficacy of antifungals in this patient population has not been reported, and an analysis is warranted. METHODS: This retrospective, matched cohort, single-center study, included AML, MDS, or HCT patients who began treatment or underwent transplant between January 1, 2015 and July 31, 2021. Isavuconazole patients were matched 1:2 with patients receiving posaconazole or voriconazole prophylaxis. RESULTS: A total of 126 patients were included, 42 received isavuconazole, 81 received posaconazole, and three received voriconazole. The majority of patients were male receiving secondary IFI prophylaxis while receiving steroids for treatment of GVHD. The incidence of possible, probable or proven IFI was 16.7% in the isavuconazole group compared to 10.7% in the posaconazole and voriconazole group (OR 1.28, 95% CI -0.9-1.4; p = .67). Hepatotoxicity occurred in 16 total patients, 14 receiving posaconazole and two receiving isavuconazole. CONCLUSION: Patients who received isavuconazole prophylaxis during AML induction therapy or post-HCT experienced a similar incidence of breakthrough fungal infections compared to those who received posaconazole or voriconazole. These results suggest no difference in antifungal prophylactic efficacy; however larger prospective comparative studies are needed.

Adverse Hematological and Non-Hematological Events in Patients With Relapsed/Refractory Multiple Myeloma That Are Responsive to Daratumumab, Pomalidomide and Dexamethasone.

Background: Daratumumab, pomalidomide, and dexamethasone (DPd) is an effective option for treatment of patients with relapsed/refractory multiple myeloma (RRMM). In this study, we sought to analyze the risk of hematological and non-hematological toxicities in patients who responded to DPd treatment. Methods: We analyzed 97 patients with RRMM who were treated with DPd between January 2015 and June 2022. The patients and disease characteristics, as well as safety and efficacy outcomes were summarized as descriptive analysis. Results: The overall response rate for the entire group was 74% (n = 72). The most common grade III/IV hematological toxicities in those who responded to treatment were neutropenia (79%), leukopenia (65%), lymphopenia (56%), anemia (18%), and thrombocytopenia (8%). The most common grade III/IV non-hematological toxicities were pneumonia (17%) and peripheral neuropathy (8%). The incidence of dose reduction/interruption was 76% (55/72), which was due to hematological toxicity in 73% of the cases. The most common reason for discontinuing treatment was disease progression in 61% (44 out of 72 patients). Conclusions: Our study revealed that patients who respond to DPd are at high risk of dose reduction or treatment interruption because of hematological toxicity, typically due to neutropenia and leukopenia leading to increased risk of hospitalization and pneumonia.

Clinical efficacy of retreatment of daratumumab-based therapy (D2) in daratumumab-refractory multiple myeloma.

Daratumumab demonstrates activity as a single agent and in combination with either immunomodulatory agents (IMiDs) or proteasome inhibitors (PIs) in relapsed refractory multiple myeloma (RRMM). However, little is known about the benefit of daratumumab retreatment in daratumumab-refractory MM. This study aimed to analyze the clinical efficacy of daratumumab-based retreatment (D2) in patients who are daratumumab refractory MM. Retrospectively, we identified 43 RRMM patients from a single-center database review. The median age was 65 years, 42% patients had high-risk cytogenetics, and 23% had an extramedullary disease, while the median time between D2 and prior daratumumab was 1 (0.25-39) month. All D2 patients received combination therapy with either pomalidomide, carfilzomib, bortezomib, or lenalidomide. The response rate, median progression-free, and overall survival were 49%, 7.97 and 32.6 months, respectively. Our study raises the possibility of re-utilizing daratumumab in combination with different classes of anti-myeloma drugs to generate responses in RRMM patients who are daratumumab-refractory.

Daratumumab, pomalidomide, and dexamethasone (DPd) followed by high dose chemotherapy-Autologous Stem Cell Transplantation leads to superior outcomes when compared to DPd-alone for patients with Relapsed Refractory Multiple Myeloma.

BACKGROUND AND OBJECTIVES: While the role of autologous stem cell transplant (ASCT) in the first line therapy for newly diagnosed multiple myeloma is well established, efficacy of ASCT for patients with relapsed refractory multiple myeloma (RRMM) in the era of novel therapeutic agents remains unknown. In this single center retrospective analysis, we evaluated and compared the efficacy and safety outcomes of patients with RRMM treated with daratumumab pomalidomide dexamethasone (DPd) alone versus (vs) DPd followed by ASCT. METHODS: A total of 83 patients with RRMM who were treated with and achieved at least partial response (PR) with DPd were evaluated by electronic medical records. All patients who responded to DPd and were deemed eligible for ASCT proceeded with high dose melphalan followed by autologous stem cell infusion (DPd + ASCT group). Remaining patients continued DPd until disease progression or intolerable toxicities (DPd-alone group). Responses were evaluated using the International Myeloma Working Group response criteria and toxicities were graded using National Cancer Institute Common Terminology Criteria for Adverse Events. Patient and disease characteristics, as well as efficacy and safety outcomes were summarized using descriptive statistics. Kaplan-Meier analyses were used to estimate progression-free survival (PFS) and overall survival (OS). RESULTS: A total of 21/83 (25%) patients with RRMM who achieved at least PR to DPd underwent ASCT (DPd + ASCT group) while the remaining 62/83 (75%) continued DPd without ASCT (DPd-alone group). For the entire patient population, median age was 66 years (42-81), 49 (59%) patients were male, 54 (65%) patients had IgG isotype, 21 (25%) patients had R-ISS stage III disease, 51 (61%) patients had high-risk cytogenetics, and 17 (20%) patients had extramedullary disease. Patient age, disease stage, cytogenetic risk profile were well balanced between two groups. A stringent complete response was seen in 10 (16%) and 12 (57%) patients in the DPd-alone and DPd + AST groups, respectively. Median PFS was 17.5 months in the DPd-alone vs 42.2 months (p=0.006) in the DPd + ASCT group. Median OS was 38.1 months in the DPd-alone group vs not reached in the DPD + ASCT group (p=0.009). The most common grade 3 or 4 treatment-related adverse events (TRAE) were myelosuppression and gastrointestinal toxicities, more commonly seen in the DPd + ASCT group. No treatment-related mortalities were observed in either group. CONCLUSION: Patients with RRMM who responded to DPd and underwent HDT-ASCT demonstrated superior depth and duration of remission compared to those who received DPd-alone. Although DPd followed by ASCT is associated with more cytopenias and gastrointestinal toxicities, this treatment appears to be overall safe for patients with RRMM.

Belantamab in Combination with Dexamethasone in Patients with Triple-class Relapsed/Refractory Multiple Myeloma.

BACKGROUND: Triple-class relapsed/refractory multiple myeloma (RRMM) has a poor prognosis. This study analyzed the clinical outcomes of Belantamab mafadotin in combination with dexamethasone (Bd) in triple-class RRMM. METHODS: We identified 35 patients with triple-class RRMM who received Bd at the University of Kansas from October 2019 to November 2021. RESULTS: The median age was 66 years (42-85) and the median prior lines of therapy was 5 (3-15). Nineteen (54%) patients had R-ISS stage III disease, 15 (43%) patients had high-risk cytogenetics, and 15 patients (43%) had extramedullary disease (EMD). Eight patients received prior BCMA-targeted therapy. Overall response rate (ORR) was 43%, with 23% achieving very good partial response and better. At a median follow up of 10.7 months, the median progression-free survival and survival were 4.9 and 10.7 months, respectively. The most common adverse event was keratopathy, which occurred in 30 (86%) patients. Twenty-four patients required dose reduction or delay due to keratopathy. Other common toxicities included anemia (83%), thrombocytopenia (80%), neutropenia (34%), and elevated liver function tests (51%). CONCLUSION: Our analysis shows Bd has good activity in triple-class RRMM. Keratopathy remains a challenging AE and the leading cause of dose reduction, delay and treatment cessation.

Neutralizing antibody responses against SARS-CoV-2 in patients with plasma cell disorders who are on active treatment after two doses of mRNA vaccination.

Many patients with plasma cell disorder (PCD) on active treatment with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) require hospitalization, with an increased mortality rate over healthy adults. The FDA approved two mRNA vaccines against SARS-CoV-2: BNT162b2 and mRNA-1273. To assess the efficacy of vaccination in patients with PCD, retrospectively, we identified all patients on active treatment. A total of 149 patients were included. Neutralizing antibodies (NAbs) levels against SARS-CoV-2 adequate, intermediate, and no response were observed in 42%, 32%, and 26%, respectively. Low NAbs were seen in patients on daratumumab combinations or anti-BCMA therapy, low lymphocytes, and low IgG levels. Twenty-three (15%) patients have SARS CoV-2, while 8% required hospitalization, majority of these patients had intermediate or no response based on NAbs levels. Therefore, checking NAbs may be clinically helpful in identifying patients' responses. Further prospective studies should ascertain the value of a third vaccine dose in this population.