Impact of extramedullary multiple myeloma on outcomes with idecabtagene vicleucel.

Idecabtagene vicleucel (Ide-cel) has demonstrated excellent efficacy and durable responses in patients with relapsed/refractory multiple myeloma (RRMM). However, the outcomes with ide-cel in patients with extramedullary disease (EMD) remain incompletely characterized. We included patients with RRMM treated with ide-cel between May 2021 and April 2023 across 11 US academic institutions. Visceral or soft tissue lesions non-contiguous from bone was classified as EMD. Time-to-event analyses were performed from date of ide-cel infusion. Among 351 patients, 84 (24%) had EMD prior to infusion. The median follow-up from ide-cel infusion was 18.2 months (95% CI: 17-19.3). The day 90 overall response rates (ORR) were 52% vs. 82% for the EMD and non-EMD cohorts, respectively (p < 0.001). The median progression-free survival (PFS) was 5.3 months (95% CI: 4.1-6.9) for the EMD cohort vs. 11.1 months (95% CI: 9.2-12.6; p < 0.0001) for the non-EMD cohort. In a multivariable analysis, EMD was an independent predictor of inferior PFS [hazard ratio 1.5 (1.1-2.2), p = 0.02]. The median overall survival was 14.8 months [95% CI: 9-Not reached (NR)] vs. 26.9 months (26.3 vs. NR, p = 0.006) for the EMD and non-EMD cohorts, respectively. Extramedullary disease represents an independent predictor of inferior day 90 ORR and PFS among patients treated with ide-cel.

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.

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.

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.

Use of Endpoints in Phase III Randomized Controlled Trials for Hematopoietic Stem Cell Transplantation Over the Last 15 Years: A Systematic Review.

This systematic review aimed to evaluate the proportion of primary and secondary endpoints in hematopoietic stem cell transplant (HSCT) phase III randomized clinical trials (RCTs) and analyze their trends in time and study sponsorship status. The Chi-square test and logistic regression analyses were performed using SPSS version 28. A total of 147 HSCT phase III RCTs from 2006 to 2021 reported 197 primary and 600 secondary endpoints. Overall survival (OS, 17 %), progression-free survival (PFS, 15 %), graft versus host disease (GVHD, 8 %), event-free survival (EFS, 8 %), and organ function (8 %) were the most common primary endpoints. GVHD (12.3 %, n = 74), safety/toxicity/adverse events (11.8 %, n = 71), OS (11.5 %, n = 69), PFS (9.3 %, n = 56), and relapse rate (RR; 7.5 %, n = 45) were the most common secondary endpoints during 2006-2021. After 2013, an increase was noted in the use of PFS as a primary endpoint (12 %-18 %, p = 0.196), while the use of OS as a primary endpoint declined (20 %-13 %, p = 0.170). An increase was observed in using the secondary endpoints RR (5 %-10 %, p = 0.047) and NRM (3 %-6 %, p = 0.047). EFS was used more (14 % vs. 4 %, p = 0.012) than ORR (11 % vs. 2 %, p = 0.003) as a primary endpoint in pharmaceutical-compared to non-pharmaceutical-sponsored studies. As secondary endpoints, the use of EFS (4 % vs. 1 %, p = 0.013) and ORR (4 % vs. 1 %, p = 0.028) was higher, whereas that of organ systems/functions (1.5 % vs. 5.5 %, p = 0.022) and GVHD (6.5 % vs. 15 %, p = 0.002) was lower in pharmaceutical-compared to non-pharmaceutical sponsored studies. GVHD-free relapse-free survival was reported as a primary endpoint in 2 % of studies, while only 5 % reported quality of life as a secondary endpoint. We described commonly used endpoints in HSCT phase III RCTs and patterns in their use over time by funding source and study intervention category.

Successful treatment with fludarabine and cyclophosphamide in a VEXAS syndrome patient with associated myelodysplastic syndrome: a case report and systematic review.

Vacuoles, E1 syndrome, X-linked, autoinflammatory, somatic (VEXAS) syndrome is a chronic inflammatory disorder that affects various organ systems. It is associated with hematologic malignancies and is generally refractory to therapies. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) may be considered for selected patients. We report a case wherein systemic and hematological manifestations completely resolved in a patient with VEXAS and associated myelodysplastic syndrome (MDS), following the administration of fludarabine and cyclophosphamide as part of the preparation for allo-HSCT. We conducted a systematic literature review and included 86 patients with VEXAS syndrome and associated MDS. Most cases presented with musculoskeletal involvement (71%) and anemia (72%) with lower-risk MDS. Most patients responded to corticosteroids (CS) but had a recurrence of symptoms with CS taper and were refractory to other immunosuppressive agents. Hypomethylating agents and Janus kinase inhibitors achieved a complete response in some cases. Further research is needed to develop more effective treatment strategies.

Predictors of cytomegalovirus reactivation after allogeneic hematopoietic cell transplantation: Insights from a real-world experience.

BACKGROUND: We aimed to investigate factors associated with cytomegalovirus (CMV) viremia and CMV disease and its impact on post-transplant outcomes including overall survival (OS) following allogeneic hematopoietic stem cell transplantation (Allo-SCT). METHODS: We conducted a single-center retrospective study including 452 Allo-SCT recipients (matched unrelated donor, MUD 61%; haploidentical, haplo 39%) from 2016 to 2021. Data were analyzed using SPSS v28. Descriptive (chi-square and t-test), Kaplan-Meier and regression analyses were conducted. RESULTS: The median age was 57 years. Sixty-one percent were males and 84.3% were Caucasians. CMV serostatus was positive in 59.1% of recipients. The median follow-up was 24.4 months. CMV viremia and CMV disease were observed in 181 (40%) and 32 (7%) patients, respectively. Among CMV seropositive recipients, 65% developed CMV viremia and 11% were noted to have CMV disease compared to 4% and 1% in seronegative recipients, respectively (p < 0.001). Patients with CMV disease had significantly lower OS than those without CMV disease (median 14.1 months vs. not reached, p = 0.024); however, OS was not associated with CMV viremia (median not reached in both groups, p = 0.640). Letermovir prophylaxis was used in 66% (n = 176/267) of CMV seropositive recipients, but no impact was observed on the incidence of CMV viremia or CMV disease and OS. CONCLUSIONS: CMV disease leads to significantly inferior survival after an allogeneic hematopoietic cell transplantation. Recipient CMV seropositive status was associated with the risk of CMV viremia and CMV disease, and this was not abrogated with the use of Letermovir prophylaxis.

Outcomes with allogeneic hematopoietic stem cell transplantation in TP53-mutated myelodysplastic syndrome: A systematic review and meta-analysis.

We conducted a systematic review and meta-analysis to evaluate outcomes after allogeneic hematopoietic stem cell transplantation (Allo-HSCT) in TP53-mutated myelodysplastic syndromes (MDS). A literature search was performed on PubMed, Cochrane, Embase, and Clinicaltrials.gov. After screening 626 articles, eight studies were included. Data were extracted following the PRISMA guidelines and analyzed using the meta-package by Schwarzer et al. We analyzed 540 patients. The pooled median 3 (1-5) year overall survival was 21% (95% CI 0.08-0.37, I2=91%, n=540). The pooled relapse rate was 58.9% (95% CI 0.38-0.77, I2=93%, n=487) at a median of 1.75 (1-3) years. The pooled 4-year progression- free survival was 34.8% (95% CI 0.15-0.57, I2=72%, n=105). Outcomes of Allo-HSCT for TP53-mutated MDS patients remain poor, with 21% OS at three years; however, Allo-HSCT confers a survival advantage as compared to non-transplant palliative therapies. Our findings suggest the need to explore novel therapeutic agents in prospective clinical trials.

Outcomes of subsequent anti-lymphoma therapies after second-line axicabtagene ciloleucel or standard of care in ZUMA-7.

In ZUMA-7 (NCT03391466), axicabtagene ciloleucel (axi-cel) significantly improved outcomes versus second-line (2L) standard of care (SOC) for adults with relapsed/refractory large B-cell lymphoma (LBCL). The optimal management of patients after disease progression or lack of response to 2L therapy remains unclear. Here, we report outcomes among patients who received subsequent anti-lymphoma therapy per investigator discretion separately by their randomized 2L arm in ZUMA-7. Progression-free survival (PFS) and overall survival (OS) were calculated from 3L therapy initiation by randomized 2L arm. In the SOC arm, 127/179 randomized patients (71%) received 3L therapy. Median PFS among those who received 3L cellular immunotherapy (n=68) versus those who did not (n=59) was 6.3 versus 1.9 months, respectively; median OS was 16.3 versus 9.5 months, respectively. In the axi-cel arm, 84/180 randomized patients (47%) received 3L therapy. Median PFS among those who received 3L chemotherapy (n=60) versus cellular immunotherapy (n=8) was 1.7 versus 3.5 months, respectively; median OS was 8.1 months versus not reached, respectively. Of the 60 patients who received 3L chemotherapy, 10 underwent stem cell transplantation (SCT; 9 autologous; 1 allogeneic) after salvage chemotherapy. Median PFS was 11.5 versus 1.6 months, and median OS was 17.5 versus 7.2 months for those who did versus those who did not reach SCT, respectively. Eight patients received 3L cellular immunotherapy after 2L axi-cel. Of these, 6 patients received subsequent SCT in any line, and all 6 were alive at data cutoff. These findings help inform subsequent treatment choices after failure of 2L therapy for relapsed/refractory LBCL.

Cost-Effectiveness of Reduced-Intensity Allogeneic Hematopoietic Cell Transplantation for Older Patients With High-Risk Myelodysplastic Syndrome: Analysis of BMT CTN 1102.

PURPOSE: BMT CTN 1102 was a phase III trial comparing reduced-intensity allogeneic hematopoietic cell transplantation (RIC alloHCT) to standard of care for persons with intermediate- or high-risk myelodysplastic syndrome (MDS). We report results of a cost-effectiveness analysis conducted alongside the clinical trial. METHODS: Three hundred eighty-four patients received HCT (n = 260) or standard of care (n = 124) according to availability of a human leukocyte antigen-matched donor. Cost-effectiveness was calculated from US commercial and Medicare perspectives over a 20-year time horizon. Health care utilization and costs were estimated using propensity score-matched cohorts of HCT recipients in the OptumLabs Data Warehouse (age 50-64 years) and Medicare (age 65 years and older). EuroQol 5 Dimension (EQ-5D) surveys of trial participants were used to derive health state utilities. RESULTS: Extrapolated 20-year overall survival for those age 50-64 years was 29% for HCT (n = 105) versus 13% for usual care (n = 44) and 31% for HCT (n = 155) versus 12% for non-HCT (n = 80) for those age 65 years and older. HCT was more effective (+2.36 quality-adjusted life-years [QALYs] for age 50-64 years and +2.92 QALYs for age 65 years and older) and more costly (+$452,242 in US dollars (USD) for age 50-64 years and +$233,214 USD for age 65 years and older) than usual care, with incremental cost-effectiveness ratios of $191,487 (USD)/QALY and $79,834 (USD)/QALY, respectively. For persons age 50-64 years, there was a 29% chance that HCT was cost-effective using a willingness-to-pay (WTP) threshold of $150K (USD)/QALY and 51% at a $200K (USD)/QALY. For persons age 65 years and older, the probability was 100% at a WTP >$150K (USD)/QALY. CONCLUSION: Among patients age 65 years and older with high-risk MDS, RIC HCT is a high-value strategy. For those age 50-64 years, HCT is a lower-value strategy but has similar cost-effectiveness to other therapies commonly used in oncology.

Outcomes with HLA-matched unrelated donor versus haploidentical hematopoietic cell transplantation.

We investigated the outcomes after adult haploidentical (haplo) and matched unrelated donor (MUD) hematopoietic cell transplantation (HCT) in a single-center study (n = 452) including 276 MUD and 176 haplo transplants. Myeloablative (37%) and reduced-intensity conditioning (63%) were performed. Graft sources included peripheral blood (50%) and bone marrow (50%). GVHD prophylaxis included tacrolimus/methotrexate (53%) and post-transplant cyclophosphamide-based (47%). In MUD versus haplo HCT recipients, a similar incidence of neutrophil engraftment (18 vs 17 days, p = 0.895), grade II-IV acute GVHD (51% vs 50%, p = 0.773), relapse (26% vs 23%, p = 0.578), non-relapse mortality (22% vs 23%, p = 0.817), 1-year disease-free survival (62% vs 63%. p = 0.921), and 1-year overall survival (73% vs 74%, p = 0.744) were observed. Earlier platelet engraftment (22 vs 27 days, p < 0.001) and higher chronic GVHD (45% vs 35%, p = 0.040) were noted in MUD as compared to haplo HCT. Allogeneic transplantation should be done promptly whenever indicated, utilizing either matched unrelated or haploidentical donors.

Durable response after tisagenlecleucel in adults with relapsed/refractory follicular lymphoma: ELARA trial update.

ABSTRACT: Tisagenlecleucel is approved for adults with relapsed/refractory (r/r) follicular lymphoma (FL) in the third- or later-line setting. The primary analysis (median follow-up, 17 months) of the phase 2 ELARA trial reported high response rates and excellent safety profile in patients with extensively pretreated r/r FL. Here, we report longer-term efficacy, safety, pharmacokinetic, and exploratory biomarker analyses after median follow-up of 29 months (interquartile range, 22.2-37.7). As of 29 March 2022, 97 patients with r/r FL (grades 1-3A) received tisagenlecleucel infusion (0.6 × 108-6 × 108 chimeric antigen receptor-positive viable T cells). Bridging chemotherapy was allowed. Baseline clinical factors, tumor microenvironment, blood soluble factors, and circulating blood cells were correlated with clinical response. Cellular kinetics were assessed by quantitative polymerase chain reaction. Median progression-free survival (PFS), duration of response (DOR), and overall survival (OS) were not reached. Estimated 24-month PFS, DOR, and OS rates in all patients were 57.4% (95% confidence interval [CI], 46.2-67), 66.4% (95% CI, 54.3-76), and 87.7% (95% CI, 78.3-93.2), respectively. Complete response rate and overall response rate were 68.1% (95% CI, 57.7-77.3) and 86.2% (95% CI, 77.5-92.4), respectively. No new safety signals or treatment-related deaths were reported. Low levels of tumor-infiltrating LAG3+CD3+ exhausted T cells and higher baseline levels of naïve CD8+ T cells were associated with improved outcomes. Tisagenlecleucel continued to demonstrate highly durable efficacy and a favorable safety profile in this extended follow-up of 29 months in patients with r/r FL enrolled in ELARA. This trial was registered at www.clinicaltrials.gov as #NCT03568461.

Real-world experience of patients with multiple myeloma receiving ide-cel after a prior BCMA-targeted therapy.

Most patients with multiple myeloma experience disease relapse after treatment with a B-cell maturation antigen-targeted therapy (BCMA-TT), and data describing outcomes for patients treated with sequential BCMA-TT are limited. We analyzed clinical outcomes for patients infused with standard-of-care idecabtagene vicleucel, an anti-BCMA chimeric antigen receptor (CAR) T-cell therapy, at 11 US medical centers. A total of 50 patients with prior BCMA-TT exposure (38 antibody-drug conjugate, 7 bispecific, 5 CAR T) and 153 patients with no prior BCMA-TT were infused with ide-cel, with a median follow-up duration of 4.5 and 6.0 months, respectively. Safety outcomes between cohorts were comparable. The prior BCMA-TT cohort had a lower overall response rate (74% versus 88%; p = 0.021), median duration of response (7.4 versus 9.6 months; p = 0.03), and median progression-free survival (3.2 months versus 9.0 months; p = 0.0002) compared to the cohort without prior BCMA-TT. All five patients who received a prior anti-BCMA CAR T responded to ide-cel, and survival outcomes were best for this subgroup. In conclusion, treatment with ide-cel yielded meaningful clinical responses in real-world patients exposed to a prior BCMA-TT, though response rates and durability were suboptimal compared to those not treated with a prior BCMA-TT.

Placental expanded mesenchymal-like cells (PLX-R18) for poor graft function after hematopoietic cell transplantation: A phase I study.

Persistent cytopenia in the post-hematopoietic cell transplantation (HCT) setting can occur despite adequate engraftment of donor cells. PLX-R18, a placental-derived mesenchymal-like cell product, is expanded ex vivo in a 3-dimensional environment. PLX-R18 cells secrete a large array of hematopoietic factors, which promote regeneration, maturation, and differentiation of hematopoietic cells and stimulate their migration to peripheral blood. This phase 1, first-in-human study (NCT03002519), included 21 patients with incomplete hematopoietic recovery post-HCT. Patients were treated with escalating doses of PLX-R18: 3 patients received 1 million cells/kg, 6 received 2 million cells/kg, and 12 received 4 million cells/kg via multiple intramuscular injections. While patients received only two administrations of cells during the first week, peripheral blood counts continued to increase for months, peaking at 6 months for hemoglobin (Hb, p = 0.002), lymphocytes (p = 0.008), and neutrophils (ANC, p = 0.063), and at 9 months for platelets (p < 0.001) and was maintained until 12 months for all but ANC. The need for platelet transfusions was reduced from 5.09 units/month at baseline to 0.55 at month 12 (p = 0.05). Likewise, red blood cell transfusions decreased from 2.91 units/month at baseline to 0 at month 12 (p = 0.0005). PLX-R18 was safe and well tolerated and shows promise in improving incomplete hematopoietic recovery post-HCT.

Lessons learned from COVID-19 pandemic: outcomes after SARS-CoV-2 infection in hematopoietic cell transplant and cell therapy recipients.

We investigated the outcomes after Coronavirus disease 2019 (COVID) in hematopoietic cell transplant (HCT) or chimeric antigen receptor-T cell (CART) therapy recipients in a single-centre study including all (n = 261)HCT/CART recipients (allogeneic-HCT 49%, autologous-HCT 40%, CART 11%). The median age was 60 (22-80) years. COVID severity was mild (74%), moderate (11%), and severe/critical (16%) with a mortality rate of 7% and a median duration of infection of 5.7 weeks. Significant predictors of COVID severe disease or mortality included concurrent infection (HR 14.9, 95% CI 2.2-5.6) and immunosuppressive therapy (OR 4.8, 95% CI 1.2-3.4).HCT/CART recipients have a higher risk of mortality with COVID and warrant vigilant interventions.

Imaging Biomarkers to Predict Outcomes in Patients With Large B-Cell Lymphoma With a Day 28 Partial Response by 18F-FDG PET/CT Imaging Following CAR-T Therapy.

BACKGROUND: CD19 directed CAR-T therapy for Large B-cell lymphoma (LBCL) has shown great therapeutic response in patients with relapsed/refractory disease with response rates of 60-80%. However, in patients with a partial response (PR) on initial day 28 post CAR-T therapy imaging, clinical uncertainty remains as half of these patients will ultimately have relapsed disease.   PATIENTS: In 24 patients receiving CD19 directed CAR-T therapy for relapsed/refractory LBCL achieving a PR on day 28, we utilize imaging biomarkers by 18F-FDG PET/CT imaging at pre CAR-T therapy baseline and day 28 to determine factors that may predict best overall response (B-OR), progression free survival (PFS), and overall survival (OS).   METHODS: Out of 75 patients receiving CAR-T therapy at a single institution, we retrospectively identified and reviewed 25 (33%) as achieving a PR on day 28. PR was defined using the 2014 Lugano classification system. All patients received standard of care CD19 directed CAR-T therapy with axicabtagene ciloleucel. Two independent nuclear medicine physicians measured baseline (pre-CAR-T therapy) and day 28 PET/CT SUVmax, SUVmean and TMV (cm3) of each lesion (node, organ or marrow uptake, if any) using ROVER software. All statistical tests were two-sided and conducted at the 0.05 level of significance. R version 1.3.1099 (R-studio) was used for statistical modeling.   CONCLUSION: We demonstrate that a higher day 28 SUVmax was significantly higher in those with a B-OR of PR and in our modeling, a lower day 28 SUVmax may predict favorable PFS and OS. Additionally, lower TMV, both at baseline and day 28, may also be predictive of longer PFS and OS, while lower TLG at baseline, but not day 28 is significantly associated with a B-OR of CR. While further study is warranted, these imaging biomarkers may allow for early identification of those with a day 28 PR at highest risk for relapse leading to early intervention to improve long term outcomes.

Identifying an optimal fludarabine exposure for improved outcomes after axi-cel therapy for aggressive B-cell non-Hodgkin lymphoma.

Fludarabine is one of the most common agents given for lymphodepletion before CD19 chimeric antigen receptor T cells, but its optimal therapeutic intensity is unknown. Using data from a multicenter consortium, we estimated fludarabine exposure (area under the curve [AUC]) using a population pharmacokinetic (PK) model in 199 adult patients with aggressive B-cell non-Hodgkin lymphomas who received commercial axicabtagene ciloleucel (Axi-cel). We evaluated the association of estimated fludarabine AUC with key outcomes, aiming to find an AUC that optimized efficacy and tolerability. We identified low (<18 mg × hour/L [mgh/L]), optimal (18-20 mgh/L), and high (>20 mgh/L) AUC groups for analyses; the 6-month cumulative incidences of relapse/progression of disease (relapse/POD) by AUC groups were 54% (45%-62%), 28% (15%-44%), and 30% (14%-47%), respectively; and the 1-year progression-free survival (PFS) rates were 39% (31%-48%), 66% (52%-84%), and 46% (30%-70%) and the overall survival (OS) rates were 58% (50%-67%), 77% (64%-92%), and 66% (50%-87%), respectively. In multivariable analyses compared with low AUC, an optimal AUC was associated with the highest PFS (hazard ratio [HR], 0.52; 0.3-0.91; P = .02) and lowest risk of relapse/POD (HR, 0.46; 0.25-0.84; P = .01) without an increased risk of any-grade cytokine release syndrome (HR, 1.1; 0.7-1.6; P = .8) or and immune effector cell-associated neurotoxicity syndrome (ICANS) (HR, 1.36; 0.83-2.3; P = .2). A high AUC was associated with the greatest risk of any-grade ICANS (HR, 1.9; 1.1-3.2; P = .02). Although the main cause of death in all groups was relapse/POD, nonrelapse-related deaths, including 3 deaths from ICANS, were more frequent in the high AUC group. These findings suggest that PK-directed fludarabine dosing to achieve an optimal AUC may result in improved outcomes for patients receiving axi-cel.

Efficacy and Safety of CD34+ Stem Cell Boost for Delayed Hematopoietic Recovery After BCMA Directed CAR T-cell Therapy.

Chimeric antigen receptor (CAR) T-cell therapy has revolutionized treatment outcomes for patients with relapsed refractory multiple myeloma (RRMM). Despite supportive care with growth factors and thrombopoietin (TPO) mimetics, nearly half of the patients experience severe and prolonged cytopenias after CAR T infusion, which have become a major therapeutic challenge for patients with RRMM. Given the successful use of CD34+ autologous hematopoietic stem cells for treatment of non- or delayed engraftment after allogeneic and autologous stem cell transplantations, there is a need to explore the role of previously stored autologous stem cells as a boost for post-CAR T cytopenias in RRMM. We performed a multicenter retrospective analysis of adult patients with RRMM who received previously collected and stored CD34+ stem cell boosts after CAR T-cell therapy between 2 July 2020 and 18 January 2023. Indications for boost were determined per physician discretion and primarily included cytopenias and related complications. Overall, a total of 19 patients received stem cell boost, at a median dose of 2.75 × 106 CD34+ cells/kg (range 1.76-7.38), given at a median of 53 days (range 24-126) after CAR T infusion. Eighteen (95%) patients successfully recovered hematopoiesis after stem cell boost with median time for neutrophil, platelet, and hemoglobin engraftment of 14 (range 9-39), 17 (range 12-39), and 23 (range 6-34) days after the boost, respectively. Stem cell boosts were well tolerated, with no patients experiencing infusion reactions. Although infections were common and severe before stem cell boost, only 1 patient experienced a new infection after boost. All patients had experienced independence from use of growth factors, TPO agonists, and transfusions at the last follow-up. Autologous stem cell boosts can be effectively and safely used to promote hematopoietic recovery for post-CAR T cytopenias in patients with RRMM. Stem cell boosts can be a very effective rescue measure for post-CAR T cytopenias and related complications, as well as supportive care needs.