Nicotinamide-Expanded Allogeneic Natural Killer Cells with CD38 Deletion, Expressing an Enhanced CD38 Chimeric Antigen Receptor, Target Multiple Myeloma Cells

Natural killer (NK) cells are a vital component of cancer immune surveillance. They provide a rapid and potent immune response, including direct cytotoxicity and mobilization of the immune system, without the need for antigen processing and presentation. NK cells may also be better tolerated than T cell therapy approaches and are susceptible to various gene manipulations. Therefore, NK cells have become the focus of extensive translational research. Gamida Cell's nicotinamide (NAM) platform for cultured NK cells provides an opportunity to enhance the therapeutic potential of NK cells. CD38 is an ectoenzyme ubiquitously expressed on the surface of various hematologic cells, including multiple myeloma (MM). It has been selected as a lead target for numerous monoclonal therapeutic antibodies against MM. Monoclonal antibodies target CD38, resulting in the lysis of MM plasma cells through various antibody-mediated mechanisms such as antibody-dependent cellular cytotoxicity (ADCC), complement-dependent cytotoxicity, and antibody-dependent cellular phagocytosis, significantly improving the outcomes of patients with relapsed or refractory MM. However, this therapeutic strategy has inherent limitations, such as the anti-CD38-induced depletion of CD38-expressing NK cells, thus hindering ADCC. We have developed genetically engineered NK cells tailored to treat MM, in which CD38 was knocked-out using CRISPR-Cas9 technology and an enhanced chimeric antigen receptor (CAR) targeting CD38 was introduced using mRNA electroporation. This combined genetic approach allows for an improved cytotoxic activity directed against CD38-expressing MM cells without self-inflicted NK-cell-mediated fratricide. Preliminary results show near-complete abolition of fratricide with a 24-fold reduction in self-lysis from 19% in mock-transfected and untreated NK cells to 0.8% of self-lysis in CD38 knock-out CAR NK cells. Furthermore, we have observed significant enhancements in CD38-mediated activity in vitro, resulting in increased lysis of MM target cell lines. CD38 knock-out CAR NK cells also demonstrated significantly higher levels of NK activation markers in co-cultures with both untreated and αCD38-treated MM cell lines. These NAM-cultured NK cells with the combined genetic approach of CD38 knockout and addition of CD38 CAR represent a promising immunotherapeutic tool to target MM.

Alemtuzumab treatment in real clinical practice: Experience in a multicenter cohort

BACKGROUND

Alemtuzumab is a highly effective treatment for relapsing remitting multiple sclerosis (RRMS), but in recent years safety-related concerns had emerged due to description of novel serious side effects not registered in CARE-MS I and CARE-MS II phase 3 studies, nor in TOPAZ extension study. Data about alemtuzumab use in real clinical practice are limited and based mainly on retrospective studies with small sample sizes. Therefore, more information about effectiveness and safety of alemtuzumab in this context is needed.

METHODS

A multicenter observational prospective study to investigate effectivity and safety of alemtuzumab in a real-world setting was performed. Primary endpoints were the change in annualized relapse rate (ARR), and in disability measured by EDSS score. Secondary endpoints were the cumulative probability of confirmed 6-month disability improvement and worsening. Disability worsening and disability improvement were considered when the EDSS score was increased or decreased, respectively, in 1 point if baseline EDSS score was <5.0, or in 0.5 point if baseline EDSS score was ≥5.5, confirmed over 6 months. Other secondary endpoint was the proportion of patients who achieved NEDA-3 status (absence of clinical relapses, disability EDSS progression, and MRI disease activity as depicted by new/enlarging T2 lesions or Gadolinium enhancing T1 lesions). Adverse events also were recorded.

RESULTS

A total of 195 RRMS patients (70% female) who started alemtuzumab treatment were included. Mean of follow-up was 2.38 years. Alemtuzumab significantly reduced the annualized relapse rate from baseline with risk reductions of 86%, 83.5%, and 84%, at 12, 24, and 36 months of follow-up respectively (Friedman test, p-value < 0.05 for all comparisons). Alemtuzumab also significantly reduced EDSS score over one and two years after starting alemtuzumab treatment (Friedman test, p-value<0.001 for both comparisons). A high proportion of patients presented confirmed 6-month stability or disability improvement (92%, 82%, and 79%, over 1, 2 and 3 years of follow-up respectively). The proportion of patients who retained NEDA-3 status at 12, 24 and 36 months were 61%, 49%, and 42%, respectively. Baseline characteristics associated with a lower probability of achieving NEDA-3 were younger age, sex female, high ARR, elevated number of previous treatments, and switch from a second line therapy. Infusion related reactions were the most frequent adverse event observed. The most common infections were urinary tract infections (50%), and upper respiratory tract infections (19%) over the 3 years of follow- up. Secondary thyroid autoimmunity was developed in 18.5% of patients.

CONCLUSION

Alemtuzumab has demonstrated in real clinical practice high effectiveness in controlling multiple sclerosis activity, and no unexpected adverse events were observed.

162 Nicotinamide rejuvenates ex-vivo expanded natural killer cells and enhances their tumor killing capacity

Background

Adoptive transfer of Natural Killer cells (NKs) is a growing area of innovation in cancer immunotherapy. Nicotinamide (NAM), an allosteric inhibitor of NAD-dependent enzymes, has been shown to preserve cell function and prevent differentiation in ex vivo culture of NK (NAM-NK) and other cells. Clinical responses were observed in a Phase 1 trial of NAM-NK (GDA-201) in patients with refractory non-Hodgkin lymphoma (Bachanova, et. al., Blood 134:777, 2019). We now characterize the mechanisms underlying the activity of NAM-NK by exploring their phenotype, functionality, and antitumor activity.

Methods

CD56 positive cells obtained from healthy donors were cultured for 14 days with IL-15 in the presence or absence of NAM (7 mM). Cell-surface antigens were characterized using flow cytometry (FACS). Mitochondrial reactive oxygen species (ROS) were measured using MitoSox-based FACS. In vitro killing of tumor cells was evaluated by FACS after co-culture of NAM-NK with HER-2-positive A549 (lung adenocarcinoma) or SKOV-3 (ovarian cancer) cells in the presence or absence of trastuzumab; NK cell CD107a and intracellular IFNγ, TNFα, and GM-CSF were also measured by FACS. In vivo activity was determined using a subcutaneous tumor model in NSG mice injected with A549 cells (5x106 sc) and treated with NAM-NK cells (20x106 cells ip/day) on Day 9–12 with IL-2 (300 ug ip), with or without trastuzumab (100ug ip).

Results

Characterization of cell surface markers revealed elevated CD56, CD62L, and CD49a and decreased CD16, CD57, and NKp80 in NAM-NK compared to NK cultured without NAM. CD200R and LAG3 were decreased. NAM-NKs also demonstrated decreased mitochondrial superoxide formation triggered by H2O2 oxidative stress.NAM-NK co-cultured with A549 and SKOV-3 cells had increased expression of the degranulation marker CD107a and the proinflammatory cytokines INF-γ, TNF-α, and GM-CSF compared to NK without NAM, and demonstrated increased cytotoxicity in the presence and absence of trastuzumab. Finally, NAM-NK inhibited A549 tumor growth in vivo; tumor growth inhibition was potentiated in the presence of trastuzumab and greater than with trastuzumab alone.

Conclusions

These data suggest that NAM rejuvenates cultured NK, generating activated and potent NK cells. NAM-NK (GDA-201) display a distinct phenotype similar to cytokine-induced memory like (CIML) NK, but with downregulation of immune checkpoint inhibitors such as CD200R and LAG3. In addition, NAM-NK are greatly resistant to ROS−a known mechanism of tumor resistance−and highly cytotoxic in in vitro and in vivo assays. The promising potential of GDA-201 as an anticancer immunotherapy is being explored further in clinical trials

Ethics Approval

We hereby declare that the collection of the Apheresis units in the three participating institutes (sites) has been done under an approved clinical study that meets the following requirements:1. Ethics approval has been obtained from the local EC at each of the sites, prior to any study related activities.2. The working procedures of the EC at the sites for conduct of clinical studies are in due compliance with local regulations (Israeli Ministry of Health) and provisions of Harmonized International Guidelines for Good Clinical Practice, namely: ICH-GCP.3. Sites follow EC conditions & requirements in terms of submissions, notifications, and approval renewals. 4. Participants gave Informed Consent (approved by the EC) before taking part in the study.5. Informed Consent has been approved by the ECs. The Israeli template of Informed Consent is in used and it includes study specific information (e.g. study goal, design, method, duration, risks, etc.). Name of the Institute Name of the EC/IRB EC Study No.Hadassah Medical Center Helsinki Committee 0483-16-HMORambam Health Care Campus Helsinki Committee 0641-18-RMBIchilov Sourasky Medical Center Tel-Aviv Helsinki Committee 0025-17-TLVAnimal study- All experiments were approved by the Animal Care and Use Committee of the Hebrew University.MD 19-15815-5.

217 Cytotoxicity of nicotinamide enhanced natural killer cells GDA201 is based on metabolic modulation as demonstrated by artificial intelligence assisted analysis of NK cell transcriptome and metabolome

Background

Nicotinamide (NAM), an allosteric inhibitor of NAD-dependent enzymes, has been shown to preserve cell function and prevent differentiation in ex vivo cell culture. GDA-201 is an investigational natural killer (NK) cell immunotherapy derived from allogeneic donors and expanded using IL-15 and NAM. In previous preclinical studies, NAM led to increased homing and cytotoxicity, preserved proliferation, and enhanced tumor reduction of NK cells. In a phase I clinical trial, treatment with GDA-201 showed tolerability and clinical responses in patients with refractory non-Hodgkin lymphoma (NHL) (Bachanova, et. al., Blood 134:777, 2019). While NAM is known to affect cellular metabolism and participate in 510 enzymatic reactions −in 66 as an inhibitor or activator− its mechanism of action and role in GDA-201 cytotoxicity is unknown.

Methods

In order to define the network of intracellular interactions that leads to the GDA-201 phenotype, flow-cytometry, next generation sequencing (NGS), and liquid chromatography–mass spectrometry (LC-MS)-based metabolite quantification were performed on NK cells cultured for 14 days with IL-15 and human serum in the presence or absence of NAM (7 mM). Artificial Intelligence (AI) machine learning analysis was applied by Pomicell in order to analyze the data using the Pomicell databases supporting data extracted from multiple origins including scientific articles organized using natural language processing tools. AI training was done using a combined algorithm designed to blindly explain and predict the transcriptomic and metabolomic (omics) profile.

Results

Omics analyses defined 1,204 differentially expressed genes, and 100 significantly modified metabolites in the presence of NAM. An in silico model was created that successfully predicted the experimental data in 83% of the cases. Upregulation of TIM-3 expression in GDA-201 was predicted to be mediated by inhibition of IL-10 and SIRT3, via CREB1/HLA-G signaling and adrenoceptor beta 2 (ADRB2) upregulation. Adenosine metabolite reduction supports this and suggests dopaminergic activation of NK cytotoxicity. Upregulation of CD62L in the presence of NAM was predicted to be mediated by transcription factor Dp-1 (TFDP1) via dihydrofolate reductase (DHFR) activation and intracellular folic acid reduction. Interferon-gamma and CASP3 modulation (via JUN and MCL1, respectively), via PPARa inhibition, support that finding.

Conclusions

In conclusion, AI machine learning of transcriptome and metabolome data revealed multiple pleiotropic metabolic pathways modulated by NAM. These data serve to further elucidate the mechanism by which NAM enhances cell function, leading to the observed cytotoxicity and potency of GDA-201.

Ethics Approval

We hereby declare that the collection of the Apheresis units in the three participating institutes (sites) has been done under an approved clinical study that meets the following requirements:1. Ethics approval has been obtained from the local EC at each of the sites, prior to any study related activities.2. The working procedures of the EC at the sites for conduct of clinical studies are in due compliance with local regulations (Israeli Ministry of Health) and provisions of Harmonized International Guidelines for Good Clinical Practice, namely: ICH-GCP.3. Sites follow EC conditions & requirements in terms of submissions, notifications, and approval renewals. 4. Participants gave Informed Consent (approved by the EC) before taking part in the study.5. Informed Consent has been approved by the ECs. The Israeli template of Informed Consent is in used and it includes study specific information (e.g. study goal, design, method, duration, risks, etc.). Name of the Institute Name of the EC/IRB EC Study No.Hadassah Medical Center Helsinki Committee 0483-16-HMORambam Health Care Campus Helsinki Committee 0641-18-RMBIchilov Sourasky Medical Center Tel-Aviv Helsinki Committee 0025-17-TLV

Four-year safety and effectiveness data from patients with multiple sclerosis treated with fingolimod: The Spanish GILENYA registry

Objective

To describe the profile of patients with multiple sclerosis (MS) treated with fingolimod in Spain and to assess the effectiveness and safety of fingolimod after 4 years of inclusion in the Spanish Gilenya Registry.

Methods

An observational, retrospective/prospective, multicenter case registry, including all patients with relapsing-remitting MS (RRMS) starting treatment with fingolimod in 43 centers in Spain. Analyses were performed in the overall population and in subgroups according to prior disease-modifying therapy (DMT): glatiramer acetate/interferon beta-1 (BRACE), natalizumab, other treatment, or naïve.

Results

Six hundred and sixty-six evaluable patients were included (91.1% previously treated with at least one DMT). The mean annualized relapse rate (ARR) prior to fingolimod was 1.12, and the mean EDSS at fingolimod initiation was 3.03. Fingolimod reduced the ARR by 71.4%, 75%, 75.5%, and 80.3%, after 1, 2, 3 and 4 years, respectively (p<0.001). This significant reduction in the ARR continued to be observed in all subgroups. After 4 years, the EDSS showed a minimal deterioration, with the EDSS scores from year 1 to year 4 remaining mostly stable. The percentage of patients without T1 Gd+ lesions progressively increased from 45.6% during the year prior to fingolimod initiation to 88.2% at year 4. The proportion of patients free from new/enlarged T2 lesions after 4 years of fingolimod treatment was 80.3%. This trend in both radiological measures was also observed in the subgroups. Adverse events (AEs) were experienced by up to 41.6% of patients (most commonly: lymphopenia [12.5%] and urinary tract infection [3.7%]). Most AEs were mild in severity, 3.6% of patients had serious AEs.

Conclusions

The patient profile was similar to other observational studies. The results obtained from the long-term use of fingolimod showed that it was effective, regardless of prior DMT, and it had adequate safety results, with a positive benefit-risk balance.

Potent Activation of Human T Cells by mRNA Encoding Constitutively Active CD40

New strategies for augmenting the actual performance of therapeutic T cells in vivo are needed for improving clinical outcome of adoptive cell therapy. Cumulative findings suggest that CD40 plays an intrinsic role in T cell costimulation. Recently, we demonstrated the ability of truncated, auto-oligomerizing CD40 derivatives to induce strong activation of APCs in a ligand-independent manner. We reasoned that constitutively active CD40 (caCD40) can similarly exert enhancing effects on human antitumor T cells. To test this assumption, we transfected human T cells with in vitro-transcribed caCD40 mRNA. In polyclonal T cells, caCD40 triggered IFN-γ secretion and upregulated CD25 and 4-1BB. In antimelanoma tumor-infiltrating lymphocytes (TILs), caCD40 induced massive production of IFN-γ, exerting a pronounced synergistic effect when coexpressed with constitutively active TLR4 devoid of its extracellular ligand binding. In unselected "young" TILs, caCD40 reproducibly increased surface expression of CD25, OX40, 4-1BB, CD127, and CD28. Three days post-mRNA electroporation of CD8 TILs, caCD40 elevated IFN-γ and TNF-α production and cytolytic activity in the presence of autologous but not HLA-I-mismatched melanoma. Enhanced killing of autologous melanoma by young TILs was observed 4 d posttransfection. These findings suggest that caCD40 can function as a potent T cell adjuvant and provide essential guidelines for similar manipulation of other key members of the TNFR family.

Abstract A095: New genes for enhancing T cell function in adoptive cell therapy of cancer

A growing number of clinical trials point to the exquisite ability of adoptively transferred T cells to eradicate vast masses of tumor cells, including aggressive metastatic tumors. In one therapeutic approach T cells are derived from tumor biopsies (tumor-infiltrating lymphocytes, or TILs) and express endogenous TCRs. In others T cells are expanded from the peripheral blood lymphocyte pool and redirected to recognize tumor antigens by virtue of exogenous TCR or chimeric antigen receptor (CAR) genes. Although reports on enduring clinical responses are encouraging, a significant portion of patients who do not respond, or respond only partially and transiently, underscore the critical challenge of improving T cell function and survival at the tumor site.

In attempt to improve the clinical efficacy of adoptive cell therapy we created three classes of genetic adjuvants designed to operate autonomously in gene-modified T cells. One class encodes constitutively-active (ca) toll-like receptors devoid of their ligand-binding domain, the other produces membrane-anchored immunostimulatory cytokines and the third encodes a novel homo-oligomerizing configuration of tumor necrosis factor receptors, inducing constitutive ligand-free activation. For gene delivery into human TILs or peripheral blood T cells we have been using electroporation of in-vitro-transcribed mRNA.

Here we present data obtained in preliminary ex-vivo experiments designed to assess the function of caTLR4, membrane IL-2, IL-12 (single chain) and IL-15 and trimeric caCD40 and their level of cooperation. The mere expression of caTLR4 mRNA in polyclonal human CD8 and CD4 T cells induced the production of IFN-γ, triggered the surface expression of CD25, CD69 and 4-1BB and upregulated a panel of cytokines and chemokines. In all samples of anti-melanoma TILs tested, caTLR4 induced a burst of IFN-γ secretion, which usually ceased within 24 hours post-transfection. Furthermore, caTLR4 enhanced the cytolytic activity of TILs and augmented the secretion of IFN-γ, TNF-α and GM-CSF in the presence of autologous, but not mismatched, melanoma for at least 4 days post-transfection. The membrane cytokines were found to act mainly in-cis and each could support the proliferation of human CD8 and CD4 T cells for at least 6 days post-transfection, at a magnitude comparable to a saturating dose of soluble IL-2. Following mRNA electroporation of anti-melanoma TILs, membrane cytokines cooperated with caTLR4 in inducing IFN-γ secretion and upregulating the activation and costimulatory molecules CD25, CD69, 4-1BB and OX40. Different combinations of caTLR4, membrane cytokines and caCD40 mRNA induced spontaneous cytokine secretion in mRNA-transfected TILs, typically acting in a synergistic manner. Even when the spontaneous, initial effect waned, a considerably higher fraction of mRNA-transfected, compared to control-transfected TILs could still respond robustly to autologous, but not allogeneic, melanoma. In the presence of the three classes of adjuvants, transfected short-term cultured ‘young’ TILs revealed exceptional upregulation of 4-1BB, OX40, CD25 and CD28 and an increase in IFN-γ production and no, or only minimal change in the inhibitory receptors PD-1 and CTLA-4. Here, too, the different adjuvants displayed marked synergy, with caCD40 often exerting a prominent effect even when delivered as a single gene. Enhanced killing of autologous melanoma cells by electroporated young TILs was observed up to ten days post-electroporation.

Our findings suggest that this new panel of genetic adjuvants can substantially improve the functional properties of antitumor T cells for extended periods, offering a new tool in all approaches for cancer immunotherapy employing adoptive T cell transfer.

Citation Format: Gideon Gross, Aviad Pato, Hadas Weinstein-Marom, Noam Levin, Alon Margalit, Orit Itzhaki, Michal Besser, Tamar Peretz, Arthur Machlenkin, Michal Lotem. New genes for enhancing T cell function in adoptive cell therapy of cancer. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr A095.

Messenger RNA encoding constitutively active Toll-like receptor 4 enhances effector functions of human T cells

Adoptive T cell therapy of cancer employs a large number of ex-vivo-propagated T cells which recognize their targets either by virtue of their endogenous T cell receptor (TCR) or via genetic reprogramming. However, both cell-extrinsic and intrinsic mechanisms often diminish the in-vivo potency of these therapeutic T cells, limiting their clinical efficacy and broader use. Direct activation of human T cells by Toll-like receptor (TLR) ligands induces T cell survival and proliferation, boosts the production of proinflammatory cytokines and augments resistance to regulatory T cell (Treg) suppression. Removal of the TLR ligand-binding region results in constitutive signalling triggered by the remaining cytosolic Toll/interleukin-1 receptor (TIR) domain. The use of such TIR domains therefore offers an ideal means for equipping anti-tumour T cells with the arsenal of functional attributes required for improving current clinical protocols. Here we show that constitutively active (ca)TLR-4 can be expressed efficiently in human T cells using mRNA electroporation. The mere expression of caTLR-4 mRNA in polyclonal CD8 and CD4 T cells induced the production of interferon (IFN)-γ, triggered the surface expression of CD25, CD69 and 4-1BB and up-regulated a panel of cytokines and chemokines. In tumour-infiltrating lymphocytes prepared from melanoma patients, caTLR-4 induced robust IFN-γ secretion in all samples tested. Furthermore, caTLR-4 enhanced the anti-melanoma cytolytic activity of tumour-infiltrating lymphocytes and augmented the secretion of IFN-γ, tumour necrosis factor (TNF)-α and granulocyte-macrophage colony-stimulating factor (GM-CSF) for at least 4 days post-transfection. Our results demonstrate that caTLR-4 is capable of exerting multiple T cell-enhancing effects and can potentially be used as a genetic adjuvant in adoptive cell therapy.

Human T cell crosstalk is induced by tumor membrane transfer

Trogocytosis is a contact-dependent unidirectional transfer of membrane fragments between immune effector cells and their targets, initially detected in T cells following interaction with professional antigen presenting cells (APC). Previously, we have demonstrated that trogocytosis also takes place between melanoma-specific cytotoxic T lymphocytes (CTLs) and their cognate tumors. In the present study, we took this finding a step further, focusing on the ability of melanoma membrane-imprinted CD8+ T cells to act as APCs (CD8+ T-APCs). We demonstrate that, following trogocytosis, CD8+ T-APCs directly present a variety of melanoma derived peptides to fraternal T cells with the same TCR specificity or to T cells with different TCRs. The resulting T cell-T cell immune synapse leads to (1) Activation of effector CTLs, as determined by proliferation, cytokine secretion and degranulation; (2) Fratricide (killing) of CD8+ T-APCs by the activated CTLs. Thus, trogocytosis enables cross-reactivity among CD8+ T cells with interchanging roles of effectors and APCs. This dual function of tumor-reactive CTLs may hint at their ability to amplify or restrict reactivity against the tumor and participate in modulation of the anti-cancer immune response.

Unique ζ-chain motifs mediate a direct TCR-actin linkage critical for immunological synapse formation and T-cell activation

TCR-mediated activation induces receptor microclusters that evolve to a defined immune synapse (IS). Many studies showed that actin polymerization and remodeling, which create a scaffold critical to IS formation and stabilization, are TCR mediated. However, the mechanisms controlling simultaneous TCR and actin dynamic rearrangement in the IS are yet not fully understood. Herein, we identify two novel TCR ζ-chain motifs, mediating the TCR's direct interaction with actin and inducing actin bundling. While T cells expressing the ζ-chain mutated in these motifs lack cytoskeleton (actin) associated (cska)-TCRs, they express normal levels of non-cska and surface TCRs as cells expressing wild-type ζ-chain. However, such mutant cells are unable to display activation-dependent TCR clustering, IS formation, expression of CD25/CD69 activation markers, or produce/secrete cytokine, effects also seen in the corresponding APCs. We are the first to show a direct TCR-actin linkage, providing the missing gap linking between TCR-mediated Ag recognition, specific cytoskeleton orientation toward the T-cell-APC interacting pole and long-lived IS maintenance.

Imprinting of lymphocytes with melanoma antigens acquired by trogocytosis facilitates identification of tumor-reactive T cells

Trogocytosis is a contact-dependent intercellular transfer of membrane fragments and associated molecules from APCs to effector lymphocytes. We previously demonstrated that trogocytosis also occurs between tumor target and cognate melanoma Ag-specific cytotoxic T cells (CTL). In this study, we show that, following trogocytosis, immune effector cells acquire molecular components of the tumor, including surface Ags, which are detectable by specific mAbs. We demonstrate that CD8(+) and CD4(+) T cells from melanoma patients' PBMC and tumor-infiltrating lymphocytes (TIL) capture melanoma Ags, enabling identification of trogocytosing lymphocytes by staining with Ag-specific Abs. This finding circumvents the necessity of tumor prelabeling, which in the past was mandatory to detect membrane-capturing T cells. Through the detection of melanoma Ags on TIL, we sorted trogocytosing T cells and verified their preferential reactivity and cytotoxicity. Furthermore, tumor Ag-imprinted T cells were detected at low frequency in fresh TIL cultures shortly after extraction from the tumor. Thus, T cell imprinting by tumor Ags may allow the enrichment of melanoma Ag-specific T cells for research and potentially even for the adoptive immunotherapy of patients with cancer.

Efficacy of intravenous lacosamide as an add-on treatment in refractory status epilepticus: a multicentric prospective study

OBJECTIVE

Treatment of status epilepticus (SE) has not changed in the last few decades, benzodiazepines plus phenytoin or valproate being the most common treatment. Once this first and second line treatment has failed SE is considered refractory (RSE). This study aimed to assess the efficacy and tolerability of intravenous (iv) lacosamide (LCM) in RSE.

METHOD

Patients with RSE who were treated with ivLCM in six Spanish centers were prospectively included. Efficacy was defined as cessation of seizures after starting ivLCM, with no need for any further antiepileptic drug. All patients had been unsuccessfully treated following the standard protocol (benzodiazepines plus phenytoin or valproate) before ivLCM was added.

RESULTS

Thirty-four patients were included, 52.9% men, with mean age of 60.15 years. In 58.9% of patients the etiology was symptomatic, and the most common type of SE was focal convulsive (82.4%). Mean initial bolus dose of LCM was 323.53mg. ivLCM was effective in more than half of patients (64.7%), with termination of SE before 12h in 50% of them. ivLCM was used as a fourth or later option in 76.5% of patients. No serious adverse events attributable to LCM were reported.

CONCLUSIONS

LCM might be a fast, effective and safe add-on treatment in RSE.