Unscheduled healthcare interactions in multiple myeloma patients receiving T cell redirection therapies

Outcomes for relapsed/refractory multiple myeloma (RRMM) patients have dramatically improved following the development and now growing utilization of B cell maturation antigen targeted chimeric antigen receptor (CAR) T cell therapy and bispecific antibody (BsAb) therapy. However, healthcare utilization as a quality-of-life metric in these growing populations has not been thoroughly evaluated. We performed a retrospective cohort study evaluating the frequency and cause of unscheduled healthcare interactions (UHIs) among RRMM patients responding to B-cell maturation antigen targeted BsAbs and CAR T cell therapies (N = 46). This included analysis of remote UHIs including calls to physicians' offices and messages sent through an online patient portal. Our results showed that nearly all (89%) RRMM patients receiving these therapies required a UHI during the first 125 days of treatment, with a mean of 3.7 UHIs per patient. RRMM patients responding to BsAbs were significantly more likely to remotely contact their physicians' offices (1.8-fold increase, p = 0.038) or visit an urgent care center (>3-fold increase, p = 0.012) than RRMM patients responding to CAR T cell therapies. This was largely due to increased reports of mild upper respiratory tract infections in BsAb patients. Our results underscore the need to develop preemptive management strategies for commonly reported symptoms that RRMM patients experience while receiving CAR T cell or BsAb therapies. This preemptive management may significantly reduce unnecessary healthcare utilization in this vulnerable patient population.

Patterns of CRS with Teclistamab in Relapsed/Refractory Multiple Myeloma patients with Prior T-Cell Redirection Therapy

Teclistamab (Tec) is a first-in-class BCMA X CD3 bispecific T-cell engager antibody approved for treating multiple myeloma progressing after at least 4 lines of therapy. The objective of this study was to evaluate the rate of cytokine release syndrome (CRS) in patients who were treated with commercial Tec and had prior exposure to other T-cell redirection therapies. A retrospective chart review was performed to identify patients who completed the Tec step-up dosing phase between November 2022 and November 2023. Patients were divided into 2 cohorts based on prior exposure to T-cell redirection therapy (cohort 1: T-cell redirection therapy experienced; cohort 2: T-cell redirection therapy naïve). The primary objective was to compare the differences in the rates of CRS between the two cohorts. Univariate and multivariate logistic regression analyses were performed to assess the association between CRS rates with Tec and prior treatment with T-cell redirection therapy. A total of 72 patients were included in the analysis (27 in cohort 1 and 45 in cohort 2). The CRS rates were significantly lower in cohort 1 (37%, n=10) compared to cohort 2 (80%, n=36; p=0.0004). Based on multivariate logistic regression analysis, patients without prior exposure to T-cell redirection therapy (cohort 2) had about a 4-fold increase in the incidence of CRS (95% CI: 1.40-14.90, p=0.0002) with Tec. In our study, prior exposure to T-cell redirection therapy reduced the risk of CRS with Tec during the step-up dosing phase. This observation will allow for the optimization of CRS prophylactic strategies for Tec.

Transplantation and Cellular Therapy for Older Adults-The MSK Approach

PURPOSE OF REVIEW

Hematologic malignances more commonly affect older individuals and often present with advanced, higher risk disease than younger patients. Allogeneic and autologous hematopoietic cell transplantation is well-established treatment modalities with curative potential following either frontline treatments for these diseases or salvage therapy in the relapsed or refractory setting. More recently, novel cellular immunotherapy such as chimeric antigen receptor T-cell therapy has been shown to lead to high response rate and durable remission in many patients with advanced blood cancers.

RECENT FINDINGS

Given unique characteristics of older patients, how best to deliver these higher-intensity and time sensitive treatment modalities for them remains challenging. Moreover, their short-term and potential long-term impact on their functional status, cognitive status, and quality of life may be significant considerations for many older patients. All these issues contributed to the lack of access and significant underutilization of these potential curative treatment strategies. In this review, we present up to date evidence to support potential benefits of transplantation and cellular therapy for older adults, their steady improving outcomes, and most importantly, highlight the use of geriatric assessment to help select appropriate older patients and optimize them prior to and following transplantation and cellular therapy. We specifically describe our approach at Memorial Sloan Kettering Cancer Center and encouraging early results from its implementation.

Outcomes and Management of the SARS-CoV2 Omicron Variant in Recipients of Hematopoietic Cell Transplantation and Chimeric Antigen Receptor T Cell Therapy

Hematopoietic cell transplantation (HCT) and chimeric antigen receptor T cell therapy (CAR-T) recipients who develop Coronavirus disease 2019 (COVID-19) can have decreased overall survival (OS), likely due to disease-inherent and therapy-related immunodeficiency. The availability of COVID-19-directed therapies and vaccines have improved COVID-19-related outcomes, but immunocompromised individuals remain vulnerable. Specifically, the effects of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant infections, including Omicron and its sublineages, particularly in HCT recipients, remain to be defined. The aim of this study was to compare the impact of SARS-CoV-2 Omicron infections in HCT/CAR-T recipients with outcomes previously reported for ancestral SARS-CoV-2 infections early in the pandemic (March to June 2020). This was a retrospective analysis of adult HCT/CAR-T recipients diagnosed with COVID-19 at Memorial Sloan Kettering Cancer Center between July 2021 and July 2022. We identified 353 patients (172 autologous HCT recipients [49%], 152 allogeneic HCT recipients [43%], and 29 CAR-T recipients [8%]), with a median time from HCT/CAR-T to SARS-CoV-2 infection of 1010 days (interquartile range, 300 to 2046 days). Forty-one patients (12%) were diagnosed with COVID-19 during the delta wave, and 312 patients (88%) were diagnosed during the Omicron wave. Risk factors associated with increased odds of COVID-19-related hospitalization were the presence of 2 or more comorbidities (odds ratio [OR], 4.9; 95% confidence interval [CI], 2.4 to 10.7; P < .001), CAR-T therapy compared to allogeneic HCT (OR, 7.7; 95% CI, 3.0 to 20.0; P < .001), hypogammaglobulinemia (OR, 2.71; 95% CI, 1.06 to 6.40; P = .027), and age at COVID-19 diagnosis (OR, 1.03; 95% CI, 1.0 to 1.05; P = .04). In contrast, infection during the Omicron variant BA5/BA4-dominant period compared to variant BA1 (OR, .21; 95% CI, .03 to .73; P = .037) and more than 3 years from HCT/CAR-T therapy to COVID-19 diagnosis compared to early infection at <100 days (OR, .31; 95% CI, .12 to .79; P = .011) were associated with a decreased odds for hospitalization. The OS at 12 months from COVID-19 diagnosis was 89% (95% CI, 84% to 94%), with 6 of 26 deaths attributable to COVID-19. Patients with the ancestral strain of SAR-CoV-2 had a lower OS at 12 months, with 73% (95% CI, 62% to 84%) versus 89% (95% CI, 84% to 94%; P < .001) in the Omicron cohort. Specific COVID-19 treatment was administered in 62% of patients, and 84% were vaccinated with mRNA COVID-19 vaccines. Vaccinated patients had significantly better OS than unvaccinated patients (90% [95% CI, 86% to 95%] versus 82% [95% CI, 72% to 94%] at 12 months; P = .003). No significant difference in OS was observed in patients infected with the Omicron and those infected with the Delta variant (P = .4) or treated with specific COVID-19 treatments compared with those not treated (P = .2). We observed higher OS in HCT and CAR-T recipients infected with the Omicron variants compared to those infected with the ancestral strain of SARS-CoV2. The use of COVID-19 antivirals, mAbs, and vaccines might have contributed to the improved outcomes.

Utility of routine pulmonary function test after autologous hematopoietic cell transplantation in lymphoma

This study aims to evaluate the predictive value of routine pulmonary function testing (PFT) at the 12-month mark post-autologous hematopoietic cell transplant (AHCT) in identifying clinically significant lung disease in lymphoma survivors. In 247 patients, 173 (70%) received BEAM (carmustine, etoposide, cytarabine, melphalan), and 49 (20%) received TBC (thiotepa, busulfan, cyclophosphamide) conditioning regimens. Abnormal baseline PFT was noted in 149 patients (60%). Thirty-four patients had a significant decline (reduction of >/= 20% in DLCO or FEV1 or FVC) in post-AHCT PFT, with the highest incidence in the CNS lymphoma group (39%). The incidence of clinically significant lung disease post-transplant was low at 2% and there was no association between abnormal pre- and 1-year post-transplant PFTs with the development of clinical lung disease. While this study illustrates the impact of treatment regimens on PFT changes, it did not demonstrate a predictive value of scheduled PFTs in identifying clinically significant post-AHCT lung disease.

Prospective analysis to determine barriers to allogeneic hematopoietic cell transplantation in patients with acute leukemia

Allogeneic hematopoietic cell transplantation (allo-HCT) is a potentially curative treatment for patients with acute leukemia. Despite this, studies have shown that only a minority of patients ultimately proceed to allo-HCT. The primary objective of this prospective, observational study was to identify the rate of allo-HCT in patients for whom it was recommended, and reasons why patients deemed appropriate and eligible for HCT did not subsequently undergo transplant. Between April 2016 and April 2021, adult patients with newly diagnosed or relapsed/refractory acute leukemia were enrolled at the time of induction/reinduction therapy. Initial transplantation workup and allo-HCT recommendations were made during the early phase of induction/reinduction. Of the 307 enrolled patients, allo-HCT was recommended to 85% (n = 259), of whom 66% (n = 170) underwent transplant. Donor sources comprised 54% human leukocyte antigen (HLA)-matched unrelated donors, 20% HLA-matched sibling donors and HLA-mismatched graft sources with 15% umbilical cord blood units, 8% HLA-mismatched unrelated donors, and 4% HLA-haploidentical donors. The most common reason for transplant disqualification in the 89 patients in whom it was initially recommended was persistent/relapsed disease (70%), followed by early patient death (10%). In this prospective study, we report a high allo-HCT rate, which may be due to early transplant referral and workup. The main allo-HCT barrier was disease control, followed by early patient death. With the increasing availability of HLA-mismatched graft sources, the lack of donor availability was not a transplant barrier. Further development of novel transplant strategies for patients not achieving remission and improvements in induction regimens could result in increased allo-HCT utilization.

Application of the CIBMTR One Year Survival Outcomes Calculator as a tool for retrospective analysis

The Web-based One Year Survival Outcomes Calculator developed by the Center for International Blood and Marrow Transplant Research (CIBMTR) applies large-scale registry data to generate individualized estimates of overall survival (OS) probability 1 year after first allogeneic hematopoietic cell transplant (HCT) and can therefore provide a data-driven foundation for personalized patient counseling. We assessed the calibration of the CIBMTR One Year Survival Outcomes Calculator when applied to retrospective data among adult recipients of first allogeneic HCT for acute myeloid leukemia (AML), acute lymphoblastic leukemia (ALL), or myelodysplastic syndrome (MDS) with peripheral blood stem cell transplant (PBSCT) from a 7/8- or 8/8-matched donor from 2000 through 2015 at a single center. Predicted 1 year OS was estimated for each patient using the CIBMTR Calculator. Corresponding observed 1 year OS was estimated for each group by the Kaplan-Meier method. A weighted Kaplan-Meier estimator was used to visually display the average of observed 1 year survival estimates over the continuous range of predicted OS. In the first analysis of its kind, we demonstrated that the CIBMTR One Year Survival Outcomes Calculator could be applied to larger patient cohorts and predicted 1 year prognosis with general agreement between predicted and observed survival.

Association between busulfan exposure and survival in patients undergoing a CD34+ selected stem cell transplantation

Busulfan is an alkylating drug routinely used in conditioning regimens for allogeneic hematopoietic cell transplantation (allo-HCT). A myeloablative conditioning regimen, including busulfan, is commonly used in patients undergoing T-cell depletion (TCD) and allo-HCT, but data on optimal busulfan pharmacokinetic (PK) exposure in this setting are limited. Between 2012 and 2019, busulfan PK was performed to target an area under the curve exposure between 55 and 66 mg × h/L over 3 days using a noncompartmental analysis model. We retrospectively re-estimated busulfan exposure following the published population PK (popPK) model (2021) and correlated it with outcomes. To define optimal exposure, univariable models were performed with P splines, wherein hazard ratio (HR) plots were drawn, and thresholds were found graphically as the points at which the confidence interval crossed 1. Cox proportional hazard and competing risk models were used for analyses. 176 patients were included, with a median age of 59 years (range, 2-71). Using the popPK model, the median cumulative busulfan exposure was 63.4 mg × h/L (range, 46.3-90.7). The optimal threshold was at the upper limit of the lowest quartile (59.5 mg × h/L). 5-year overall survival (OS) with busulfan exposure ≥59.5 vs <59.5 mg × h/L was 67% (95% CI, 59-76) vs 40% (95% CI, 53-68), respectively (P = .02), and this association remained in a multivariate analyses (HR, 0.5; 95% CI, 0.29; 0.88; P = .02). In patients undergoing TCD allo-HCT, busulfan exposure is significantly associated with OS. The use of a published popPK model to optimize exposure may significantly improve the OS.

Analysis of disparities in time to allogeneic transplantation in adults with acute myelogenous leukemia

Although alternative donors extend transplant access, whether recipient ancestry affects the time to allogeneic transplant is not established. We analyzed the likelihood of clinically significant delays to allograft by patient ancestry in 313 adult patients with acute myelogenous leukemia (AML) who underwent transplantation. Non-European ancestry patients (n = 99) were more likely than Europeans (n = 214) to receive HLA-mismatched donor allografts (45% vs 24%). Overall, the median time from transplant indication to allograft was 127 days (range, 57-1683). In multivariable analysis, non-Europeans had an increased risk of prolonged indication to transplant time >180 days owing to significant delays in indication to consult >90 days and consult to transplant >120 days. Compared with recipients of HLA-matched unrelated donors (URDs), HLA-mismatched adult donor recipients were at an increased risk of delayed indication to transplant, whereas HLA-identical sibling and cord blood recipients were at a lower risk. Subanalysis showed more indication to transplant delays >180 days in non-European (44%) vs European (19%) 8/8 URD recipients. Finally, the pandemic further exacerbated delays for non-Europeans. In summary, although non-European patients with AML are less likely to receive 8/8 URDs as expected, if they do, their transplants are delayed. HLA-identical siblings and cord blood facilitate the fastest transplants regardless of patient ancestry, whereas other adult donor transplants are delayed. Strategies to mitigate referral barriers, hasten donor evaluation, and use all alternative donor sources are critical to ensure timely transplantation for patients with AML.

Tissue-specific features of the T cell repertoire after allogeneic hematopoietic cell transplantation in human and mouse

T cells are the central drivers of many inflammatory diseases, but the repertoire of tissue-resident T cells at sites of pathology in human organs remains poorly understood. We examined the site-specificity of T cell receptor (TCR) repertoires across tissues (5 to 18 tissues per patient) in prospectively collected autopsies of patients with and without graft-versus-host disease (GVHD), a potentially lethal tissue-targeting complication of allogeneic hematopoietic cell transplantation, and in mouse models of GVHD. Anatomic similarity between tissues was a key determinant of TCR repertoire composition within patients, independent of disease or transplant status. The T cells recovered from peripheral blood and spleens in patients and mice captured a limited portion of the TCR repertoire detected in tissues. Whereas few T cell clones were shared across patients, motif-based clustering revealed shared repertoire signatures across patients in a tissue-specific fashion. T cells at disease sites had a tissue-resident phenotype and were of donor origin based on single-cell chimerism analysis. These data demonstrate the complex composition of T cell populations that persist in human tissues at the end stage of an inflammatory disorder after lymphocyte-directed therapy. These findings also underscore the importance of studying T cell in tissues rather than blood for tissue-based pathologies and suggest the tissue-specific nature of both the endogenous and posttransplant T cell landscape.

Bortezomib, lenalidomide and dexamethasone (VRd) vs carfilzomib, lenalidomide and dexamethasone (KRd) as induction therapy in newly diagnosed multiple myeloma

Lenalidomide and dexamethasone with bortezomib (VRd) or carfilzomib (KRd) are commonly used induction regimens in the U.S. This single-center, retrospective study evaluated outcomes and safety of VRd and KRd. Primary endpoint was progression-free survival (PFS). Of 389 patients with newly diagnosed multiple myeloma, 198 received VRd and 191 received KRd. Median PFS was not reached (NR) in both groups; 5-year PFS was 56% (95%CI, 48-64%) for VRd and 67% (60-75%) for KRd (P = 0.027). Estimated 5-year EFS was 34% (95%CI, 27-42%) for VRd and 52% (45-60%) for KRd (P < 0.001) with corresponding 5-year OS of 80% (95%CI, 75-87%) and 90% (85-95%), respectively (P = 0.053). For standard-risk patients, 5-year PFS was 68% (95%CI, 60-78%) for VRd and 75% (65-85%) for KRd (P = 0.20) with 5-year OS of 87% (95%CI, 81-94%) and 93% (87-99%), respectively (P = 0.13). For high-risk patients, median PFS was 41 months (95%CI, 32.8-61.1) for VRd and 70.9 months (58.2-NR) for KRd (P = 0.016). Respective 5-year PFS and OS were 35% (95%CI, 24-51%) and 69% (58-82%) for VRd and 58% (47-71%) and 88% (80-97%, P = 0.044) for KRd. Overall, KRd resulted in improved PFS and EFS with a trend toward improved OS compared to VRd with associations primarily driven by improvements in outcome for high-risk patients.

High-resolution analyses of associations between medications, microbiome, and mortality in cancer patients

Discerning the effect of pharmacological exposures on intestinal bacterial communities in cancer patients is challenging. Here, we deconvoluted the relationship between drug exposures and changes in microbial composition by developing and applying a new computational method, PARADIGM (parameters associated with dynamics of gut microbiota), to a large set of longitudinal fecal microbiome profiles with detailed medication-administration records from patients undergoing allogeneic hematopoietic cell transplantation. We observed that several non-antibiotic drugs, including laxatives, antiemetics, and opioids, are associated with increased Enterococcus relative abundance and decreased alpha diversity. Shotgun metagenomic sequencing further demonstrated subspecies competition, leading to increased dominant-strain genetic convergence during allo-HCT that is significantly associated with antibiotic exposures. We integrated drug-microbiome associations to predict clinical outcomes in two validation cohorts on the basis of drug exposures alone, suggesting that this approach can generate biologically and clinically relevant insights into how pharmacological exposures can perturb or preserve microbiota composition. The application of a computational method called PARADIGM to a large dataset of cancer patients' longitudinal fecal specimens and detailed daily medication records reveals associations between drug exposures and the intestinal microbiota that recapitulate in vitro findings and are also predictive of clinical outcomes.

EASIX score predicts inferior survival after allogeneic hematopoietic cell transplantation

The Endothelial Activation and Stress Index (EASIX) is a prognostic tool that uses common clinical laboratory values and has been shown to predict non-relapse mortality (NRM) and overall survival (OS) at the onset of acute graft-versus-host disease (GVHD) after allogeneic hematopoietic cell transplantation (HCT). We hypothesized that EASIX calculated at different time points pre- and post- HCT may predict NRM and OS, and that EASIX calculated at onset of GVHD may predict response to steroids. We evaluated the EASIX score pre- and post-HCT in 152 patients with lymphoid malignancies undergoing unmodified reduced intensity conditioning (RIC) alloHCT with uniform GVHD prophylaxis. In multivariate analysis, EASIX calculated pre-HCT was significantly associated with higher NRM (HR = 1.64, p = 0.009) and lower OS (HR = 1.33, p = 0.046). Furthermore, EASIX calculated at day 30 and at day 100 was associated with increased NRM (HR = 1.65, p < 0.001; and HR = 1.65, p < 0.001) and decreased OS (HR = 1.27, p = 0.018; and HR = 1.49, p < 0.001), independent of HCT-CI, disease and conditioning regimen. Our study shows that high EASIX scores at various time points pre- and post-HCT are significantly associated with poorer overall outcomes. EASIX provides an independent and easily accessible tool to predict outcomes that can be complementary to other measures of risk stratification for patients undergoing HCT.

Assessment of renal outcome following therapy in monoclonal immunoglobulin deposition disease: Emphasizing the need for a consensus approach

Monoclonal immunoglobulin deposition disease (MIDD), often associated with plasma cell dyscrasias, predominantly affects the kidneys. In this disease, hematologic response (HR) to treatment can be reliably assessed by International Myeloma Working Group (IMWG) consensus criteria, while uniform criteria for assessing renal response are lacking. We report a retrospective analysis of renal outcomes among 34 patients with MIDD. With most patients treated with bortezomib and autologous stem cell transplantation, 26 of 28 (94%) achieved very good partial HR or better. We demonstrate that both IMWG (based on estimated glomerular filtration rate, eGFR) and amyloid (based on proteinuria) criteria are needed to capture renal response: among 28 evaluable patients, 6 (21%) had isolated proteinuria, while 13 (46%) had isolated decreased eGFR. Using both criteria, which were concordant in patients with both decreased eGFR and proteinuria, 22 of 28 patients (79%) achieved a renal response, including 2 of 7 discontinuing dialyses. All 6 patients (100%) with isolated proteinuria and 7 of 13 (54%) with isolated decreased eGFR achieved renal response, suggesting that isolated proteinuria is an early manifestation of MIDD associated with reversible renal damage. Baseline eGFR predicted renal response (p = .02 by quartile) and survival (p = .02), while HR (CR vs. non-CR) did not, probably because of high HR rate. With a median follow-up of 110 months, the median overall survival was 136 months (95% CI: 79-NR) and median renal survival had not been reached. Prospective studies using uniform renal response criteria are needed to optimize the management of MIDD.

Characteristics of Distress and Support Group Participation in Caregivers of Older Allogeneic Hematopoietic Cell Transplantation Patients: A Single Institution Retrospective Review

Older patients with hematologic malignancies are increasingly considered for allogeneic hematopoietic cell transplant (allo-HCT). However, older patients often have increased comorbidities and thus may require an increased level of post-transplant care. These factors can contribute to increased caregiver distress, which has been associated with worsened health outcomes for caregivers and patients. To examine predictors of caregiver distress and support group participation in caregivers of older allo-HCT patients, we retrospectively reviewed charts of 208 patients aged 60 and older who underwent their first allo-HCT at our institution from 2014 through 2016. We systematically characterized and identified the incidence of caregiver distress and attendance in a caregiver support group from the start of conditioning through 1 year post allo-HCT. Evidence of caregiver distress and support group participation was recorded by reviewing clinical and/or social work documentation. We found that 20 caregivers (10%) endorsed stress and 44 caregivers (21%) attended our support group at least once. A patient's prior history of psychiatric diagnosis (p = .046) or the use of potentially inappropriate medications for older adults (p = .046) was found to be associated with caregiver stress. Caregivers who were spouses or partners of patients (p = .048) or caregivers of married patients were more likely to attend the support group (p = .007). While limited by retrospective design and likely underreporting, this study reveals factors associated with caregiver distress in the older allo-HCT caregiver population. This information can help providers identify caregivers at risk for distress and improve caregiver resources, which may improve both caregiver and patient outcomes.

Conditioning Regimens are Associated with Distinct Patterns of Microbiota Injury in Allogeneic Hematopoietic Cell Transplantation

PURPOSE

The gut microbiota is subject to multiple insults in allogeneic hematopoietic cell transplantation (allo-HCT) recipients. We hypothesized that preparative conditioning regimens contribute to microbiota perturbation in allo-HCT.

EXPERIMENTAL DESIGN

This was a retrospective study that evaluated the relationship between conditioning regimens exposure in 1,188 allo-HCT recipients and the gut microbiome. Stool samples collected from 20 days before transplantation up to 30 days after were profiled using 16S rRNA sequencing. Microbiota injury was quantified by changes in α-diversity.

RESULTS

We identified distinct patterns of microbiota injury that varied by conditioning regimen. Diversity loss was graded into three levels of conditioning-associated microbiota injury (CMBI) in a multivariable model that included antibiotic exposures. High-intensity regimens, such as total body irradiation (TBI)-thiotepa-cyclophosphamide, were associated with the greatest injury (CMBI III). In contrast, the nonmyeloablative regimen fludarabine-cyclophosphamide with low-dose TBI (Flu/Cy/TBI200) had a low-grade injury (CMBI I). The risk of acute GVHD correlated with CMBI degree. Pretransplant microbial compositions were best preserved with Flu/Cy/TBI200, whereas other regimens were associated with loss of commensal bacteria and expansion of Enterococcus.

CONCLUSIONS

Our findings support an interaction between conditioning at the regimen level and the extent of microbiota injury.

Molecular predictors of immunophenotypic measurable residual disease clearance in acute myeloid leukemia

Measurable residual disease (MRD) is a powerful prognostic factor in acute myeloid leukemia (AML). However, pre-treatment molecular predictors of immunophenotypic MRD clearance remain unclear. We analyzed a dataset of 211 patients with pre-treatment next-generation sequencing who received induction chemotherapy and had MRD assessed by serial immunophenotypic monitoring after induction, subsequent therapy, and allogeneic stem cell transplant (allo-SCT). Induction chemotherapy led to MRD- remission, MRD+ remission, and persistent disease in 35%, 27%, and 38% of patients, respectively. With subsequent therapy, 34% of patients with MRD+ and 26% of patients with persistent disease converted to MRD-. Mutations in CEBPA, NRAS, KRAS, and NPM1 predicted high rates of MRD- remission, while mutations in TP53, SF3B1, ASXL1, and RUNX1 and karyotypic abnormalities including inv (3), monosomy 5 or 7 predicted low rates of MRD- remission. Patients with fewer individual clones were more likely to achieve MRD- remission. Among 132 patients who underwent allo-SCT, outcomes were favorable whether patients achieved early MRD- after induction or later MRD- after subsequent therapy prior to allo-SCT. As MRD conversion with chemotherapy prior to allo-SCT is rarely achieved in patients with specific baseline mutational patterns and high clone numbers, upfront inclusion of these patients into clinical trials should be considered.

Pilot Trial of Homebound Hematopoietic Cell Transplantation

For eligible patients with multiple myeloma (MM) and amyloid light chain (AL) amyloidosis, high-dose chemotherapy and autologous hematopoietic cell transplantation (HCT) is a standard and widely used consolidation therapy. Autologous HCT requires specialized care at a transplantation center and investment from patients and caregivers. We studied the safety and feasibility of delivering transplantation care in a homebound setting to decrease the burden of therapy and increase access to autologous HCT. Patients with MM and AL amyloidosis undergoing autologous HCT were eligible if they resided in designated ZIP codes and had a full-time caregiver, Wi-Fi connection, HCT Comorbidity Index ≤3, and Karnofsky Performance Status score ≥80. High-dose melphalan (on day -2) and hematopoietic cell reinfusion (day 0) were administered in the outpatient clinic. Protocol-specific home care was provided from day +1 through engraftment. Patients were assessed and blood was drawn daily by advanced practice providers. Interventions were delivered by registered nurses. Attending physicians communicated daily through telemedicine. Quality of life, patient and caregiver satisfaction, and fecal microbiota profiling data were collected. Fifteen patients were enrolled and received transplantation care at home starting on day +1 following hematopoietic cell infusion. Patients remained in the program for an average of 12 days and required an average of 2 outpatient visits while receiving home care. Seven of 15 patients were admitted for a median of 4 days (range, 3 to 10 days); admission occurred on day +7 in 5 patients, on day +8 in 1 patient, and on day +12 in 1 patient for neutropenic fever in 2 patients, fever attributed to engraftment syndrome in 2 patients, diarrhea in 2 patients, and dehydration in 1 patient. Only 1 patient had a documented infection (Clostridioides difficile). One patient admitted with neutropenic fever required intensive care unit admission for a gastrointestinal bleed. Forty-seven percent of the patients experienced a grade ≥3 nonhematologic toxicity. There were no deaths on the study. Patients and caregivers reported high satisfaction with care. Microbiota diversity patterns were similar to those of autologous HCT recipients who did not receive post-HCT care at home, although a subset of the cohort maintained microbiota diversity throughout. Homebound HCT in an urban setting is safe and feasible, with less than one-half of patients requiring inpatient admission. Despite increased patient and caregiver responsibility in the homebound setting compared with an inpatient setting, patient and caregiver satisfaction was high. These results support expansion of homebound transplantation care programs.

Dynamic EASIX scores closely predict nonrelapse mortality after allogeneic hematopoietic cell transplantation

Endothelial activation and stress index (EASIX) predicts nonrelapse mortality (NRM) when assessed before hematopoietic cell transplantation (HCT). We sought to determine whether changes in EASIX after HCT may be an informative marker of NRM. We evaluated 509 adults who underwent reduced intensity, unmodified (N = 149, 29%), or myeloablative ex vivo CD34+-selected allogeneic HCT (allo-HCT) (N = 306, 71%) between 2008 and 2016. Patients who underwent unmodified allo-HCT received tacrolimus-based graft-versus-host disease (GVHD) prophylaxis, whereas CD34+-selected patients received no planned immunosuppression. EASIX (lactate dehydrogenase × creatinine/platelet count) was calculated continuously until 1-year after HCT. Log transformation using base 2 (log2) was applied to all EASIX variables to reduce skew. In total, 360 patients (71%) received CD34+-selected and 149 (29%) unmodified allo-HCT. Among all patients, EASIX scores increased rapidly, peaked at day +8, then declined rapidly until day +33. Thereafter, scores declined gradually but remained above the pre-HCT baseline. In unmodified HCT, scores appeared higher over time than in CD34+-selected patients. EASIX discrimination of NRM was highest around day +180 (concordance index = 0.85) in both platforms, but the prognostic impact of EASIX across time points differed between the 2 platforms. Mean EASIX scores were higher in men (mean log2 +0.52) and in patients who developed grade 2 to 4 GVHD (+0.81) and lower in patients who received matched vs mismatched donors (-0.81, all P < .01). EASIX scores are dynamic and variably concordant with NRM when analyzed longitudinally, and patterns differ between HCT platforms. Compared to pre-HCT evaluation, post-HCT EASIX scores may better predict risk of NRM as patients acquire additional endothelial injury and toxicities.

A prospective study of dysgeusia and related symptoms in patients with multiple myeloma after autologous hematopoietic cell transplantation

BACKGROUND

Dysgeusia is a common but understudied complication in patients undergoing autologous hematopoietic cell transplantation (auto-HCT). We assessed the feasibility of using chemical gustometry (CG) to measure dysgeusia and explored its associations with symptom burden, nutrition, chemotherapy pharmacokinetics (PK), and the oral microbiome.

METHODS

We conducted a single-center, prospective feasibility study (NCT03276481) of patients with multiple myeloma undergoing auto-HCT. CG was performed longitudinally testing five flavors (sweet, sour, salty, bitter, umami) to calculate a total taste score (maximum score, 30). We measured caloric intake and patient-reported symptoms, assessing their correlation with oral microbiota composition and salivary and blood melphalan PK exposure.

RESULTS

Among all 45 patients, 39 (87%) completed at least four (>60%) and 22 (49%) completed all six CG assessments. Median total CG scores remained stable over time but were lowest at day +7 (27, range 24-30) with recovery by day +100. Symptom burden was highest by day +10 (area under the curve, 2.9; range, 1.0-4.6) corresponding with the lowest median overall caloric intake (1624 kcal; range, 1345-2267). Higher serum/salivary melphalan levels correlated with higher patient-reported dysgeusia and lower caloric intake. Oral microbiota α-diversity was stable early and increased slightly by day +100.

CONCLUSIONS

Assessment of dysgeusia by CG is feasible after auto-HCT. Most dysgeusia, symptom burden, and lowest caloric intake occurred during the blood count nadir. Higher melphalan concentrations correlated with more dysgeusia and poorer caloric intake. Future studies will aim to modulate melphalan exposure by PK-targeted dosing and characterize patient taste preferences to personalize diets for improved nutritional intake.

LAY SUMMARY

Taste changes after cancer treatments are very common. We used chemical gustometry (taste testing) to study taste changes and to better understand why patients with multiple myeloma experience this symptom after autologous hematopoietic cell transplantation. We found that taste testing was feasible, taste changes peaked when blood counts were lowest, and most patients recovered their taste by 100 days after transplantation. Taste changes correlated with lower food intake and with higher levels of chemotherapy in the body. Future work will focus on using personalized chemotherapy doses to reduce taste changes and to match patients' individual taste preferences with their diets.

Vitamin D Insufficiency and Clinical Outcomes with Chimeric Antigen Receptor T-Cell Therapy in Large B-cell Lymphoma

Vitamin D insufficiency is a potentially modifiable risk factor for poor outcomes in newly diagnosed large B-cell lymphoma (LBCL). However, the role of circulating vitamin D concentrations in relapsed/refractory LBCL treated with CD19-directed chimeric antigen receptor T-cell therapy (CAR-T) is currently unknown. This was a single-center, observational study that evaluated the association of pre-CAR-T 25-hydroxyvitamin D (25-OHD) status with 100-day complete response, progression-free survival, overall survival, and CAR-T-related toxicity in 111 adult relapsed/refractory LBCL patients. Vitamin D insufficiency was defined as ≤30 ng/mL in accordance with the Endocrine Society guidelines. The median pre-CAR-T 25-hydroxyvitamin D concentration was 24 ng/mL (interquarile range = 18-34). Vitamin D-insufficient patients (≤30 ng/mL; n = 73 [66%]) were significantly younger than their vitamin D-replete (>30 ng/mL; n = 38 [34%]) counterparts (P= .039). The vitamin D-insufficient cohort was enriched for de novo LBCL as the histological subtype (P= .026) and had a higher proportion of tisagenlecleucel as the CAR-T product (P= .049). There were no other significant differences in the baseline characteristics between the two groups. In vitamin D-insufficient compared to -replete patients, 100-day complete response was 55% versus 76% (P= .029), and 2-year overall survival was 41% versus 71% (P= .061), respectively. In multivariate analysis, vitamin D insufficiency remained significantly associated with 100-day complete response (odds ratio 2.58 [1.05-6.83]; P= .045) and overall survival (hazard ratio 2.24 [1.08-4.66], P= .030). In recipients of tisagenlecleucel, vitamin D insufficiency was associated with significantly lower cell viability of the infused CAR-T product (P= .015). Finally, pretreatment vitamin D insufficiency did not predict for subsequent CAR-T-related toxicity. This is the first report to demonstrate that vitamin D insufficiency is associated with inferior clinical outcomes in CAR-T recipients. Further study into the mechanistic insights of this finding, and the potential role of vitamin D supplementation to optimize CAR-T are warranted.

GPRC5D-Targeted CAR T Cells for Myeloma

BACKGROUND

B-cell maturation antigen (BCMA)-directed chimeric antigen receptor (CAR) T-cell therapies have generated responses in patients with advanced myeloma, but relapses are common. G protein-coupled receptor, class C, group 5, member D (GPRC5D) has been identified as an immunotherapeutic target in multiple myeloma. Preclinical studies have shown the efficacy of GPRC5D-targeted CAR T cells, including activity in a BCMA antigen escape model.

METHODS

In this phase 1 dose-escalation study, we administered a GPRC5D-targeted CAR T-cell therapy (MCARH109) at four dose levels to patients with heavily pretreated multiple myeloma, including patients with relapse after BCMA CAR T-cell therapy.

RESULTS

A total of 17 patients were enrolled and received MCARH109 therapy. The maximum tolerated dose was identified at 150×10⁶ CAR T cells. At the 450×10⁶ CAR T-cell dose, 1 patient had grade 4 cytokine release syndrome and immune effector cell-associated neurotoxicity syndrome (ICANS), and 2 patients had a grade 3 cerebellar disorder of unclear cause. No cerebellar disorder, ICANS of any grade, or cytokine release syndrome of grade 3 or higher occurred in the 12 patients who received doses of 25×10⁶ to 150×10⁶ cells. A response was reported in 71% of the patients in the entire cohort and in 58% of those who received doses of 25×10⁶ to 150×10⁶ cells. The patients who had a response included those who had received previous BCMA therapies; responses were observed in 7 of 10 such patients in the entire cohort and in 3 of 6 such patients who received 25×10⁶ to 150×10⁶ cells.

CONCLUSIONS

The results of this study of a GPRC5D-targeted CAR T-cell therapy (MCARH109) confirm that GPRC5D is an active immunotherapeutic target in multiple myeloma. (Funded by Juno Therapeutics/Bristol Myers Squibb; ClinicalTrials.gov number, NCT04555551.).

Evaluation of Melphalan Exposure in Lymphoma Patients Undergoing BEAM and Autologous Hematopoietic Cell Transplantation

High-dose melphalan is one of the main cytotoxic DNA alkylating agents and is used in many transplantation conditioning regimens. Studies have shown a wide range of drug exposure when a traditional weight-based dose of melphalan is used. The optimal melphalan dose in BEAM (carmustine, etoposide, cytarabine, and melphalan), which results in maximum efficacy with acceptable toxicity, is unknown. In this pharmacokinetic (PK) analysis of 105 patients with lymphoma undergoing treatment with BEAM and autologous hematopoietic cell transplantation, we initially estimated melphalan exposure as area under the curve (AUC) by a noncompartmental analysis and subsequently compared it with a newly developed 2-compartment population-PK model. The 2 models correlated closely with each other. We found that the traditional fixed weight-based dosing of propylene glycol-free (captisol-enabled) melphalan in BEAM results in a wide variation in exposure as estimated by both models. Higher melphalan exposure was significantly associated with increased metabolic toxicities but did not seem to impact progression-free survival. Although our study suggests a melphalan AUC of 8 mg·h/L as a potential target in BEAM, larger prospective studies using personalized PK-directed melphalan dosing are needed to determine the optimal melphalan exposure in lymphomas.

Triplet Therapy, Transplantation, and Maintenance until Progression in Myeloma

BACKGROUND

In patients with newly diagnosed multiple myeloma, the effect of adding autologous stem-cell transplantation (ASCT) to triplet therapy (lenalidomide, bortezomib, and dexamethasone [RVD]), followed by lenalidomide maintenance therapy until disease progression, is unknown.

METHODS

In this phase 3 trial, adults (18 to 65 years of age) with symptomatic myeloma received one cycle of RVD. We randomly assigned these patients, in a 1:1 ratio, to receive two additional RVD cycles plus stem-cell mobilization, followed by either five additional RVD cycles (the RVD-alone group) or high-dose melphalan plus ASCT followed by two additional RVD cycles (the transplantation group). Both groups received lenalidomide until disease progression, unacceptable side effects, or both. The primary end point was progression-free survival.

RESULTS

Among 357 patients in the RVD-alone group and 365 in the transplantation group, at a median follow-up of 76.0 months, 328 events of disease progression or death occurred; the risk was 53% higher in the RVD-alone group than in the transplantation group (hazard ratio, 1.53; 95% confidence interval [CI], 1.23 to 1.91; P<0.001); median progression-free survival was 46.2 months and 67.5 months. The percentage of patients with a partial response or better was 95.0% in the RVD-alone group and 97.5% in the transplantation group (P = 0.55); 42.0% and 46.8%, respectively, had a complete response or better (P = 0.99). Treatment-related adverse events of grade 3 or higher occurred in 78.2% and 94.2%, respectively; 5-year survival was 79.2% and 80.7% (hazard ratio for death, 1.10; 95% CI, 0.73 to 1.65).

CONCLUSIONS

Among adults with multiple myeloma, RVD plus ASCT was associated with longer progression-free survival than RVD alone. No overall survival benefit was observed. (Funded by the National Heart, Lung, and Blood Institute and others; DETERMINATION ClinicalTrials.gov number, NCT01208662.).

Impact of omitting post-transplant minidose-methotrexate doses in allogeneic hematopoietic cell transplantation

Given prophylactic methotrexate (MTX) is often held in the setting of toxicity we investigated the impact of omitting minidose-MTX dose(s). Outcomes were compared between patients who had 1-3 doses omitted and those who received all four planned doses of minidose-MTX. Of 370 consecutive patients, 50 had MTX dose(s) omitted. When MTX was omitted, initial management was mycophenolate mofetil (MMF; 36/50 patients) with or without corticosteroids (14/50 patients). Rates of grade 3-4 acute GVHD were similar between groups. Omission of minidose-MTX resulted in an increased risk of chronic GVHD (cGVHD; HR 2.27; p = .024) and decreased overall survival (HR 1.61; p = .024). However, other transplant-related outcomes were comparable. In summary, omission of minidose-MTX doses was not associated with an increased risk of acute GVHD when an alternative was added (e.g. MMF ± corticosteroids). This did not abrogate the increased risk of cGVHD or decreased overall survival.

Gaps and opportunities in the treatment of relapsed-refractory multiple myeloma: Consensus recommendations of the NCI Multiple Myeloma Steering Committee

A wide variety of new therapeutic options for Multiple Myeloma (MM) have recently become available, extending progression-free and overall survival for patients in meaningful ways. However, these treatments are not curative, and patients eventually relapse, necessitating decisions on the appropriate choice of treatment(s) for the next phase of the disease. Additionally, an important subset of MM patients will prove to be refractory to the majority of the available treatments, requiring selection of effective therapies from the remaining options. Immunomodulatory agents (IMiDs), proteasome inhibitors, monoclonal antibodies, and alkylating agents are the major classes of MM therapies, with several options in each class. Patients who are refractory to one agent in a class may be responsive to a related compound or to a drug from a different class. However, rules for selection of alternative treatments in these situations are somewhat empirical and later phase clinical trials to inform those choices are ongoing. To address these issues the NCI Multiple Myeloma Steering Committee formed a relapsed/refractory working group to review optimal treatment choices, timing, and sequencing and provide recommendations. Additional issues considered include the role of salvage autologous stem cell transplantation, risk stratification, targeted approaches for genetic subsets of MM, appropriate clinical trial endpoints, and promising investigational agents. This report summarizes the deliberations of the working group and suggests potential avenues of research to improve the precision, timing, and durability of treatments for Myeloma.

Population Pharmacokinetics of Melphalan in a Large Cohort of Autologous and Allogeneic Hematopoietic Cell Transplantation Recipients: Towards Individualized Dosing Regimens

BACKGROUND AND OBJECTIVES

High-dose melphalan is an integral part of conditioning chemotherapy prior to both autologous and allogeneic hematopoietic cell transplantation. While underexposure may lead to relapse, overexposure may lead to toxicities include mucositis, diarrhea, bone marrow suppression, and rarely sinusoidal obstruction syndrome. In this study, we describe the population pharmacokinetics of high-dose melphalan as a first step towards individualized dosing.

METHODS

Melphalan samples were collected in patients receiving an allogeneic or autologous hematopoietic cell transplantation between August 2016 and August 2020 at the Memorial Sloan Kettering Cancer Center. A population-pharmacokinetic model was developed using NONMEM.

RESULTS

Based on a total of 3418 samples from 452 patients receiving a median cumulative dose of 140 mg/m2, a two-compartment population-pharmacokinetic model was developed. Fat-free mass was a covariate for clearance, central volume of distribution, and inter-compartmental clearance, while glomerular filtration rate predicted clearance. Simulation studies showed that based on fixed body surface area-based dosing, renal impairment has a higher impact in increasing melphalan exposure compared with obesity.

CONCLUSIONS

The proposed model adequately describes the population pharmacokinetics of melphalan in adult patients receiving a hematopoietic cell transplantation. This model can be used to define the therapeutic window of melphalan, and subsequently to develop individualized dosing regimens aiming for that therapeutic window in all patients.

Impact of TP53 Genomic Alterations in Large B-Cell Lymphoma Treated With CD19-Chimeric Antigen Receptor T-Cell Therapy

PURPOSE

Tumor-intrinsic features may render large B-cell lymphoma (LBCL) insensitive to CD19-directed chimeric antigen receptor T cells (CAR-T). We hypothesized that TP53 genomic alterations are detrimental to response outcomes in LBCL treated with CD19-CAR-T.

MATERIALS AND METHODS

Patients with LBCL treated with CD19-CAR-T were included. Targeted next-generation sequencing was performed on pre-CAR-T tumor samples in a subset of patients. Response and survival rates by histologic, cytogenetic, and molecular features were assessed. Within a cohort of newly diagnosed LBCL with genomic and transcriptomic profiling, we studied interactions between cellular pathways and TP53 status.

RESULTS

We included 153 adults with relapsed or refractory LBCL treated with CD19-CAR-T (axicabtagene ciloleucel [50%], tisagenlecleucel [32%], and lisocabtagene maraleucel [18%]). Outcomes echoed pivotal trials: complete response (CR) rate 54%, median overall survival (OS) 21.1 months (95% CI, 14.8 to not reached), and progression-free survival 6 months (3.4 to 9.7). Histologic and cytogenetic LBCL features were not predictive of CR. In a subset of 82 patients with next-generation sequencing profiling, CR and OS rates were comparable with the unsequenced cohort. TP53 alterations (mutations and/or copy number alterations) were common (37%) and associated with inferior CR and OS rates in univariable and multivariable regression models; the 1-year OS in TP53-altered LBCL was 44% (95% CI, 29 to 67) versus 76% (65 to 89) in wild-type (P = .012). Transcriptomic profiling from a separate cohort of patients with newly diagnosed lymphoma (n = 562) demonstrated that TP53 alterations are associated with dysregulation of pathways related to CAR-T-cell cytotoxicity, including interferon and death receptor signaling pathway and reduced CD8 T-cell tumor infiltration.

CONCLUSION

TP53 is a potent tumor-intrinsic biomarker that can inform risk stratification and clinical trial design in patients with LBCL treated with CD19-CAR-T. The role of TP53 should be further validated in independent cohorts.

Hematopoietic Cell Transplantation is Feasible in Patients with Prior COVID-19 Infection

There are limited data on outcomes of patients with prior Coronavirus disease 2019 (COVID-19) who proceeded to autologous or allogeneic hematopoietic cell transplantation (HCT). Whether these patients are more susceptible to poor outcomes and recurrence of COVID-19 is unknown. We report a retrospective analysis of outcomes of 15 consecutive patients with hematologic malignancies who experienced COVID-19 and subsequently underwent autologous (n = 8) or allogeneic (n = 7) HCT between June 17, 2020, and February 17, 2021. The cohort included patients with asymptomatic past infections or symptomatic COVID-19 disease. Data were obtained from chart review. Descriptive statistics were used to summarize patient characteristics. Among eight patients who underwent autologous HCT, four had a diagnosis of multiple myeloma and four had a diagnosis of non-Hodgkin's lymphoma. Four of these eight patients did not test positive for anti-SARS-CoV-2 IgG antibody at any point during the course of treatment. The other four patients had detectable anti-SARS-CoV-2 IgG antibodies before undergoing autologous HCT, but only two of these patients remained anti-SARS-CoV-2 IgG antibody-positive at their last follow-up. One patient died from progression of disease. Seven patients with prior COVID-19 underwent allogeneic HCT for acute lymphoblastic leukemia (n = 3), acute myelogenous leukemia (n = 1), chronic myelogenous leukemia in lymphoid blast crisis (n = 1), myelodysplastic syndrome (n = 1), or myelofibrosis (n = 1). Three of the seven patients tested positive for anti-SARS-CoV-2 IgG antibodies following the initial COVID-19 diagnosis; however, only one of these patients retained anti-SARS-CoV-2 IgG antibody following allogeneic HCT. One patient died of infection (fungal and Pneumocystis jirovecii pneumonia) occurring in the context of ongoing treatment for graft-versus-host disease. None of the 15 patients had recurrent COVID-19 infection. Based on our experience, autologous and allogeneic HCT can be safely performed in selected patients with previous COVID-19 infection.

Fractionated Infusion of Hematopoietic Progenitor Cells Does Not Improve Neutrophil Recovery or Survival in Allograft Recipients

Allogeneic hematopoietic cell transplantation (HCT) offers a potentially curative therapy in patients with hematologic malignancies; however, nonrelapse mortality (NRM) remains a concern. Strategies to improve neutrophil recovery and immune reconstitution are needed to decrease NRM. Murine models of allogeneic HCT suggest that fractionated hematopoietic progenitor cell (HPC) infusion may improve engraftment through improved access of HPCs to a viable hematopoietic niche. The primary objective of the present study was to determine the impact of fractionated infusion versus unfractionated (bulk) infusion of HPCs on the time to achieve neutrophil engraftment. Secondary objectives included the effect of fractionated versus bulk infusion of HPCs on platelet engraftment, immune reconstitution, the incidence of acute graft-versus-host disease (GVHD) grade II-IV, NRM, and overall survival (OS). In this randomized phase 2 study, patients with hematologic malignancies undergoing allogeneic HCT were randomized to receive HPC infusion as a bulk (bulk arm) or in fractions (fractionated arm): 4 × 106 CD34+ cells/kg recipient weight infused on day 0, with the remaining HPCs CD34+ cell-selected then infused in equally distributed aliquots on days 2, 4, and 6 post-HCT. Randomization was stratified by type of transplant, unmodified (i.e. T cell-replete graft) versus CD34+ cell-selected (T cell-depleted graft). Patients whose donor failed to collect at least 7 × 106 CD34+ cells/kg of recipient weight received bulk HPC infusions regardless of randomization, for safety. These patients continued the HCT process on study but were replaced until each arm reached the prespecified accrual target. Per protocol, these patients were not included in this modified intention-to-treat analysis. A total of 116 patients were enrolled. Donors of 42 patients failed to mobilize the minimum CD34+ cell dose (7 × 106 cells/kg recipient weight) and were excluded from the analysis. The 74 evaluable patients included 38 randomized to the bulk arm and 36 randomized to the fractionated arm. All patients engrafted. The median time to an absolute neutrophil count of ≥0.5 × 109/L was 11 days on both arms. The day +180 median CD4+ cell count was 179 cells/µL in the bulk arm and 111 cells/µL in the fractionated arm (P = .779). The cumulative incidence of grade II-IV acute GVHD on post-transplant day +100 was 32% in the bulk arm and 17% in the fractionated arm (P = .131). Two patients in the bulk arm, but none in the fractionated arm, experienced grade III-IV GVHD. The 4-year OS was 60% in the bulk arm and 62% in the fractionated arm (P = .414), whereas the 4-year cumulative incidences of NRM and relapse were similar in the 2 arms. Fractionated infusion of HPCs in allogeneic HCT recipients did not impact neutrophil or CD4+ cell recovery, NRM, relapse, or OS when compared with bulk HPC infusion. We also observed that with current mobilization techniques, it was unlikely that more than 60% of healthy donors would be able to collect >7 × 106 CD34+ cells/kg recipient weight for adult recipients. © 2021 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc.

The post-transplant scoring system (PTSS) is associated with outcomes in patients with MDS after CD34+selected allogeneic stem cell transplant

The post-transplant scoring system (PTSS), developed by the Francophone Society of Bone Marrow Transplantation and Cellular Therapy, is based on three independent post-transplant risk factors: grade of acute graft-versus-host disease, lack of platelet recovery before day 100, and relapse before day 100; discriminating low- (0), intermediate- (1–3), and high-risk (4–8) patients. We investigated the prognostic value of the PTSS in a cohort of patients with MDS who underwent myeloablative CD34-selected TCD transplants. From 2008 to 2018, 109 patients underwent a first TCD-HCT for MDS at our center. We used Cox proportional hazards models and different landmark analyses to evaluate the association of categorized PTSS score risk groups with overall survival (OS). Patients with an intermediate/ high risk PTSS score had decreased OS at day 180 (univariate HR 3.25 [95% CI 1.60, 6.60], p = 0.001) and at day 365 (univariate HR 5.42 [95% CI 2.21, 13.3], p < 0.001) compared to low risk PTSS scores. This association remained significant after adjusting for HCT-CI. PTSS score calculated at day 100 was not associated with OS, even after adjusting for HCT-CI subgroups. In summary, the PTSS predicted survival at day 180 and day 365 in recipients of T-cell-depleted allografts for myelodysplastic syndrome.

A phase 1, multicenter study evaluating the safety and efficacy of KITE-585, an autologous anti-BCMA CAR T-cell therapy, in patients with relapsed/refractory multiple myeloma

Despite advances in treatment, most patients with multiple myeloma (MM) will relapse, and long-term survival remains poor. B-cell maturation antigen (BCMA) is an ideal therapeutic target as it is expressed throughout the disease course with normal tissue expression limited to plasma and some B-cell lineages. This phase 1, multicenter, first-in-human study evaluated the safety and efficacy of KITE-585, an autologous anti-BCMA chimeric antigen receptor (CAR) T-cell therapy, in patients with relapsed/refractory MM (RRMM). Key eligibility criteria included measurable MM and progression, defined by the International Myeloma Working Group Consensus Criteria within 60 days of the last treatment. Patients underwent leukapheresis and subsequently received a 3-day conditioning therapy regimen (cyclophosphamide [300 mg/m²/day] and fludarabine [30 mg/m²/day]). Patients then received a flat dose of 3 × 10⁷ to 1 × 10⁹ KITE-585 CAR T cells in a 3+3 dose-escalation design. The primary endpoint was incidence of adverse events (AEs) defined as dose-limiting toxicities (DLTs). Key secondary and exploratory endpoints included efficacy outcomes, incidence of AEs, levels of KITE-585 in blood, serum cytokines, and incidence of anti-BCMA CAR antibodies. Seventeen patients were enrolled, and 14 received KITE-585 with a median follow-up of 12.0 months. The median age of patients was 56 years, 41.2% had an Eastern Cooperative Oncology Group performance status of 1, 92.9% had baseline BCMA expression on plasma cells, and median number of prior therapies was 5.5. No patients experienced a DLT, all patients experienced ≥ 1 grade ≥ 3 treatment-emergent AE (TEAE), and no grade 5 TEAEs were observed. There were no grade ≥ 3 events of cytokine release syndrome, neurologic events, or infections; all were grade 1 or 2, and each occurred in 21.4% of patients. Among all patients infused with KITE-585, 1 patient who received 3 × 10⁷ anti-BCMA CAR T cells experienced a partial response. Median peak CAR T-cell expansion was low (0.98 cells/μL), as were median peak serum levels of CAR-associated cytokines, including interferon-γ (61.45 pg/mL) and interleukin-2 (0.9 pg/mL). KITE-585 demonstrated a manageable safety profile; however, the limited CAR T-cell expansion and associated lack of anti-tumor response in patients with RRMM treated with KITE-585 is consistent with the minimal CAR T-cell activity observed.

Dynamics of minimal residual disease in patients with multiple myeloma on continuous lenalidomide maintenance: a single-arm, single-centre, phase 2 trial

Background Lenalidomide maintenance improves progression-free survival for patients with multiple myeloma, although its optimal duration is unknown. Clearance of minimal residual disease (MRD) in the bone marrow results in superior outcomes, although its attainment or sustainment does not alter clinical decision-making. Studies that have evaluated MRD serially are limited in length. We therefore aimed to evaluate longitudinal changes in MRD-status (dynamics) and their association with progression-free survival in patients with multiple myeloma.

METHODS

In this single-centre, single-arm, phase 2 study, we enrolled patients aged 18 years and older from the Memorial Sloan Kettering Cancer Center (New York, NY, USA) who had newly diagnosed multiple myeloma following unrestricted frontline therapy and an Eastern Cooperative Oncology Group Performance Status of 2 or lower, including patients who started maintenance before study enrolment. All participants received lenalidomide maintenance at 10 mg for 21 days of 28-day cycles until progression or unacceptable toxic effects for up to 5 years on protocol. The primary endpoint was progression-free survival at 60 months per protocol and key secondary endpoints were MRD rates after completion of the 12th, 24th, and 36th cycle of maintenance and the association between progression-free survival and annual measurement of MRD status. MRD was assessed from first-pull bone marrow aspirates at baseline and annually by flow cytometry per International Myeloma Working Group criteria, (limit of detection of at least 1 × 10^-5) up to a maximum of 5 years. Patients who completed at least four cycles of treatment were included in the analysis of the primary endpoint, and patients who had completed at least one dose of treatment on protocol were assessable for secondary endpoints. The study was registered at ClinicalTrials.gov, NCT02538198, and is now closed to accrual.

FINDINGS

Between Sept 8, 2015, and Jan 25, 2019, 108 patients (100 evaluable for the primary endpoint) were enrolled. Median follow-up was 40·7 months (95% CI 38·7-45·0). At 60 months, progression-free survival was 64% (95% CI 52-79). Median progression-free survival was unreached (95% CI unreached-unreached). MRD dynamics were assessed using 340 MRD assessments done over 5 years for 103 evaluable patients. Patients who sustained MRD negativity for 2 years (n=34) had no recorded disease progression at median 19·8 months (95% CI 15·8-22·3) past the 2-year maintenance landmark. By contrast, patients who lost their MRD-negative responses (n=10) were more likely to progress than those with sustained MRD negativity (HR infinite; p<0·0001) and those with persistent MRD positivity (HR 5·88, 95% CI 1·18-33·33; p=0·015) at the 2-year landmark. Haematological and non-haematological serious adverse events occurred in 19 patients (18%). The most common adverse events of grade 3 or worse were decreased lymphocyte count in 48 (44%) patients and decreased neutrophil count in 47 (44%) patients. One death occurred on study due to sepsis and heart failure and was considered unrelated to the study drug.

INTERPRETATION

Serial measurements of MRD allow for dynamic assessment of risk for disease progression. Early intervention should be investigated for patients with loss of MRD negativity. Sustained MRD positivity is not categorically an unfavourable outcome and might portend prolonged stability of low-level disease.

FUNDING

Memorial Sloan Kettering and Celgene.