Three-year follow-up analysis of axicabtagene ciloleucel in relapsed/refractory indolent non-Hodgkin lymphoma (ZUMA-5).

ABSTRACT: Axicabtagene ciloleucel (axi-cel) is an autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy approved for relapsed/refractory (R/R) follicular lymphoma (FL). Approval was supported by the phase 2, multicenter, single-arm ZUMA-5 study of axi-cel for patients with R/R indolent non-Hodgkin lymphoma (iNHL; N = 104), including FL and marginal zone lymphoma (MZL). In the primary analysis (median follow-up, 17.5 months), the overall response rate (ORR) was 92% (complete response rate, 74%). Here, we report long-term outcomes from ZUMA-5. Eligible patients with R/R iNHL after ≥2 lines of therapy underwent leukapheresis, followed by lymphodepleting chemotherapy and axi-cel infusion (2 × 106 CAR T cells per kg). The primary end point was ORR, assessed in this analysis by investigators in all enrolled patients (intent-to-treat). After median follow-up of 41.7 months in FL (n = 127) and 31.8 months in MZL (n = 31), ORR was comparable with that of the primary analysis (FL, 94%; MZL, 77%). Median progression-free survival was 40.2 months in FL and not reached in MZL. Medians of overall survival were not reached in either disease type. Grade ≥3 adverse events of interest that occurred after the prior analyses were largely in recently treated patients. Clinical and pharmacokinetic outcomes correlated negatively with recent exposure to bendamustine and high metabolic tumor volume. After 3 years of follow-up in ZUMA-5, axi-cel demonstrated continued durable responses, with very few relapses beyond 2 years, and manageable safety in patients with R/R iNHL. The ZUMA-5 study was registered at www.clinicaltrials.gov as #NCT03105336.

Axicabtagene ciloleucel in relapsed or refractory indolent non-Hodgkin lymphoma (ZUMA-5): a single-arm, multicentre, phase 2 trial.

BACKGROUND: Most patients with advanced-stage indolent non-Hodgkin lymphoma have multiple relapses. We assessed axicabtagene ciloleucel autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy in relapsed or refractory indolent non-Hodgkin lymphoma. METHODS: ZUMA-5 is a single-arm, multicentre, phase 2 trial being conducted at 15 medical cancer centres in the USA and two medical cancer centres in France. Patients were eligible if they were aged 18 years or older, with histologically confirmed indolent non-Hodgkin lymphoma (follicular lymphoma or marginal zone lymphoma), had relapsed or refractory disease, previously had two or more lines of therapy (including an anti-CD20 monoclonal antibody with an alkylating agent), and an Eastern Cooperative Oncology Group performance score of 0 or 1. Patients underwent leukapheresis and received conditioning chemotherapy (cyclophosphamide at 500 mg/m2 per day and fludarabine at 30 mg/m2 per day on days -5, -4, and -3) followed by a single infusion of axicabtagene ciloleucel (2 × 106 CAR T cells per kg) on day 0. The primary endpoint was overall response rate (complete response and partial response) assessed by an independent review committee per Lugano classification. The primary activity analysis was done after at least 80 treated patients with follicular lymphoma had been followed up for at least 12 months after the first response assessment at week 4 after infusion. The primary analyses were done in the per-protocol population (ie, eligible patients with follicular lymphoma who had 12 months of follow-up after the first response assessment and eligible patients with marginal zone lymphoma who had at least 4 weeks of follow-up after infusion of axicabtagene ciloleucel). Safety analyses were done in patients who received an infusion of axicabtagene ciloleucel. This study is registered with ClinicalTrials.gov, NCT03105336, and is closed to accrual. FINDINGS: Between June 20, 2017, and July 16, 2020, 153 patients were enrolled and underwent leukapheresis, and axicabtagene ciloleucel was successfully manufactured for all enrolled patients. As of data cutoff (Sept 14, 2020), 148 patients had received an infusion of axicabtagene ciloleucel (124 [84%] who had follicular lymphoma and 24 [16%] who had marginal zone lymphoma). The median follow-up for the primary analysis was 17·5 months (IQR 14·1-22·6). Among patients who were eligible for the primary analysis (n=104, of whom 84 had follicular lymphoma and 20 had marginal zone lymphoma), 96 (92%; 95% CI 85-97) had an overall response and 77 (74%) had a complete response. The most common grade 3 or worse adverse events were cytopenias (104 [70%] of 148 patients) and infections (26 [18%]). Grade 3 or worse cytokine release syndrome occurred in ten (7%) patients and grade 3 or 4 neurological events occurred in 28 (19%) patients. Serious adverse events (any grade) occurred in 74 (50%) patients. Deaths due to adverse events occurred in four (3%) patients, one of which was deemed to be treatment-related (multisystem organ failure). INTERPRETATION: Axicabtagene ciloleucel showed high rates of durable responses and had a manageable safety profile in patients with relapsed or refractory indolent non-Hodgkin lymphoma. FUNDING: Kite, a Gilead Company.

R-MACLO-IVAM regimen followed by maintenance therapy induces durable remissions in untreated mantle cell lymphoma - Long term follow up results.

We present long-term combined results of two clinical trials implementing R-MACLO-IVAM induction followed by thalidomide or rituximab maintenance in 44 patients with untreated mantle cell lymphoma (MCL). The first 22 patients (UM-MCL1 ClinicalTrials.gov identifier NCT00450801) received maintenance with thalidomide (200 mg daily until relapse/intolerable toxicity) and a subsequent cohort of 22 patients (UM-MCL2 ClinicalTrials.gov identifier NCT00878254) received rituximab (375 mg/m2 IV weekly × 4, repeated every 6 months for 3 years). Considering all 44 patients, 41 (93.2%) achieved complete response (CR), two (4.5%) partial response (PR), and one (2.3%) was not evaluated for response. With a median follow up of 7.2 years (range < 1 month to 16 years), the 5-year progression-free survival (PFS) was 55.6% (95% CI: 38.9%-69.4%) and median PFS 7.9 years (95% CI: 3.7-11 years). The 5-year OS was 83.3% (95% CI: 68.1%-91.7%) and median OS was not reached. Patients with blastic variant (n = 6) had a 5-year PFS and OS of 20.8% and 60%, respectively. Myelosuppression was the most common adverse event during immunochemotherapy. Long-term treatment-related mortality was 6.8%. Note, R-MACLO-IVAM followed by maintenance therapy is an effective regimen to induce long-term remission in MCL without need for consolidation with ASCT.

Anti-CD20-interleukin-21 fusokine targets malignant B cells via direct apoptosis and NK-cell-dependent cytotoxicity.

In spite of newly emerging therapies and the improved survival of patients with non-Hodgkin lymphoma (NHL), relapses or primary refractory disease are commonly observed and associated with dismal prognosis. Although discovery of the anti-CD20 antibody rituximab has markedly improved outcomes in B-cell NHL, rituximab resistance remains an important obstacle to successful treatment of these tumors. To improve the efficacy of CD20-targeted therapy, we fused interleukin 21 (IL-21), which induces direct lymphoma cytotoxicity and activates immune effector cells, to the anti-CD20 antibody (αCD20-IL-21 fusokine). We observed substantially enhanced IL-21R-mediated signaling by the fusokine compared with native IL-21 at equimolar concentrations. Fusokine treatment led to direct apoptosis of lymphoma cell lines and primary tumors that otherwise were resistant to native IL-21 treatment. In addition to direct cytotoxicity, the fusokine enhanced NK cell activation, effector functions, and interferon γ production, resulting in greater antibody-dependent cell-mediated cytotoxicity compared with IL-21 and/or anti-CD20 antibody treatments. Further, the αCD20-IL-21 fusokine stabilizes IL-21 and prolongs its half-life. In vivo αCD20-IL-21 therapy resulted in a significant tumor control in the rituximab-resistant A20-huCD20 tumors. Collectively, the dual functional ability of the αCD20-IL-21 fusokine to induce direct apoptosis and activate immune effector cells may provide benefit over existing treatments for NHL.

Five-year results of brentuximab vedotin in patients with relapsed or refractory systemic anaplastic large cell lymphoma.

This pivotal phase 2 study evaluated the safety and efficacy of brentuximab vedotin in patients with relapsed or refractory (R/R) systemic anaplastic large cell lymphoma (ALCL). After a median observation period of approximately 6 years from first treatment, we examined the durability of remission, progression-free survival (PFS), overall survival (OS), and safety outcomes of patients treated on this trial. Among all enrolled patients (n = 58), no progressions were observed beyond 40 months, and median OS was not reached. Patients with a complete response (CR), as assessed by the investigator (38 of 58, 66%), continued to demonstrate improved outcomes with neither median OS nor PFS reached. Of the 38 CR patients, 16 received a consolidative stem cell transplant (SCT) with median PFS not reached. Among patients who were on-study and in remission at study closure, 16 patients had not received any new treatment after single-agent brentuximab vedotin other than consolidative SCT. Among this subset of 16 patients, 8 received SCT, and the remaining 8 patients (14% of all enrolled patients) remained in sustained remission without consolidative SCT or any new anticancer therapy. Thirty-three patients experienced peripheral neuropathy, among whom, the majority (30 of 33, 91%) had experienced resolution or improvement at their last assessment. These final results, which demonstrated a high rate of peripheral neuropathy resolution, and durable remissions in a subset of patients with relapsed or refractory systemic ALCL, provide evidence that single-agent brentuximab vedotin may be a potentially curative treatment option. This trial was registered at www.clinicaltrials.gov as #NCT00866047.

Short survival and frequent transformation in extranodal marginal zone lymphoma with multiple mucosal sites presentation.

Between 11 and 37% of extranodal marginal zone lymphoma (EMZL) patients present with disease involvement in multiple mucosal sites (MMS). We analyzed 405 EMZL patients seen between 1995 and 2017: 265 (65.4%) patients presented with stage I disease, 49 of 309 (15.8%) patients with bone marrow involvement, and 35 of 328 (10.7%) patients with monoclonal gammopathy (MG). Forty-three (10.6%) patients had MMS presentation, which was more frequently seen in patients aged >60 years (55.8%). Five (17.9%) of 28 MMS patients had MG. MMS patients commonly exhibited the International Prognostic Index (IPI) >2 (79.1%), Follicular Lymphoma International Prognostic Index (FLIPI) >2 (39.5%), and Mucosa-Associated Lymphoid Tissue Lymphoma International Prognostic Index (MALT-IPI) 2-3 (60.5%). Both MMS presentation and MG were associated with shorter survival univariately. In multivariable Cox regression models, shorter progression-free survival (PFS) and overall survival (OS) were observed in patients with MMS (hazard ratio [HR] = 3.08 and 2.92, respectively), age ≥60 years (HR = 1.52 and 2.45, respectively), and in patients who failed to attain a complete remission following initial therapy (HR = 3.27 and 2.13, respectively). Elevated lactate dehydrogenase was associated with shorter PFS (HR = 1.92), while anemia (HR = 2.46) was associated with shortened OS. MALT-IPI ≥2 (HR = 2.47 and 4.75), FLIPI >2 (HR = 1.65 and 2.09), and IPI >2 (HR = 2.09 and 1.73) were associated with shorter PFS and OS, respectively. Higher grade transformation (HGT) occurred in 11 (25.6%) MMS patients with a 5-year cumulative incidence of 13.2% (95% CI 4.7-26.1%). EMZL patients with MMS presentation represent a novel clinical subset associated with shorter PFS, OS, and higher incidence of HGT that needs novel therapeutic approaches.

Understanding Unicameral and Aneurysmal Bone Cysts.

Bone cysts in the pediatric population are often found incidentally on radiographs or after a cyst has created cortical weakness leading to a pathologic fracture. Most bone cysts are benign, are pain free, and resolve spontaneously. The most common bone cyst is unicameral 1-chamber bone cyst, also known as simple bone cyst. General practice pediatricians may be the first to encounter these lesions, and this article aims to help elucidate their incidence, etiology, clinical findings, radiologic findings, and modern treatment approaches. The other differential diagnoses that should be considered, specifically, aneurysmal bone cyst, are also explored. This summary is not all inclusive, and it is recommended that all patients be referred to a pediatric orthopedist.

Five-year survival and durability results of brentuximab vedotin in patients with relapsed or refractory Hodgkin lymphoma.

Presented here are the 5-year end-of-study results from the pivotal phase 2 trial of brentuximab vedotin in patients with relapsed/refractory (R/R) Hodgkin lymphoma (HL) after failed hematopoietic autologous stem cell transplantation. At 5 years, the overall patient population (N = 102) had an estimated overall survival (OS) rate of 41% (95% confidence interval [CI]: 31-51) and progression-free survival (PFS) rate of 22% (95% CI: 13-31). Patients who achieved a complete response (CR) to brentuximab vedotin (N = 34) had estimated OS and PFS rates of 64% (95% CI: 48-80%) and 52% (95% CI: 34-69%), respectively. The median OS and PFS were not reached in CR patients, with 13 patients (38% of all CR patients) remaining in follow-up and in remission at study closure. Of the 13 patients, 4 received consolidative hematopoietic allogeneic stem cell transplant, and 9 (9% of all enrolled patients) remain in sustained CR without receiving any further anticancer therapy after treatment with brentuximab vedotin. Of the patients who experienced treatment-emergent peripheral neuropathy, 88% experienced either resolution (73%) or improvement (14%) in symptoms. These 5-year follow-up data demonstrate that a subset of patients with R/R HL who obtained CR with single-agent brentuximab vedotin achieved long-term disease control and may potentially be cured. The trial was registered at www.clinicaltrials.gov as #NCT00848926.

Durable remissions in a pivotal phase 2 study of brentuximab vedotin in relapsed or refractory Hodgkin lymphoma.

We present response and survival outcomes of a pivotal phase 2 trial of the antibody-drug conjugate brentuximab vedotin in patients with relapsed/refractory Hodgkin lymphoma following autologous stem cell transplant (N = 102) after a median observation period of approximately 3 years. Median overall survival and progression-free survival were estimated at 40.5 months and 9.3 months, respectively. Improved outcomes were observed in patients who achieved a complete remission (CR) on brentuximab vedotin, with estimated 3-year overall survival and progression-free survival rates of 73% (95% confidence interval [CI]: 57%, 88%) and 58% (95% CI: 41%, 76%), respectively, in this group (medians not reached). Of the 34 patients who obtained CR, 16 (47%) remain progression-free after a median of 53.3 months (range, 29.0 to 56.2 months) of observation; 12 patients remain progression-free without a consolidative allogeneic stem cell transplant. Younger age, good performance status, and lower disease burden at baseline were characteristic of patients who achieved a CR and were favorable prognostic factors for overall survival. These results suggest that a significant proportion of patients who respond to brentuximab vedotin can achieve prolonged disease control. The trial was registered at www.clinicaltrials.gov as #NCT00848926.

Mammary-tumor-educated B cells acquire LAP/TGF-ß and PD-L1 expression and suppress anti-tumor immune responses.

B lymphocytes play a role in inhibiting the immune response against certain tumors, but the underlying mechanisms are poorly understood. EMT-6 mammary tumors grow well in wild-type (WT) mice but show reduced growth in B-cell-deficient µ(-/-) BALB/c mice (BCDM). WT mice demonstrate extensive B-cell infiltration into the tumor bed, reduced CD8(+) T cell and CD49(+) NK cell infiltration, and markedly reduced cytolytic T-cell response relative to BCDM. Expression of LAP/TGF-ß1, CD80, CD86 and PD-L1 is significantly increased in tumor-infiltrating B cells (TIL-B) relative to splenic B cells. LAP/TGF-ß1 expression on TIL-B progressively increased from 5.4±1.7% on day 8 to 43.1±6.1% by day 21 post tumor implantation. Co-culture of EMT-6 tumor cells with Naive-B cells ex vivo generated B cells (EMT6-B) with a similar immunophenotype to TIL-B. Purified TIL-B, or in-vitro-generated EMT6-B suppressed CD4(+), CD8(+) and CD4(+)CD25(-) T-cell proliferation, and Th1 cytokine secretion, and also suppressed purified NK-cell proliferation in response to IL-15, compared to naive splenic B cells. Acquired B regulatory function required direct tumor cell: B-cell contact, and was partially reversed by antibody to TGF-ß or PD-L1, leading to tumor rejection in vivo B-cell acquisition of a suppressive phenotype following tumor infiltration may result in profound inhibition of T-cell anti-tumor responses.

Regulatory B cells in anti-tumor immunity.

Advances in understanding of the immune microenvironment have highlighted the role of immunosuppressive T cell, myeloid, dendritic and monocytic sub-populations in inhibition of the anti-tumor immune response. The role of B cells in modulating the immune response to solid tumors as well as lymphoid malignancies is less well understood. Murine models of autoimmune disease have defined B regulatory cell (Breg) subsets with immune suppressive activity, including B cell subsets that express IL-10, and transforming growth factor-ß, which can facilitate T regulatory cell recruitment and expansion. Multiple murine tumor models point to the existence of similar immune suppressive B cell sub-populations that can migrate into tumor deposits and acquire an immune suppressive phenotype, which then leads to attenuation of the local anti-tumor immune response. Other murine models of viral or chemically induced skin carcinogenesis have identified a pivotal role for B cells in promoting inflammation and carcinogenesis. While many human solid tumors demonstrate significant B cell infiltration and/or tertiary lymphoid structure formation, the functional properties of tumor-infiltrating B cells and their effects on immunity are poorly understood. Recent successes in early Phase I/II trials using anti-checkpoint inhibitor antibodies such as nivolumab or pidilizumab directed against PD-1 in the setting of Hodgkin's and non-Hodgkin's lymphomas validate the therapeutic utility of reversing B cell-mediated immune suppression. Further studies to define Breg subsets, and mechanisms of suppression, may provide new avenues for modulation of the immune response and meaningful therapeutic intervention in both lymphoid and solid tumors.

Updated survival analysis of two sequential prospective trials of R-MACLO-IVAM followed by maintenance for newly diagnosed mantle cell lymphoma.

A phase II trial of R-MACLO-IVAM followed by thalidomide maintenance for mantle cell lymphoma (MCL) demonstrated promising progression-free survival (PFS) and overall survival (OS) rates. Thalidomide maintenance was associated with significant toxicity and was subsequently modified to rituximab maintenance. Herein, we present updated results and follow-up. Two sequential phase II trials included chemotherapy-naïve patients with MCL up to 75 years old. Four cycles of R-MACLO-IVAM chemotherapy were delivered as previously described. Patients who achieved complete responses (CR) were eligible for thalidomide or rituximab maintenance therapy. Among 36 patients enrolled, the MCL International Prognostic Index (MIPI) was low in 53%, intermediate in 36% and high in 11%. Thirty-five patients completed at least 2 cycles of chemotherapy; 34 (94%) achieved a CR. After a median follow-up of 74.4 months, the 5-year PFS was 51% (95% CI 33-68%) and the 5-year OS was 85% (95% CI 73-97%). Two deaths occurred during the chemotherapy phase due to disease progression and neutropenic sepsis, respectively. One patient developed secondary acute myeloid leukemia after 7 years. R-MACLO-IVAM chemotherapy is effective for patients with newly diagnosed MCL.

Tumor immunogenicity and responsiveness to cancer vaccine therapy: the state of the art.

Despite enormous effort, promising pre-clinical data in animal studies and over 900 clinical trials in the United States, no cancer vaccine has ever been approved for clinical use. Over the past decade a great deal of progress has been in both laboratory and clinical studies defining the interactions between developing tumors and the immune system. The results of these studies provide a rationale that may help explain the failure of recent therapeutic cancer vaccines in terms of vaccine principles, in selecting which tumors are the most appropriate to target and instruct the design and implementation of state-of-the-art cancer vaccines.

Diagnosis and treatment of diffuse large B-cell lymphoma in an orangutan (Pongo pygmaeus).

Lymphoma is a common malignancy observed in companion animals. This type of naturally occurring neoplasia has been uncommonly reported in great apes. Diffuse large B-cell lymphoma was diagnosed in an 8-yr-old captive orangutan (Pongo pygmaeus) with gastrointestinal disease by histologic and immunohistochemical methodologies. The orangutan was treated with three cycles of combination chemotherapy (intravenous Rituxan, cyclophosphamide, doxorubicin, and vincristine). The primate has been in good health and exhibiting normal behaviors for more than 15 mo following treatment.

Antibody-Drug Conjugate αEGFR-E-P125A Reduces Triple-negative Breast Cancer Vasculogenic Mimicry, Motility, and Metastasis through Inhibition of EGFR, Integrin, and FAK/STAT3 Signaling.

Primary tumor growth and metastasis in triple-negative breast cancer (TNBC) require supporting vasculature, which develop through a combination of endothelial angiogenesis and vasculogenic mimicry (VM), a process associated with aggressive metastatic behavior in which vascular-like structures are lined by tumor cells. We developed αEGFR-E-P125A, an antibody-endostatin fusion protein that delivers a dimeric, mutant endostatin (E-P125A) payload that inhibits TNBC angiogenesis and VM in vitro and in vivo. To characterize the mechanisms associated with induction and inhibition of VM, RNA sequencing (RNA-seq) of MDA-MB-231-4175 TNBC cells grown in a monolayer (two-dimensional) was compared with cells plated on Matrigel undergoing VM [three-dimensional (3D)]. We then compared RNA-seq between TNBC cells in 3D and cells in 3D with VM inhibited by αEGFR-E-P125A (EGFR-E-P125A). Gene set enrichment analysis demonstrated that VM induction activated the IL6-JAK-STAT3 and angiogenesis pathways, which were downregulated by αEGFR-E-P125A treatment.Correlative analysis of the phosphoproteome demonstrated decreased EGFR phosphorylation at Y1069, along with decreased phosphorylation of focal adhesion kinase Y397 and STAT3 Y705 sites downstream of α5ß1 integrin. Suppression of phosphorylation events downstream of EGFR and α5ß1 integrin demonstrated that αEGFR-E-P125A interferes with ligand-receptor activation, inhibits VM, and overcomes oncogenic signaling associated with EGFR and α5ß1 integrin cross-talk. In vivo, αEGFR-E-P125A treatment decreased primary tumor growth and VM, reduced lung metastasis, and confirmed the inhibition of signaling events observed in vitro. Simultaneous inhibition of EGFR and α5ß1 integrin signaling by αEGFR-E-P125A is a promising strategy for the inhibition of VM, tumor growth, motility, and metastasis in TNBC and other EGFR-overexpressing tumors. SIGNIFICANCE: αEGFR-E-P125A reduces VM, angiogenesis, tumor growth, and metastasis by inhibiting EGFR and α5ß1 integrin signaling, and is a promising therapeutic agent for TNBC treatment, used alone or in combination with chemotherapy.

B lymphocyte inhibition of anti-tumor response depends on expansion of Treg but is independent of B-cell IL-10 secretion.

The mechanisms by which B lymphocytes inhibit anti-tumor immunity remain poorly understood. Murine EMT-6 mammary tumors grow readily in immune competent mice (BALB/c), but poorly in B-cell-deficient µ(-/-) BALB/c mice (BCDM). T regulatory cell (Treg) expansion and function were impaired in BCDM compared with BALB/c. In this study, we compared tumor growth, Treg cell proliferation, tumor lymphocyte infiltration and cytolytic T cell activity in BALB/c, BCDM and BCDM partially reconstituted with B cells by adoptive transfer (BCDM+B). Partial reconstitution of BCDM with adoptively transferred B cells restored EMT-6 tumor growth, which was independent of IL-10 secretion by B cells. Instead, high frequencies of intratumoral B cells were associated with increased recruitment and proliferation of Treg cells within the tumor microenvironment. The B-cell-dependent accumulation of Treg within the tumor microenvironment was associated with reduced tumor infiltration by CD49+ NK and CD8+ T cells and reduced cytotoxic T cell activity against EMT-6 targets. Our studies indicate that tumor-dependent immunosuppression of T-cell-mediated anti-tumor immunity is coordinated within the tumor microenvironment by B-cell-dependent cross talk with Treg cells, which does not require production of IL-10 by B cells.

Brentuximab vedotin in transplant-naive patients with relapsed or refractory hodgkin lymphoma: analysis of two phase I studies.

BACKGROUND: Brentuximab vedotin is an antibody-drug conjugate designed to selectively deliver monomethyl auristatin E, a microtubule-disrupting agent, to CD30-expressing cells. Brentuximab vedotin induces durable objective responses in patients with relapsed or refractory Hodgkin lymphoma (HL) after autologous stem cell transplantation (ASCT). The objective of this post-hoc analysis was to characterize the safety and efficacy of brentuximab vedotin for patients with relapsed or refractory HL who refused or were ineligible for ASCT. METHODS: This case series included 20 transplant-naïve patients who were enrolled in two phase I multicenter studies. Patients received brentuximab vedotin intravenously every 3 weeks or every week for 3 out of 4 weeks. RESULTS: The majority of patients were transplant-naïve because of chemorefractory disease. Median age was 31.5 years (range, 12-87 years). Treatment-emergent adverse events in >20% of patients were peripheral neuropathy, fatigue, nausea, pyrexia, diarrhea, weight decreased, anemia, back pain, decreased appetite, night sweats, and vomiting; most events were grade 1 or 2. Six patients obtained objective responses: two complete remissions and four partial remissions. Median duration of response was not met; censored durations ranged from >6.8 to >13.8 months. Three of six responders subsequently received ASCT. CONCLUSION: Brentuximab vedotin was associated with manageable adverse events in transplant-naïve patients with relapsed or refractory HL. The objective responses observed demonstrate that antitumor activity is not limited to patients who received brentuximab vedotin after ASCT. The promising activity observed in this population warrants further study.

Time is of the Essence: Using Extended Hemin Treatment for a Case of Severe Acute Intermittent Porphyria.

Acute intermittent porphyria (AIP) is a disorder that affects heme synthesis, leading to accumulation of upstream precursors, and can cause an array of visceral and neurological symptoms. These can be severely debilitating and even fatal if not diagnosed and treated in a timely fashion. We outline a rare case of severe AIP masquerading as ascending polyneuropathy and how it was correctly diagnosed and treated with an extended course of hemin despite initial barriers to biochemical testing for AIP.

The absence of B lymphocytes reduces the number and function of T-regulatory cells and enhances the anti-tumor response in a murine tumor model.

Increasing evidence suggests that B lymphocytes play a central role in inhibiting the immune response against certain tumors, but the underlying mechanisms by which B cells facilitate tumor growth are still poorly understood. In this study, we investigated how the presence or absence of B cells affects expansion and function of T-regulatory cells ('T-regs') in a murine breast tumor model (EMT-6). We compared tumor growth, and the number and function of T-reg cells in wild-type immune-competent mice (ICM) and B-cell-deficient mice (BCDM). Mice were either tumor-naive or implanted with EMT-6 mammary adenocarcinoma cells. Tumor growth was markedly inhibited in BCDM, compared to wild-type mice (ICM). Increased T-reg expansion as defined by CD4+/CD25+/FOXP3+ cells was evident following EMT-6 inoculation in ICM in comparison with non-tumor-bearing mice or compared to BCDM in which tumor had been implanted. The percentage and absolute number of T-regs in the spleen, tumor draining lymph nodes, and tumor bed were significantly reduced in BCDM compared to ICM. T-reg function, measured by suppression and proliferation assays, was also reduced in tumor inoculated BCDM compared to ICM. Our studies indicate that absence of B cells may play a role in augmenting the T-cell anti-tumor response, in part due to effects on T-regulatory cell expansion and function.

Inhibition of Vasculogenic Mimicry and Angiogenesis by an Anti-EGFR IgG1-Human Endostatin-P125A Fusion Protein Reduces Triple Negative Breast Cancer Metastases.

Triple negative breast cancer (TNBC) is an aggressive breast cancer subtype with limited therapeutic options. Metastasis is the major cause of TNBC mortality. Angiogenesis facilitates TNBC metastases. Many TNBCs also form vascular channels lined by tumor cells rather than endothelial cells, known as 'vasculogenic mimicry' (VM). VM has been linked to metastatic TNBC behavior and resistance to anti-angiogenic agents. Epidermal growth factor receptor (EGFR) is frequently expressed on TNBC, but anti-EGFR antibodies have limited efficacy. We synthesized an anti-EGFR antibody-endostatin fusion protein, αEGFR IgG1-huEndo-P125A (αEGFR-E-P125A), designed to deliver a mutant endostatin, huEndo-P125A (E-P125A), to EGFR expressing tumors, and tested its effects on angiogenesis, TNBC VM, and motility in vitro, and on the growth and metastasis of two independent human TNBC xenograft models in vivo. αEGFR-E-P125A completely inhibited the ability of human umbilical vein endothelial cells to form capillary-like structures (CLS) and of TNBC cells to engage in VM and form tubes in vitro. αEGFR-E-P125A treatment reduced endothelial and TNBC motility in vitro more effectively than E-P125A or cetuximab, delivered alone or in combination. Treatment of TNBC with αEGFR-E-P125A was associated with a reduction in cytoplasmic and nuclear ß-catenin and reduced phosphorylation of vimentin. αEGFR-E-P125A treatment of TNBC xenografts in vivo inhibited angiogenesis and VM, reduced primary tumor growth and lung metastasis of orthotopically implanted MDA-MB-468 TNBC cells, and markedly decreased lung metastases following intravenous injection of MDA-MB-231-4175 lung-tropic TNBC cells. Combined inhibition of angiogenesis, VM, and TNBC motility mediated by αEGFR-E-P125A is a promising strategy for the prevention of TNBC metastases.