Rare Case of Mixed Phenotype Acute Leukemia Presenting as a Myeloid Sarcoma Without Leukemic Involvement.

INTRODUCTION: Mixed phenotype acute leukemia (MPAL) is a rare type of acute leukemia with immunophenotypic features of both myeloid-derived and lymphoid-derived lineages. CASE PRESENTATION: We present an atypical case of a 32-year-old woman presenting with an anterior mediastinal mass and pericardial/pleural involvement that was initially diagnosed as primary mediastinal diffuse large B-cell lymphoma. However, flow cytometry on pleural fluid confirmed the diagnosis of MPAL of B-cell/myeloid lineage without peripheral blood/bone marrow involvement. The patient was treated with an acute lymphoblastic leukemia-type regimen and proceeded with myeloablative allogeneic hematopoietic cell transplantation in first complete remission. CONCLUSION: MPAL can rarely present with isolated extramedullary disease without leukemic involvement and can often be misdiagnosed as a non-Hodgkin lymphoma. Careful integration of all the clinical data, particularly flow cytometry results, can clarify the diagnosis and change the treatment plan.

Standard-of-Care Axicabtagene Ciloleucel for Relapsed or Refractory Large B-Cell Lymphoma: Results From the US Lymphoma CAR T Consortium.

PURPOSE: Axicabtagene ciloleucel (axi-cel) is an autologous CD19-directed chimeric antigen receptor (CAR) T-cell therapy approved for relapsed/refractory large B-cell lymphoma (LBCL) on the basis of the single-arm phase II ZUMA-1 trial, which showed best overall and complete response rates in infused patients of 83% and 58%, respectively. We report clinical outcomes with axi-cel in the standard-of-care (SOC) setting for the approved indication. PATIENTS AND METHODS: Data were collected retrospectively from all patients with relapsed/refractory LBCL who underwent leukapheresis as of September 30, 2018, at 17 US institutions with the intent to receive SOC axi-cel. Toxicities were graded and managed according to each institution's guidelines. Responses were assessed as per Lugano 2014 classification. RESULTS: Of 298 patients who underwent leukapheresis, 275 (92%) received axi-cel therapy. Compared with the registrational ZUMA-1 trial, 129 patients (43%) in this SOC study would not have met ZUMA-1 eligibility criteria because of comorbidities at the time of leukapheresis. Among the axi-cel-treated patients, grade ≥ 3 cytokine release syndrome and neurotoxicity occurred in 7% and 31%, respectively. Nonrelapse mortality was 4.4%. Best overall and complete response rates in infused patients were 82% (95% CI, 77% to 86%) and 64% (95% CI, 58% to 69%), respectively. At a median follow-up of 12.9 months from the time of CAR T-cell infusion, median progression-free survival was 8.3 months (95% CI, 6.0 to15.1 months), and median overall survival was not reached. Patients with poor Eastern Cooperative Oncology Group performance status of 2-4 and elevated lactate dehydrogenase had shorter progression-free and overall survival on univariable and multivariable analysis. CONCLUSION: The safety and efficacy of axi-cel in the SOC setting in patients with relapsed/refractory LBCL was comparable to the registrational ZUMA-1 trial.

Romidepsin Plus Liposomal Doxorubicin Is Safe and Effective in Patients with Relapsed or Refractory T-Cell Lymphoma: Results of a Phase I Dose-Escalation Study.

PURPOSE: The histone deacetylase (HDAC) inhibitor romidepsin and the anthracycline liposomal doxorubicin (LD) have modest single-agent activity in cutaneous T-cell lymphoma (CTCL) and peripheral T-cell lymphoma (PTCL). We investigated the safety and efficacy of the combination of these two agents in CTCL and PTCL. PATIENTS AND METHODS: Using CTCL cell lines and primary CTCL tumor cells, we demonstrated synergistic antitumor activity with romidepsin plus doxorubicin. We then conducted a phase I dose-escalation study of the romidepsin/LD combination in relapsed/refractory CTCL and PTCL. The primary objective was to determine the MTD of romidepsin in combination with LD at 20 mg/m2 i.v., once every 28 days. RESULTS: Eleven patients with CTCL and 12 patients with PTCL were treated. The MTD of romidepsin was determined to be 12 mg/m2. Grade 3/4 hematologic toxicities included thrombocytopenia (17%), anemia (13%), and neutropenia (9%). The most frequent treatment-related nonhematologic adverse events were fatigue (48%), nausea (48%), vomiting (35%), and anorexia (30%). Among 21 evaluable patients, the overall response rate was 70% [1 complete response (CR), 6 partial responses (PR)] in CTCL and 27% (3 CR, 0 PR) in PTCL. Of the patients with CTCL, 8 of 10 had skin response, including 6 patients (60%) achieving skin involvement less than 10% of their body surface area at time of best response. CONCLUSIONS: Romidepsin plus LD demonstrated an acceptable safety profile and promising clinical efficacy with deep skin responses in relapsed/refractory CTCL. Thus, this combination could be considered as a bridge to skin-directed treatment or allogeneic hematopoietic cell transplantation in patients with aggressive CTCL.

Outcomes and Toxicities of Programmed Death-1 (PD-1) Inhibitors in Hodgkin Lymphoma Patients in the United States: A Real-World, Multicenter Retrospective Analysis.

BACKGROUND: Although classical Hodgkin lymphoma (cHL) is highly curable, 20%-30% of patients will not be cured with conventional treatments. The programmed death-1 (PD-1) inhibitors (PD-1i) nivolumab and pembrolizumab have been Food and Drug Administration-approved for relapsed/refractory (R/R) cHL. There is limited data on the real-world experience with PD-1i in cHL and it is unknown whether fewer selected patients treated with PD-1i derive benefits similar to those observed in published trials. MATERIALS AND METHODS: We performed a multicenter, retrospective analysis of R/R cHL patients treated with PD-1i in the nontrial setting. The primary objective was to describe progression-free survival (PFS) and overall survival (OS) in this population. Secondary objectives were to characterize response rates, toxicities, discontinuation patterns, and post-PD-1i therapies. RESULTS: The study included 53 patients from nine U.S. centers. Overall response rate (ORR), complete response (CR), and partial response (PR) to PD-1i were 68%, 45%, and 23%, respectively. Twelve-month OS and PFS were 89% and 75%, respectively; median PFS was 29 months. Ninety-six percent of patients with CR continue to respond at a median follow-up of 20 months. Toxicities were similar to those previously described. Seventy percent of patients treated with systemic therapy after PD-1i demonstrated objective responses. CONCLUSION: To our knowledge, this analysis is the first describing real-world experience with PD-1i in cHL patients in the U.S. Here, we demonstrate similar response rates compared to prior studies. The toxicity profile of PD-1i was similar to that seen in previous studies; we further describe toxicity patterns in those with prior autoimmune disease or allogeneic transplant. Post-PD-1i systemic therapies appear active. These results support the effectiveness and tolerability of PD-1i therapy in R/R cHL in a real-world setting. IMPLICATIONS FOR PRACTICE: Two PD-1 inhibitors have recently been approved for patients with relapsed/refractory classical Hodgkin lymphoma based on results from nonrandomized clinical trials. However, to date, there have been no studies evaluating the effectiveness and toxicity profile of these drugs in the real-world setting in the U.S. The present study demonstrates that patients treated in a real-world context experience similar rates of overall effectiveness compared with published clinical trials. Patients who discontinue PD-1 inhibitors may experience clinical responses to subsequent treatment with systemic chemotherapy or targeted therapy. This study provides clinicians with further insight into the effectiveness and tolerability of PD-1 inhibitors and suggests that when patients progress while on these drugs, conventional systemic chemotherapy may be an effective treatment option.

Posttransfusion purpura with antibodies against human platelet antigen-4a following checkpoint inhibitor therapy: a case report and review of the literature.

BACKGROUND: Posttransfusion purpura (PTP) is a rare condition characterized by severe thrombocytopenia following receipt of blood products. Most reported PTP cases involve alloantibodies directed against human platelet antigen (HPA)-1a. We present a case of PTP-mediated severe thrombocytopenia associated with alloantibodies directed against HPA-4a in the setting of combination checkpoint inhibitor therapy. CASE REPORT: A 62-year-old woman with rectal melanoma that progressed on combination checkpoint inhibitors (ipilimumab and nivolumab) was admitted for abdominoperineal resection. She received multiple blood products during surgery, and between the sixth and eighth days post-surgery her platelet (PLT) count decreased from 126 × 109 /L to a nadir of 1 × 109 /L. She received intravenous immunoglobulin (IVIG), steroids, and romiplostim with eventual recovery of her PLT count to 50 × 109 /L 20 days after surgery. She tested positive for anti-HPA-4a and was shown not to express HPA-4a, confirming a diagnosis of PTP. CONCLUSION: Alloantibodies strongly reactive to HPA-4a were detected in this patient who received multiple blood products during abdominoperineal resection surgery. Her thrombocytopenia improved with prompt administration of IVIG, steroids, and romiplostim. PTP must always be considered in patients with acute severe thrombocytopenia after receipt of blood products, and treatment should not be delayed while awaiting laboratory confirmation. To our knowledge, this is the second reported case of PTP with antibodies against HPA-4a.

Update on the Treatment of Anaplastic Large Cell Lymphoma.

PURPOSE OF REVIEW: Given the rarity of anaplastic large cell lymphoma (ALCL), studies evaluating new therapies have typically grouped ALCL together with other peripheral T cell lymphomas (PTCL). Thus, the treatment paradigm for ALCL largely mirrors that of PTCL in general. In this review, we discuss the current standard of care as well as emerging therapies, including antibody-based drugs, in systemic ALCL as well as primary cutaneous and breast implant-associated ALCL. RECENT FINDINGS: High CD30 expression in ALCL has allowed the use of brentuximab vedotin, an anti-CD30 antibody-drug conjugate, in both systemic and primary cutaneous ALCL. Recent clinical trials with brentuximab have shown substantial activity in the relapsed/refractory setting. A randomized phase III study is ongoing comparing brentuximab plus CHP (cyclophosphamide, doxorubicin, prednisone) with standard CHOP in the front-line setting. The use of targeted therapies and other novel agents have improved outcomes for ALCL patients and in the future can complement or even replace the current standard of care and front-line treatment options.

Allogeneic Hematopoietic Cell Transplantation for Adult T Cell Acute Lymphoblastic Leukemia.

Allogeneic hematopoietic cell transplantation (HCT) is recommended for patients with T cell acute lymphoblastic leukemia (T-ALL) in second or later complete remission (CR) and high-risk patients in first CR. Given its relative rarity, data on outcomes of HCT for T-ALL are limited. We conducted a multicenter retrospective cohort study using data from 208 adult patients who underwent HCT between 2000 and 2014 to describe outcomes of allogeneic HCT for T-ALL in the contemporary era. The median age at HCT was 37 years, and the majority of patients underwent HCT in CR, using total body irradiation (TBI)-based myeloablative conditioning regimens. One-quarter of the patients underwent alternative donor HCT using a mismatched, umbilical cord blood, or haploidentical donor. With a median follow up of 38 months, overall survival at 5 years was 34%. The corresponding cumulative incidence of non-relapse mortality and relapse was 26% and 41%, respectively. In multivariable analysis, factors significantly associated with overall survival were the use of TBI (HR, 0.57; P = .021), age >35 years (HR, 1.55; P = .025), and disease status at HCT (HR, 1.98; P = .005 for relapsed/refractory disease compared with CR). Relapse was the most common cause of death (58% of patients). Allogeneic HCT remains a potentially curative option in selected patients with adult T-ALL, although relapse is a major cause of treatment failure.

T Cell-Replete Peripheral Blood Haploidentical Hematopoietic Cell Transplantation with Post-Transplantation Cyclophosphamide Results in Outcomes Similar to Transplantation from Traditionally Matched Donors in Active Disease Acute Myeloid Leukemia.

Outcomes for patients with acute myeloid leukemia (AML) who fail to achieve complete remission remain poor. Hematopoietic cell transplantation (HCT) has been shown to induce long-term survival in AML patients with active disease. HCT is largely performed with HLA-matched unrelated or HLA-matched related donors. Recently, HCT with HLA-haploidentical related donors has been identified as a feasible option when HLA-matched donors are not immediately available. However, there are little data comparing outcomes for AML patients with active disease who receive haploidentical versus traditionally matched HCT. We retrospectively analyzed data from 99 AML patients with active disease undergoing allogeneic HCT at a single institution. Forty-three patients received unrelated donor HCT, 32 patients received matched related donor HCT, and 24 patients received peripheral blood haploidentical HCT with post-transplantation cyclophosphamide. We found no significant differences between treatment groups in terms of overall survival (OS), event-free survival, transplantation-related mortality, cumulative incidence of relapse, and cumulative incidence of acute and chronic graft-versus-host disease (GVHD). We performed univariate regression analysis of variables that modified OS in all patients and found only younger age at transplantation and development of chronic GVHD significantly improved outcome. Although limited by our relatively small sample size, these results indicate that haploidentical HCT in active AML patients have comparable outcomes to HCT with traditionally matched donors. Haploidentical HCT can be considered in this population of high-risk patients when matched donors are unavailable or when wait times for transplantation are unacceptably long.

Hematologic Recovery after Pretransplant Chemotherapy Does Not Influence Survival after Allogeneic Hematopoietic Cell Transplantation in Acute Myeloid Leukemia Patients.

Pretransplant remission status in patients with acute myeloid leukemia (AML) is 1 of the most important factors determining their outcomes after allogeneic hematopoietic cell transplantation (allo-HCT). Most patients are in complete remission with full hematologic recovery (CR) before undergoing allo-HCT. However, some patients achieve CR without recovery of platelet count (CRp) or a morphologic leukemia-free state (MLFS), defined as meeting all CR criteria without recovery of both neutrophil and platelet counts. Currently, there is a paucity of data regarding transplant outcomes in AML patients achieving MLFS after chemotherapy. To address this question, we evaluated transplant outcomes in 270 AML patients who received 6/6 HLA-matched sibling or 10/10 HLA-matched unrelated donor transplantation at a single institution between 2006 and 2013. Of our 270 patients, 206 were in CR, 45 were in CRp, and 19 were in MLFS before allo-HCT. Patients in CR, CRp, or MLFS had similar 3-year overall survival rates (49%, 46%, and 47%, respectively; P = .88) and 3-year event-free survival rates (45%, 36%, and 40%, respectively; P = .53). However, the cumulative incidence of nonrelapse mortality was significantly higher in patients in MLFS compared with those in CR (58% versus 22%, P = .0004), whereas the cumulative incidence of relapse in patients in MLFS was significantly lower compared with those in CR (11% versus 36%, P = .03). Our results suggest that survival outcomes in AML patients are not influenced by degree of hematologic recovery before allo-HCT.

The redundant aminotransferases in lysine and arginine synthesis and the extent of aminotransferase redundancy in Escherichia coli.

Aminotransferases can be redundant or promiscuous, but the extent and significance of these properties is not known in any organism, even in Escherichia coli. To determine the extent of redundancy, it was first necessary to identify the redundant aminotransferases in arginine and lysine synthesis, and then complement all aminotransferase-deficient mutants with genes for all aminotransferases. The enzymes with N-acetylornithine aminotransferase (ACOAT) activity in arginine synthesis were ArgD, AstC, GabT and PuuE; the major anaerobic ACOAT was ArgD. The major enzymes with N-succinyl-l,l-diaminopimelate aminotransferase (SDAP-AT) activity in lysine synthesis were ArgD, AstC, and SerC. Seven other aminotransferases, when overproduced, complemented the defect in a triple mutant. Lysine availability did not regulate synthesis of the major SDAP-ATs. Complementation analysis of mutants lacking aminotransferases showed that the SDAP-ATs and alanine aminotransferases were exceptionally redundant, and it is proposed that this redundancy may ensure peptidoglycan synthesis. An overview of all aminotransferase reactions indicates that redundancy and broad specificity are common properties of aminotransferases.