Phase I clinical trial of adoptive transfer of expanded natural killer cells in combination with IgG1 antibody in patients with gastric or colorectal cancer

Natural killer (NK) cells exhibit strong cytotoxic activity against tumor cells without prior sensitization, and have the potential to exert antibody-dependent cellular cytotoxicity (ADCC). In this clinical trial, we examined the safety and efficacy of the use of NK cells, generated using a novel expansion system, in combination with IgG1 antibodies for the treatment of advanced gastric or colorectal cancers. Treatment consisted of trastuzumab- or cetuximab-based chemotherapy, plus adoptive NK cell therapy. For administration of expanded NK cells, dose escalation with a sequential 3 + 3 design was performed in three steps, at doses of 0.5 × 109 , 1.0 × 109 , and 2.0 × 109 cells/injection (N = 9). After 3 days of IgG1 antibody administration, patients were infused with expanded NK cells three times at triweekly intervals. NK cell populations expanded with our system were confirmed as being enriched in NK cells (median 92.9%) with high expression of NKG2D (97.6%) and CD16 (69.6%). The combination therapy was very well tolerated with no severe adverse events. Among six evaluable patients, four presented stable disease (SD) and two presented progressive disease. Of the four SD patients, three showed an overall decrease in tumor size after combination therapy. Immune monitoring suggested that combination therapy enhanced whole blood IFN-γ production and reduced peripheral regulatory T cells (Tregs). In conclusion, this phase I trial provides evidence of good tolerability, induction of Th1 immune responses, and preliminary anti-tumor activity for this combination therapy, in patients with advanced gastric and colorectal cancer that have received previous therapy.

Phase I clinical trial of adoptive transfer of expanded natural killer cells in combination with IgG1 antibody in patients with gastric or colorectal cancer

Natural killer (NK) cells exhibit strong cytotoxic activity against tumor cells without prior sensitization, and have the potential to exert antibody-dependent cellular cytotoxicity (ADCC). In this clinical trial, we examined the safety and efficacy of the use of NK cells, generated using a novel expansion system, in combination with IgG1 antibodies for the treatment of advanced gastric or colorectal cancers. Treatment consisted of trastuzumab- or cetuximab-based chemotherapy, plus adoptive NK cell therapy. For administration of expanded NK cells, dose escalation with a sequential 3 + 3 design was performed in three steps, at doses of 0.5 × 109 , 1.0 × 109 , and 2.0 × 109 cells/injection (N = 9). After 3 days of IgG1 antibody administration, patients were infused with expanded NK cells three times at triweekly intervals. NK cell populations expanded with our system were confirmed as being enriched in NK cells (median 92.9%) with high expression of NKG2D (97.6%) and CD16 (69.6%). The combination therapy was very well tolerated with no severe adverse events. Among six evaluable patients, four presented stable disease (SD) and two presented progressive disease. Of the four SD patients, three showed an overall decrease in tumor size after combination therapy. Immune monitoring suggested that combination therapy enhanced whole blood IFN-γ production and reduced peripheral regulatory T cells (Tregs). In conclusion, this phase I trial provides evidence of good tolerability, induction of Th1 immune responses, and preliminary anti-tumor activity for this combination therapy, in patients with advanced gastric and colorectal cancer that have received previous therapy.

Phase I clinical trial of adoptive transfer of expanded natural killer cells in combination with IgG1 antibody in patients with gastric or colorectal cancer

Natural killer (NK) cells exhibit strong cytotoxic activity against tumor cells without prior sensitization, and have the potential to exert antibody-dependent cellular cytotoxicity (ADCC). In this clinical trial, we examined the safety and efficacy of the use of NK cells, generated using a novel expansion system, in combination with IgG1 antibodies for the treatment of advanced gastric or colorectal cancers. Treatment consisted of trastuzumab- or cetuximab-based chemotherapy, plus adoptive NK cell therapy. For administration of expanded NK cells, dose escalation with a sequential 3 + 3 design was performed in three steps, at doses of 0.5 × 109 , 1.0 × 109 , and 2.0 × 109 cells/injection (N = 9). After 3 days of IgG1 antibody administration, patients were infused with expanded NK cells three times at triweekly intervals. NK cell populations expanded with our system were confirmed as being enriched in NK cells (median 92.9%) with high expression of NKG2D (97.6%) and CD16 (69.6%). The combination therapy was very well tolerated with no severe adverse events. Among six evaluable patients, four presented stable disease (SD) and two presented progressive disease. Of the four SD patients, three showed an overall decrease in tumor size after combination therapy. Immune monitoring suggested that combination therapy enhanced whole blood IFN-γ production and reduced peripheral regulatory T cells (Tregs). In conclusion, this phase I trial provides evidence of good tolerability, induction of Th1 immune responses, and preliminary anti-tumor activity for this combination therapy, in patients with advanced gastric and colorectal cancer that have received previous therapy.

Phase I clinical trial of adoptive transfer of expanded natural killer cells in combination with IgG1 antibody in patients with gastric or colorectal cancer

Natural killer (NK) cells exhibit strong cytotoxic activity against tumor cells without prior sensitization, and have the potential to exert antibody-dependent cellular cytotoxicity (ADCC). In this clinical trial, we examined the safety and efficacy of the use of NK cells, generated using a novel expansion system, in combination with IgG1 antibodies for the treatment of advanced gastric or colorectal cancers. Treatment consisted of trastuzumab- or cetuximab-based chemotherapy, plus adoptive NK cell therapy. For administration of expanded NK cells, dose escalation with a sequential 3 + 3 design was performed in three steps, at doses of 0.5 × 109 , 1.0 × 109 , and 2.0 × 109 cells/injection (N = 9). After 3 days of IgG1 antibody administration, patients were infused with expanded NK cells three times at triweekly intervals. NK cell populations expanded with our system were confirmed as being enriched in NK cells (median 92.9%) with high expression of NKG2D (97.6%) and CD16 (69.6%). The combination therapy was very well tolerated with no severe adverse events. Among six evaluable patients, four presented stable disease (SD) and two presented progressive disease. Of the four SD patients, three showed an overall decrease in tumor size after combination therapy. Immune monitoring suggested that combination therapy enhanced whole blood IFN-γ production and reduced peripheral regulatory T cells (Tregs). In conclusion, this phase I trial provides evidence of good tolerability, induction of Th1 immune responses, and preliminary anti-tumor activity for this combination therapy, in patients with advanced gastric and colorectal cancer that have received previous therapy.

Phase I clinical trial of adoptive transfer of expanded natural killer cells in combination with IgG1 antibody in patients with gastric or colorectal cancer

Natural killer (NK) cells exhibit strong cytotoxic activity against tumor cells without prior sensitization, and have the potential to exert antibody-dependent cellular cytotoxicity (ADCC). In this clinical trial, we examined the safety and efficacy of the use of NK cells, generated using a novel expansion system, in combination with IgG1 antibodies for the treatment of advanced gastric or colorectal cancers. Treatment consisted of trastuzumab- or cetuximab-based chemotherapy, plus adoptive NK cell therapy. For administration of expanded NK cells, dose escalation with a sequential 3 + 3 design was performed in three steps, at doses of 0.5 × 10⁹ , 1.0 × 10⁹ , and 2.0 × 10⁹ cells/injection (N = 9). After 3 days of IgG1 antibody administration, patients were infused with expanded NK cells three times at triweekly intervals. NK cell populations expanded with our system were confirmed as being enriched in NK cells (median 92.9%) with high expression of NKG2D (97.6%) and CD16 (69.6%). The combination therapy was very well tolerated with no severe adverse events. Among six evaluable patients, four presented stable disease (SD) and two presented progressive disease. Of the four SD patients, three showed an overall decrease in tumor size after combination therapy. Immune monitoring suggested that combination therapy enhanced whole blood IFN-γ production and reduced peripheral regulatory T cells (Tregs). In conclusion, this phase I trial provides evidence of good tolerability, induction of Th1 immune responses, and preliminary anti-tumor activity for this combination therapy, in patients with advanced gastric and colorectal cancer that have received previous therapy.

Efficient tumor regression by adoptively transferred CEA-specific CAR-T cells associated with symptoms of mild cytokine release syndrome

Carcinoembryonic antigen (CEA) is a cell surface antigen highly expressed in various cancer cell types and in healthy tissues. It has the potential to be a target for chimeric antigen receptor (CAR)-modified T-cell therapy; however, the safety of this approach in terms of on-target/off-tumor effects needs to be determined. To address this issue in a clinically relevant model, we used a mouse model in which the T cells expressing CEA-specific CAR were transferred into tumor-bearing CEA-transgenic (Tg) mice that physiologically expressed CEA as a self-antigen. The adoptive transfer in conjunction with lymphodepleting and myeloablative preconditioning mediated significant tumor regression but caused weight loss in CEA-Tg, but not in wild-type mice. The weight loss was not associated with overt inflammation in the CEA-expressing gastrointestinal tract but was associated with malnutrition, reflected in elevated systemic levels of cytokines linked to anorexia, which could be controlled by the administration of an anti-IL-6 receptor monoclonal antibody without compromising efficacy. The apparent relationship between lymphodepleting and myeloablative preconditioning, efficacy, and off-tumor toxicity of CAR-T cells would necessitate the development of CEA-specific CAR-T cells with improved signaling domains that require less stringent preconditioning for their efficacy. Taken together, these results suggest that CEA-specific CAR-based adoptive T-cell therapy may be effective for patients with CEA⁺ solid tumors. Distinguishing the fine line between therapeutic efficacy and off-tumor toxicity would involve further modifications of CAR-T cells and preconditioning regimens.

A Functionally Superior Second-Generation Vector Expressing an Aurora Kinase-A-Specific T-Cell Receptor for Anti-Leukaemia Adoptive Immunotherapy

Aurora Kinase A is a cancer-associated protein normally involved in the regulation of mitosis. Being over-expressed in a range of cancers, it is a suitable target for cell-based immunotherapy. Gene transfer of T-cell receptor sequences cognisant of HLA-A*0201-restricted Aurora Kinase A antigen has previously been shown to transfer specific immunoreactivity against the target peptide in a Human Lymphocyte Antigen-restricted manner. While T cell receptor gene-transfer has great potential in overcoming the difficulties of isolating and expanding tumour-reactive lymphocytes from a patient’s own cells, one hurdle is potential mispairing and competition between exogenous and endogenous T cell receptor chains. We have used a retroviral vector design bearing a short-interfering RNA that downregulates endogenous T cell receptor chains, without affecting expression of the transgenic T cell receptor sequences. The T cell receptor expression cassette also includes a 2A self-cleaving peptide, resulting in equimolar expression of the T cell receptor alpha and beta chains, further enhancing formation of the desired T cell receptor. Via a simple, modular cloning method, we have cloned the alpha and beta chains of the anti-Aurora Kinase A-reactive T cell receptor into this ‘siTCR’ vector. We then compared the activity of this vector against the original, ‘conventional’ vector across a panel of assays. T cell receptors expressed from the siTCR-vector retained the cytotoxic functionality of the original vector, with evidence of reduced off-target reactivity. The rate of expression of correctly-formed T cell receptors was superior using the siTCR design, and this was achieved at lower vector copy numbers. Maintaining T cell receptor efficacy with a reduced vector copy number reduces the risk of genotoxicity. The siTCR design also reduces the risk of mispairing and cross-reactivity, while increasing the functional titre. Such improvements in the safety of T cell receptor gene-transfer will be crucial for clinical applications of this technology.

Development of Engineered T Cells Expressing a Chimeric CD16-CD3ζ Receptor to Improve the Clinical Efficacy of Mogamulizumab Therapy Against Adult T-Cell Leukemia

PURPOSE

Mogamulizumab (Mog), a humanized anti-CC chemokine receptor 4 (CCR4) mAb that mediates antibody-dependent cellular cytotoxicity (ADCC) using FcγR IIIa (CD16)-expressing effector cells, has recently been approved for treatment of CCR4-positive adult T-cell leukemia (ATL) in Japan. However, Mog failure has sometimes been observed in patients who have accompanying chemotherapy-associated lymphocytopenia. In this study, we examined whether adoptive transfer of artificial ADCC effector cells combined with Mog would overcome this drawback.

EXPERIMENTAL DESIGN

We lentivirally gene-modified peripheral blood T cells from healthy volunteers and ATL patients expressing the affinity-increased chimeric CD16-CD3ζ receptor (cCD16ζ-T cells). Subsequently, we examined the ADCC effect mediated by those cCD16ζ-T cells in the presence of Mog against ATL tumor cells both in vitro and in vivo

RESULTS

cCD16ζ-T cells derived from healthy donors killed in vitro Mog-opsonized ATL cell line cells (n = 7) and primary ATL cells (n = 4) depending on both the number of effector cells and the dose of the antibody. cCD16ζ-T cells generated from ATL patients (n = 3) also exerted cytocidal activity in vitro against Mog-opsonized autologous ATL cells. Using both intravenously disseminated model (n = 5) and subcutaneously inoculated model (n = 4), coadministration of Mog and human cCD16ζ-T cells successfully suppressed tumor growth in xenografted immunodeficient mice, and significantly prolonged their survival (P < 0.01 and P = 0.02, respectively).

CONCLUSIONS

These data strongly suggest clinical feasibility of the novel combined adoptive immunotherapy using cCD16ζ-T cells and Mog for treatment of aggressive ATL, particularly in patients who are ineligible for allogeneic hematopoietic stem cell transplantation. Clin Cancer Res; 22(17); 4405-16. ©2016 AACR.

Donor lymphocytes expressing the herpes simplex virus thymidine kinase suicide gene: detailed immunological function following add-back after haplo-identical transplantation

BACKGROUND AIMS

Haplo-identical hematopoietic stem cell transplantation (HSCT) with add-back of donor lymphocytes expressing the herpes simplex virus thymidine kinase suicide gene (TK cells) is one of the most widely applied promising new gene therapy approaches. However, the immunological status of added-back TK cells after HSCT has yet to be well characterized.

METHODS

We investigated TK cells through the use of flow cytometry, T-cell receptor (TCR) Vβ repertoire spectratyping and linear amplification-mediated polymerase chain reaction followed by insertion site analysis in a patient enrolled in our clinical trial.

RESULTS

A comparison of onset with remission of acute graft-versus-host disease confirmed that TK cells were predominantly eliminated and that proliferative CD8(+) non-TK cells were also depleted in response to ganciclovir administration. The TCR Vβ-chain repertoire of both TK cells and non-TK cells markedly changed after administration of ganciclovir, and, whereas the TCR repertoire of non-TK cells returned to a normal spectratype long after transplantation, that of TK cells remained skewed. With the long-term prophylactic administration of acyclovir, TK cells oligoclonally expanded and the frequency of spliced variants of TK cells increased. Known cancer-associated genes were not evident near the oligoclonally expanded herpes simplex virus (HSV)-TK insertion sites.

CONCLUSIONS

We demonstrate obvious differences in immunological status between TK cells and non-TK cells. In addition, we speculate that long-term prophylactic administration of acyclovir increases the risk of oligoclonal expansion of spliced forms of TK cells.

Phase I clinical trial of autologous NK cell therapy using novel expansion method in patients with advanced digestive cancer

Background

NK cells can destroy tumor cells without prior sensitization or immunization. Tumors often lose expression of MHC molecules and/or antigens. However, NK cells can lyse tumor cells in a non-MHC-restricted manner and independent of the expression of tumor-associated antigens. NK cells are therefore considered ideal for adoptive cancer immunotherapy; however the difficulty of obtaining large numbers of fully functional NK cells that are safe to administer deters its clinical use. This phase I clinical trial seeks to address this obstacle by first developing a novel system that expands large numbers of highly activated clinical grade NK cells, and second, determining if these cells are safe in a mono-treatment so they can be combined with other reagents in the next round of clinical trials.

Methods

Patients with unresectable, locally advanced and/or metastatic digestive cancer who did not succeed with standard therapy were enrolled. NK cells were expanded ex vivo by stimulating PBMCs with OK432, IL-2, and modified FN-CH296 induced T cells. Patients were administered autologous natural killer cell three times weekly via intravenous infusions in a dose-escalating manner (dose 0.5 × 10⁹, 1.0 × 10⁹, 2.0 × 10⁹ cells/injection, three patients/one cohort).

Results

Total cell population had a median expansion of 586-fold (range 95–1102), with a significantly pure (90.96 %) NK cell population. Consequently, NK cells were expanded to approximately 4720-fold (range 1372–14,116) with cells being highly lytic in vitro and strongly expressing functional markers such as NKG2D and CD16. This NK cell therapy was very well tolerated with no severe adverse events. Although no clinical responses were observed, cytotoxicity of peripheral blood was elevated approximately twofolds up to 4 weeks post the last transfer.

Conclusion

We successfully generated large numbers of activated NK cells from small quantities of blood without prior purification of the cells. We also determined that the expanded cells were safe to administer in a monotherapy and are suitable for the next round of clinical trials where their efficacy will be tested combined with other reagents.

Trial Registration: UMIN UMIN000007527

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-015-0632-8) contains supplementary material, which is available to authorized users.

Abstract 3137: A novel expansion method for functional natural killer cells and its clinical application

Background: Natural killer (NK) cell-based adoptive immunotherapy is a promising approach for the treatment of cancer. But, it is difficult to generate the sufficient scale and purity of NK cells, and reliable methods to produce large number of functional NK cells have not been established yet. We have developed novel clinical-grade NK cells expansion method to produce the high purity, large scale and functional NK cells using a combination of recombinant human fibronectin fragment (RetroNectin®) -induced T-cells (RN-T cells), OK-432 and IL-2. We subsequently conducted a Phase 1 clinical study to evaluate the safety and efficacy of this NK cell therapy. In this paper, we address the characteristics of the NK cells elicited by this method and the results of immune monitoring in the clinical trial.

Methods: To confirm the significance of RN-T cells as stimulator, we compared the stimulation effects on NK cells between RN-T cells and aCD3-T cells, which stimulated by anti-CD3 mAb only. Next, we analyzed expanded NK cells from PBMCs obtained from 31 cancer patients to verify the efficacy of this method. In the Phase 1 trial, patients with unresectable digestive cancer were enrolled. They received weekly intravenous administration of autologous NK cells elicited by the novel method three times to assess the safety of the number of adoptive cells at 0.5 × 109(cohort1), 1 × 109(cohort 2) and 2 × 109 cells (cohort 3) per dose. The phenotype and cytotoxicity of expanded NK cells were analyzed. For immune monitoring, cytotoxicity of PBMCs and whole blood cytokine levels were examined following NK cell infusion.

Results: The stimulation by RN-T cells could induce preferable NK cell proliferation rather than the one by aCD3-T. As results of 31 cancer patients, 688±76-fold expansion was achieved in this system with PBMCs, and the NK cell populations were highly purified (84.7±3.6%) and highly expressed functional markers such as NKG2D (97.3±0.6%) and CD16 (96.8±0.7%). In the Phase 1 clinical trial, no NK cell infusion related severe or unexpected toxicities were observed. The response rate and the disease control rate in 10 per protocol patients were 0% and 50.0%, respectively. Although no clinical responses were observed, the cytotoxicity of PBMCs against K-562 targets increased in most patients (80%). The average of cytotoxic activity of PBMCs increased more than two times after the NK cell infusion.

Conclusion:

Although no patients receiving the NK cell therapy alone experienced a clinical response, adoptive immunotherapy of the NK cells elicited by the novel method is expected to exert considerable ADCC activity in vivo because of their high expression of CD16. Now, we are conducting clinical trial in which we explore the combination of this novel NK therapy with IgG1 antibodies such as trastuzumab and cetuximab. We also address the ongoing clinical trial in this paper.

Citation Format: Takeshi Ishikawa, Naoyuki Sakamoto, Tetsuya Okayama, Kaname Oka, Satoshi Kokura, Mitsuko Ideno, Akiko Kato, Tatsuji Enoki, Masanari Kitagawa, Junichi Mineno, Tomoyo Yasuda, Toshifumi Doi, Yuji Naito, Yoshito Itoh, Toshikazu Yoshikawa. A novel expansion method for functional natural killer cells and its clinical application. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3137. doi:10.1158/1538-7445.AM2015-3137

Antileukemia multifunctionality of CD4(+) T cells genetically engineered by HLA class I-restricted and WT1-specific T-cell receptor gene transfer

To develop gene-modified T-cell-based antileukemia adoptive immunotherapy, concomitant administration of CD4(+) and CD8(+) T cells that have been gene modified using identical HLA class I-restricted leukemia antigen-specific T-cell receptor (TCR) gene transfer has not yet been fully investigated. Here, using CD4(+) and CD8(+) T cells that had been gene modified with a retroviral vector expressing HLA-A*24:02-restricted and Wilms' tumor 1 (WT1)-specific TCR-α/β genes and siRNAs for endogenous TCRs (WT1-siTCR/CD4(+) T cells and WT1-siTCR/CD8(+) T cells), we examined the utility of this strategy. WT1-siTCR/CD4(+) T cells sufficiently recognized leukemia cells in an HLA class I-restricted manner and provided target-specific Th1 help for WT1-siTCR/CD8(+) T cells. By using a xenografted mouse model, we found that WT1-siTCR/CD4(+) T cells migrated to leukemia sites and subsequently attracted WT1-siTCR/CD8(+) T cells via chemotaxis. Therapy-oriented experiments revealed effective enhancement of leukemia suppression mediated by concomitant administration of WT1-siTCR/CD4(+) T cells and WT1-siTCR/CD8(+) T cells. Importantly, this augmented efficacy in the presence of WT1-siTCR/CD4(+) T cells was correlated with longer survival and enhanced formation of memory T cells by WT1-siTCR/CD8(+) T cells. Collectively, our experimental findings strongly suggest that this strategy would be clinically advantageous for the treatment of human leukemia.

Outcomes in two Japanese adenosine deaminase-deficiency patients treated by stem cell gene therapy with no cytoreductive conditioning

OBJECTIVE

We here describe treatment outcomes in two adenosine deaminase (ADA)-deficiency patients (pt) who received stem cell gene therapy (SCGT) with no cytoreductive conditioning. As this protocol has features distinct from those of other clinical trials, its results provide insights into SCGT for ADA deficiency.

PATIENTS AND METHODS

Pt 1 was treated at age 4.7 years, whereas pt 2, who had previously received T-cell gene therapy, was treated at age 13 years. Bone marrow CD34(+) cells were harvested after enzyme replacement therapy (ERT) was withdrawn; following transduction of ADA cDNA by the γ-retroviral vector GCsapM-ADA, they were administered intravenously. No cytoreductive conditioning, at present considered critical for therapeutic benefit, was given before cell infusion. Hematological/immunological reconstitution kinetics, levels of systemic detoxification, gene-marking levels, and proviral insertion sites in hematopoietic cells were assessed.

RESULTS

Treatment was well tolerated, and no serious adverse events were observed. Engraftment of gene-modified repopulating cells was evidenced by the appearance and maintenance of peripheral lymphocytes expressing functional ADA. Systemic detoxification was moderately achieved, allowing temporary discontinuation of ERT for 6 and 10 years in pt 1 and pt 2, respectively. Recovery of immunity remained partial, with lymphocyte counts in pts 1 and 2, peaked at 408/mm(3) and 1248/mm(3), approximately 2 and 5 years after SCGT. Vector integration site analyses confirmed that hematopoiesis was reconstituted with a limited number of clones, some of which were shown to have myelo-lymphoid potential.

CONCLUSIONS

Outcomes in SCGT for ADA-SCID are described in the context of a unique protocol, which used neither ERT nor cytoreductive conditioning. Although proven safe, immune reconstitution was partial and temporary. Our results reiterate the importance of cytoreductive conditioning to ensure greater benefits from SCGT.

Adoptive Transfer of MAGE-A4 T-cell Receptor Gene-Transduced Lymphocytes in Patients with Recurrent Esophageal Cancer

PURPOSE

Preparative lymphodepletion, the temporal ablation of the immune system, has been reported to promote persistence of transferred cells along with increased rates of tumor regression in patients treated with adoptive T-cell therapy. However, it remains unclear whether lymphodepletion is indispensable for immunotherapy with T-cell receptor (TCR) gene-engineered T cells.

EXPERIMENTAL DESIGN

We conducted a first-in-man clinical trial of TCR gene-transduced T-cell transfer in patients with recurrent MAGE-A4-expressing esophageal cancer. The patients were given sequential MAGE-A4 peptide vaccinations. The regimen included neither lymphocyte-depleting conditioning nor administration of IL2. Ten patients, divided into 3 dose cohorts, received T-cell transfer.

RESULTS

TCR-transduced cells were detected in the peripheral blood for 1 month at levels proportional to the dose administered, and in 5 patients they persisted for more than 5 months. The persisting cells maintained ex vivo antigen-specific tumor reactivity. Despite the long persistence of the transferred T cells, 7 patients exhibited tumor progression within 2 months after the treatment. Three patients who had minimal tumor lesions at baseline survived for more than 27 months.

CONCLUSIONS

These results suggest that TCR-engineered T cells created by relatively short-duration in vitro culture of polyclonal lymphocytes in peripheral blood retained the capacity to survive in a host. The discordance between T-cell survival and tumor regression suggests that multiple mechanisms underlie the benefits of preparative lymphodepletion in adoptive T-cell therapy.

Abstract 2791: Advantages and clinical application of fibronectin CH296-stimulated T cells in cancer immunotherapy

Background: In adoptive T-cell therapy (ACT), the differentiation state of transferred T cells is considered to be crucial to the success of ACT-based approaches. It has been reported that less-differentiated T cells, which have a higher proliferative potential and less prone to apoptosis than more differentiated cells, are ideal for ACT transfer therapy. In this study, we compared the co-stimulation effects of fibronectin CH296 (FN-CH296, RetroNectin®) with that of anti-28Ab or anti-4-1 BB Ab on T-cell expansion and its phenotype. Furthermore, we examined persistence of T cells expanded by these methods in NOG® mice. In addition, we conducted phase 1 clinical study to evaluate the safety and efficacy of FN-CH296 stimulated T cell therapy in patients with advanced cancer.

Methods: PBMCs were activated by various stimulation methods and cultured in gas-permeable culture bag CultiLifeTM 215 and CultiLifeTM Eva for 10-14 days. After that, each expanded cells were analyzed for its phenotypes, in vivo persistence and the ability of accumulation in lymph node. In clinical study, patients underwent FN-CH296 stimulated T cell therapy up to six times every two weeks and safety and antitumor activity of the ACT were assessed. In order to determine immune function, whole blood cytokine levels were analyzed prior to ACT and during the follow up.

Results: Co-stimulation by FN-CH296 with anti-CD3Ab led to higher T-cell expansion and proportion of CCR7+CD45RA+ T cells than that by the others (anti-28Ab/anti-4-1BB Ab). In the experiment for engraftment of expanded T cells in NOG mice, human CD3+ cells were detected in all groups, but the proportion of CCR7+CD45RA+ and CD8+ T cells was significantly higher specifically in the FN-CH296 co-stimulation condition. In addition, higher accumulation of human CD3+ cells in lymph node of NOG® mice was observed when stimulated by the FN-CH296 co-stimulation condition. In phase 1 clinical trial, nine patients were enrolled and infused 1, 3, or 9×109 of T cells to each cohort group (3 patients in each group). As a result, there was no ACT-related serious adverse event in all doses and one patient achieved CR, one achieved PR, four had SD, and three had PD. The number of less-differentiated cells that was infused showed a strong positive correlation with the change in whole blood IFN-γ level after ACT treatment.

Conclusion: These results indicated that FN-CH296 stimulated T cells therapy was very well tolerated with a level of efficacy that is promising and the FN-CH296 stimulation method for ex vivo T-cell expansion is useful as basic technology for adoptive T-cell therapy, as it can be expanded preferentially less-differentiated T cells.

Citation Format: Takeshi Ishikawa, Satoshi Kokura, Tetsuya Okayama, Naoyuki Sakamoto, Mitsuko Ideno, Nobuko Muraki, Akiko Kato, Tatsuji Enoki, Junichi Mineno, Yuji Naito, Yoshito Itoh, Toshikazu Yoshikawa. Advantages and clinical application of fibronectin CH296-stimulated T cells in cancer immunotherapy. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2791. doi:10.1158/1538-7445.AM2014-2791

Abstract CT214: High purity and activity NK cells therapy in patients with advanced gastrointestinal cancer: Phase I study

PURPOSE:

Our group exploited the novel technique of cultivating high purity and activity NK cells compared with traditional technique from peripheral blood of cancer patients. This phase I study investigated the safety and maximum-tolerated dose of the infusion NK cell number in patients with untreatable advanced gastrointestinal cancer.

PATIENTS AND METHODS:

Patients with gastrointestinal cancer who previously failed standard chemotherapy regimens were treated with three doses of NK cells infusion. We set three dose levels of NK cells infusion. The numbers of infusion NK cells were 5 X 108 cells as cohort 1, 1 X 109 cells as cohort 2, 2 X 109 cells as cohort 3 and each patient was infused NK cells three times per 1 or 2 weeks. The culture method of NK cells described as below; firstly CH296 (FN-CH296, RetroNctin®) induced T cells (RN-T) were prepared in advance by previously reported method, and processed to use as stimulator cells. NK cells were expanded from peripheral blood mononuclear cells by stimulating with modified RN-T, OK-432 and IL-2, then cultured for 21-22 days. We also established large-scale culture system using gas-permeable culture bag for clinical application.

RESULTS:

14 patients were totally enrolled in this study. Of 14 patients, 7 patients were enrolled in cohort 1 study. Of 7 patients, 4 patients couldn't complete NK cells infusion because of some reasons such as bad NK cell proliferation, less purity of active NK cells and worsening of primary cancer. 3 patients could complete in cohort 1. 4 patients were enrolled in cohort 2 study. Of 4 patients, 1 patient couldn't complete the NK cell infusion because of worsening of primary cancer. 3 patients could complete and 1 patient experienced grade 2 pleural effusion accumulation. In cohort 3 study, 3 patients were enrolled. All of 3 patients could complete NK cells infusion, and only 1 patient experienced grade 1 low grade fever. As clinical response, 1 partial response (PR) at cohort 2 and 6 stable diseases (SD) at 4 patients in cohort 1, 1 patient in cohort2 and 1 patient in cohort 3 were observed. In addition, we checked the immune monitoring in detail for all patients.

CONCLUSIONS:

High purity and activity NK cells therapy was safety and maximum-tolerated dose was 2 X 109 cells. The evaluation is needed to further refine the efficacy and the toxicity of the combination therapy, chemotherapy, IgG1 molecular target drugs and this therapy for using this therapy in clinical in the future.

Citation Format: Tetsuya Okayama, Satoshi Kokura, Takeshi ishikawa, Naoyuki Sakamoto, Mitsuko Ideno, Fumiyo Sakai, Akiko Kato, Tatsuji Enoki, Junichi Mineno, Hideyuki Konishi, Yuji Naito, Yoshito Itoh, Toshikazu Yoshikawa. High purity and activity NK cells therapy in patients with advanced gastrointestinal cancer: Phase I study. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr CT214. doi:10.1158/1538-7445.AM2014-CT214

Abstract CT212: Adoptive transfer of wild-type TCR gene transduced T lymphocytes targeting MAGE-A4 antigen to patients with refractory esophageal cancer

Introduction:

Engineering an antigen receptor gene in patients' lymphocytes is one promising strategy to create antigen-specific lymphocytes without senescent phenotypes. The strategy provides an opportunity to extend the application of adoptive T cell therapy for cancer patients. However, this concept has not been tested in epithelial cancer patients.

Material and methods:

MAGE-A4-specific TCR α and β chains were isolated from a human T cell clone that recognizes MAGE-A4 143-151 peptide in an HLA-A*24:02 restricted manner. This T cell clone did not show any cross reactivity to the peptides with a homology to the MAGE-A4 epitope. A retroviral vector that encodes these TCR chains without any artificial modification was constructed; the lymphocytes transduced with the retroviral vector killed the MAGE-A4 expressing tumor in vitro and inhibited the tumor growth in the NOG immmunodeficient mice.

Patients were eligible if they had previously-treated recurrent MAGE-A4-expressing esophageal cancer, and were positive for HLA-A*24;02. Lymphocytes harvested from the patients were infected with the retroviral vector. The TCR-gene transduced T lymphocytes were once transferred to the patients without lymphocyte-depleting treatment, and MAGE-A4 peptide was given 2 and 4 weeks after. The cell doses were divided into 3 cohorts of 2x108 1x109 and 5x109, with a dose-escalating design, by evaluating the safety.

Results:

10 patients received the TCR-gene transduced T lymphocytes. No adverse events related to the cell transfer were observed. The TCR-gene transduced lymphocytes were detected in their peripheral blood in all 10 patients, which showed a dose-dependent appearance during the first 14 days, reaching peak and plateau levels from 3 to 7 days, and declined within 14 days. The cells persisted at 0.5% to 1% level in the peripheral mononuclear cells from day 14 to 63 after the cell transfer. In 6 patients whose blood samples had been collected for over 6 months, 3 patients maintained stable levels as long as 16 months, maintaining the immune reactivity to MAGE-A4-expressing tumor cells. In one patient, whose esophageal tumor was biopsied after the transfer, the TCR-gene transduced cells were detected in the tumor site.

7 patients developed tumor progressions within 2 months after the transfer. Their overall survivals were ranged from 3 to 18+ months, with a median of 10. 3 patients who had minimal tumor lesions at baseline have been free from disease-progression for 12, 15, and 19 months, respectively.

Conclusion:

Wild-type TCR-gene transduced lymphocytes targeting MAGE-A4 antigen were safely given to refractory esophageal cancer patients. The cells persisted in their peripheral blood in a dose-dependent manner in the early phase, and they have been stably persisting over 6 months. Three patients are free from disease progression more than a year. These results encourage us to proceed to further phase trials.

Citation Format: Shinichi Kageyama, Hiroaki Ikeda, Naoko Imai, Mikiya Ishihara, Yoshihiro Miyahara, Shugo Ueda, Takeshi Ishikawa, Hiroaki Naota, Kohshi Ohishi, Taizo Shiraishi, Naoki Inoue, Masashige Tanabe, Tomohide Kidokoro, Hirofumi Yoshioka, Daisuke Tomura, Ikuei Nukaya, Junichi Mineno, Kazutoh Takesako, Naoyuki Katayama, Hiroshi Shiku. Adoptive transfer of wild-type TCR gene transduced T lymphocytes targeting MAGE-A4 antigen to patients with refractory esophageal cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr CT212. doi:10.1158/1538-7445.AM2014-CT212

Systemic CD8+ T cell-mediated tumoricidal effects by intratumoral treatment of oncolytic herpes simplex virus with the agonistic monoclonal antibody for murine glucocorticoid-induced tumor necrosis factor receptor

Oncolytic virotherapy combined with immunomodulators is a novel noninvasive strategy for cancer treatment. In this study, we examined the tumoricidal effects of oncolytic HF10, a naturally occurring mutant of herpes simplex virus type-1, combined with an agonistic DTA-1 monoclonal antibody specific for the glucocorticoid-induced tumor necrosis factor receptor. Two murine tumor models were used to evaluate the therapeutic efficacies of HF10 virotherapy combined with DTA-1. The kinetics and immunological mechanisms of DTA-1 in HF10 infection were examined using flow cytometry and immunohistochemistry. Intratumoral administration of HF10 in combination with DTA-1 at a low dose resulted in a more vigorous attenuation of growth of the untreated contralateral as well as the treated tumors than treatment with either HF10 or DTA-1 alone. An accumulation of CD8⁺ T cells, including tumor- and herpes simplex virus type-1-specific populations, and a decrease in the number of CD4⁺ Foxp3⁺ T regulatory cells were seen in both HF10- and DTA-1-treated tumors. Studies using Fc-digested DTA-1 and Fcγ receptor knockout mice demonstrated the direct participation of DTA-1 in regulatory T cell depletion by antibody-dependent cellular cytotoxicity primarily via macrophages. These results indicated the potential therapeutic efficacy of a glucocorticoid-induced tumor necrosis factor receptor-specific monoclonal antibody in oncolytic virotherapy at local tumor sites.

CD4(+) T Cells Modified by the Endoribonuclease MazF Are Safe and Can Persist in SHIV-infected Rhesus Macaques

MazF, an endoribonuclease encoded by Escherichia coli, specifically cleaves the ACA (adenine–cytosine–adenine) sequence of single-stranded RNAs. Conditional expression of MazF under the control of the HIV-1 LTR promoter rendered CD4⁺ T cells resistant to HIV-1 replication without affecting cell growth. To investigate the safety, persistence and efficacy of MazF-modified CD4⁺ T cells in a nonhuman primate model in vivo, rhesus macaques were infected with a pathogenic simian/human immunodeficiency virus (SHIV) and transplanted with autologous MazF-modified CD4⁺ T cells. MazF-modified CD4⁺ T cells were clearly detected throughout the experimental period of more than 6 months. The CD4⁺ T cell count values increased in all four rhesus macaques. Moreover, the transplantation of the MazF-modified CD4⁺ T cells was not immunogenic, and did not elicit cellular or humoral immune responses. These data suggest that the autologous transplantation of MazF-modified CD4⁺ T cells in the presence of SHIV is effective, safe and not immunogenic, indicating that this is an attractive strategy for HIV-1 gene therapy.

Stimulation through very late antigen-4 and -5 improves the multifunctionality and memory formation of CD8⁺ T cells

T cells express multiple integrin molecules. The significance of signaling through these molecules on acquisition of T-cell effector functions and memory formation capacity remains largely unknown. Moreover, the impact of stimulation through these signals on the generation of T cells for adoptive immunotherapy has not been elucidated. In this study, using a recombinant fragment of fibronectin, CH-296, we demonstrated that stimulation via very late Ag (VLA)-4 and VLA-5 in human and BALB/c mouse CD8(+) T cells, in combination with TCR stimulation, enhances effector multifunctionality and in vivo memory formation. Using TCR-transgenic mouse-derived CD8(+) T cells expressing TCR specific for the syngeneic CMS5 fibrosarcoma-derived tumor Ag, we showed that stimulation by CH-296 improved the ability of tumor-specific CD8(+) T cells to inhibit CMS5 tumor growth when adoptively transferred into hosts with progressing tumors. Improved antitumor effects were associated with decreased infiltration of Foxp3(+) CD4(+) Treg cells in tumors. These results suggest that stimulation via VLA-4 and VLA-5 modulates the qualities of effector T cells and could potentially increase the efficacy of adoptive therapy against cancer.