Generation and optimization of off-the-shelf immunotherapeutics targeting TCR-Vβ2+ T cell malignancy

Current treatments for T cell malignancies encounter issues of disease relapse and off-target toxicity. Using T cell receptor (TCR)Vβ2 as a model, here we demonstrate the rapid generation of an off-the-shelf allogeneic chimeric antigen receptor (CAR)-T platform targeting the clone-specific TCR Vβ chain for malignant T cell killing while limiting normal cell destruction. Healthy donor T cells undergo CRISPR-induced TRAC, B2M and CIITA knockout to eliminate T cell-dependent graft-versus-host and host-versus-graft reactivity. Second generation 4-1BB/CD3zeta CAR containing high affinity humanized anti-Vβ scFv is expressed efficiently on donor T cells via both lentivirus and adeno-associated virus transduction with limited detectable pre-existing immunoreactivity. Our optimized CAR-T cells demonstrate specific and persistent killing of Vβ2+ Jurkat cells and Vβ2+ patient derived malignant T cells, in vitro and in vivo, without affecting normal T cells. In parallel, we generate humanized anti-Vβ2 antibody with enhanced antibody-dependent cellular cytotoxicity (ADCC) by Fc-engineering for NK cell ADCC therapy.

Allogeneic stem cell transplant for treatment of mycosis fungoides and Sezary syndrome: a systematic review and meta-analysis

Allogeneic hematopoietic stem cell transplant (allo-HSCT) has been noted to be a potential curative treatment in cases of advanced-stage mycosis fungoides (MF) or Sezary syndrome (SS). To assess outcomes of allo-HSCT for MF/SS we performed a systematic review and meta-analysis including 15 manuscripts and 557 patients, published from 2010-2023. Meta-analysis revealed 1-year and 3+year overall survival (OS) of 51% (95% CI 39-64%) and 40% (32-49%). Progression-free survival at 1 year and 3+years were 42% (31-53%) and 33% (25-42%). Non-relapse mortality was 18% (13-23%). Relapse occurred in of 47% (40-53%) with a median time to relapse of 7.9 months (range 1.6-24 months). Rates of acute and chronic graft-versus-host disease (GVHD) were 45% (35-55%) and 40% (33-48%). Reduced-intensity conditioning (RIC) was associated with superior OS compared to myeloablative conditioning (MAC) (58% vs. 30%, p < 0.001). Of patients with relapse after allo-HSCT, 46% treated with donor lymphocyte infusion (DLI) achieved complete remission. These data support use of allo-HSCT for treatment of advanced-stage MF/SS and suggest superiority of RIC over MAC. Rates of GVHD were comparable to allo-HSCT in general. The improved OS for RIC and high rate of CR with DLI underscore the importance of the graft-versus-lymphoma effect in allo-HSCT for MF/SS.

Allogeneic transplantation and cellular therapies in cutaneous T-cell lymphoma

INTRODUCTION

Mycosis fungoides (MF) and Sezary syndrome (SS) are the most common types of cutaneous T-cell lymphoma. Although many available treatments offer temporary disease control, allogeneic hematopoietic stem cell transplant (allo-HSCT) is the only curative treatment option for advanced stage MF and SS. CAR T-cell therapy is a promising new avenue for treatment.

AREAS COVERED

In this review, we discuss the evidence supporting the use of allo-HSCT for the treatment of MF/SS, including disease status at the time of transplant, conditioning regimen, total body irradiation (TBI), and donor lymphocyte infusion (DLI). We also address the potential role for CAR T-cell therapy in CTCL.

EXPERT OPINION

Allo-HSCT is an effective treatment for patients with advanced MF and SS. However, significant research is required to determine optimal treatment protocols. Data support the use of reduced-intensity conditioning regimens and suggests that the use of TBI for debulking of skin disease may result in more durable remissions. Donor lymphocyte infusions (DLI) appear to be particularly effective in inducing complete remission in MF/SS patients with relapsed or residual disease. Challenges with CAR-T therapies in T-cell lymphoma include T-cell fratricide due to shared antigens on malignant and nonmalignant T-cells, penetrance into the skin compartment, and CAR-T cell persistence.

Clinicopathologic Features of Cutaneous T-Cell Lymphomas With Extracutaneous Metastasis: A Case Series

BACKGROUND

In advanced stages, Cutaneous T-cell lymphomas (CTCL) can metastasize to extracutaneous regions. CTCL with metastasis exhibits unique clinicopathologic characteristics.

PATIENTS AND METHODS

This study collected 35 cases of primary CTCL with extracutaneous metastasis from a single institution over a period of 20 years. Clinicopathologic features including demographics, CD30 expression, large cell transformation, metastatic sites, T-cell receptor clonality studies and survival data were analyzed.

RESULTS

The study identified various CTCL entities including mycosis fungoides (MF), Sezary syndrome (SS), cutaneous anaplastic large cell lymphoma (C-ALCL), and primary cutaneous peripheral T-cell lymphoma, not otherwise specified (pcPTCL-NOS). Limited data showed that metastasis can be independent of large cell transformation and/or CD30 expression. Lymph nodes were the most common site of metastasis, followed by the bone marrow. Oropharyngeal metastasis is likely to accompany visceral organ or brain metastasis (P = .049). MF had a longer interval to metastasis than SS (P = .038). Patients with lymph node only metastasis have better survival than patients with metastasis to other sites (P = .012).

CONCLUSION

To the best of our knowledge, there are limited studies analyzing the clinicopathologic features of different CTCL entities with metastasis as a single population. This research provides valuable insights into the unique characteristics of metastatic CTCL.

Impact of Memory T Cells on SARS-COV-2 Vaccine Response in Hematopoietic Stem Cell Transplant

During the COVID-19 pandemic, hematopoietic stem cell transplant (HSCT) recipients faced an elevated mortality rate from SARS-CoV-2 infection, ranging between 10-40%. The SARS-CoV-2 mRNA vaccines are important tools in preventing severe disease, yet their efficacy in the post-transplant setting remains unclear, especially in patients subjected to myeloablative chemotherapy and immunosuppression. We evaluated the humoral and adaptive immune responses to the SARS-CoV-2 mRNA vaccination series in 42 HSCT recipients and 5 healthy controls. Peripheral blood mononuclear nuclear cells and serum were prospectively collected before and after each dose of the SARS-CoV-2 vaccine. Post-vaccination responses were assessed by measuring anti-spike IgG and nucleocapsid titers, and antigen specific T cell activity, before and after vaccination. In order to examine mechanisms behind a lack of response, pre-and post-vaccine samples were selected based on humoral and cellular responses for single-cell RNA sequencing with TCR and BCR sequencing. Our observations revealed that while all participants eventually mounted a humoral response, transplant recipients had defects in memory T cell populations that were associated with an absence of T cell response, some of which could be detected pre-vaccination.

FISH Panel for Leukemic Cutaneous T-Cell Lymphoma: Extended Patient Cohort Correlation with Blood Involvement and Clinical Outcomes

The genomic basis of cutaneous T-cell lymphoma has been characterized by gene copy number alterations and genomic sequencing, but there are few clinical tests that are being widely used to inform the diagnosis and prognosis of leukemic cutaneous T-cell lymphoma that may arise as a progression from mycosis fungoides or de novo as Sézary syndrome. An 11-gene FISH panel of TP53, RB1, DNMT3A, FAS, ZEB1, ARID1A, ATM, and CDKN2A deletions and MYC, signal transducer and activator of transcription gene (STAT)3/5B, and CARD11 amplifications was previously found to encapsulate >95% of gene copy number variations in leukemic cutaneous T-cell lymphoma. Through a retrospective analysis of patients with leukemic cutaneous T-cell lymphoma seen at the Yale Cancer Center from 2014 to 2020, we gathered the relevant genes as they became available and correlated them to factors with prognostic relevance as a proof of concept to show the potential utility in further developing a limited gene panel for prognosis. In this study, we show that the abnormal FISH results show an association with clinically relevant factors (blood stage, CD4:8 ratio, and percentage blood involvement) and have a nonsignificant statistical trend (>90%) toward correlation with overall survival. In addition, the previous cost-effective panels were signal transducer and activator of transcription (STAT)3/5B, MYC, TP53, and ARID1A. We now suggest adding RB1 and ZEB1 on the basis of our findings.

Real-Life Barriers to Diagnosis of Early Mycosis Fungoides: An International Expert Panel Discussion

Mycosis fungoides (MF) is a rare, primary cutaneous T-cell lymphoma that is challenging to diagnose due to its heterogeneous clinical presentation and complex histology. The subtlety of the initial clinical appearance of MF can result in diagnostic delays and hesitancy to refer suspected cases to specialist clinics. An unmet need remains for greater awareness and education. Therefore, an international expert panel of dermatologists, oncologists, hematologists, and dermatopathologists convened to discuss and identify barriers to early and accurate MF diagnosis that could guide clinicians toward making a correct diagnosis. Confirmation of MF requires accurate assessment of symptoms and clinical signs, and subsequent correlation with dermatopathological findings. This review summarizes the expert panel's guidance, based on the literature and real-life experience, for dermatologists to help include MF in their list of differential diagnoses, along with simple clinical and histopathologic checklists that may help clinicians to suspect and identify potential MF lesions and reduce diagnostic delays.

Peripheral Blood Involvement at Staging in Patients With Aggressive Peripheral T-Cell Lymphoma

INTRODUCTION

Peripheral T-Cell Lymphomas (PTCL) are a rare subgroup of lymphomas with a poor outcome.Traditional prognostic measures rely heavily on disease stage, and with the advent of targeted treatment, further stratificationcriteria are needed to guide treatment. To date, the impact of blood involvement at diagnosis on outcomes has not been assessed.

MATERIALS AND METHODS

We retrospectively reviewed blood involvement by flow cytometry at diagnosis in 102 consecutivelytreated patients who had flow cytometry data available at diagnosis. Of these, 78 patients with nodal subtypes were identified andstudied in this analysis.

RESULTS

Of 78 patients with nodal subtypes of PTCL who had flow data available at the time ofdiagnosis, circulating populations of malignant T cells matching those in the biopsied lymph nodes were found in 21 patients bymultiparameter flow cytometry. A positive flow cytometry was highly correlated with bone marrow involvement. The patientswith a negative flow cytometry had a trend toward a longer median PFS compared to those with a positive flow but there was noimpact on overall survival.

CONCLUSIONS

Circulating malignant tumor cells can be found in the peripheral blood in a subset ofpatients with aggressive nodal T-cell lymphomas, including peripheral t-cell lymphoma not otherwise specified andangioimmunoblastic T-cell lymphomas, and blood involvement is correlated with bone marrow involvement.

Primary cutaneous lymphoma: recommendations for clinical trial design and staging update from the ISCL, USCLC, and EORTC

The number of patients with primary cutaneous lymphoma (PCL) relative to other non-Hodgkin lymphomas (NHLs) is small and the number of subtypes large. Although clinical trial guidelines have been published for mycosis fungoides/Sézary syndrome, the most common type of PCL, none exist for the other PCLs. In addition, staging of the PCLs has been evolving based on new data on potential prognostic factors, diagnosis, and assessment methods of both skin and extracutaneous disease and a desire to align the latter with the Lugano guidelines for all NHLs. The International Society for Cutaneous Lymphomas (ISCL), the United States Cutaneous LymphomaConsortium (USCLC), and the Cutaneous Lymphoma Task Force of the European Organization for the Research and Treatment of Cancer (EORTC) now propose updated staging and guidelines for the study design, assessment, endpoints, and response criteria in clinical trials for all the PCLs in alignment with that of the Lugano guidelines. These recommendations provide standardized methodology that should facilitate planning and regulatory approval of new treatments for these lymphomas worldwide, encourage cooperative investigator-initiated trials, and help to assess the comparative efficacy of therapeutic agents tested across sites and studies.

T-Cell Lymphomas, Version 2.2022, NCCN Clinical Practice Guidelines in Oncology

Peripheral T-cell lymphomas (PTCLs) are a heterogeneous group of lymphoproliferative disorders arising from mature T cells, accounting for about 10% of non-Hodgkin lymphomas. PTCL-not otherwise specified is the most common subtype, followed by angioimmunoblastic T-cell lymphoma, anaplastic large cell lymphoma, anaplastic lymphoma kinase-positive, anaplastic large cell lymphoma, anaplastic lymphoma kinase-negative, and enteropathy-associated T-cell lymphoma. This discussion section focuses on the diagnosis and treatment of PTCLs as outlined in the NCCN Guidelines for T-Cell Lymphomas.

Safety considerations with the current treatments for peripheral T-cell lymphoma

INTRODUCTION

Peripheral T-Cell Lymphomas (PTCL) constitute a heterogeneous group of aggressive T - and natural killer (NK)-cell disorders and are associated with a poor prognosis. Frontline treatments often consist of anthracycline-based combination chemotherapy with the exception of NK-T cell lymphomas, where such combinations are ineffective due to the presence of P-glycoprotein which leads to multidrug resistance. Infectious and immune mediated side effects might be more pronounced in or unique to T-cell lymphomas due to the selection of agents which target multiple T-cell subtypes and also an immunocompromised state induced by the lymphomas themselves.

AREAS COVERED

This review provides a comprehensive overview of safety considerations of treatment regimens used for peripheral T-cell lymphomas. We cover regimens used in both frontline and relapsed settings including combination chemotherapy, single agent chemotherapies and immunotherapies.

EXPERT OPINION

Treatment of T-cell lymphomas often requires sequencing of several therapies due to lower efficacy of available treatment regimens in curing the disease compared to that seen in B-cell non-Hodgkin lymphomas. In addition, certain complications are more common in T-cell lymphomas due to their unique immunobiology. An understanding of these salient aspects is important for all providers who treat patients with this challenging disease group.

Outcomes of Allogeneic Hematopoietic Cell Transplantation in T-cell Prolymphocytic Leukemia: A Contemporary Analysis from the Center for International Blood and Marrow Transplant Research

T cell prolymphocytic leukemia (T-PLL) is a rare, aggressive malignancy with limited treatment options and poor long-term survival. Previous studies of allogeneic hematopoietic cell transplantation (alloHCT) for T-PLL are limited by small numbers, and descriptions of patient and transplantation characteristics and outcomes after alloHCT are sparse. In this study, we evaluated outcomes of alloHCT in patients with T-PLL and attempted to identify predictors of post-transplantation relapse and survival. We conducted an analysis of data using the Center for International Blood and Marrow Transplant Research database on 266 patients with T-PLL who underwent alloHCT between 2008 and 2018. The 4-year rates of overall survival (OS), disease-free survival (DFS), relapse, and treatment-related mortality (TRM) were 30.0% (95% confidence interval [CI], 23.8% to 36.5%), 25.7% (95% CI, 20% to 32%), 41.9% (95% CI, 35.5% to 48.4%), and 32.4% (95% CI, 26.4% to 38.6%), respectively. In multivariable analyses, 3 variables were associated with inferior OS: receipt of a myeloablative conditioning (MAC) regimen (hazard ratio [HR], 2.18; P < .0001), age >60 years (HR, 1.61; P = .0053), and suboptimal performance status, defined by Karnofsky Performance Status (KPS) <90 (HR, 1.53; P = .0073). Receipt of an MAC regimen also was associated with increased TRM (HR, 3.31; P < .0001), an elevated cumulative incidence of grade II-IV acute graft-versus-host disease (HR, 2.94; P = .0011), and inferior DFS (HR, 1.86; P = .0004). Conditioning intensity was not associated with relapse; however, stable disease/progression was correlated with increased risk of relapse (HR, 2.13; P = .0072). Both in vivo T cell depletion (TCD) as part of conditioning and KPS <90 were associated with worse TRM and inferior DFS. Receipt of total body irradiation had no significant effect on OS, DFS, or TRM. Our data show that reduced-intensity conditioning without in vivo TCD (ie, without antithymocyte globulin or alemtuzumab) before alloHCT was associated with long-term DFS in patients with T-PLL who were age ≤60 years or who had a KPS >90 or chemosensitive disease.

Adverse cardiovascular events in patients treated with mogamulizumab

Study objectives

Mogamulizumab is an important treatment for T-cell leukemia and lymphoma. Adverse cardiovascular events (ACE) after mogamulizumab therapy have not been investigated. The aim of the study is to investigate ACE occurrence after mogamulizumab therapy.

Methods

The International World Health Organization database, VigiBase, was analyzed from January 2013 to August 2019 for all adverse events, including ACE, that occurred after mogamulizumab treatment. ACE was defined as: cardiac death, myocardial infarction, heart failure, myocarditis, arrhythmia, vasculitis, thrombosis, palpitations and new hypertension.

Results

ACE after mogamulizumab therapy affected 28 out of 650 unique patients (4.3%). Heart failure (42.8%) and ventricular arrhythmias (17.85%) were most common. ACE accounted for 10% of all fatal adverse outcomes, and 25% of all ACE were fatal. Time to fatal outcome was significantly shorter for patients with ACE compared to non-cardiovascular events, with a mean of 7.7 days (SD 6.91) vs 73 days (SD 90.7), p = 0.017, respectively. There was an increased total number of adverse cardiovascular events in patients greater than 65 and in Asian countries.

Conclusions

Cardiovascular toxicity with mogamulizumab is a possible early occurring adverse outcome associated with high mortality.

New nonchemotherapy treatment options for cutaneous T-cell lymphomas

INTRODUCTION

The most common types of CTCL are mycosis fungoides (MF) and Sézary syndrome (SS). In both MF and SS, complete responses to treatment are uncommon. Recent developments and understanding of the biology of MF/SS have led to novel agents which may offer prolonged responses with less toxicity compared to conventional chemotherapy approaches.

AREAS COVERED

In this review, we discuss the efficacy and safety of new nonchemotherapy treatment options including antibody agents, small molecule inhibitors, fusion proteins, and CAR T-cell therapy. We also reflect on older immunomodulatory treatments including retinoids and histone deacetylase inhibitors.

EXPERT OPINION

Patients with MF/SS who require systemic therapy often progress through multiple agents sequentially, thus the need for additional novel agents in the treatment armamentarium. Antibody-based therapies such as alemtuzumab are highly effective in the blood compartment of disease, while brentuximab vedotin has shown higher activity in skin and lymph nodes. Checkpoint inhibitors may play a role in treating MF/SS but may induce hyperprogression, and engineered T cells and bispecific antibodies recruiting immune effectors are being developed and may show promise in the future.

Efficacy and safety of mogamulizumab by patient baseline blood tumour burden: a post hoc analysis of the MAVORIC trial

Background

Mogamulizumab was compared with vorinostat in the phase 3 MAVORIC trial (NCT01728805) in 372 patients with relapsed/refractory mycosis fungoides (MF) or Sézary syndrome (SS) who had failed ≥1 prior systemic therapy. Mogamulizumab significantly prolonged progression‐free survival (PFS), with a superior objective response rate (ORR) vs. vorinostat.

Objectives

This post hoc analysis was performed to evaluate the effect of baseline blood tumour burden on patient response to mogamulizumab.

Methods

PFS, ORR, time to next treatment (TTNT), skin response (modified Severity‐Weighted Assessment Tool [mSWAT]) and safety were assessed in patients stratified by blood classification (B0 [n = 126], B1 [n = 62], or B2 [n = 184], indicating increasing blood involvement).

Results

Investigator‐assessed PFS was longer for mogamulizumab versus vorinostat across all blood classes, significantly so for B1 and B2 patients. ORR was higher with mogamulizumab than with vorinostat in all blood classification groups and more markedly so with escalating B class (B0: 15.6% vs. 6.5%, P = 0.0549; B1: 25.8% vs. 6.5%, P = 0.2758; B2: 37.4% vs. 3.2%, P < 0.0001). TTNT was significantly longer for patients treated with mogamulizumab versus vorinostat with B1 (12.63 vs. 3.07 months; HR 0.32 [95% CI 0.16–0.67]; P = 0.0018) and B2 (13.07 vs. 3.53 months; HR 0.30 [95% CI 0.21–0.43]; P < 0.0001) blood involvement. In the mogamulizumab arm, 81 patients (43.5%) had ≥50% change in the mSWAT vs. 41 patients (22.0%) with vorinostat; mSWAT improvements with mogamulizumab occurred most often in B1 and B2 patients. Rapid, sustained reductions were seen in CD4⁺CD26^‐ cell counts and CD4:CD8 ratios in mogamulizumab patients for all B classes. Treatment‐emergent adverse events were less frequent overall with mogamulizumab and similar in frequency regardless of B class.

Conclusions

This post hoc analysis indicates greater clinical benefit with mogamulizumab vs. vorinostat in patients with MF and SS classified as having B1 and B2 blood involvement.

Mitigating the risk of COVID-19 exposure by transitioning from clinic-based to home-based immune globulin infusion

PURPOSE

Intravenous immune globulin (IVIG) therapy is used in patients with hypogammaglobulinemia to lower the risk of infections. IVIG and subcutaneous IVIG (SCIG) therapy have been to shown to be safe and effective when administered as clinic-based infusions. Concern from both patients and providers for increased transmission of the coronavirus disease 2019 (COVID-19) virus to immunosuppressed patients with scheduled medical visits and procedures made it necessary for us to reassess our process of how we manage patient care in general and chronic clinic infusions in particular. Here we describe our experience of transitioning patients from clinic-based to home based IVIG and/or SCIG infusions to decrease the risk of COVID-19 exposure.

METHODS

Criteria were developed to identify high-risk immunosuppressed patients who would be appropriate candidates for potential conversion to home based IVIG infusions. Data were collected via chart review, and cost analysis was performed using Medicare Part B reimbursement data. A patient outcome questionnaire was developed for administration through follow-up phone calls.

RESULTS

From March to May 2020, 45 patients met criteria for home-based infusion, with 27 patients (60%) agreeing to home-based infusion. Posttransition patient outcomes assessment, conducted in 26 patients (96%), demonstrated good patient understanding of the home-based infusion process. No infusion-related complications were reported, and 24 patients (92%) had no concerns about receiving future IVIG and/or SCIG doses at home. No patient tested positive for COVID-19 during the study period. Clinic infusion visits decreased by 26.6 visits per month, resulting in a total of 106 hours of additional available infusion chair time per month and associated cost savings of $12,877.

CONCLUSION

Transition of clinic based to home based IVIG/SCIG infusion can be successfully done to decrease potential exposure during a pandemic in a high-risk immunosuppressed population, with no impact on patient satisfaction, adherence, or efficacy. The home-based infusion initiative was associated with a reduction in costs to patients and an increase in available chair time in the infusion clinic.

How we treat advanced stage cutaneous T-cell lymphoma - mycosis fungoides and Sézary syndrome

T-cell lymphomas (TCLs) constitute a rare subset of non-Hodgkin lymphomas, with mycosis fungoides/Sézary syndrome (MF/SS) being the most common subtype of cutaneous TCLs (CTCLs). Considered an incurable but treatable disease, MF/SS management presents several challenges including diagnostic delays, debilitating effect on patients' quality of life, need for several lines of therapies, multidisciplinary care and cumulative drug toxicities limiting duration of use. The present review intends to provide an overview of the recent advances in our understanding of the biology of CTCL and how these are being leveraged to provide additional treatment options for management of advanced and recurrent disease. In addition, the discussion of the different modalities of treatment is summarised to further outline the importance of multidisciplinary care and early referral to CTCL centres.

577. Incidence and Outcomes of Positive Outpatient Surveillance Blood Cultures in Hematopoietic Stem Cell Transplant (HSCT) Patients with Graft Versus Host Disease (GvHD) On High Dose ≥ 0.5 mg/kg/day (HD) and Low Dose &lt; 0.5mg/kg/day (LD) Steroid Therapy

Background

Treatment of GvHD with steroids increases the risk of infection in HSCT patients due to additive immunosuppression and may delay the diagnosis of infection due to lack of symptoms. Outpatient surveillance blood cultures in HSCT with GvHD being treated with HD steroids has demonstrated a blood culture positivity rate of 3.5%. Currently, the utility of surveillance cultures in patients receiving LD steroid therapy is unknown. Our practice includes weekly outpatient surveillance cultures for all GvHD patients treated with steroids regardless of the dose. The primary endpoint of this study was to assess the incidence of positive surveillance blood cultures in GvHD patients receiving HD or LD steroids. Secondary endpoints included number of patients treated, hospitalization, 30 day mortality due to infection, and organisms isolated.

Methods

This was a single-center, retrospective review of GvHD patients at Yale New Haven Hospital between January 2013 and May 2019. Patients were excluded if: lack of signs or symptoms of GvHD, treatment with steroids for any indication other than GvHD, and active GvHD without central line. Cultures from patients receiving antibiotics for concurrent infection were also excluded.

Results

A total of 71 patients met criteria with 901 blood cultures. On HD, eight patients (14%) had 12 positive cultures (4%), and on LD, 16 patients (25%) had 22 positive cultures (4%) (p=0.15). Treatment occurred in six patients (75%) with four (24%) requiring hospitalization on HD, and 12 patients (75%) with 10 (83%) requiring hospitalization on LD (p=0.45). The median duration of steroid therapy was 93 and 236 days with a median dose of steroids of 1mg/kg/day and 0.15mg/kg/day, respectively. The number of positive cultures/1000 steroid days was 1.2 on HD and 0.5 on LD (RR 2.2). 30 day mortality was only noted in one patient (8%) on LD. The most common organism in both groups was Coagulase-negative staphylococci with all six cultures on HD classified as contaminants and 6/10 cultures requiring treatment on LD.

Conclusion

Although the relative risk of positive surveillance blood cultures in HD patients compared to LD was twofold higher, there were clinically significant infections identified in the LD group.

Disclosures

All Authors: No reported disclosures

574. De-escalation of Broad Spectrum Antibiotics during Cytokine Release Syndrome with Haploidentical Hematopoietic Stem Cell Transplantation

Background

Fever is a common component of cytokine release syndrome (CRS) occurring in 90% of patients undergoing haploidentical hematopoietic stem cell transplantation (Haplo-HSCT). Fevers typically occur between the stem cell infusion (Day 0) and initiation of post-transplant cyclophosphamide and are often confused with febrile neutropenia (FN). Due to longer time to engraftment in Haplo-HSCT, CRS/FN exposes patients to prolonged courses of empiric broad spectrum antibiotic (BSA) therapy increasing the risk for multi-drug resistant organisms. Recently, at Yale New Haven Health, our practice has changed to now recommend antibiotic de-escalation to prophylaxis after 7 days of BSA if no infection is identified. The objective of this study was to assess the incidence of breakthrough infections with the de-escalation of BSA in CRS/FN. Secondary endpoints include rate of FN, rate of de-escalation, rate of recurrent fevers, duration of BSA, and positive blood culture data.

Methods

The patient population included those undergoing Haplo-HSCT between July 2016 and February 2020 and who developed CRS/FN between Day 0 and Day +5. Patients were excluded if they had prolonged hospitalization due to non-infectious complications or engraftment failure. Bacteremia was defined using NHSN definitions.

Results

Of the 53 Haplo-HSCTs assessed, 43 experienced CRS/FN. Thirty-five Haplo-HSCT (81%) with CRS/FN had negative cultures and 23 (66%) of these were de-escalated back to antibacterial prophylaxis. The median duration of BSA in the de-escalated group was 7 days (range 5–13) compared to 16.5 days range (13–21) in the non-de-escalated group (p< 0.001). Among those de-escalated, 7 (30%) had recurrent fever occurring at a median of 4 days (range 2–14) and were placed back on BSA. Two Haplo-HSCT (9%) that had fever after de-escalation developed a breakthrough bacteremia. No Haplo-HSCT after de-escalation had fever or re-admission for bacteremia 30 days after engraftment. Four Haplo-HSCT (9%) with CRS/FN had positive blood cultures; however, three (7%) were still able to be de-escalated from BSA to narrower agents based on susceptibilities.

Conclusion

De-escalation of BSA in FN/CRS in Haplo-HSCT patients reduced unnecessary, prolonged antibiotic exposure with a low incidence of breakthrough infections.

Disclosures

All Authors: No reported disclosures

Cost-effectiveness of polatuzumab vedotin in relapsed or refractory diffuse large B-cell lymphoma

A recent phase II trial showed that use of polatuzumab vedotin in combination with bendamustine plus rituximab (Pola-BR) in transplant-ineligible patients with relapsed or refractory (R/R) diffuse large B-cell lymphoma (DLBCL) resulted in longer progression-free survival and overall survival compared to bendamustine plus rituximab (BR) alone. In this study, we constructed a Markov model to assess the cost-effectiveness of Pola-BR versus BR in transplant-ineligible R/R DLBCL. We calculated the incremental cost-effectiveness ratio (ICER) of each treatment strategy from a US payer perspective, using a lifetime horizon and a willingness-to-pay threshold of $100,000 per quality-adjusted life-year (QALY). Use of Pola-BR was associated with an incremental cost of $92,641 compared to BR alone ($200,905 vs $108,265, respectively), an incremental effectiveness of 1.76 QALYs (2.35 vs 0.59 QALYs, respectively), and an ICER of $52,519/QALY. These data suggest that use of Pola-BR for R/R DLBCL is likely to be cost-effective compared to BR alone.

Pembrolizumab in Relapsed and Refractory Mycosis Fungoides and Sézary Syndrome: A Multicenter Phase II Study

PURPOSE

To assess the efficacy of pembrolizumab in patients with advanced relapsed or refractory mycosis fungoides (MF) or Sézary syndrome (SS).

PATIENTS AND METHODS

CITN-10 is a single-arm, multicenter phase II trial of 24 patients with advanced MF or SS. Patients were treated with pembrolizumab 2 mg/kg every 3 weeks for up to 24 months. The primary end point was overall response rate by consensus global response criteria.

RESULTS

Patients had advanced-stage disease (23 of 24 with stage IIB to IV MF/SS) and were heavily pretreated with a median of four prior systemic therapies. The overall response rate was 38% with two complete responses and seven partial responses. Of the nine responding patients, six had 90% or more improvement in skin disease by modified Severity Weighted Assessment Tool, and eight had ongoing responses at last follow-up. The median duration of response was not reached, with a median response follow-up time of 58 weeks. Immune-related adverse events led to treatment discontinuation in four patients. A transient worsening of erythroderma and pruritus occurred in 53% of patients with SS. This cutaneous flare reaction did not result in treatment discontinuation for any patient. The flare reaction correlated with high PD-1 expression on Sézary cells but did not associate with subsequent clinical responses or lack of response. Treatment responses did not correlate with expression of PD-L1, total mutation burden, or an interferon-γ gene expression signature.

CONCLUSION

Pembrolizumab demonstrated significant antitumor activity with durable responses and a favorable safety profile in patients with advanced MF/SS.

Abstract A072: Preliminary results of ASTX660, a novel non-peptidomimetic cIAP1/2 and XIAP antagonist, in 107 patients with solid tumors or lymphoma

Background: ASTX660 is an oral, novel nonpeptidomimetic, small-molecule antagonist of cellular/X-linked inhibitors of apoptosis proteins (cIAP1/2 and XIAP). ASTX660 is currently being evaluated in a first-in-human phase 1–2 study in patients (pts) with advanced solid tumors or lymphoma (ClinicalTrials.gov NCT02503423). In the ongoing phase 2, ASTX660 has demonstrated preliminary evidence of clinical activity in the relapsed/refractory peripheral T-cell lymphoma (PTCL) and cutaneous T-cell lymphoma (CTCL) cohorts (Mehta et al, presented at the EHA Conference 2019, abs PS1073). Here, we report overall efficacy and safety data from the solid tumors (head and neck squamous cell carcinoma [HNSCC]; cervical carcinoma and other solid tumors) and lymphoma (diffuse large B-cell lymphoma [DLBCL], PTCL, CTCL,) phase 2 cohorts. Methods: Pts received treatment with ASTX660 orally at the RP2D 180mg/day on days 1 to 7, and 15 to 22 in a 28-day cycle. In the first stage 14 evaluable pts were enrolled in each of the 6 phase 2 cohorts with the option to expand the cohort if activity was observed. The primary endpoint was response rate as assessed by the investigator according to the Lugano criteria (DLBCL and PTCL), Global Assessment (CTCL), or RECIST 1.1 (solid tumors). Adverse events (AEs) were assessed per CTCAE V4.03. Results: As of June 4, 2019, a total of 107 pts have received ASTX660 in the solid tumors and lymphoma phase 2 cohorts (HNSCC n=14; DLBCL n=16; PTCL n=26; CTCL n=23; cervical carcinoma n=14; other solid tumors n= 14). Median age (range) was 61 (23-84) years and median number (range) of prior anticancer regimens was 3 (0-12). Among all pts, the most common related AEs of any grade (≥ 10%) were rash (35%), lipase elevation (34%), amylase elevation (29%), diarrhea (14%), fatigue (14%), AST elevation (13%), nausea (13%), and anemia (11%). Related AEs ≥ Grade 3 occurring in ≥ 5% of pts were rash (18%), lipase elevation (16%) and amylase elevation (9%). As of 4 June 2019, 86 pts (80%) discontinued study treatment: 64 (60%) due to progressive disease, 13 (12%) due to AE, 4 (4%) due to death, 4 (4%) due to withdrawal by participant and 1 (1%) for investigator’s decision. At the time of analysis, the ORR was 36% in the PTCL cohort and 15% in the CTCL cohort. One PR was reported in a pt with metastatic melanoma after 12 cycles of treatment. No objective responses were reported in the HNSCC, DLBCL or cervical cohorts. Accrual in the PTCL and CTCL continues; updated efficacy and safety data will be presented at the meeting. Conclusion: In the phase 2 part of the study ASTX660 monotherapy has demonstrated a manageable safety profile and encouraging activity in PTCL and CTCL warranting cohort expansion. Future plans include evaluation of ASXT660 both as mono- or combination therapy in selected malignancies.

Citation Format: Antoine Hollebecque, Sarit Assouline, Felipe Samaniego, Benoit You, Francine Foss, Anca Prica, Sarah W. Gordon, Marc Webster, Martin JS. Dyer, Dima El-Sharkawi, Geoffrey I. Shapiro, Lisa Nabell, Sarah P. Blagden, John Lister, Susanna V. Ulahannan, Yijun Sun, Danna Chan, Roberta Ferraldeschi, Monica Mita. Preliminary results of ASTX660, a novel non-peptidomimetic cIAP1/2 and XIAP antagonist, in 107 patients with solid tumors or lymphoma [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr A072. doi:10.1158/1535-7163.TARG-19-A072

2694. Incidence of Pneumocytis jiroveci (PJP) Infection with 3-Month Prophylaxis of Aerosolized Pentamidine (AP) in Autologous Hematopoietic Stem Cell Transplantation (HSCT)

Background

HSCT patients are at an increased risk of developing PJP after transplant due to treatment induced immunosuppression. Given the risk of cytopenias with co-trimoxazole, AP is utilized as an alternative for PJP prophylaxis. A prior study revealed a 0% (0/19 patients) incidence when AP prophylaxis was given for one year post autologous HSCT. Current guidelines recommend a duration of 3 – 6 months for PJP prophylaxis in autologous HSCT. The primary endpoint of this study was to assess the incidence of PJP infection within one year post autologous HSCT in patients who received 3 months of AP. Secondary endpoint was a cost comparison of 3 months compared with 6 months of AP.

Methods

A single-center, retrospective study of adult autologous HSCT patients at Yale New Haven Hospital between February 2013 and December 2017 was performed. Patients were excluded if: <18 years of age, received < or >3 months of AP, changed to alternative PJP prophylactic agent or received no PJP prophylaxis, received tandem HSCT, deceased prior to one year post-transplant from a non PJP-related infection, HIV positive, or lost to follow-up. Pentamidine was given as a 300 mg inhalation monthly for 3 months starting Day +15 after autologous HSCT.

Results

A total of 288 patients were analyzed, no PJP infections occurred within one year post HSCT. Additionally, 187 (65%) patients received treatment post HSCT with 135/215 (63%) receiving maintenance immunomodulatory drugs for myeloma and 40/288 (14%) patients developing relapsed disease. 43% of the chemotherapy regimens for relapsed disease included high dose corticosteroids. The cost difference of using 3 months vs. 6 months of AP is $790, reflecting the cost of drug and its administration. Applying our incidence of 0%, potential cost savings of 3 months vs. 6 months of AP would be $330,000 over 5 years or $66,000 per year.

Conclusion

Three months of AP for PJP prophylaxis in autologous HSCT patients is safe and effective as well as cost-effective compared with a 6 month regimen.

Disclosures

All authors: No reported disclosures.

DUSP22-IRF4 rearrangement in AIDS-associated ALK-negative anaplastic large cell lymphoma

Patients with AIDS have increased risk of developing lymphomas, such as anaplastic large cell lymphoma (ALCL), which generally carry a poor prognosis. The DUSP-IRF4 genetic rearrangement in ALCL confers a favourable prognosis in HIV-negative patients; it is unknown how this interacts clinically with HIV/AIDS. A man aged 53 years presented with subcutaneous nodules on the scalp and axillae, and diffuse lymphadenopathy. Biopsy of subcutaneous nodule and lymph node showed large atypical anaplastic lymphocytes which were CD30+ and anaplastic lymphoma kinase-negative, consistent with primary systemic ALCL. In addition, he was found to be HIV-positive and diagnosed with AIDS. Genetic testing of the tissue revealed a DUSP22-IRF4 rearrangement. Complete remission was achieved with HyperCVAD and subsequent brentuximab vedotin monotherapy. We report a case of AIDS-associated primary systemic ALCL with a DUSP22-IRF4 rearrangement. AIDS-associated ALCL is an aggressive lymphoma, with a poor prognosis. However, the presence of the genetic rearrangement, previously unseen in this disease, drastically altered the disease course. This case highlights the value of genetic testing and identifies DUSP22-IRF4-associated ALCL in the setting of HIV-associated lymphoproliferative disorders.

The impact of a multimodal approach to vancomycin discontinuation in hematopoietic stem cell transplant recipients (HSCT) with febrile neutropenia (FN)

BACKGROUND

Current guidelines recommend adding vancomycin to empiric treatment of FN in patients who meet specific criteria. After 48 hours, the guidelines recommend discontinuing vancomycin if resistant Gram-positive organisms are not identified. Based on these recommendations, a vancomycin stewardship team defined criteria for discontinuation of vancomycin at 48 hours and increased surveillance of vancomycin usage through a multimodal approach. The purpose of this retrospective analysis is to assess the impact of this multimodal approach on the discontinuation of empiric vancomycin at 48 hours in FN.

METHODS

This retrospective analysis included a pre- and post-intervention cohort of 200 HSCT recipients with FN from 2015 to 2018. Criteria for continued vancomycin use beyond 48 hours included culture-documented resistant Gram-positive infection, positive Methicillin-Resistant S aureus (MRSA) nasal swab with evidence of pneumonia, or hemodynamic instability with concern for sepsis. The following patient characteristics were collected: previous MRSA infection, MRSA nasal swab collection and results, culture results, duration of vancomycin use, rationale for continuation of vancomycin beyond 48 hours, and re-initiation of vancomycin.

RESULTS

In the post-intervention cohort, vancomycin discontinuation at 48 hours increased from 31% (95% CI 21.94-40.05) to 70% (95% CI 61.02-78.97; P < 0.0001). An additional 23% of vancomycin orders were discontinued at 72 hours. Off criteria vancomycin use decreased from 33% in pre to 1% in the post-implementation cohort.

CONCLUSION

Establishing define criteria for vancomycin use in FN patients with a multimodal approach of physicians from hematology and infectious diseases, clinical pharmacists and the antibiotic stewardship team significantly improved vancomycin discontinuation.

Randomized Phase III Study of Alisertib or Investigator's Choice (Selected Single Agent) in Patients With Relapsed or Refractory Peripheral T-Cell Lymphoma

PURPOSE

The aim of this open-label, first-in-setting, randomized phase III trial was to evaluate the efficacy of alisertib, an investigational Aurora A kinase inhibitor, in patients with relapsed/refractory peripheral T-cell lymphoma (PTCL).

PATIENTS AND METHODS

Adult patients with relapsed/refractory PTCL—one or more prior therapy—were randomly assigned 1:1 to receive oral alisertib 50 mg two times per day (days 1 to 7; 21-day cycle) or investigator-selected single-agent comparator, including intravenous pralatrexate 30 mg/m² (once per week for 6 weeks; 7-week cycle), or intravenous gemcitabine 1,000 mg/m² or intravenous romidepsin 14 mg/m² (days 1, 8, and 15; 28-day cycle). Tumor tissue (disease subtype) and imaging were assessed by independent central review. Primary outcomes were overall response rate and progression-free survival (PFS). Two interim analyses and one final analysis were planned.

RESULTS

Between May 2012 and October 2014, 271 patients were randomly assigned (alisertib, n = 138; comparator, n = 133). Enrollment was stopped early on the recommendation of the independent data monitoring committee as a result of the low probability of alisertib achieving PFS superiority with full enrollment. Centrally assessed overall response rate was 33% for alisertib and 45% for the comparator arm (odds ratio, 0.60; 95% CI, 0.33 to 1.08). Median PFS was 115 days for alisertib and 104 days for the comparator arm (hazard ratio, 0.87; 95% CI, 0.637 to 1.178). The most common adverse events were anemia (53% of alisertib-treated patients v 34% of comparator-treated patients) and neutropenia (47% v 31%, respectively). A lower percentage of patients who received alisertib (9%) compared with the comparator (14%) experienced events that led to study drug discontinuation. Of 26 on-study deaths, five were considered treatment related (alisertib, n = 3 of 11; comparator, n = 2 of 15). Two-year overall survival was 35% for each arm.

CONCLUSION

In patients with relapsed/refractory PTCL, alisertib was not statistically significantly superior to the comparator arm.

2487. Vaccination Rates in Post-Transplant Hematopoietic Stem Cell Transplant (HSCT) Patients: Where Do We Stand?

Background

Methods

Results

Conclusion

Disclosures

Skin Microbiota as Antigenic Triggers for Cutaneous T Cell Lymphoma

Background

Cutaneous T Cell lymphoma (CTCL) is a debilitating malignancy of lymphocytes that home to the skin, thereby manifesting in a variety of chronic skin lesions. CTCL is thought to arise from a combination of genetic, epigenetic and environmental factors, but specific triggers remain unknown. We propose a model in which adaptive immune responses to particular skin commensals evolve into clonal proliferation of T cells in genetically predisposed patients.

Methods and Results

10 CTCL patients with active skin lesions were sampled at 3 time points (blood, stool and lesional vs non-lesional skin). Skin swabs of SLE patients and healthy donors served as control. Dual-index V1–3 and V4 16S rRNA sequencing was performed on the MiSeq platform and revealed significantly more Firmicutes in patient skin compared to controls. In addition, single bacterial colonies were cultured from 3 subjects. Full-length 16S rRNA sequencing demonstrated unique bacterial strains in lesional compared to non-lesional cultures. Malignant cutaneous T cells from patient biopsies were extracted and cultured in vitro for antigenic challenge with patient-isolated skin commensal candidates. One patient’s T cells showed significant proliferation to lesionally enriched B. safensis, while not responding to non-lesional bacteria.

Discussion

Dissecting cancer cell-microbiota interactions revealed potential skin commensal candidates involved in the pathogenesis of CTCL. Pathobionts enriched in lesional skin might act as antigenic drivers for progression to clonality similar to processes involved in H. pylori-induced MALT lymphoma, a paradigm that may be applicable to skin lymphomagenesis.

Clinical Practice Recommendations on Indication and Timing of Hematopoietic Cell Transplantation in Mature T Cell and NK/T Cell Lymphomas: An International Collaborative Effort on Behalf of the Guidelines Committee of the American Society for Blood and Marrow Transplantation

Recognizing the significant biological and clinical heterogeneity of mature T cell and natural killer (NK)/T cell lymphomas, the American Society for Blood and Marrow Transplantation invited experts to develop clinical practice recommendations related to the role of autologous hematopoietic cell transplantation (auto-HCT) and allogeneic HCT (allo-HCT) for specific histological subtypes. We used the GRADE methodology to aid in moving from evidence to decision making and ultimately to generating final recommendations. Auto-HCT in front-line consolidation is recommended in peripheral T cell lymphoma not otherwise specified (PTCL-NOS), angioimmunoblastic T cell lymphoma (AITL), anaplastic large cell lymphoma-anaplastic lymphoma kinase (ALCL-ALK)-negative, NK/T cell (disseminated), enteropathy-associated T cell lymphoma (EATL), and hepatosplenic lymphomas. Auto-HCT in relapsed-sensitive disease is recommended for NK/T cell (localized and disseminated), EATL, subcutaneous panniculitis-like T cell, and ALCL-ALK-positive lymphomas. Auto-HCT is also recommended for PTCL-NOS, AITL, and ALCL-ALK-negative lymphomas if not performed as front-line therapy. Auto-HCT in refractory (primary or relapsed) disease is not recommended for any of the histological subtypes discussed. Allo-HCT in front-line consolidation is recommended for NK/T cell (disseminated), adult T cell leukemia/lymphoma (ATLL; acute and lymphoma type), and hepatosplenic lymphomas. Allo-HCT for relapsed-sensitive disease is recommended for PTCL-NOS, AITL, ALCL-ALK-negative, ALCL-ALK-positive, NK/T cell (localized and disseminated), ATLL (acute, lymphoma type, smoldering/chronic), mycosis fungoides/Sezary syndrome (advanced stage IIB-IVB or tumor stage/extracutaneous), EATL, subcutaneous panniculitis-like T cell, and hepatosplenic lymphoma. Allo-HCT in refractory (primary or relapsed refractory) disease is recommended for any aforementioned histological subtypes. Emerging novel therapies will likely be incorporated into the pretransplantation, peritransplantation, and post-transplantation algorithms (auto-HCT or allo-HCT) with the goals of optimizing efficacy and improving outcomes. We acknowledge that there are unique clinical scenarios not covered by these recommendations that may require individualized decisions.

Responses to romidepsin by line of therapy in patients with relapsed or refractory peripheral T-cell lymphoma

Peripheral T-cell lymphoma (PTCL) is a heterogeneous group of aggressive non-Hodgkin lymphomas typically associated with poor prognosis. Most patients with PTCL receive chemotherapy as first-line treatment, but many experience rapid relapse. For patients with relapsed/refractory PTCL, responses to treatment and long-term outcomes tend to worsen with increasing lines of therapy. Romidepsin is a potent class I histone deacetylase inhibitor approved by the US Food and Drug Administration for the treatment of PTCL in patients who have received ≥1 prior therapy. A pivotal phase 2 trial of romidepsin in patients with relapsed/refractory PTCL demonstrated an objective response rate of 25% (33/130), including 15% with confirmed/unconfirmed complete response, and a median duration of response of 28 months. In the analysis presented herein, romidepsin was shown to have similar responses and long-term outcomes in patients with 1, 2, and ≥3 prior lines of treatment, including in patients with disease refractory to the last prior therapy. Although adverse events increased with increasing lines of treatment, the rate of dose modifications and discontinuations due to adverse events was not significantly different. These data support the use of romidepsin as salvage treatment for PTCL irrespective of the number of prior therapies.