Publications by authors named "Carlos A Ramos"

58 Publications

T-Cell Therapy for Lymphoma Using Nonengineered Multiantigen-Targeted T Cells Is Safe and Produces Durable Clinical Effects.

J Clin Oncol 2021 Jan 28:JCO2002224. Epub 2021 Jan 28.

Center for Cell and Gene Therapy, Baylor College of Medicine, Texas Children's Hospital and Houston Methodist Hospital, Houston, TX.

Purpose: Patients with relapsed lymphomas often fail salvage therapies including high-dose chemotherapy and mono-antigen-specific T-cell therapies, highlighting the need for nontoxic, novel treatments. To that end, we clinically tested an autologous T-cell product that targets multiple tumor-associated antigens (TAAs) expressed by lymphomas with the intent of treating disease and preventing immune escape.

Patients And Methods: We expanded polyclonal T cells reactive to five TAAs: PRAME, SSX2, MAGEA4, SURVIVIN, and NY-ESO-1. Products were administered to 32 patients with Hodgkin lymphomas (n = 14) or non-Hodgkin lymphomas (n = 18) in a two-part phase I clinical trial, where the objective of the first phase was to establish the safety of targeting all five TAAs (fixed dose, 0.5 × 10 cells/m) simultaneously and the second stage was to establish the maximum tolerated dose. Patients had received a median of three prior lines of therapy and either were at high risk for relapse (adjuvant arm, n = 17) or had chemorefractory disease (n = 15) at enrollment.

Results: Infusions were safe with no dose-limiting toxicities observed in either the antigen- or dose-escalation phases. Although the maximum tolerated dose was not reached, the maximum tested dose at which efficacy was observed (two infusions, 2 × 10 cells/m) was determined as the recommended phase II dose. Of the patients with chemorefractory lymphomas, two (of seven) with Hodgkin lymphomas and four (of eight) with non-Hodgkin lymphomas achieved durable complete remissions (> 3 years).

Conclusion: T cells targeting five TAAs and administered at doses of up to two infusions of 2 × 10 cells/m are well-tolerated by patients with lymphoma both as adjuvant and to treat chemorefractory lymphoma. Preliminary indicators of antilymphoma activity were seen in the chemorefractory cohort across both antigen- and dose-escalation phases.
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http://dx.doi.org/10.1200/JCO.20.02224DOI Listing
January 2021

Efficacy of anti-CD147 chimeric antigen receptors targeting hepatocellular carcinoma.

Nat Commun 2020 09 23;11(1):4810. Epub 2020 Sep 23.

Department of Pathology, Immunology and Laboratory Medicine, Rutgers University-New Jersey Medical School, 185 South Orange Avenue, Newark, NJ, 07103, USA.

Chimeric antigen receptor (CAR) therapy is a promising immunotherapeutic strategy for treating multiple refractory blood cancers, but further advances are required for solid tumor CAR therapy. One challenge is identifying a safe and effective tumor antigen. Here, we devise a strategy for targeting hepatocellular carcinoma (HCC, one of the deadliest malignancies). We report that T and NK cells transduced with a CAR that recognizes the surface marker, CD147, also known as Basigin, can effectively kill various malignant HCC cell lines in vitro, and HCC tumors in xenograft and patient-derived xenograft mouse models. To minimize any on-target/off-tumor toxicity, we use logic-gated (log) GPC3-synNotch-inducible CD147-CAR to target HCC. LogCD147-CAR selectively kills dual antigen (GPC3CD147), but not single antigen (GPC3CD147) positive HCC cells and does not cause severe on-target/off-tumor toxicity in a human CD147 transgenic mouse model. In conclusion, these findings support the therapeutic potential of CD147-CAR-modified immune cells for HCC patients.
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http://dx.doi.org/10.1038/s41467-020-18444-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7511348PMC
September 2020

The safety and clinical effects of administering a multiantigen-targeted T cell therapy to patients with multiple myeloma.

Sci Transl Med 2020 07;12(554)

Center for Cell and Gene Therapy, Baylor College of Medicine, Texas Children's Hospital and Houston Methodist Hospital, Houston, TX 77030, USA.

Multiple myeloma (MM) is an almost always incurable malignancy of plasma cells. Despite the advent of new therapies, most patients eventually relapse or become treatment-refractory. Consequently, therapies with nonoverlapping mechanisms of action that are nontoxic and provide long-term benefit to patients with MM are greatly needed. To this end, we clinically tested an autologous multitumor-associated antigen (mTAA)-specific T cell product for the treatment of patients with high-risk, relapsed or refractory MM. In this study, we expanded polyclonal T cells from 23 patients with MM. T cells whose native T cell receptors were reactive toward five myeloma-expressed target TAAs (PRAME, SSX2, MAGEA4, Survivin, and NY-ESO-1) were enriched ex vivo. To date, we have administered escalating doses of these nonengineered mTAA-specific T cells (0.5 × 10 to 2 × 10 cells/m) to 21 patients with MM, 9 of whom were at high risk of relapse after a median of 3 lines of prior therapy and 12 with active, relapsed or refractory disease after a median of 3.5 prior lines. The cells were well tolerated, with only two transient, grade III infusion-related adverse events. Furthermore, patients with active relapsed or refractory myeloma enjoyed a longer than expected progression-free survival and responders included three patients who achieved objective responses concomitant with detection of functional TAA-reactive T cell clonotypes derived from the infused mTAA product.
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http://dx.doi.org/10.1126/scitranslmed.aaz3339DOI Listing
July 2020

Anti-CD30 CAR-T Cell Therapy in Relapsed and Refractory Hodgkin Lymphoma.

J Clin Oncol 2020 11 23;38(32):3794-3804. Epub 2020 Jul 23.

Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC.

Purpose: Chimeric antigen receptor (CAR) T-cell therapy of B-cell malignancies has proved to be effective. We show how the same approach of CAR T cells specific for CD30 (CD30.CAR-Ts) can be used to treat Hodgkin lymphoma (HL).

Methods: We conducted 2 parallel phase I/II studies (ClinicalTrials.gov identifiers: NCT02690545 and NCT02917083) at 2 independent centers involving patients with relapsed or refractory HL and administered CD30.CAR-Ts after lymphodepletion with either bendamustine alone, bendamustine and fludarabine, or cyclophosphamide and fludarabine. The primary end point was safety.

Results: Forty-one patients received CD30.CAR-Ts. Treated patients had a median of 7 prior lines of therapy (range, 2-23), including brentuximab vedotin, checkpoint inhibitors, and autologous or allogeneic stem cell transplantation. The most common toxicities were grade 3 or higher hematologic adverse events. Cytokine release syndrome was observed in 10 patients, all of which were grade 1. No neurologic toxicity was observed. The overall response rate in the 32 patients with active disease who received fludarabine-based lymphodepletion was 72%, including 19 patients (59%) with complete response. With a median follow-up of 533 days, the 1-year progression-free survival and overall survival for all evaluable patients were 36% (95% CI, 21% to 51%) and 94% (95% CI, 79% to 99%), respectively. CAR-T cell expansion in vivo was cell dose dependent.

Conclusion: Heavily pretreated patients with relapsed or refractory HL who received fludarabine-based lymphodepletion followed by CD30.CAR-Ts had a high rate of durable responses with an excellent safety profile, highlighting the feasibility of extending CAR-T cell therapies beyond canonical B-cell malignancies.
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http://dx.doi.org/10.1200/JCO.20.01342DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7655020PMC
November 2020

Outbreak investigation of septicemic salmonellosis in calves.

J Infect Dev Ctries 2020 01 31;14(1):104-108. Epub 2020 Jan 31.

Laboratório de Anatomia Patológica, Faculdade de Medicina Veterinária e Zootecnia (FAMEZ), Universidade Federal de Mato Grosso do Sul (UFMS), MS, Campo Grande, Brazil.

Introduction: An early and accurate diagnosis of septicemic salmonellosis is critical for implementing timely and proper treatment, prevention, and control measures.

Methodology: Here, we report a study on three outbreaks of septicemic salmonellosis in calves from Midwestern Brazil.

Results: the morbidity, mortality and lethality rates were of 10.55%, 2.79%, and 26.4%, respectively. Higher susceptibility was detected in Bos taurus than in Bos indicus cattle. Clinical manifestations consisted of apathy, hyperthermia, difficulty breathing and panting, and pallor of the mucous membranes. Chronic cases had necrosis of the tail tip and ears. Gross findings included enlarged liver, non-collapsed edematous lungs and diphtheritic enteritis. Significant histopathological changes included paratyphoid nodules in the liver and acute interstitial pneumonia. Salmonella enterica subsp. enterica serotype Dublin was detected by culture and by PCR from the blood of live calves, and from the spleen, liver, bile, mesenteric lymph node and lung samples of necropsied calves.

Conclusions: We suggest that in clinical cases of septicemic salmonellosis, blood samples are better than fecal samples for detection of the agent, being a sound test to identify animal carriers in the herd.
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http://dx.doi.org/10.3855/jidc.12087DOI Listing
January 2020

Cellular Immunotherapy in Lymphoma: Beyond CART Cells.

Curr Treat Options Oncol 2020 02 11;21(3):21. Epub 2020 Feb 11.

Hematology-Oncology Section, Department of Medicine, Baylor College of Medicine, 6565 Fannin A6-080, Houston, TX, 77019, USA.

Opinion Statement: Cellular immunotherapy has been rapidly evolving and increasingly utilized in the management of relapsed and refractory lymphoma. CD19-specific chimeric antigen receptor T cells (CARTs) have achieved impressive results in pivotal clinical trials. Although CART development continues, these products have fundamental limitations that may make them less desirable in particular settings. For example, CARTs can only target cell surface antigens and thus are incapable of targeting intracellular tumor-associated proteins. In contrast to CARTs, conventional T cell receptors (TCR) allow T cells to target any cellular antigen, including intracellular proteins, since they interact with peptides presented by MHC I and II molecules. T cells recognizing EBV antigens through native TCRs have been successfully employed for treatment and prophylaxis of EBV-associated lymphomas, including post-transplant lymphoproliferative disorder. Currently, transgenic TCR-transduced T cells targeting nonviral tumor antigens remain experimental but, if successful, could become an invaluable cellular therapy option. Because the manufacturing process of autologous T cell products, including CARTs and other tumor-specific T cells, takes several weeks, patients often need bridging therapy to maintain disease control, which may be challenging. Novel cellular platforms, such as genetically modified NK and NKT cells, may be amenable to allogeneic use and thus may allow production as a readily available, "off-the-shelf" product. As cellular therapies beyond CART continue to grow, available therapeutic options for relapsed and refractory lymphoma patients are expected to expand further.
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http://dx.doi.org/10.1007/s11864-020-0709-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7254551PMC
February 2020

Expanding CAR T cells in human platelet lysate renders T cells with in vivo longevity.

J Immunother Cancer 2019 11 28;7(1):330. Epub 2019 Nov 28.

Center for Cell and Gene Therapy, Baylor College of Medicine, 1102 Bates Avenue, Houston, TX, 77030, USA.

Background: Pre-clinical and clinical studies have shown that the infusion of CAR T cells with a naive-like (T) and central memory (T) phenotype is associated with prolonged in vivo T cell persistence and superior anti-tumor effects. To optimize the maintenance of such populations during the in vitro preparation process, we explored the impact of T cell exposure to both traditional [fetal bovine serum (FBS), human AB serum (ABS)] and non-traditional [human platelet lysate (HPL) - a xeno-free protein supplement primarily used for the production of clinical grade mesenchymal stromal / stem cells (MSCs)] serum supplements.

Methods: Second generation chimeric antigen receptor with CD28 and CD3ζ endodomain targeting prostate stem cell antigen (PSCA) (P28z) or CD19 (1928z) were constructed and used for this study. After retroviral transduction, CAR T cells were divided into 3 conditions containing either FBS, ABS or HPL and expanded for 7 days. To evaluate the effect of different sera on CAR T cell function, we performed a series of in vitro and in vivo experiments.

Results: HPL-exposed CAR T cells exhibited the less differentiated T cell phenotype and gene signature, which displayed inferior short-term killing abilities (compared to their FBS- or ABS-cultured counterparts) but superior proliferative and anti-tumor effects in long-term in vitro coculture experiments. Importantly, in mouse xenograft model, HPL-exposed CAR T cells outperformed their ABS or FBS counterparts against both subcutaneous tumor (P28z T cells against Capan-1) and systemic tumor (1928z T cells against NALM6). We further observed maintenance of less differentiated T cell phenotype in HPL-exposed 1928z T cells generated from patient's PBMCs with superior anti-tumor effect in long-term in vitro coculture experiments.

Conclusions: Our study highlights the importance of serum choice in the generation of CAR T cells for clinical use.
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http://dx.doi.org/10.1186/s40425-019-0804-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6883585PMC
November 2019

T-Cell Receptor Stimulation Enhances the Expansion and Function of CD19 Chimeric Antigen Receptor-Expressing T Cells.

Clin Cancer Res 2019 12 26;25(24):7340-7350. Epub 2019 Sep 26.

Center for Cell and Gene Therapy, Baylor College of Medicine, Houston Methodist Hospital, Texas Children's Hospital, Houston, Texas.

Purpose: Current protocols for CD19 chimeric antigen receptor-expressing T cells (CD19.CAR-T cells) require recipients to tolerate preinfusion cytoreductive chemotherapy, and the presence of sufficient target antigen on normal or malignant B cells.

Patients And Methods: We investigated whether additional stimulation of CD19.CAR-T cells through their native receptors can substitute for cytoreductive chemotherapy, inducing expansion and functional persistence of CD19.CAR-T even in patients in remission of B-cell acute lymphocytic leukemia. We infused a low dose of CD19.CAR-modified virus-specific T cells (CD19.CAR-VST) without prior cytoreductive chemotherapy into 8 patients after allogeneic stem cell transplant.

Results: Absent virus reactivation, we saw no CD19.CAR-VST expansion. In contrast, in patients with viral reactivation, up to 30,000-fold expansion of CD19.CAR-VSTs was observed, with depletion of CD19 B cells. Five patients remain in remission at 42-60+ months.

Conclusions: Dual T-cell receptor and CAR stimulation can thus potentiate effector cell expansion and CAR-target cell killing, even when infusing low numbers of effector cells without cytoreduction.
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http://dx.doi.org/10.1158/1078-0432.CCR-18-3199DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7062259PMC
December 2019

Rapid generation of multivirus-specific T lymphocytes for the prevention and treatment of respiratory viral infections.

Haematologica 2020 01 19;105(1):235-243. Epub 2019 Apr 19.

Center for Cell and Gene Therapy, Baylor College of Medicine, Texas Children's Hospital and Houston Methodist Hospital, Houston, TX, USA

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http://dx.doi.org/10.3324/haematol.2018.206896DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6939529PMC
January 2020

CD7 CAR T Cells for the Therapy of Acute Myeloid Leukemia.

Mol Ther 2019 01 4;27(1):272-280. Epub 2018 Oct 4.

Center for Cell and Gene Therapy, Baylor College of Medicine, Texas Children's Hospital, Houston Methodist Hospital, Houston, TX 77030, USA; Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX 77030, USA. Electronic address:

Chimeric antigen receptor (CAR) T cell therapy for the treatment of acute myeloid leukemia (AML) has the risk of toxicity to normal myeloid cells. CD7 is expressed by the leukemic blasts and malignant progenitor cells of approximately 30% of AML patients but is absent on normal myeloid and erythroid cells. Since CD7 expression by malignant blasts is also linked with chemoresistance and poor outcomes, targeting this antigen may be beneficial for this subset of AML patients. Here, we show that expression of a CD7-directed CAR in CD7 gene-edited (CD7) T cells effectively eliminates CD7 AML cell lines, primary CD7 AML, and colony-forming cells but spares myeloid and erythroid progenitor cells and their progeny. In a xenograft model, CD7 CAR T cells protect mice against systemic leukemia, prolonging survival. Our results support the feasibility of using CD7 CD7 CAR T cells for the non-myeloablative treatment of CD7 AML.
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http://dx.doi.org/10.1016/j.ymthe.2018.10.001DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6318703PMC
January 2019

In Vivo Fate and Activity of Second- versus Third-Generation CD19-Specific CAR-T Cells in B Cell Non-Hodgkin's Lymphomas.

Mol Ther 2018 12 13;26(12):2727-2737. Epub 2018 Sep 13.

Center for Cell and Gene Therapy, Baylor College of Medicine, Houston Methodist Hospital and Texas Children's Hospital, Houston, TX 77030, USA; Department of Medicine, Baylor College of Medicine, Houston, TX 77030, USA. Electronic address:

Second-generation (2G) chimeric antigen receptors (CARs) targeting CD19 are highly active against B cell malignancies, but it is unknown whether any of the costimulatory domains incorporated in the CAR have superior activity to others. Because CD28 and 4-1BB signaling activate different pathways, combining them in a single third-generation (3G) CAR may overcome the limitations of each individual costimulatory domain. We designed a clinical trial in which two autologous CD19-specific CAR-transduced T cell products (CD19.CARTs), 2G (with CD28 only) and 3G (CD28 and 4-1BB), were infused simultaneously in 16 patients with relapsed or refractory non-Hodgkin's lymphoma. 3G CD19.CARTs had superior expansion and longer persistence than 2G CD19.CARTs. This difference was most striking in the five patients with low disease burden and few circulating normal B cells, in whom 2G CD19.CARTs had limited expansion and persistence and correspondingly reduced area under the curve. Of the 11 patients with measurable disease, three achieved complete responses and three had partial responses. Cytokine release syndrome occurred in six patients but was mild, and no patient required anti-IL-6 therapy. Hence, 3G CD19.CARTs combining 4-1BB with CD28 produce superior CART expansion and may be of particular value when treating low disease burden in patients whose normal B cells are depleted by prior therapy.
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http://dx.doi.org/10.1016/j.ymthe.2018.09.009DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6277484PMC
December 2018

The use of chimeric antigen receptor T cells in patients with non-Hodgkin lymphoma.

Clin Adv Hematol Oncol 2018 May;16(5):375-386

Baylor College of Medicine, Houston, Texas.

Resistance to conventional lines of therapy develops in approximately 20% of all patients with lymphoma. These patients have a dismal prognosis, with an expected median survival of 6.3 months. In recent years, T-cell immunotherapy has demonstrated a remarkable capacity to induce complete and durable clinical responses in patients with chemotherapy-refractory lymphoma. A major contributor to the success of immunotherapy has been the advent of genetic engineering technologies that introduce a chimeric antigen receptor (CAR) into T cells to focus their killing activity on tumor cells. The adoptive transfer of autologous CAR T-cell products specific for the pan-B-cell antigen CD19 have now received approval from the US Food and Drug Administration (FDA) for the treatment of relapsed or chemotherapy-resistant B-cell non-Hodgkin lymphoma. This review is designed to showcase the clinical efficacy and unique toxicities of individually developed CAR T-cell products for the treatment of lymphomas and their evolution from the laboratory bench to commercialization.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6469642PMC
May 2018

Tumor-Specific T-Cells Engineered to Overcome Tumor Immune Evasion Induce Clinical Responses in Patients With Relapsed Hodgkin Lymphoma.

J Clin Oncol 2018 04 9;36(11):1128-1139. Epub 2018 Jan 9.

Catherine M. Bollard, Tamara Tripic, Gianpietro Dotti, Stephen Gottschalk, Vicky Torrano, Olga Dakhova, George Carrum, Carlos A. Ramos, Adrian P. Gee, Malcolm K. Brenner, Helen E. Heslop, and Cliona M. Rooney, Houston Methodist Hospital, and Texas Children's Hospital; Catherine M. Bollard, Gianpietro Dotti, Stephen Gottschalk, George Carrum, Carlos A. Ramos, Hao Liu, Meng-Fen Wu, Andrea N. Marcogliese, Adrian P. Gee, Malcolm K. Brenner, Helen E. Heslop, and Cliona M. Rooney, Baylor College of Medicine, Houston, TX; Catherine M. Bollard, Conrad Russell Cruz, and Cecilia Barese, Children's National Health System, Washington, DC; Youli Zu and Daniel Y. Lee, Weill Medical College of Cornell University; and Owen O'Connor, Columbia University College of Physicians and Surgeons, The New York Presbyterian Hospital, New York, NY.

Purpose Transforming growth factor-β (TGF-β) production in the tumor microenvironment is a potent and ubiquitous tumor immune evasion mechanism that inhibits the expansion and function of tumor-directed responses; therefore, we conducted a clinical study to discover the effects of the forced expression of a dominant-negative TGF-β receptor type 2 (DNRII) on the safety, survival, and activity of infused tumor-directed T cells. Materials and Methods In a dose escalation study, eight patients with Epstein Barr virus-positive Hodgkin lymphoma received two to 12 doses of between 2 × 10 and 1.5 × 10 cells/m of DNRII-expressing T cells with specificity for the Epstein Barr virus-derived tumor antigens, latent membrane protein (LMP)-1 and LMP-2 (DNRII-LSTs). Lymphodepleting chemotherapy was not used before infusion. Results DNRII-LSTs were resistant to otherwise inhibitory concentrations of TGF-β in vitro and retained their tumor antigen-specific activity. After infusion, the signal from transgenic T cells in peripheral blood increased up to 100-fold as measured by quantitative polymerase chain reaction for the transgene, with a corresponding increase in the frequency of functional LMP-specific T cells. Expansion was not associated with any acute or long-term toxicity. DNRII-LSTs persisted for up to ≥ 4 years. Four of the seven evaluable patients with active disease achieved clinical responses that were complete and ongoing in two patients at > 4 years, including in one patient who achieved only a partial response to unmodified tumor-directed T cells. Conclusion TGF-β-resistant tumor-specific T cells safely expand and persist in patients with Hodgkin lymphoma without lymphodepleting chemotherapy before infusion. DNRII-LSTs can induce complete responses even in patients with resistant disease. Expression of DNRII may be useful for the many other tumors that exploit this potent immune evasion mechanism.
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http://dx.doi.org/10.1200/JCO.2017.74.3179DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5891126PMC
April 2018

Cancer Immunotherapy Using CAR-T Cells: From the Research Bench to the Assembly Line.

Biotechnol J 2018 Feb 30;13(2). Epub 2017 Oct 30.

Center for Cell and Gene Therapy, Baylor College of Medicine, Texas Children's Hospital and Houston Methodist Hospital, Houston, TX, 77030, USA.

The focus of cancer treatment has recently shifted toward targeted therapies, including immunotherapy, which allow better individualization of care and are hoped to increase the probability of success for patients. Specifically, T cells genetically modified to express chimeric antigen receptors (CARs; CAR-T cells) have generated exciting results. Recent clinical successes with this cutting-edge therapy have helped to push CAR-T cells toward approval for wider use. However, several limitations need to be addressed before the widespread use of CAR-T cells as a standard treatment. Here, a succinct background on adoptive T-cell therapy (ATCT)is given. A brief overview of the structure of CARs, how they are introduced into T cells, and how CAR-T cell expansion and selection is achieved in vitro is then presented. Some of the challenges in CAR design are discussed, as well as the difficulties that arise in large-scale CAR-T cell manufacture that will need to be addressed to achieve successful commercialization of this type of cell therapy. Finally, developments already on the horizon are discussed.
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http://dx.doi.org/10.1002/biot.201700097DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5966018PMC
February 2018

Clinical and immunological responses after CD30-specific chimeric antigen receptor-redirected lymphocytes.

J Clin Invest 2017 Sep 14;127(9):3462-3471. Epub 2017 Aug 14.

Center for Cell and Gene Therapy, Baylor College of Medicine, Houston Methodist Hospital and Texas Children's Hospital, Houston, Texas, USA.

Background: Targeting CD30 with monoclonal antibodies in Hodgkin lymphoma (HL) and anaplastic large cell lymphoma (ALCL) has had profound clinical success. However, adverse events, mainly mediated by the toxin component of the conjugated antibodies, cause treatment discontinuation in many patients. Targeting CD30 with T cells expressing a CD30-specific chimeric antigen receptor (CAR) may reduce the side effects and augment antitumor activity.

Methods: We conducted a phase I dose escalation study in which 9 patients with relapsed/refractory HL or ALCL were infused with autologous T cells that were gene-modified with a retroviral vector to express the CD30-specific CAR (CD30.CAR-Ts) encoding the CD28 costimulatory endodomain. Three dose levels, from 0.2 × 108 to 2 × 108 CD30.CAR-Ts/m2, were infused without a conditioning regimen. All other therapy for malignancy was discontinued at least 4 weeks before CD30.CAR-T infusion. Seven patients had previously experienced disease progression while being treated with brentuximab.

Results: No toxicities attributable to CD30.CAR-Ts were observed. Of 7 patients with relapsed HL, 1 entered complete response (CR) lasting more than 2.5 years after the second infusion of CD30.CAR-Ts, 1 remained in continued CR for almost 2 years, and 3 had transient stable disease. Of 2 patients with ALCL, 1 had a CR that persisted 9 months after the fourth infusion of CD30.CAR-Ts. CD30.CAR-T expansion in peripheral blood peaked 1 week after infusion, and CD30.CAR-Ts remained detectable for over 6 weeks. Although CD30 may also be expressed by normal activated T cells, no patients developed impaired virus-specific immunity.

Conclusion: CD30.CAR-Ts are safe and can lead to clinical responses in patients with HL and ALCL, indicating that further assessment of this therapy is warranted.

Trial Registration: ClinicalTrials.gov NCT01316146.

Funding: National Cancer Institute (3P50CA126752, R01CA131027 and P30CA125123), National Heart, Lung, and Blood Institute (R01HL114564), and Leukemia and Lymphoma Society (LLSTR 6227-08).
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http://dx.doi.org/10.1172/JCI94306DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5669573PMC
September 2017

Off-the-Shelf Virus-Specific T Cells to Treat BK Virus, Human Herpesvirus 6, Cytomegalovirus, Epstein-Barr Virus, and Adenovirus Infections After Allogeneic Hematopoietic Stem-Cell Transplantation.

J Clin Oncol 2017 Nov 7;35(31):3547-3557. Epub 2017 Aug 7.

Ifigeneia Tzannou, Anastasia Papadopoulou, Swati Naik, Kathryn Leung, Caridad A. Martinez, Carlos A. Ramos, George Carrum, Ghadir Sasa, Premal Lulla, Ayumi Watanabe, Manik Kuvalekar, Adrian P. Gee, Bambi J. Grilley, Robert A. Krance, Stephen Gottschalk, Malcolm K. Brenner, Cliona M. Rooney, Helen E. Heslop, Ann M. Leen, and Bilal Omer, Center for Cell and Gene Therapy, Baylor College of Medicine, Texas Children's Hospital, and Houston Methodist Hospital; Meng-Fen Wu and Hao Liu, Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, TX.

Purpose Improvement of cure rates for patients treated with allogeneic hematopoietic stem-cell transplantation (HSCT) will require efforts to decrease treatment-related mortality from severe viral infections. Adoptively transferred virus-specific T cells (VSTs) generated from eligible, third-party donors could provide broad antiviral protection to recipients of HSCT as an immediately available off-the-shelf product. Patient and Methods We generated a bank of VSTs that recognized five common viral pathogens: Epstein-Barr virus (EBV), adenovirus (AdV), cytomegalovirus (CMV), BK virus (BKV), and human herpesvirus 6 (HHV-6). The VSTs were administered to 38 patients with 45 infections in a phase II clinical trial. Results A single infusion produced a cumulative complete or partial response rate of 92% (95% CI, 78.1% to 98.3%) overall and the following rates by virus: 100% for BKV (n = 16), 94% for CMV (n = 17), 71% for AdV (n = 7), 100% for EBV (n = 2), and 67% for HHV-6 (n = 3). Clinical benefit was achieved in 31 patients treated for one infection and in seven patients treated for multiple coincident infections. Thirteen of 14 patients treated for BKV-associated hemorrhagic cystitis experienced complete resolution of gross hematuria by week 6. Infusions were safe, and only two occurrences of de novo graft-versus host disease (grade 1) were observed. VST tracking by epitope profiling revealed persistence of functional VSTs of third-party origin for up to 12 weeks. Conclusion The use of banked VSTs is a feasible, safe, and effective approach to treat severe and drug-refractory infections after HSCT, including infections from two viruses (BKV and HHV-6) that had never been targeted previously with an off-the-shelf product. Furthermore, the multispecificity of the VSTs ensures extensive antiviral coverage, which facilitates the treatment of patients with multiple infections.
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http://dx.doi.org/10.1200/JCO.2017.73.0655DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5662844PMC
November 2017

Photoinactivation effect of eosin methylene blue and chlorophyllin sodium-copper against Staphylococcus aureus and Escherichia coli.

Lasers Med Sci 2017 Jul 20;32(5):1081-1088. Epub 2017 Apr 20.

Grupo de Espectroscopia e Bioinformática Aplicados a Biodiversidade e a Saúde, Faculdade de Medicina, Universidade Federal de Mato Grosso do Sul, CP 549, Campo Grande, MS, 79070-900, Brazil.

The use of eosin methylene blue according to Giemsa as photosensitizer is presented for the first time in this paper. The present study evaluated the potential application of chlorophyllin sodium copper salt (CuChlNa) and eosin methylene blue according to Giemsa (EMB) as antimicrobial photosensitizers (aPS) for photodynamic inactivation (PDI) of Staphylococcus aureus (gram-positive) and Escherichia coli (gram-negative) bacteria. The experiments were performed using S. aureus stain ATCC 25923 and E. coli ATCC 25922 in which five aPS concentrations (0.0, 1.0, 2.5, 5.0, 10.0, and 20.0 μM for S. aureus and 0.0, 5.0, 10.0, 20.0, 40.0, and 50.0 μM for E. coli) were prepared and added in 2 mL of a saline solution containing the bacterial inoculum. After aPS incubation, the samples were divided into two groups, one kept in the dark and another submitted to the illumination. Then, the bacterial inactivation was determined 18 h after the incubation at 37 °C by counting the colony-forming units (CFU). The results revealed that both EMB and CuChlNa can be used as aPS for the photoinactivation of S. aureus, while only EMB was able to photoinactivate E. coli. Nevertheless, a more complex experimental setup was needed for photoinactivation of E. coli. The data showed that EMB and CuChlNa presented similar photoinactivation effects on S. aureus, in which bacterial growth was completely inhibited at photosensitizer (PS) concentrations over 5 μM, when samples were previously incubated for 30 min and irradiated by a light dose of 30 J cm as a result of an illumination of 1 h at 8.3 mW cm by using a red light at 625 nm with a 1 cm beam diameter and output power of 6.5 mW. In the case of E. coli, bacterial growth was completely inhibited only when combining a PS incubation period of 120 min with concentrations over 20 μM.
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http://dx.doi.org/10.1007/s10103-017-2210-1DOI Listing
July 2017

Expanding Accessibility to CD19-CAR T Cells: Commercializing a "Boutique" Therapy.

Mol Ther 2017 01 4;25(1):8-9. Epub 2017 Jan 4.

The Center for Cell and Gene Therapy, Baylor College of Medicine, Houston, TX 77030, USA; Section of Hematology and Oncology, Department of Medicine, Baylor College of Medicine, Houston, TX 77030, USA.

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http://dx.doi.org/10.1016/j.ymthe.2016.12.002DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5363183PMC
January 2017

Clinical responses with T lymphocytes targeting malignancy-associated κ light chains.

J Clin Invest 2016 07 6;126(7):2588-96. Epub 2016 Jun 6.

Background: Treatment of B cell malignancies with adoptive transfer of T cells with a CD19-specific chimeric antigen receptor (CAR) shows remarkable clinical efficacy. However, long-term persistence of T cells targeting CD19, a pan-B cell marker, also depletes normal B cells and causes severe hypogammaglobulinemia. Here, we developed a strategy to target B cell malignancies more selectively by taking advantage of B cell light Ig chain restriction. We generated a CAR that is specific for the κ light chain (κ.CAR) and therefore recognizes κ-restricted cells and spares the normal B cells expressing the nontargeted λ light chain, thus potentially minimizing humoral immunity impairment.

Methods: We conducted a phase 1 clinical trial and treated 16 patients with relapsed or refractory κ+ non-Hodgkin lymphoma/chronic lymphocytic leukemia (NHL/CLL) or multiple myeloma (MM) with autologous T cells genetically modified to express κ.CAR (κ.CARTs). Other treatments were discontinued in 11 of the 16 patients at least 4 weeks prior to T cell infusion. Six patients without lymphopenia received 12.5 mg/kg cyclophosphamide 4 days before κ.CART infusion (0.2 × 108 to 2 × 108 κ.CARTs/m2). No other lymphodepletion was used.

Results: κ.CART expansion peaked 1-2 weeks after infusion, and cells remained detectable for more than 6 weeks. Of 9 patients with relapsed NHL or CLL, 2 entered complete remission after 2 and 3 infusions of κ.CARTs, and 1 had a partial response. Of 7 patients with MM, 4 had stable disease lasting 2-17 months. No toxicities attributable to κ.CARTs were observed.

Conclusion: κ.CART infusion is feasible and safe and can lead to complete clinical responses.

Trial Registration: ClinicalTrials.gov NCT00881920.

Funding: National Cancer Institute (NCI) grants 3P50CA126752 and 5P30CA125123 and Leukemia and Lymphoma Society (LLS) Specialized Centers of Research (SCOR) grant 7018.
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http://dx.doi.org/10.1172/JCI86000DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4922690PMC
July 2016

CAR-T Cell Therapy for Lymphoma.

Annu Rev Med 2016 26;67:165-83. Epub 2015 Aug 26.

Center for Cell and Gene Therapy, Houston Methodist Hospital, Texas Children's Hospital, and Baylor College of Medicine, Houston, Texas 77030.

Lymphomas arise from clonal expansions of B, T, or NK cells at different stages of differentiation. Because they occur in the immunocyte-rich lymphoid tissues, they are easily accessible to antibodies and cell-based immunotherapy. Expressing chimeric antigen receptors (CARs) on T cells is a means of combining the antigen-binding site of a monoclonal antibody with the activating machinery of a T cell, enabling antigen recognition independent of major histocompatibility complex restriction, while retaining the desirable antitumor properties of a T cell. Here, we discuss the basic design of CARs and their potential advantages and disadvantages over other immune therapies for lymphomas. We review current clinical trials in the field and consider strategies to improve the in vivo function and safety of immune cells expressing CARs. The ultimate driver of CAR development and implementation for lymphoma will be the demonstration of their ability to safely and cost-effectively cure these malignancies.
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http://dx.doi.org/10.1146/annurev-med-051914-021702DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4732525PMC
October 2016

In vitro cultivation and cryopreservation of Babesia bigemina sporokinetes in hemocytes of Rhipicephalus microplus.

Vet Parasitol 2015 Sep 10;212(3-4):400-3. Epub 2015 Jul 10.

Universidade Federal Rural do Rio de Janeiro Seropédica, BR 465, Km 7, CEP 23897-000, Seropédica, RJ, Brazil.

Cultures of tick hemocytes represent alternative cell lines for the isolation and cultivation of a variety of hemoparasites. The present study reports the development and evaluation of methods for the in vitro culture and maintenance of sporokinetes of Babesia bigemina in association with hemocytes of the tick Rhipicephalus microplus. Hemolymph, from engorged females infected with B. bigemina sporokinetes, was incubated at 28 °C in L15 culture medium supplemented with 40% fetal bovine serum. Adherence of hemocytes to flask surfaces and the development of B. bigemina sporokinetes commenced on the first day of cultivation. The protozoa demonstrated clear motility and the capacity to adhere to hemocyte membranes for up to 25 days, at which time the hemocytes began to show signs of degeneration. Examination of Giemsa stained hemocyte cultures, revealed the presence of pyriformis forms, as well as mature and immature sporokinetes with dark red nuclei, centralized or near the apical extremities. Sporokinetes harvested from culture supernatants were cryopreserved in liquid nitrogen. Inoculation of parasite-free hemocyte cultures with defrosted sporokinetes, demonstrated the viability and interaction of the protozoa with the hemocytes over 21 days. Cultured hemocytes of R. microplus hold potential for development as a tool in the study of host parasite interactions and as a substrate for the in vitro maintenance of B. bigemina sporokinetes.
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http://dx.doi.org/10.1016/j.vetpar.2015.07.008DOI Listing
September 2015

Tumor indoleamine 2,3-dioxygenase (IDO) inhibits CD19-CAR T cells and is downregulated by lymphodepleting drugs.

Blood 2015 Jun 4;125(25):3905-16. Epub 2015 May 4.

Center for Cell and Gene Therapy, Houston Methodist Hospital, Texas Children's Hospital, and Baylor College of Medicine, Houston, TX; and Medicine, and.

Although T cells expressing CD19-specific chimeric antigen receptors (CARs) are a promising new therapy for B-cell malignancies, objective responses are observed at lower frequencies in patients with lymphoma than in those with acute B-cell leukemia. We postulated that the tumor microenvironment suppresses CAR-expressing T cells (CARTs) through the activity of indoleamine 2,3-dioxygenase (IDO), an intracellular enzyme that converts tryptophan into metabolites that inhibit T -: cell activity. To investigate the effects of tumor IDO on CD19-CART therapy, we used a xenograft lymphoma model expressing IDO as a transgene. CD19-CARTs inhibited IDO-negative tumor growth but had no effect on IDO-positive tumors. An IDO inhibitor (1-methyl-tryptophan) restored IDO-positive tumor control. Moreover, tryptophan metabolites inhibited interleukin (IL)-2-, IL-7-, and IL-15-dependent expansion of CARTs; diminished their proliferation, cytotoxicity, and cytokine secretion in vitro in response to CD19 recognition; and increased their apoptosis. Inhibition of CD19-CARTs was not mitigated by the incorporation of costimulatory domains, such as 4-1BB, into the CD19-CAR. Finally, we found that fludarabine and cyclophosphamide, frequently used before CART administration, downregulated IDO expression in lymphoma cells and improved the antitumor activity of CD19-CART in vivo. Because tumor IDO inhibits CD19-CARTs, antagonizing this enzyme may benefit CD19-CART therapy.
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http://dx.doi.org/10.1182/blood-2015-01-621474DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4473118PMC
June 2015

Tumor indoleamine 2,3-dioxygenase (IDO) inhibits CD19-CAR T cells and is downregulated by lymphodepleting drugs.

Blood 2015 Jun 4;125(25):3905-16. Epub 2015 May 4.

Center for Cell and Gene Therapy, Houston Methodist Hospital, Texas Children's Hospital, and Baylor College of Medicine, Houston, TX; and Medicine, and.

Although T cells expressing CD19-specific chimeric antigen receptors (CARs) are a promising new therapy for B-cell malignancies, objective responses are observed at lower frequencies in patients with lymphoma than in those with acute B-cell leukemia. We postulated that the tumor microenvironment suppresses CAR-expressing T cells (CARTs) through the activity of indoleamine 2,3-dioxygenase (IDO), an intracellular enzyme that converts tryptophan into metabolites that inhibit T -: cell activity. To investigate the effects of tumor IDO on CD19-CART therapy, we used a xenograft lymphoma model expressing IDO as a transgene. CD19-CARTs inhibited IDO-negative tumor growth but had no effect on IDO-positive tumors. An IDO inhibitor (1-methyl-tryptophan) restored IDO-positive tumor control. Moreover, tryptophan metabolites inhibited interleukin (IL)-2-, IL-7-, and IL-15-dependent expansion of CARTs; diminished their proliferation, cytotoxicity, and cytokine secretion in vitro in response to CD19 recognition; and increased their apoptosis. Inhibition of CD19-CARTs was not mitigated by the incorporation of costimulatory domains, such as 4-1BB, into the CD19-CAR. Finally, we found that fludarabine and cyclophosphamide, frequently used before CART administration, downregulated IDO expression in lymphoma cells and improved the antitumor activity of CD19-CART in vivo. Because tumor IDO inhibits CD19-CARTs, antagonizing this enzyme may benefit CD19-CART therapy.
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http://dx.doi.org/10.1182/blood-2015-01-621474DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4473118PMC
June 2015

Direct detection of Mycobacterium tuberculosis complex in bovine and bubaline tissues through nested-PCR.

Braz J Microbiol 2014 29;45(2):633-40. Epub 2014 Aug 29.

Embrapa Gado de Corte Campo GrandeMS Brazil Embrapa Gado de Corte, Campo Grande, MS, Brazil.

Post-mortem bacterial culture and specific biochemical tests are currently performed to characterize the etiologic agent of bovine tuberculosis. Cultures take up to 90 days to develop. A diagnosis by molecular tests such as PCR can provide fast and reliable results while significantly decreasing the time of confirmation. In the present study, a nested-PCR system, targeting rv2807, with conventional PCR followed by real-time PCR, was developed to detect Mycobacterium tuberculosis complex (MTC) organisms directly from bovine and bubaline tissue homogenates. The sensitivity and specificity of the reactions were assessed with DNA samples extracted from tuberculous and non-tuberculous mycobacteria, as well as other Actinomycetales species and DNA samples extracted directly from bovine and bubaline tissue homogenates. Regarding the analytical sensitivity, DNA of the M. bovis AN5 strain was detected up to 1.5 pg by nested-PCR, whereas DNA of M. tuberculosis H37Rv strain was detected up to 6.1 pg. The nested-PCR system showed 100% analytical specificity for MTC when tested with DNA of reference strains of non-tuberculous mycobacteria and closely-related Actinomycetales. A clinical sensitivity level of 76.7% was detected with tissues samples positive for MTC by means of the culture and conventional PCR. A clinical specificity of 100% was detected with DNA from tissue samples of cattle with negative results in the comparative intradermal tuberculin test. These cattle exhibited no visible lesions and were negative in the culture for MTC. The use of the nested-PCR assay to detect M. tuberculosis complex in tissue homogenates provided a rapid diagnosis of bovine and bubaline tuberculosis.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4166292PMC
http://dx.doi.org/10.1590/s1517-83822014000200035DOI Listing
May 2015

Development and assessment of a latex agglutination test based on recombinant MSP5 to detect antibodies against Anaplasma marginale in cattle.

Braz J Microbiol 2014 2;45(1):199-204. Epub 2014 May 2.

Department of Veterinary Medicine Universita degli Studi de Bari ValenzanoBari Italy.

The recombinant protein MSP5 has been established as an important antigen for serological diagnosis of Anaplasma marginale by enzyme-linked immunosorbent assay (ELISA). However, due to the high cost of specialized equipment, this technique is not accessible to all laboratories, especially in developing countries in areas where the disease is endemic. The present study describes the standardization of a latex agglutination test (LAT) to detect antibodies against A. marginale based on recombinant MSP5. Compared with indirect enzyme-linked immunosorbent assay (iELISA), the relative sensitivity and specificity of the LAT were 95.21% and 91.86% respectively, with an almost perfect agreement between tests (kappa index = 0.863). These results can be considered important for the serological diagnosis of A. marginale, as they indicate that the test represents a rapid and low cost alternative to ELISA.
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http://dx.doi.org/10.1590/S1517-83822014005000039DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4059296PMC
February 2015

Closely related T-memory stem cells correlate with in vivo expansion of CAR.CD19-T cells and are preserved by IL-7 and IL-15.

Blood 2014 Jun 29;123(24):3750-9. Epub 2014 Apr 29.

Center for Cell and Gene Therapy, Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX; Department of Medicine, Baylor College of Medicine, Houston, TX; Texas Children's Hospital, Houston, TX.

Adoptive transfer of T lymphocytes expressing a CD19-specific chimeric antigen receptor (CAR.CD19) induces complete tumor regression in patients with lymphoid malignancies. Although in vivo persistence of CAR-T cells correlates with clinical responses, it remains unknown whether specific cell subsets within the CAR-T-cell product correlate with their subsequent in vivo expansion and persistence. We analyzed 14 patients with B-cell malignancies infused with autologous CAR.CD19-redirected T cells expanded ex vivo using IL-2, and found that their in vivo expansion only correlated with the frequency within the infused product of a CD8(+)CD45RA(+)CCR7(+) subset, whose phenotype is closest to "T-memory stem cells." Preclinical models showed that increasing the frequency of CD8(+)CD45RA(+)CCR7(+) CAR-T cells in the infused line by culturing the cells with IL-7 and IL-15 produced greater antitumor activity of CAR-T cells mediated by increased resistance to cell death, following repetitive encounters with the antigen, while preserving their migration to secondary lymphoid organs. This trial was registered at www.clinicaltrials.gov as #NCT00586391 and #NCT00709033.
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http://dx.doi.org/10.1182/blood-2014-01-552174DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4055922PMC
June 2014

CD19-CAR trials.

Cancer J 2014 Mar-Apr;20(2):112-8

From the *Center for Cell and Gene Therapy, Baylor College of Medicine, The Methodist Hospital and Texas Children's Hospital, Houston, TX, †Departments of Medicine, and ‡Pediatrics, Baylor College of Medicine, Houston, TX.

CD19 is a B-lineage-specific transmembrane glycoprotein, the expression of which is maintained on more than 95% B-cell malignancies. This strict lineage restriction makes CD19 an ideal target for immune therapies using chimeric antigen receptors (CARs). Here, we review published phase 1 trials of T cells expressing CARs targeting CD19 and describe briefly the biological questions that they addressed. All patients treated in these trials had relapsed B-cell malignancies, which in many cases were chemorefractory. Nonetheless, major responses have been observed, especially in patients with chronic lymphocytic leukemia and acute lymphoblastic leukemia. Many of these responses were accompanied by a systemic inflammatory reaction syndrome that could be life threatening but was almost always reversible with adequate medical management. Given their remarkable activity, CD19-CAR T cells are likely to be quickly incorporated into the management of B-cell neoplasms; these cells have become the paradigm for similar strategies targeting other cancers.
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http://dx.doi.org/10.1097/PPO.0000000000000031DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3979594PMC
November 2014

Ultra low-dose IL-2 for GVHD prophylaxis after allogeneic hematopoietic stem cell transplantation mediates expansion of regulatory T cells without diminishing antiviral and antileukemic activity.

Clin Cancer Res 2014 Apr 26;20(8):2215-25. Epub 2014 Feb 26.

Authors' Affiliations: Center for Cell and Gene Therapy, Dan L. Duncan Cancer Center, Baylor College of Medicine; The Methodist Hospital, Houston, Texas; and National Heart, Lung, and Blood Institute, NIH, Bethesda, Maryland.

Purpose: GVHD after allogeneic hematopoietic stem cell transplantation (alloSCT) has been associated with low numbers of circulating CD4(+)CD25(+)FoxP3(+) regulatory T cells (Tregs). Because Tregs express high levels of the interleukin (IL)-2 receptor, they may selectively expand in vivo in response to doses of IL-2 insufficient to stimulate T effector T-cell populations, thereby preventing GVHD.

Experimental Design: We prospectively evaluated the effects of ultra low-dose (ULD) IL-2 injections on Treg recovery in pediatric patients after alloSCT and compared this recovery with Treg reconstitution post alloSCT in patients without IL-2. Sixteen recipients of related (n = 12) or unrelated (n = 4) donor grafts received ULD IL-2 post hematopoietic stem cell transplantation (HSCT; 100,000-200,000 IU/m(2) ×3 per week), starting
Results: No grade 3/4 toxicities were associated with ULD IL-2. CD4(+)CD25(+)FoxP3(+) Tregs increased from a mean of 4.8% (range, 0%-11.0%) pre IL-2 to 11.1% (range, 1.2%-31.1%) following therapy, with the greatest change occurring in the recipients of matched related donor (MRD) transplants. No IL-2 patients developed grade 2-4 acute GVHD (aGVHD), compared with 4 of 33 (12%) of the comparator group who did not receive IL-2. IL-2 recipients retained T cells reactive to viral and leukemia antigens, and in the MRD recipients, only 2 of 13 (15%) of the IL-2 patients developed viral infections versus 63% of the comparator group (P = 0.022).

Conclusions: Hence, ULD IL-2 is well tolerated, expands a Treg population in vivo, and may be associated with a lower incidence of viral infections and GVHD.
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http://dx.doi.org/10.1158/1078-0432.CCR-13-3205DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3989436PMC
April 2014

Infusion of donor-derived CD19-redirected virus-specific T cells for B-cell malignancies relapsed after allogeneic stem cell transplant: a phase 1 study.

Blood 2013 Oct 12;122(17):2965-73. Epub 2013 Sep 12.

Center for Cell and Gene Therapy, Baylor College of Medicine, Houston, TX;

Autologous T cells expressing a CD19-specific chimeric antigen receptor (CD19.CAR) are active against B-cell malignancies, but it is unknown whether allogeneic CD19.CAR T cells are safe or effective. After allogeneic hematopoietic stem cell transplantation (HSCT), infused donor-derived virus-specific T cells (VSTs) expand in vivo, persist long term, and display antiviral activity without inducing graft-vs-host disease; therefore, we determined whether donor VSTs, engineered to express CD19.CAR, retained the characteristics of nonmanipulated allogeneic VSTs while gaining antitumor activity. We treated 8 patients with allogeneic (donor-derived) CD19.CAR-VSTs 3 months to 13 years after HSCT. There were no infusion-related toxicities. VSTs persisted for a median of 8 weeks in blood and up to 9 weeks at disease sites. Objective antitumor activity was evident in 2 of 6 patients with relapsed disease during the period of CD19.CAR-VST persistence, whereas 2 patients who received cells while in remission remain disease free. In 2 of 3 patients with viral reactivation, donor CD19.CAR-VSTs expanded concomitantly with VSTs. Hence CD19.CAR-VSTs display antitumor activity and, because their number may be increased in the presence of viral stimuli, earlier treatment post-HSCT (when lymphodepletion is greater and the incidence of viral infection is higher) or planned vaccination with viral antigens may enhance disease control.
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http://dx.doi.org/10.1182/blood-2013-06-506741DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3811171PMC
October 2013

Human papillomavirus type 16 E6/E7-specific cytotoxic T lymphocytes for adoptive immunotherapy of HPV-associated malignancies.

J Immunother 2013 Jan;36(1):66-76

Center for Cell and Gene Therapy, Baylor College of Medicine, The Methodist Hospital and Texas Children's Hospital, Houston, TX77030, USA.

Vaccines prevent human papillomavirus (HPV)-associated cancer but, although these tumors express foreign, viral antigens (E6 and E7 proteins), they have little benefit in established malignancies, likely due to negative environmental cues that block tumor recognition and induce T-cell anergy in vivo. We postulated that we could identify mechanisms by which ex vivo stimulation of T cells could reactivate and expand tumor-directed T-cell lines from HPV cancer patients for subsequent adoptive immunotherapy. A total of 68 patients with HPV-associated cancers were studied. Peripheral blood T cells were stimulated with monocyte-derived dendritic cells loaded with pepmixes [peptide libraries of 15-mers overlapping by 11 amino acids (aa)] spanning E6/E7, in the presence or absence of specific accessory cytokines. The resulting T-cell lines were further expanded with pepmix-loaded activated B-cell blasts. Interferon-γ release and cytotoxic responses to E6/E7 were assessed. We successfully reactivated and expanded (>1200-fold) E6-specific/E7-specific T cells from 8/16 cervical and 33/52 oropharyngeal cancer patients. The presence of the cytokines interleukin (IL)-6, IL-7, IL-12, and IL-15 is critical for this process. These T-cell lines possess the desirable characteristics of polyclonality, multiple T-cell subset representation (including the memory compartment) and a TH1 bias, and may eliminate E6/E7 targets. In conclusion, we have shown it is possible to robustly generate HPV16 E6/E7-directed T-cell lines from patients with HPV16-associated cancers. Because our technique is scalable and good-manufacturing procedures-compliant, these lines could be used for adoptive cellular immunotherapy of patients with HPV16 cancers.
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http://dx.doi.org/10.1097/CJI.0b013e318279652eDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3521877PMC
January 2013