CD155/PVR determines acute myeloid leukemia targeting by Delta One T cells.

ABSTRACT: Relapsed or refractory acute myeloid leukemia (AML) remains a major therapeutic challenge. We have recently developed a Vδ1+ γδ T cell-based product for adoptive immunotherapy, named Delta One T (DOT) cells, and demonstrated their cytolytic capacity to eliminate AML cell lines and primary blasts in vitro and in vivo. However, the molecular mechanisms responsible for the broad DOT-cell recognition of AML cells remain poorly understood. Here, we dissected the role of natural killer (NK) cell receptor ligands in AML cell recognition by DOT cells. Screening of multiple AML cell lines highlighted a strong upregulation of the DNAM-1 ligands, CD155/pulmonary vascular resistance (PVR), CD112/nectin-2, as well as the NKp30 ligand, B7-H6, in contrast with NKG2D ligands. CRISPR-mediated ablation revealed key nonredundant and synergistic contributions of PVR and B7-H6 but not nectin-2 to DOT-cell targeting of AML cells. We further demonstrate that PVR and B7-H6 are critical for the formation of robust immunological synapses between AML and DOT cells. Importantly, PVR but not B7-H6 expression in primary AML samples predicted their elimination by DOT cells. These data provide new mechanistic insight into tumor targeting by DOT cells and suggest that assessing PVR expression levels may be highly relevant to DOT cell-based clinical trials.

Management of Lymph Node-positive Penile Cancer: A Systematic Review.

CONTEXT: Lymph node (LN) involvement in penile cancer is associated with poor survival. Early diagnosis and management significantly impact survival, with multimodal treatment approaches often considered in advanced disease. OBJECTIVE: To assess the clinical effectiveness of treatment options available for the management of inguinal and pelvic lymphadenopathy in men with penile cancer. EVIDENCE ACQUISITION: EMBASE, MEDLINE, the Cochrane Database of Systematic Reviews, and other databases were searched from 1990 to July 2022. Randomised controlled trials (RCTs), nonrandomised comparative studies (NRCSs), and case series (CSs) were included. EVIDENCE SYNTHESIS: We identified 107 studies, involving 9582 patients from two RCTs, 28 NRCSs, and 77 CSs. The quality of evidence is considered poor. Surgery is the mainstay of LN disease management, with early inguinal LN dissection (ILND) associated with better outcomes. Videoendoscopic ILND may offer comparable survival outcomes to open ILND with lower wound-related morbidity. Ipsilateral pelvic LN dissection (PLND) in N2-3 cases improves overall survival in comparison to no pelvic surgery. Neoadjuvant chemotherapy in N2-3 disease showed a pathological complete response rate of 13% and an objective response rate of 51%. Adjuvant radiotherapy may benefit pN2-3 but not pN1 disease. Adjuvant chemoradiotherapy may provide a small survival benefit in N3 disease. Adjuvant radiotherapy and chemotherapy improve outcomes after PLND for pelvic LN metastases. CONCLUSIONS: Early LND improves survival in nodal disease in penile cancer. Multimodal treatments may provide additional benefit in pN2-3 cases; however, data are limited. Therefore, individualised management of patients with nodal disease should be discussed in a multidisciplinary team setting. PATIENT SUMMARY: Spread of penile cancer to the lymph nodes is best managed with surgery, which improves survival and has curative potential. Supplementary treatment, including the use of chemotherapy and/or radiotherapy, may further improve survival in advanced disease. Patients with penile cancer with lymph node involvement should be treated by a multidisciplinary team.

Systematic Review and Meta-analysis of Minimally Invasive Procedures for Surgical Inguinal Nodal Staging in Penile Carcinoma.

CONTEXT: There are several procedures for surgical nodal staging in clinically node-negative (cN0) penile carcinoma. OBJECTIVE: To evaluate the diagnostic accuracy, perioperative outcomes, and complications of minimally invasive surgical procedures for nodal staging in penile carcinoma. EVIDENCE ACQUISITION: A systematic review of the Medline, Embase, and Cochrane controlled trials databases and ClinicalTrials.gov was conducted. Published and ongoing studies reporting on the management of cN0 penile cancer were included without any design restriction. Outcomes included the false negative (FN) rate, the number of nodes removed, surgical time, and postoperative complications. EVIDENCE SYNTHESIS: Forty-one studies were eligible for inclusion. Four studies comparing robot-assisted (RA-VEIL) and video-endoscopic inguinal lymphadenectomy (VEIL) to open inguinal lymph node dissection (ILND) were suitable for meta-analysis. A descriptive synthesis was performed for single-arm studies on modified open ILND, dynamic sentinel node biopsy (DSNB) with and without preoperative inguinal ultrasound (US), and fine-needle aspiration cytology (FNAC). DSNB with US + FNAC had lower FN rates (3.5-22% vs 0-42.9%) and complication rates (Clavien Dindo grade I-II: 1.1-20% vs 2.9-11.9%; grade III-V: 0-6.8% vs 0-9.4%) in comparison to DSNB alone. Favourable results were observed for VEIL/RA-VEIL over open ILND in terms of major complications (2-10.6% vs 6.9-40.6%; odds ratio [OR] 0.18; p < 0.01). Overall, VEIL/RA-VEIL had lower wound-related complication rates (OR 0.14; p < 0.01), including wound infections (OR 0.229; p < 0.01) and skin necrosis (OR 0.16; p < 0.01). The incidence of lymphatic complications varied between 20.6% and 49%. CONCLUSIONS: Of all the surgical staging options, DSNB with inguinal US + FNAC had the lowest complication rates and high diagnostic accuracy, especially when performed in high-volume centres. If DSNB is not available, favourable results were also found for VEIL/RA-VEIL over open ILND. Lymphatic-related complications were comparable across open and video-endoscopic ILND. PATIENT SUMMARY: We reviewed studies on different surgical approaches for assessing lymph node involvement in cases with penile cancer. The results show that a technique called dynamic sentinel node biopsy with ultrasound guidance and fine-needle sampling has high diagnostic accuracy and low complication rates. For lymph node dissection in penile cancer cases, a minimally invasive approach may offer favourable postoperative outcomes.

European Association of Urology-American Society of Clinical Oncology Collaborative Guideline on Penile Cancer: 2023 Update.

CONTEXT: Penile cancer is a rare disease but has a significant impact on quality of life. Its incidence is increasing, so it is important to include new and relevant evidence in clinical practice guidelines. OBJECTIVE: To provide a collaborative guideline that offers worldwide physician and patient guidance for the management of penile cancer. EVIDENCE ACQUISITION: Comprehensive literature searches were performed for each section topic. In addition, three systematic reviews were conducted. Levels of evidence were assessed, and a strength rating for each recommendation was assigned according to the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) methodology. EVIDENCE SYNTHESIS: Penile cancer is a rare disease but its global incidence is increasing. Human papillomavirus (HPV) is the main risk factor for penile cancer and pathology should include an assessment of HPV status. The main aim of primary tumour treatment is complete tumour eradication, which has to be balanced against optimal organ preservation without compromising oncological control. Early detection and treatment of lymph node (LN) metastasis is the main determinant of survival. Surgical LN staging with sentinel node biopsy is recommended for patients with a high-risk (≥pT1b) tumour with cN0 status. While (inguinal) LN dissection remains the standard for node-positive disease, multimodal treatment is needed in patients with advanced disease. Owing to a lack of controlled trials and large series, the levels of evidence and grades of recommendation are low in comparison to those for more common diseases. CONCLUSIONS: This collaborative penile cancer guideline provides updated information on the diagnosis and treatment of penile cancer for use in clinical practice. Organ-preserving surgery should be offered for treatment of the primary tumour when feasible. Adequate and timely LN management remains a challenge, especially in advanced disease stages. Referral to centres of expertise is recommended. PATIENT SUMMARY: Penile cancer is a rare disease that significantly impacts quality of life. While the disease can be cured in most cases without lymph node involvement, management of advanced disease remains challenging. Many unmet needs and unanswered questions remain, underlining the importance of research collaborations and centralisation of penile cancer services.

Efficient preclinical treatment of cortical T cell acute lymphoblastic leukemia with T lymphocytes secreting anti-CD1a T cell engagers.

BACKGROUND: The dismal clinical outcome of relapsed/refractory (R/R) T cell acute lymphoblastic leukemia (T-ALL) highlights the need for innovative targeted therapies. Although chimeric antigen receptor (CAR)-engineered T cells have revolutionized the treatment of B cell malignancies, their clinical implementation in T-ALL is in its infancy. CD1a represents a safe target for cortical T-ALL (coT-ALL) patients, and fratricide-resistant CD1a-directed CAR T cells have been preclinically validated as an immunotherapeutic strategy for R/R coT-ALL. Nonetheless, T-ALL relapses are commonly very aggressive and hyperleukocytic, posing a challenge to recover sufficient non-leukemic effector T cells from leukapheresis in R/R T-ALL patients. METHODS: We carried out a comprehensive study using robust in vitro and in vivo assays comparing the efficacy of engineered T cells either expressing a second-generation CD1a-CAR or secreting CD1a x CD3 T cell-engaging Antibodies (CD1a-STAb). RESULTS: We show that CD1a-T cell engagers bind to cell surface expressed CD1a and CD3 and induce specific T cell activation. Recruitment of bystander T cells endows CD1a-STAbs with an enhanced in vitro cytotoxicity than CD1a-CAR T cells at lower effector:target ratios. CD1a-STAb T cells are as effective as CD1a-CAR T cells in cutting-edge in vivo T-ALL patient-derived xenograft models. CONCLUSIONS: Our data suggest that CD1a-STAb T cells could be an alternative to CD1a-CAR T cells in coT-ALL patients with aggressive and hyperleukocytic relapses with limited numbers of non-leukemic effector T cells.

Utilización de antidepresivos y prescripción fuera de ficha técnica en atención primaria en España (2013-2018) / Antidepressant use and off-label prescribing in primary care in Spain (2013–2018)

Introducción: Estudios recientes muestran un aumento del uso de antidepresivos en menores de 18 años, aunque pocos de ellos cuentan con indicación en este grupo de edad. El objetivo de este estudio es calcular la prevalencia anual del uso de antidepresivos en niños y adolescentes y revisar la adecuación de la prescripción a las indicaciones actuales. Métodos: Estudio de prevalencia de la utilización de antidepresivos en menores de 18 años a partir de los registros de la Base de datos para la Investigación Farmacoepidemiológica en Atención Primaria (BIFAP) durante el periodo 2013-2018, considerando al menos una prescripción por año para un mismo paciente. Resultados: La prevalencia de prescripción de antidepresivos entre los pacientes de la cohorte BIFAP ha aumentado de 2013 (7,97 prescripciones/1.000 pacientes) a 2018 (8,87 prescripciones/1.000 pacientes) en la mayoría de los grupos y en ambos sexos. El sexo femenino suma la mayoría de las prescripciones, superando al masculino en hasta 2,5 puntos en las tasas generales. En menores de 13 años la tendencia se invierte y los antidepresivos predominan en los chicos. La prevalencia de las prescripciones aumenta con la edad de los pacientes, igual que la proporción de tratamientos fuera de ficha técnica. El empleo de fármacos sin indicación disminuye con el transcurso del tiempo. Conclusiones: Observamos un aumento gradual en la prevalencia de prescripción de antidepresivos en menores de 18 años, preponderante en el sexo femenino. La elevada proporción de uso de estos fármacos sin indicación autorizada exige profundizar en el balance beneficio-riesgo y en alternativas de tratamiento más seguras. (AU)

Introduction: Recent studies show an increase in the use of antidepressants in minors (younger than 18 years), although few antidepressants are indicated for this age group. The aim of our study was to calculate the annual prevalence of antidepressant use in children and adolescents and to review the adherence of prescription to current indications. Methods: Study of the prevalence of antidepressant use in minors based on the records of the Electronic Database for Pharmacoepidemiologic Studies in Primary Care (BIFAP) of Spain for the 2013–2018 period, considering at least one prescription per year for each patient. Results: The prevalence of antidepressant prescription in patients from the BIFAP cohort increased between 2013 (7.97 prescriptions per 1000 patients) and 2018 (8.87 prescriptions per 1000 patients), in most groups and in both sexes. In this period, female patients received the most prescriptions, surpassing prescriptions in male patients by up to 2.5 points in the overall rates. In patients younger than 13 years, this trend was inverted and antidepressant use was higher in male patients. The prevalence of prescription rose with increasing patient age, as did the proportion of off-label prescriptions. The use of off-label medication decreased over time. Conclusions: There was a gradual increase in the prevalence of antidepressant prescription in minors younger than 18 years, with a predominance of the female sex. The high proportion of unapproved medication use in this age group calls for more thorough investigation of the risk–benefit balance of these treatments and of safer treatment alternatives. (AU)

Generation and proof-of-concept for allogeneic CD123 CAR-Delta One T (DOT) cells in acute myeloid leukemia.

BACKGROUND: Chimeric antigen receptor (CAR)-T cells have emerged as a breakthrough treatment for relapse/refractory hematological tumors, showing impressive complete remission rates. However, around 50% of the patients relapse before 1-year post-treatment. T-cell 'fitness' is critical to prolong CAR-T persistence and activity. Allogeneic T cells from healthy donors are less dysfunctional or exhausted than autologous patient-derived T cells; in this context, Delta One T cells (DOTs), a recently described cellular product based on MHC/HLA-independent Vδ1+γδ T cells, represent a promising allogeneic platform. METHODS: Here we generated and preclinically validated, for the first time, 4-1BB-based CAR-DOTs directed against the interleukin-3α chain receptor (CD123), a target antigen widely expressed on acute myeloid leukemia (AML) blasts. RESULTS: CD123CAR-DOTs showed vigorous, superior to control DOTs, cytotoxicity against AML cell lines and primary samples both in vitro and in vivo, even on tumor rechallenge. CONCLUSIONS: Our results provide the proof-of-concept for a DOT-based next-generation allogeneic CAR-T therapy for AML.

A novel and efficient tandem CD19- and CD22-directed CAR for B cell ALL.

CD19-directed chimeric antigen receptor (CAR) T cells have yielded impressive response rates in refractory/relapse B cell acute lymphoblastic leukemia (B-ALL); however, most patients ultimately relapse due to poor CAR T cell persistence or resistance of either CD19+ or CD19- B-ALL clones. CD22 is a pan-B marker whose expression is maintained in both CD19+ and CD19- relapses. CD22-CAR T cells have been clinically used in B-ALL patients, although relapse also occurs. T cells engineered with a tandem CAR (Tan-CAR) containing in a single construct both CD19 and CD22 scFvs may be advantageous in achieving higher remission rates and/or preventing antigen loss. We have generated and functionally validated using cutting-edge assays a 4-1BB-based CD22/CD19 Tan-CAR using in-house-developed novel CD19 and CD22 scFvs. Tan-CAR-expressing T cells showed similar in vitro expansion to CD19-CAR T cells with no increase in tonic signaling. CRISPR-Cas9-edited B-ALL cells confirmed the bispecificity of the Tan-CAR. Tan-CAR was as efficient as CD19-CAR in vitro and in vivo using B-ALL cell lines, patient samples, and patient-derived xenografts (PDXs). Strikingly, the robust antileukemic activity of the Tan-CAR was slightly more effective in controlling the disease in long-term follow-up PDX models. This Tan-CAR construct warrants a clinical appraisal to test whether simultaneous targeting of CD19 and CD22 enhances leukemia eradication and reduces/delays relapse rates and antigen loss.

Amiloidosis asociada a hemodiálisis: revisión de sus aspectos etiopatogénicos / Hemodialysis-Associated Amyloidosis: Review of its ethiopathogenic aspects

Resumen La amiloidosis constituye una complicación importante en los pacientes con enfermedad renal crónica que son sometidos a hemodiálisis durante extensos períodos de tiempo. Al igual que en otras amiloidosis sistémicas, en la amiloidosis asociada a hemodiálisis intervienen diferentes sustancias, algunas de ellas de carácter fibrilar, como la βeta-2-microglobulina, la cual representa una de las proteínas de mayor relevancia dada su implicación etiopatogénica. A pesar de que las técnicas de hemodiálisis han sido mejoradas con el paso de los años, dicha entidad continúa siendo una complicación relativamente frecuente; tal es que se puede presentar hasta en el 80 % de los pacientes con hemodiálisis prolongadas. Por lo tanto, se hizo imprescindible realizar una revisión narrativa partiendo de la literatura científica disponible en las diferentes bases de datos, con el objetivo de contribuir a mejorar y actualizar el conocimiento del médico en dicho tópico; al abarcar desde los aspectos generales y su fisiopatología, hasta su presentación clínica, diagnóstico y tratamiento.

Abstract Amyloidosis is a major complication in patients with chronic kidney disease who undergo hemodialysis for long periods of time. As in other systemic amyloidosis, different substances are involved in amyloidosis associated with different substances, some of them fibrillar in nature, such as βeta-2-microglobulin, which represents one of the most relevant proteins given its etiopathogenic involvement. Despite the fact that hemodialysis techniques have been improved over the years, this entity continues to be a frequent complication; such is that it can occur in up to 80% of patients with prolonged hemodialysis. Therefore, it was essential to carry out a narrative review based on the scientific literature available in the different databases with the aim of contributing to improve and update the doctor's knowledge on this topic; ranging from the general aspects and its pathophysiology, to its clinical presentation, diagnosis, and treatment.

Edulcorantes artificiales y su papel en la enfermedad renal crónica: una revisión

Los edulcorantes no calóricos surgieron como una opción segura y saludable en el marco de la alimentación y, por lo tanto, han sido de gran interés en la cultura dietética adquirida en la actualidad; es importante mencionar que en esta cultura adquirida el consumo de comida rápida y con altos niveles de azúcar ha tomado especial fuerza, lo que repercute negativamente en la incidencia de enfermedades metabólicas. En este orden de ideas, los edulcorantes no calóricos se convierten en una mejor opción para la salud en la que no es necesario hacer un cambio drástico en el estilo de vida. No obstante, los beneficios de los edulcorantes artificiales no calóricos no han sido estudiados a profundidad y no se ha evidenciado que una dieta a base de estos sustitutivos provoque un cambio significativo en el desarrollo de enfermedades metabólicas asociadas al consumo de azúcar, por el contrario, se han relacionado con enfermedades como obesidad, diabetes mellitus tipo 2 y síndrome metabólico. Asimismo, estos pueden provocar una serie de cambios metabólicos a través de distintos mecanismos que terminan en proteinuria progresiva y descenso de la tasa de filtrado glomerular. A partir de lo anterior, se hace necesario un análisis del riesgo que se corre al elegir esta opción alimenticia, para así no dejarse llevar por los procesos mediáticos que los promocionan, sino más bien, regirse por los hallazgos científicos.

Non-caloric artificial sweeteners have emerged to offer a safe and healthy option in the framework of food. They have received special attention in recent decades, precisely because of the current food culture, where fast food and high sugar consumption have taken on special strength, which has a negative impact on the incidence of metabolic diseases. In that order of ideas, non-caloric artificial sweeteners propose better health without the need for a drastic change in lifestyle. However, its benefits have not been studied in depth, in addition to the fact that there has been no significant change in the development of metabolic diseases associated with sugar consumption, on the contrary, they have been related to diseases such as obesity, type 2 diabetes mellitus and metabolic syndrome. Likewise, they cause a series of metabolic changes by different mechanisms that end in progressive proteinuria and a decrease in the glomerular filtration rate. In order with the above, an analysis of the risk to which one is subjected when choosing this food option is necessary, and not be deafened, much less dazzled by the media processes, if not rather, be governed by scientific findings.

Nefrolitiasis en la paciente gestante: revisión de la literatura / Renal lithiasis in pregnant patient: a literary review

Resumen La litiasis renal en la paciente gestante es una condición relativamente infrecuente; sin embargo, es la causa más común de dolor no obstétrico durante el embarazo. En el periodo de gestación se producen diversos cambios anatomofisiológicos en el tracto urinario, como la dilatación de los cálices renales, la pelvis renal y los uréteres por causa del efecto que ejerce la progesterona sobre el músculo liso uretral, y la compresión de los uréteres por el útero grávido. Estas modificaciones conducen a un aumento del flujo plasmático renal y de la tasa de filtrado glomerular, ocasionando hiperuricosuria e hipercalciuria. Del mismo modo, durante el embarazo también se produce un aumento de la secreción de inhibidores de cálculos, por lo cual la prevalencia de la formación de cálculos durante el embarazo es similar a la de las mujeres no embarazadas. El bajo índice de sospecha por parte del médico tratante puede entorpecer el diagnóstico y el tratamiento de esta patología, que también son limitados en la gestación debido a los potenciales riesgos teratogénicos. Se realiza una revisión narrativa de la literatura partiendo de la evidencia científica disponible en las diferentes bases de datos y de esta manera se pretende instruir al médico en los aspectos clave de dicho tema.

Abstract Renal lithiasis in pregnant women is a relatively rare condition. However, it is the most common cause of non-obstetric pain during pregnancy. During the gestation period, various anatomical-physiological changes occur in the urinary tract. These changes include dilation of the renal calyces, renal pelvis, and ureters due to the effect of progesterone on urethral smooth muscle and compression of the ureters by the gravid uterus. These modifications lead to an increase in renal plasma flow and glomerular filtration rate, thus causing hyperuricosuria and hypercalciuria. Similarly, during pregnancy there is also an increase in the secretion of stone inhibitors, therefore, the prevalence of stone formation during pregnancy is similar to non-pregnant women. The low index of suspicion on the part of the treating physician can hinder the diagnosis and treatment of this pathology, which is also limited in pregnancy due to teratogenic risks. A narrative review of the literature is carried out based on the scientific evidence available in the different databases and in this way it is intended to instruct the doctor in the key aspects of said topic.

Enforced sialyl-Lewis-X (sLeX) display in E-selectin ligands by exofucosylation is dispensable for CD19-CAR T-cell activity and bone marrow homing.

CD19-directed chimeric antigen receptors (CAR) T cells induce impressive rates of complete response in advanced B-cell malignancies, specially in B-cell acute lymphoblastic leukemia (B-ALL). However, CAR T-cell-treated patients eventually progress due to poor CAR T-cell persistence and/or disease relapse. The bone marrow (BM) is the primary location for acute leukemia. The rapid/efficient colonization of the BM by systemically infused CD19-CAR T cells might enhance CAR T-cell activity and persistence, thus, offering clinical benefits. Circulating cells traffic to BM upon binding of tetrasaccharide sialyl-Lewis X (sLeX)-decorated E-selectin ligands (sialofucosylated) to the E-selectin receptor expressed in the vascular endothelium. sLeX-installation in E-selectin ligands is achieved through an ex vivo fucosylation reaction. Here, we sought to characterize the basal and cell-autonomous display of sLeX in CAR T-cells activated using different cytokines, and to assess whether exofucosylation of E-selectin ligands improves CD19-CAR T-cell activity and BM homing. We report that cell-autonomous sialofucosylation (sLeX display) steadily increases in culture- and in vivo-expanded CAR T cells, and that, the cytokines used during T-cell activation influence both the degree of such endogenous sialofucosylation and the CD19-CAR T-cell efficacy and persistence in vivo. However, glycoengineered enforced sialofucosylation of E-selectin ligands was dispensable for CD19-CAR T-cell activity and BM homing in multiple xenograft models regardless the cytokines employed for T-cell expansion, thus, representing a dispensable strategy for CD19-CAR T-cell therapy.

Expanded and activated allogeneic NK cells are cytotoxic against B-chronic lymphocytic leukemia (B-CLL) cells with sporadic cases of resistance.

Adoptive transfer of allogeneic natural killer (NK) cells is becoming a credible immunotherapy for hematological malignancies. In the present work, using an optimized expansion/activation protocol of human NK cells, we generate expanded NK cells (eNK) with increased expression of CD56 and NKp44, while maintaining that of CD16. These eNK cells exerted significant cytotoxicity against cells from 34 B-CLL patients, with only 1 sample exhibiting resistance. This sporadic resistance did not correlate with match between KIR ligands expressed by the eNK cells and the leukemic cells, while cells with match resulted sensitive to eNK cells. This suggests that KIR mismatch is not relevant when expanded NK cells are used as effectors. In addition, we found two examples of de novo resistance to eNK cell cytotoxicity during the clinical course of the disease. Resistance correlated with KIR-ligand match in one of the patients, but not in the other, and was associated with a significant increase in PD-L1 expression in the cells from both patients. Treatment of one of these patients with idelalisib correlated with the loss of PD-L1 expression and with re-sensitization to eNK cytotoxicity. We confirmed the idelalisib-induced decrease in PD-L1 expression in the B-CLL cell line Mec1 and in cultured cells from B-CLL patients. As a main conclusion, our results reinforce the feasibility of using expanded and activated allogeneic NK cells in the treatment of B-CLL.

Efficient elimination of primary B-ALL cells in vitro and in vivo using a novel 4-1BB-based CAR targeting a membrane-distal CD22 epitope.

BACKGROUND: There are few therapeutic options available for patients with B-cell acute lymphoblastic leukemia (B-ALL) relapsing as CD19- either after chemotherapy or CD19-targeted immunotherapies. CD22-chimeric antigen receptor (CAR) T cells represent an attractive addition to CD19-CAR T cell therapy because they will target both CD22+CD19- B-ALL relapses and CD19- preleukemic cells. However, the immune escape mechanisms from CD22-CAR T cells, and the potential contribution of the epitope binding of the anti-CD22 single-chain variable fragment (scFv) remain understudied. METHODS: Here, we have developed and comprehensively characterized a novel CD22-CAR (clone hCD22.7) targeting a membrane-distal CD22 epitope and tested its cytotoxic effects against B-ALL cells both in in vitro and in vivo assays. RESULTS: Conformational epitope mapping, cross-blocking, and molecular docking assays revealed that the hCD22.7 scFv is a high-affinity binding antibody which specifically binds to the ESTKDGKVP sequence, located in the Ig-like V-type domain, the most distal domain of CD22. We observed efficient killing of B-ALL cells in vitro, although the kinetics were dependent on the level of CD22 expression. Importantly, we show an efficient in vivo control of patients with B-ALL derived xenografts with diverse aggressiveness, coupled to long-term hCD22.7-CAR T cell persistence. Remaining leukemic cells at sacrifice maintained full expression of CD22, ruling out CAR pressure-mediated antigen loss. Finally, the immunogenicity capacity of this hCD22.7-scFv was very similar to that of other CD22 scFv previously used in adoptive T cell therapy. CONCLUSIONS: We report a novel, high-affinity hCD22.7 scFv which targets a membrane-distal epitope of CD22. 4-1BB-based hCD22.7-CAR T cells efficiently eliminate clinically relevant B- CD22high and CD22low ALL primary samples in vitro and in vivo. Our study supports the clinical translation of this hCD22.7-CAR as either single or tandem CD22-CD19-CAR for both naive and anti-CD19-resistant patients with B-ALL.

41BB-based and CD28-based CD123-redirected T-cells ablate human normal hematopoiesis in vivo.

BACKGROUND: Acute myeloid leukemia (AML) is a hematopoietic malignancy which is biologically, phenotypically and genetically very heterogeneous. Outcome of patients with AML remains dismal, highlighting the need for improved, less toxic therapies. Chimeric antigen receptor T-cell (CART) immunotherapies for patients with refractory or relapse (R/R) AML are challenging because of the absence of a universal pan-AML target antigen and the shared expression of target antigens with normal hematopoietic stem/progenitor cells (HSPCs), which may lead to life-threating on-target/off-tumor cytotoxicity. CD33-redirected and CD123-redirected CARTs for AML are in advanced preclinical and clinical development, and they exhibit robust antileukemic activity. However, preclinical and clinical controversy exists on whether such CARTs are myeloablative. METHODS: We set out to comparatively characterize in vitro and in vivo the efficacy and safety of 41BB-based and CD28-based CARCD123. We analyzed 97 diagnostic and relapse AML primary samples to investigate whether CD123 is a suitable immunotherapeutic target, and we used several xenograft models and in vitro assays to assess the myeloablative potential of our second-generation CD123 CARTs. RESULTS: Here, we show that CD123 represents a bona fide target for AML and show that both 41BB-based and CD28-based CD123 CARTs are very efficient in eliminating both AML cell lines and primary cells in vitro and in vivo. However, both 41BB-based and CD28-based CD123 CARTs ablate normal human hematopoiesis and prevent the establishment of de novo hematopoietic reconstitution by targeting both immature and myeloid HSPCs. CONCLUSIONS: This study calls for caution when clinically implementing CD123 CARTs, encouraging its preferential use as a bridge to allo-HSCT in patients with R/R AML.

Fratricide-resistant CD1a-specific CAR T cells for the treatment of cortical T-cell acute lymphoblastic leukemia.

Relapsed/refractory T-cell acute lymphoblastic leukemia (T-ALL) has a dismal outcome, and no effective targeted immunotherapies for T-ALL exist. The extension of chimeric antigen receptor (CAR) T cells (CARTs) to T-ALL remains challenging because the shared expression of target antigens between CARTs and T-ALL blasts leads to CART fratricide. CD1a is exclusively expressed in cortical T-ALL (coT-ALL), a major subset of T-ALL, and retained at relapse. This article reports that the expression of CD1a is mainly restricted to developing cortical thymocytes, and neither CD34+ progenitors nor T cells express CD1a during ontogeny, confining the risk of on-target/off-tumor toxicity. We thus developed and preclinically validated a CD1a-specific CAR with robust and specific cytotoxicity in vitro and antileukemic activity in vivo in xenograft models of coT-ALL, using both cell lines and coT-ALL patient-derived primary blasts. CD1a-CARTs are fratricide resistant, persist long term in vivo (retaining antileukemic activity in re-challenge experiments), and respond to viral antigens. Our data support the therapeutic and safe use of fratricide-resistant CD1a-CARTs for relapsed/refractory coT-ALL.

NG2 antigen is a therapeutic target for MLL-rearranged B-cell acute lymphoblastic leukemia.

B cell acute lymphoblastic leukemia (B-ALL) is the most common childhood cancer, with cure rates of ∼80%. MLL-rearranged (MLLr) B-ALL (MLLr-B-ALL) has, however, an unfavorable prognosis with common therapy refractoriness and early relapse, and therefore new therapeutic targets are needed for relapsed/refractory MLLr-B-ALL. MLLr leukemias are characterized by the specific expression of chondroitin sulfate proteoglycan-4, also known as neuron-glial antigen-2 (NG2). NG2 was recently shown involved in leukemia invasiveness and central nervous system infiltration in MLLr-B-ALL, and correlated with lower event-free survival (EFS). We here hypothesized that blocking NG2 may synergize with established induction therapy for B-ALL based on vincristine, glucocorticoids, and L-asparaginase (VxL). Using robust patient-derived xenograft (PDX) models, we found that NG2 is crucial for MLLr-B-ALL engraftment upon intravenous (i.v.) transplantation. In vivo blockade of NG2 using either chondroitinase-ABC or an anti-NG2-specific monoclonal antibody (MoAb) resulted in a significant mobilization of MLLr-B-ALL blasts from bone marrow (BM) to peripheral blood (PB) as demonstrated by cytometric and 3D confocal imaging analysis. When combined with either NG2 antagonist, VxL treatment achieved higher rates of complete remission, and consequently higher EFS and delayed time to relapse. Mechanistically, anti-NG2 MoAb induces neither antibody-dependent cell-mediated not complement-dependent cytotoxicity. NG2 blockade rather overrides BM stroma-mediated chemoprotection through PB mobilization of MLLr-B-ALL blasts, thus becoming more accessible to chemotherapy. We provide a proof of concept for NG2 as a therapeutic target for MLLr-B-ALL.

Expansion of allogeneic NK cells with efficient antibody-dependent cell cytotoxicity against multiple tumors.

Monoclonal antibodies (mAbs) have significantly improved the treatment of certain cancers. However, in general mAbs alone have limited therapeutic activity. One of their main mechanisms of action is to induce antibody-dependent cell-mediated cytotoxicity (ADCC), which is mediated by natural killer (NK) cells. Unfortunately, most cancer patients have severe immune dysfunctions affecting NK activity. This can be circumvented by the injection of allogeneic, expanded NK cells, which is safe. Nevertheless, despite their strong cytolytic potential against different tumors, clinical results have been poor. Methods: We combined allogeneic NK cells and mAbs to improve cancer treatment. We generated expanded NK cells (e-NK) with strong in vitro and in vivo ADCC responses against different tumors and using different therapeutic mAbs, namely rituximab, obinutuzumab, daratumumab, cetuximab and trastuzumab. Results: Remarkably, e-NK cells can be stored frozen and, after thawing, armed with mAbs. They mediate ADCC through degranulation-dependent and -independent mechanisms. Furthermore, they overcome certain anti-apoptotic mechanisms found in leukemic cells. Conclusion: We have established a new protocol for activation/expansion of NK cells with high ADCC activity. The use of mAbs in combination with e-NK cells could potentially improve cancer treatment.