The 100 most influential studies in CAR-T: a bibliometric analysis

DOI: https://doi.org/10.21203/rs.3.rs-15930/v1

Abstract

Background: Bibliometric analysis of mainly cited articles is used to provide information on trends in a specific research field and objective indicators of the scientific impact of the publication. With bibliometric and network analysis, we map the scientific landscape of chimeric antigen receptors T-cells (CAR-T) research.

Methods: Extract 100 most cited articles published over the last decade (from January 1, 2009 to Dec 31, 2018; 10 years) from the Web of Science Core Collection with bibliographic details; year of publication, country of author, funding agencies, research organization, author information, and keywords. 

Results: Of the 100 papers identified, most (92%) were written in the US. US government agencies and non-profit organizations provided the most funding, and the papers funded by the NIH had the most citations, followed by those funded by the Alliance for Cancer Gene Therapy (US). 33 papers out of the top 100 most cited papers were published from the University of Pennsylvania. As for authors, Carl H. June participated in 30 papers, followed by Bruce L. Levine who participated in 11 papers. As for journals, Blood (n=20), published the most papers, followed by Science Translational Medicine (n=10). The most frequently used keyword was “adoptive immunotherapy” (n=37), followed by “lymphocytes” (n=27), and “antitumor-activity” (n=25). 

Conclusion: We performed the quantitative bibliometric analysis of funding bodies, countries, organizations, journals, authors, and keywords for the CAR-T research trends and landscape. Moving forward, Analysis of highly influential CAR-T articles provides insight into areas for future development.

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Tables

Table 1. Status of CAR-T approved by FDA or in Phase III clinical trials (as of July 1, 2019)

 

Kymriah®
(Tisagenlecleucel-T;
 CTL019)

Yescarta® (Axicabtagene
 Ciloleucel; KTE-C19)

Lisocaptagene
 Maraleucel 

(Liso-cel,
 JCAR-017)

BB2121

Company

Novartis

Gilead (Kite)

Celgene

Celgene/Bluebird

Format

Co-stimaulation

CARa-T;
 4-1BB CS

CAR-T;
CDf28 CS

CAR-T;
 4-1BB CS

CAR-T;
 4-1BB CS

Phase III Name

B-ALLb: ELINA/ DLBCLc: JULIET

TOWER 

TRANSFORM

RRMM

Status

Approved by USFDA   

Approved by USFDA

Phase III (NCT03575351)

Phase III
 (NCT03651128)

Cost (US)

$475,000 for B-ALL;
$373,000 for R/Rd DLBCL

$373,000

NAh

NA

Indication

B-ALL, R/R DLBCL

R/R DLBCL; PMBCLg

R/R DLBCL; CLLi

MMj

Sourced T-Cell

Patient PBMCse;
 autologous; unspecified

Patient PBMCs;
 autologous; unspecified

Patient CD4 and CD8 T
 cells 1:1 ratio; autologous

Patient PBMCs;
 autologous

Vector

Lentivirus

Retrovirus

Lentivirus

Lentivirus

Patient group (=No.)

B-ALL=63, R/R DLBCL=93

101

73*

33*

ORR

B-ALL=ND, DLBCL=52%

83%

80%*

85%*

CR

B-ALL=83%, DLBCL=40%

58%

59%*

45%*

PR

B-ALL=20%, DLBCL=12%

25%

21%*

39%

Median response
 duration time

(months)

B-ALL=NR, DLBCL=11.7m

11.1m

10.2m*

11.8m*

aCAR: chimeric antigen receptor, bB-ALL: B-cell acute lymphoblastic leukemia, cDLBCL: diffuse large B-cell lymphoma’dR/R: relapsed or refractory, ePBMC: peripheral blood mononuclear cells

fCD: cluster of differentiation, gPMBCL: primary mediastinal large B-cell lymphoma, hNA; not applicable, iCLL: chronic lymphocytic leukemia, jMM: multiple myeloma

*Data from the Phase I trial result

Table 2. Status of countries / funding organizations that top 100 cited publications related to CAR-T 

Rank

Country

Number of Publications

Funding Organizations

Number of Publications

ACPIa

Sum of Times Cited

1

USA

92

NIH (USA)

29

222.83

6462

2

Germany

11

LLS (USA)

8

264.38

2115

3

England

5

NCI (USA)

8

295.50

2364

4

Italy

5

LRF (USA)

7

145.00

1015

5

Canada

4

NIH+NCI (USA)

7

187.14

1310

6

China

4

NCI+NIH+HHS (USA)

6

118.00

708

7

Australia

3

ACGT (USA)

5

550.40

2752

8

Netherlands

3

DOD (USA)

5

170.40

852

9

France

2

Novartis (SUI*)

5

138.20

691

10

Israel

2

Burroughs Wellcome Fund (USA)

4

123.25

493

aACPI: Average Citations per Item field (average number of times a record has been cited) [10]

bNCI: National Cancer Institute; cLLS: Leukemia & Lymphoma Society; dNIH: National Institutes of Health;

eLRF: Lymphoma Research Foundation; fHHS: Health and Human Services; gACGT: Alliance for Cancer Gene Therapy; hDOD = Department of Defense; *Based on the location of the headquarters

 

 

 

 

Table 3. Status of journal titles that top 100 cited publications related to CAR-T 

Rank

Journal Titles (Country)

Number of Publications

APCIa

Sum of Times Cited

IFb

1

Blood (USA)

20

185.75

3715

16.56

2

Cancer Research (USA)

10

132.00

1320

8.38

3

Science Translational Medicine (USA)

10

376.80

3768

17.16

4

Clinical Cancer Research (USA)

7

159.89

1119

8.91

5

Cancer Immunology Research (USA)

6

168.83

1013

8.62

6

Journal of Clinical Investigation (USA)

6

247.33

1484

12.28

7

Nature Reviews Clinical Oncology (USA)

5

186.80

934

34.11

8

New England Journal of Medicine (USA)

5

275.60

1378

70.67

9

Journal of Clinical Oncology (USA)

4

300.25

1201

28.25

10

Nature Medicine (USA)

4

168.75

675

30.64

aACPI: Average Citations per Item field (average number of times a record has been cited) [10]

bImpact factor is based on Journal Citation Reports in June 2019.

 

Table 4. The 100 most cited articles from the Journal of CAR-T 

Title

Journal

Published year

Total citation

(n)

T Cells with Chimeric Antigen Receptors Have Potent Antitumor Effects and Can Establish Memory in Patients with Advanced Leukemia

SCIENCE TRANSLATIONAL MEDICINE

2011

1,052

T cells expressing CD19 chimeric antigen receptors for acute lymphoblastic leukaemia in children and young adults: a phase 1 dose-escalation trial

LANCET

2015

954

Efficacy and Toxicity Management of 19-28z CAR T Cell Therapy in B Cell Acute Lymphoblastic Leukemia

SCIENCE TRANSLATIONAL MEDICINE

2014

935

Chemotherapy-Refractory Diffuse Large B-Cell Lymphoma and Indolent B-Cell Malignancies Can Be Effectively Treated With Autologous T Cells Expressing an Anti-CD19 Chimeric Antigen Receptor

JOURNAL OF CLINICAL ONCOLOGY

2015

644

CD28 costimulation improves expansion and persistence of chimeric antigen receptor-modified T cells in lymphoma patients

JOURNAL OF CLINICAL INVESTIGATION

2011

522

Chimeric antigen receptor T cells persist and induce sustained remissions in relapsed refractory chronic lymphocytic leukemia

SCIENCE TRANSLATIONAL MEDICINE

2015

484

Antitumor activity and long-term fate of chimeric antigen receptor-positive T cells in patients with neuroblastoma

BLOOD

2011

465

CD19 CAR-T cells of defined CD4(+): CD8(+) composition in adult B cell ALL patients

JOURNAL OF CLINICAL INVESTIGATION

2016

424

Axicabtagene Ciloleucel CAR T-Cell Therapy in Refractory Large B-Cell Lymphoma

NEW ENGLAND JOURNAL OF MEDICINE

2017

380

Tisagenlecleucel in Children and Young Adults with B-Cell Lymphoblastic Leukemia

NEW ENGLAND JOURNAL OF MEDICINE

2018

347

Antibody-modified T cells: CARs take the front seat for hematologic malignancies

BLOOD

2014

331

Mesothelin-Specific Chimeric Antigen Receptor mRNA-Engineered T Cells Induce Antitumor Activity in Solid Malignancies

CANCER IMMUNOLOGY RESEARCH

2014

322

4-1BB costimulation ameliorates T cell exhaustion induced by tonic signaling of chimeric antigen receptors

NATURE MEDICINE

2015

308

Regression of Glioblastoma after Chimeric Antigen Receptor T-Cell Therapy

NEW ENGLAND JOURNAL OF MEDICINE

2016

283

Anti-PD-1 Antibody Therapy Potently Enhances the Eradication of Established Tumors By Gene-Modified T Cells

CLINICAL CANCER RESEARCH

2013

280

Human Epidermal Growth Factor Receptor 2 (HER2) -Specific Chimeric Antigen Receptor-Modified T Cells for the Immunotherapy of HER2-Positive Sarcoma

JOURNAL OF CLINICAL ONCOLOGY

2015

279

Donor-derived CD19-targeted T cells cause regression of malignancy persisting after allogeneic hematopoietic stem cell transplantation

BLOOD

2013

269

Treatment of Metastatic Renal Cell Carcinoma With CAIX CAR-engineered T cells: Clinical Evaluation and Management of On-target Toxicity

MOLECULAR THERAPY

2013

263

Tumor-targeted T cells modified to secrete IL-12 eradicate systemic tumors without need for prior conditioning

BLOOD

2012

260

The future of cancer treatment: immunomodulation, CARs and combination immunotherapy

NATURE REVIEWS CLINICAL ONCOLOGY

2016

258

Targeting a CAR to the TRAC locus with CRISPR/Cas9 enhances tumour rejection

NATURE

2017

249

Immunotherapy of non-Hodgkin's lymphoma with a defined ratio of CD8(+) and CD4(+) CD19-specific chimeric antigen receptor-modified T cells

SCIENCE TRANSLATIONAL MEDICINE

2016

249

Decade-Long Safety and Function of Retroviral-Modified Chimeric Antigen Receptor T Cells

SCIENCE TRANSLATIONAL MEDICINE

2012

249

CD19-targeted chimeric antigen receptor T-cell therapy for acute lymphoblastic leukemia

BLOOD

2015

239

Long-Term Follow-up of CD19 CAR Therapy in Acute Lymphoblastic Leukemia

NEW ENGLAND JOURNAL OF MEDICINE

2018

225

Toxicities of chimeric antigen receptor T cells: recognition and management

BLOOD

2016

222

Multiple Injections of Electroporated Autologous T Cells Expressing a Chimeric Antigen Receptor Mediate Regression of Human Disseminated Tumor

CANCER RESEARCH

2010

219

Treating B-cell cancer with T cells expressing anti-CD19 chimeric antigen receptors

NATURE REVIEWS CLINICAL ONCOLOGY

2013

215

The Principles of Engineering Immune Cells to Treat Cancer

CELL

2017

209

Molecular remission of infant B-ALL after infusion of universal TALEN gene-edited CAR T cells

SCIENCE TRANSLATIONAL MEDICINE

2017

206

T Cells Expressing Chimeric Antigen Receptors Can Cause Anaphylaxis in Humans

CANCER IMMUNOLOGY RESEARCH

2013

206

Chimeric antigen receptor T-cell therapy - assessment and management of toxicities

NATURE REVIEWS CLINICAL ONCOLOGY

2018

187

Identification of Predictive Biomarkers for Cytokine Release Syndrome after Chimeric Antigen Receptor T-cell Therapy for Acute Lymphoblastic Leukemia

CANCER DISCOVERY

2016

185

Toxicity and management in CAR T-cell therapy

MOLECULAR THERAPY-ONCOLYTICS

2016

182

Receptor Affinity and Extracellular Domain Modifications Affect Tumor Recognition by ROR1-Specific Chimeric Antigen Receptor T Cells

CLINICAL CANCER RESEARCH

2013

182

Design and development of therapies using chimeric antigen receptor-expressing T cells

IMMUNOLOGICAL REVIEWS

2014

181

Redirecting T-cell specificity by introducing a tumor-specific chimeric antigen receptor

BLOOD

2010

181

T cells expressing an anti-B-cell maturation antigen chimeric antigen receptor cause remissions of multiple myeloma

BLOOD

2016

178

Human CAR T cells with cell-intrinsic PD-1 checkpoint blockade resist tumor-mediated inhibition

JOURNAL OF CLINICAL INVESTIGATION

2016

178

Distinct Signaling of Coreceptors Regulates Specific Metabolism Pathways and Impacts Memory Development in CAR T Cells

IMMUNITY

2016

176

Expression of a Functional CCR2 Receptor Enhances Tumor Localization and Tumor Eradication by Retargeted Human T cells Expressing a Mesothelin-Specific Chimeric Antibody Receptor

CLINICAL CANCER RESEARCH

2011

174

Chimeric antigen receptor-modified T cells derived from defined CD8(+) and CD4(+) subsets confer superior antitumor reactivity in vivo

LEUKEMIA

2016

172

A foundation for universal T-cell based immunotherapy: T cells engineered to express a CD19-specific chimeric-antigen-receptor and eliminate expression of endogenous TCR

BLOOD

2012

172

Allogeneic T Cells That Express an Anti-CD19 Chimeric Antigen Receptor Induce Remissions of B-Cell Malignancies That Progress After Allogeneic Hematopoietic Stem-Cell Transplantation Without Causing Graft-Versus-Host Disease

JOURNAL OF CLINICAL ONCOLOGY

2016

171

CAR T cell immunotherapy for human cancer

SCIENCE

2018

164

Immune responses to transgene and retroviral vector in patients treated with ex vivo-engineered T cells

BLOOD

2011

163

A single dose of peripherally infused EGFRvIII-directed CAR T cells mediates antigen loss and induces adaptive resistance in patients with recurrent glioblastoma

SCIENCE TRANSLATIONAL MEDICINE

2017

162

Going viral: chimeric antigen receptor T-cell therapy for hematological malignancies

IMMUNOLOGICAL REVIEWS

2015

162

Persistence and Efficacy of Second Generation CAR T Cell Against the LeY Antigen in Acute Myeloid Leukemia

MOLECULAR THERAPY

2013

159

Structural Design of Engineered Costimulation Determines Tumor Rejection Kinetics and Persistence of CAR T Cells

CANCER CELL

2015

158

Rational development and characterization of humanized anti-EGFR variant III chimeric antigen receptor T cells for glioblastoma

SCIENCE TRANSLATIONAL MEDICINE

2015

155

Regional delivery of mesothelin-targeted CAR T cell therapy generates potent and long-lasting CD4-dependent tumor immunity

SCIENCE TRANSLATIONAL MEDICINE

2014

153

T cells expressing CD123-specific chimeric antigen receptors exhibit specific cytolytic effector functions and antitumor effects against human acute myeloid leukemia

BLOOD

2013

153

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

151

Driving CAR T-cells forward

NATURE REVIEWS CLINICAL ONCOLOGY

2016

149

In Vivo Persistence, Tumor Localization, and Antitumor Activity of CAR-Engineered T Cells Is Enhanced by Costimulatory Signaling through CD137 (4-1BB)

CANCER RESEARCH

2011

145

Recognition of Glioma Stem Cells by Genetically Modified T Cells Targeting EGFRvIII and Development of Adoptive Cell Therapy for Glioma

HUMAN GENE THERAPY

2012

143

IL-12 Release by Engineered T Cells Expressing Chimeric Antigen Receptors Can Effectively Muster an Antigen-Independent Macrophage Response on Tumor Cells That Have Shut Down Tumor Antigen Expression

CANCER RESEARCH

2011

143

Phase 1 Results of ZUMA-1: A Multicenter Study of KTE-C19 Anti-CD19 CAR T Cell Therapy in Refractory Aggressive Lymphoma

MOLECULAR THERAPY

2017

142

Acquisition of a CD19-negative myeloid phenotype allows immune escape of MLL-rearranged B-ALL from CD19 CAR-T-cell therapy

BLOOD

2016

141

Heparanase promotes tumor infiltration and antitumor activity of CAR-redirected T lymphocytes

NATURE MEDICINE

2015

141

Multifactorial T-cell Hypofunction That Is Reversible Can Limit the Efficacy of Chimeric Antigen Receptor-Transduced Human T cells in Solid Tumors

CLINICAL CANCER RESEARCH

2014

141

Multiplex Genome Editing to Generate Universal CAR T Cells Resistant to PD1 Inhibition

CLINICAL CANCER RESEARCH

2017

139

CD22-targeted CAR T cells induce remission in B-ALL that is naive or resistant to CD19-targeted CAR immunotherapy

NATURE MEDICINE

2018

138

The Nonsignaling Extracellular Spacer Domain of Chimeric Antigen Receptors Is Decisive for In Vivo Antitumor Activity

CANCER IMMUNOLOGY RESEARCH

2015

137

Multiplex Genome-Edited T-cell Manufacturing Platform for Off-the-Shelf Adoptive T-cell Immunotherapies

CANCER RESEARCH

2015

134

CD27 costimulation augments the survival and antitumor activity of redirected human T cells in vivo

BLOOD

2012

134

Endothelial Activation and Blood-Brain Barrier Disruption in Neurotoxicity after Adoptive Immunotherapy with CD19 CAR-T Cells

CANCER DISCOVERY

2017

127

Engineered CAR T Cells Targeting the Cancer-Associated Tn-Glycoform of the Membrane Mucin MUC1 Control Adenocarcinoma

IMMUNITY

2016

127

Intent-to-treat leukemia remission by CD19 CAR T cells of defined formulation and dose in children and young adults

BLOOD

2017

124

Phase I trials using Sleeping Beauty to generate CD19-specific CAR T cells

JOURNAL OF CLINICAL INVESTIGATION

2016

123

T Cells Expressing CD19/CD20 Bispecific Chimeric Antigen Receptors Prevent Antigen Escape by Malignant B Cells

CANCER IMMUNOLOGY RESEARCH

2016

117

Affinity-Tuned ErbB2 or EGFR Chimeric Antigen Receptor T Cells Exhibit an Increased Therapeutic Index against Tumors in Mice

CANCER RESEARCH

2015

115

Novel immunotherapies in lymphoid malignancies

NATURE REVIEWS CLINICAL ONCOLOGY

2016

114

Chimeric Antigen Receptor T Cells with Dissociated Signaling Domains Exhibit Focused Antitumor Activity with Reduced Potential for Toxicity In Vivo

CANCER IMMUNOLOGY RESEARCH

2013

112

Tandem CAR T cells targeting HER2 and IL13R alpha 2 mitigate tumor antigen escape

JOURNAL OF CLINICAL INVESTIGATION

2016

111

Cancer immunotherapy: harnessing the immune system to battle cancer

JOURNAL OF CLINICAL INVESTIGATION

2015

111

Targeting Fibroblast Activation Protein in Tumor Stroma with Chimeric Antigen Receptor T Cells Can Inhibit Tumor Growth and Augment Host Immunity without Severe Toxicity

CANCER IMMUNOLOGY RESEARCH

2014

111

CD19-targeted CAR T-cell therapeutics for hematologic malignancies: interpreting clinical outcomes to date

BLOOD

2016

108

A Chimeric Switch-Receptor Targeting PD1 Augments the Efficacy of Second-Generation CAR T Cells in Advanced Solid Tumors

CANCER RESEARCH

2016

106

Ibrutinib enhances chimeric antigen receptor T-cell engraftment and efficacy in leukemia

BLOOD

2016

106

Tuning Sensitivity of CAR to EGFR Density Limits Recognition of Normal Tissue While Maintaining Potent Antitumor Activity

CANCER RESEARCH

2015

105

ICOS-based chimeric antigen receptors program bipolar T(H)17/T(H)1 cells

BLOOD

2014

105

Mesothelin-Targeted CARs: Driving T Cells to Solid Tumors

CANCER DISCOVERY

2016

104

CAR-T cells and solid tumors: tuning T cells to challenge an inveterate foe

TRENDS IN MOLECULAR MEDICINE

2012

104

Phase I Hepatic Immunotherapy for Metastases Study of Intra-Arterial Chimeric Antigen Receptor-Modified T-cell Therapy for CEA(+) Liver Metastases

CLINICAL CANCER RESEARCH

2015

103

Chimeric Antigen Receptor Therapy

NEW ENGLAND JOURNAL OF MEDICINE

2018

102

Tumor-Promoting Desmoplasia Is Disrupted by Depleting FAP-Expressing Stromal Cells

CANCER RESEARCH

2015

102

Efficient modification of CCR5 in primary human hematopoietic cells using a megaTAL nuclease and AAV donor template

SCIENCE TRANSLATIONAL MEDICINE

2015

101

Making Better Chimeric Antigen Receptors for Adoptive T-cell Therapy

CLINICAL CANCER RESEARCH

2016

97

Treatment of Advanced Leukemia in Mice with mRNA Engineered T Cells

HUMAN GENE THERAPY

2011

97

Kinetics and biomarkers of severe cytokine release syndrome after CD19 chimeric antigen receptor-modified T-cell therapy

BLOOD

2017

96

Durable Molecular Remissions in Chronic Lymphocytic Leukemia Treated With CD19-Specific Chimeric Antigen Receptor-Modified T Cells After Failure of Ibrutinib

JOURNAL OF CLINICAL ONCOLOGY

2017

95

Switch-mediated activation and retargeting of CAR-T cells for B-cell malignancies

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA

2016

94

Engineering CAR-T cells: Design concepts

TRENDS IN IMMUNOLOGY

2015

91

Global Manufacturing of CAR T Cell Therapy

MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT

2017

90

Reprogramming CD19-Specific T Cells with IL-21 Signaling Can Improve Adoptive Immunotherapy of B-Lineage Malignancies

CANCER RESEARCH

2011

88

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

BLOOD

2015

87

Armed Oncolytic Virus Enhances Immune Functions of Chimeric Antigen Receptor-Modified T Cells in Solid Tumors

CANCER RESEARCH

2014

87

Chimeric Antigen Receptors Modified T-Cells for Cancer Therapy

JNCI-JOURNAL OF THE NATIONAL CANCER INSTITUTE

2016

86

 

 

The authorial organizations and  affiliations of the top 10 were summarized in Table 5. We found that the most cited publications were authored in the University of Pennsylvania (n=33), followed by the University of Texas (n=15). However, the difference in citation frequency was more than double. These are then proceeded by the Memorial Sloan Kettering Cancer Center (n=14), University of Washington (n=13), and Fred Hutchinson Cancer Center (n=12; Table 5). The University of Pennsylvania is the top-cited publication, along with the most cited author (C. H. June; n=30). Subsequently, B. L. Levine (University of Pennsylvania) and S. R. Riddell (Fred Hutchinson Cancer Research Center) published 11 articles each, from the top 100 most cited papers. Also notable was that the organizations and authors of the top 10 most cited papers were all from the US. 

 

 

Table 5. Status of institutions / authors (affiliations) organizations that top 100 cited publications related to CAR-T from 2009 to 2019

Rank

Institutions

Number of Publications

Authors (Affiliation)

Number of Publications

ACPIa

Sum of Times Cited

1

University of Pennsylvania (UPENN)

33

Carl H. June 

(UPENN)

30 

208.13

6244

2

University of Texas MD (UT MD) Anderson Cancer Center

15

Bruce L. Levine (UPENN)

11 

314.00

3454

3

Memorial Sloan Kettering Cancer Center (MSKCC)

14

Stanley R. Riddell
 (FHCC) 

11 

168.91

1858

4

University of Washington (UW)

13

Gianpietro Dotti

(UT MD)

10 

221.50

2215

5

Fred Hutchinson Cancer Center (FHCC)

12

Michel Sadelain (MSKCC) 

265.22

2387

6

National Institutes of Health (NIH)

11

John Scholler 

(UPENN) 

154.33

1389

7

National Cancer Institute (NCI)

11

Michael C V Jensen (SCRI) 

196.63

1573

8

Seattle Children’s

11

Steven M. Albelda (UPENN) 

182.71

1279

9

Baylor College of Medicine

(BCM)

10

Renier J. Brentjens (MSKCC) 

186.71

1159

10

Children’s Hospital of Philadelphia

(CHOP)

8

Stephan A. Grupp 

(CHOP) 

7

394.29

2760

aACPI: Average Citations per Item field (average number of times a record has been cited) [10]

Please verify. Table 3 is cited after Table 4. Consider reordering.

 

 

Table 6. Frequency of keyword that top 100 cited publications related to CAR-T from 2009 to Jun 2019

Keyword

Frequency

Keyword

Frequency

Adoptive immunotherapy

37

Acute lymphoblastic-leukemia

11

Lymphocytes

27

Lymphoma

10

Antitumor activity

25

Sustained remissions

10

Persistence

19

Activation

9

Cancer

18

CD28 costimulation

9

Expression

17

Gene-therapy

9

Therapy

17

Phase-i

9

In vivo

13

Transplantation

9

Leukemia

13

Adverse event

8

B-cell

12

Chronic lymphocytic-leukemia

7