A Phase I Clinical Trial of Treatment of B-Cell Malignancies with Autologous Anti-CD19-CAR-Transduced T Cells

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 2865-2865 ◽  
Author(s):  
James N. Kochenderfer ◽  
Mark E. Dudley ◽  
Maryalice Stetler-Stevenson ◽  
Wyndham H. Wilson ◽  
John E. Janik ◽  
...  

Abstract Abstract 2865 T cells can be genetically modified to express chimeric antigen receptors (CARs) that specifically recognize the B-cell antigen CD19. Adoptive transfer of autologous T cells expressing anti-CD19 CARs is an attractive new approach for treating B-cell malignancies. We have constructed a CAR that consists of the variable regions of a mouse-anti-human-CD19 antibody coupled to the signaling domains of CD28 and CD3-zeta. We have treated 5 patients with 2 doses of 60 mg/kg of cyclophosphamide and 5 doses of 25 mg/m2 of fludarabine followed by infusions of anti-CD19-CAR-transduced T cells and administration of high-dose IL-2. All of the patients received infusions of cells that produced cytokines in a CD19-specific manner. The percentage of the infused cells that expressed the anti-CD19 CAR as measured by flow cytometry ranged from 45% to 65%. The first patient enrolled on our trial has follicular lymphoma. He was treated twice. The patient obtained a partial remission (PR) from his first course of chemotherapy, 0.4×109 anti-CD19-CAR-transduced T cells, and IL-2 (reported in Kochenderfer et al. Blood First Edition); however, he subsequently developed progressive disease, and 40 weeks after his first CAR-transduced T cell infusion he received a second course of chemotherapy followed by 2×109 CAR-transduced T cells and IL-2. The second course of treatment resulted in an additional PR and was not associated with any toxicity that could be attributed to the CAR-transduced T cells. At last follow-up, a small amount residual disease detected only by positron emission tomography remained. In this first patient, the initial treatment course resulted in eradication of blood and bone marrow B-lineage cells for 39 weeks. In contrast to the prolonged eradication of B-lineage cells after the initial treatment course, the number of polyclonal blood B cells normalized 9 weeks after the second CAR-transduced T cell infusion. CAR-transduced T cells were present at a level of 0.1% of total peripheral blood mononuclear cells (PBMCs) one month after the first CAR-transduced T cell infusion. Despite the five-fold higher dose of CAR-transduced T cells administered with the second treatment, CAR-transduced T cells were not detected in the blood one month after the second CAR-transduced T cell infusion. The second patient treated on our protocol had follicular lymphoma and had received extensive prior therapy including autologous stem cell transplantation. After an initially uncomplicated course, this patient developed pneumonia caused by culture-proven influenza A virus and died 18 days after CAR-transduced T cell infusion. Quantitative PCR was used to measure the level of CAR-transduced cells in multiple tissues obtained from this patient at autopsy. CAR-transduced cells were widely distributed with the highest levels in the spleen and bone marrow. The third patient treated on our trial obtained a complete remission of advanced chronic lymphocytic leukemia (CLL) after treatment with chemotherapy, infusion of 2×109 anti-CD19-CAR-transduced T cells, and IL-2. At the time of last follow-up, three months after treatment, adenopathy had resolved, CLL cells were not detected by flow cytometry analysis of the blood and bone marrow, and the number of normal polyclonal B cells in the blood was below normal levels. This patient had a period of fever and hypotension 7 days after cell infusion that was associated with an elevated serum interferon-gamma level of 1532 pg/mL. At the time of the hypotensive episode 7 days after cell infusion, anti-CD19-CAR-transduced cells made up 2.1% of PBMCs. The fourth patient treated on our study obtained a PR of splenic marginal zone lymphoma that continues 2 months after treatment with chemotherapy, 2×109 CAR-transduced T cells, and IL-2. This patient did not have prolonged depletion of normal B cells after treatment, and he did not have any toxicity that could be attributed to the anti-CD19 CAR-transduced T cells. We recently treated a fifth patient who has CLL. Follow-up on this patient is too short to evaluate toxicity or response. In conclusion, we have shown that adoptive transfer of anti-CD19-CAR-transduced T cells with in vivo activity is feasible. The promising results obtained on this trial raise important questions for future research aimed at optimizing therapy with anti-CD19-CAR-transduced T cells. Disclosures: No relevant conflicts of interest to declare.

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 1554-1554
Author(s):  
Lucy S. Hodge ◽  
Steve Ziesmer ◽  
Frank J Secreto ◽  
Zhi-Zhang Yang ◽  
Anne Novak ◽  
...  

Abstract Abstract 1554 T cells in the tumor microenvironment influence the biology of malignant cells in many hematologic malignancies, often through cytokine-mediated interactions. Recent studies involving healthy B cells and CD4+T cells identified an interplay between IL-6 and IL-21, whereby IL-6 increased IL-21 production by T cells, driving the differentiation and IL-6 secretion of nearby B cells. In addition to their known effects on healthy B cell function, IL-6 and IL-21 have also been implicated in the pathology of various lymphomas. In Waldenstrom's macroglobulinemia (WM), IL-6 is elevated in the bone marrow and is associated with increased IgM production. However, the function of IL-21 in the WM tumor microenvironment and its relationship to IL-6 is poorly understood. Our objective in this study was to characterize IL-21 production and function in WM and to examine the role of IL-6 and IL-21 in regulating interactions between malignant B cells and T cells in the tumor microenvironment. Immunohistochemistry revealed significant IL-21 staining in bone marrows of patients with WM (n=5), but the areas of infiltration by WM in the bone marrow sections appeared negative for IL-21 staining. To better understand the origin of IL-21 in in the tumor microenvironment, IL-21 expression was assessed by PCR in the CD19−CD138− fraction of cells remaining in patient bone marrow aspirates after positive selection for malignant B cells (n=5). IL-21 transcript was detected in 4/5 samples. CD19−CD138− cells activated with anti-CD3 and anti-CD28 antibodies expressed higher levels of IL-21 transcript and secreted significantly higher levels of IL-21 protein compared to unstimulated cells, suggesting that IL-21 in the WM bone marrow is derived from activated T cells. Intracellular expression of IL-21 protein was confirmed in CD4+ and CD8+ cells within the CD19−CD138− population using flow cytometry. Furthermore, dual staining of WM bone marrow sections with antibodies against IL-21 and CD3 or CD20 revealed co-staining of IL-21 with CD3+ T cells but not with CD20+ B cells. The response of WM B cells to T-cell derived IL-21 was then assessed in positively selected CD19+CD138+ WM B cells (n=5) and in the MWCL-1 cell line. Using flow cytometry, both the IL-21 receptor and the required common gamma chain subunit were detected on all patient samples as well as on MWCL-1 cells. Treatment of MWCL-1 cells with IL-21 (100 ng/mL) for 72 h increased proliferation by 35% (p<0.05) and IgM secretion by 80% (p<0.005). Similarly, in primary CD19+CD138+ WM cells (n=5), proliferation increased on average by 38% and IgM secretion by 71%. No apoptotic effects were associated with IL-21 in WM. Characterization of STAT activation in response to IL-21 revealed significant phosphorylation of STAT3 in both CD19+CD138+ WM cells and MWCL-1 cells and was associated with increases in BLIMP-1 and XBP-1 protein and decreases in PAX5. As STAT3 activation is known to regulate IL-6, we assessed the effect of IL-21 on B cell-mediated IL-6 secretion using ELISA. IL-21 significantly increased IL-6 secretion by both primary CD19+CD138+ WM cells (n=4) and MWCL-1 cells (87.9 +/− 10.9 ng/mL vs. 297.8 +/− 129.2 ng/mL, p<0.05). Treatment with IL-6 and IL-21 together had no additional effect over IL-21 alone on proliferation or IgM secretion in MWCL-1 cells, but culturing anti-CD3/anti-CD28-activated CD19−CD138−cells from WM bone marrows with IL-6 significantly increased IL-21 secretion (n=3). Overall, these data indicate that T-cell derived IL-21 significantly promotes growth and immunoglobulin production by malignant WM B cells and that subsequent IL-6 secretion by malignant B cells may enhance the secretion of IL-21 by T cells within the bone marrow microenvironment. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 2684-2684
Author(s):  
Nasir Bakshi ◽  
Mansoor Aljabry ◽  
Saad Akhter ◽  
Irfan Maghfoor ◽  
Ayman Mashi

Abstract Abstract 2684 NLPHL accounts for 6.5% of all Hodgkin lymphoma cases in the West. It is characterized by a nodular or a nodular & diffuse proliferation of scattered large atypical CD20+ neoplastic B-cells referred to as lymphocyte predominant (LP) cells and typically associated with small lymphocytes mainly of B-cell type. Patients with NLPHL typically have an indolent clinical course but can frequently relapse. Progression to a higher grade lymphoma, notably T-cell/Histiocyte rich B-cell lymphoma (T/HRBCL) has been described in a relatively small number of cases. Because of its rarity, limited information is available about the role of non-neoplastic lymphocytes in NLPHL. Some studies suggest that NLPHL with T-cell rich background may behave differently than the conventional type with predominance of B-cells within the nodules. The purpose of this study was to evaluate outcomes of differential tumor microenvironment namely B-cell versus T-cell rich in patients with NLPHL. We document the clinicopathologic profiles of 29 patients with biopsy proven NLPHL, consisting of 22 male & 7 female, median age 26 years (range, 13–80 years). All patients had lymphoadenopathy & 2 cases showed extranodal involvement in addition to nodal disease. Two patients had a bulky mass, and three had stage 4 disease at presentation. The pathological diagnoses was reviewed and confirmed by an expert hematopathologist in all 29 cases. The LP cells in all cases had a prototypic immunophenotype of CD20+, CD79a+, PU.1+, Bcl-6+, CD15− CD30− & Fascin−. T/HRBCL was excluded as all cases demonstrated preservation of follicular dendritic meshwork by CD21 staining. The meshwork was expanded in 20 cases & in 9 cases it was partially disrupted evincing an irregular architectural pattern. Epstein-Barr Virus encoded RNA by in situ hybridization was negative in 8/8 cases tested. 27/29 patients received systemic multi-agent chemotherapy consisting of: doxorubicin, bleomycin, vinblastine, and dacarbacin (ABVD), 24 patients; cyclophosphamide, doxorubicin, vincristin, and prednisone (CHOP), 2 patients; Rituximab + CHOP (R-CHOP), 1 patient. 9/29 (31%) cases underwent autologous stem cell transplant. One patient in stage 2A refused therapy and one patient (stage 3A) developed significantly decreased cardiac ejection fraction following initial 2 cycles of ABVD. Both of these cases did not have adequate follow-up information available. Results: Twelve of the 29 cases (42%) were designated as having T-cell rich background population, whereas 17 (58%) were considered as conventional variant with a vast predominance of non-neoplastic small lymphocytes being B-cells. A few of the cases seemed to show admixture of both B-cells & T-cells. Comparing T-cell rich & B-cell rich background NLPHL no significant differences were detected in clinical parameters: age, sex, and stage at presentation, absolute lymphocyte count, LDH & Hb. All 27 (100%) patients in this study responded to first-line treatment: 23 with complete response & 4 with partial response. 13/27 (48%) had relapse/s. Five cases had more than one relapses. No patient died within a clinical follow-up period ranging from 18 to 84 months. When the overall survival (OS) of T-cell rich NLPHL was compared with the conventional variant there was no statistical significance between the two groups (log rank p= 0.1206). However, comparison of relapse rate showed that cases with T-cell rich background had higher relapse rate as well as greater incidence of multiple relapses as compared to B-cell rich type of NLPHL even after adjusting for the type of treatment received (log rank p= 0.003). Moreover, 2/12 (17%) T-cell rich NLPHL cases showed transformation to a high grade lymphoma (both T/HRBCL) at the time of recurrence. These findings suggest that in NLPHL a tumor microenvironment rich in T-cells rather than B-cells is characterized by an unfavorable clinical course although OS appears to be similar. These cases perhaps represent a distinctive clinicopathologic variant within the framework of NLPHL. Lately, the term ‘NLPHL with nodules resembling T/HRBCL’ has been used to express the immunobiological overlap between these two entities. It is possible that such cases could be regarded as “intermediate lymphomas” treading between NLPHL and T/HRLBCL. Further studies using gene array profiling analysis may help clarify the molecular differences between these closely related entities. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 5190-5190
Author(s):  
Jonathan Brauner ◽  
Ingrid Beukinga ◽  
Zoulikha Amraoui ◽  
Zaina Kassengera ◽  
Michel Toungouz ◽  
...  

Abstract Abstract 5190 Objectives: Definition of the primary antibodies panel for 10 colours flow cytometry able to describe normal and clonal T, B lymphocytes and plamocytes in blood and bone marrow. Once clonalities are detected, the complete characterisation of Chronic Lymphoproliferative Diseases (CLPD) is supported by secondary panels chosen based on the results of CD5/CD10 expression for clonal B lymphocytes, CD27/CD38 for plasmatocytes and CD3/CD27 for clonal T cells. Materials and Methods: Blood and bone marrow of patients (N=50) with CLPD (mainly B-CLL). Samples are enumerated by haematology analyzer DxH 800 then 106 cells are washed three times, stained with the antibodies combination and red blood cells lysed with Versalyse (TM. Beckman Coulter). The samples were analysed on a 10 colours Navios flow cytometer (Beckman Coulter Fullerton, CA). The staining panel consists of 14 antibodies (CD45, CD8, CD4, CD5, CD3, CD19, CD38, λ, κ, CD23, CD5, CD10, CD14, CD27) conjugated with 10 different fluorochromes. The fixed gating strategy allows linking Navios analysis software to the middleware Remisol which drives the choice of the secondary panel. In some cases a third tube is performed for Ki67 or Zap-70 intra-cytoplasmic staining. Results: Monocytes are removed on the basis of their CD14/CD4 expression. B lymphocytes are CD19 positive. Normal naïve/memory B cells, hematogones and plasma cells are defined by their CD27, CD10 and CD38 expression. Eventual monoclonality is sought by analysis of the distribution of Kappa and Lambda light chains. A first classification of B cell lymphoma is achieved with the CD5 and CD10 expression of the clone (CD5+/CD10−: B-CLL MCL and few MZL, CD5−/CD10−: MZL and related, CD5−/CD10+ DLBCL and FL). Analysis of CD27, CD20 and CD23 expression allows discriminating between CD5+/CD10- lymphomas. All the 50 samples were correctly detected as CLPD and the automated Remisol choice of the second panel fit to the final diagnosis of all the cases of this small series. T lymphocytes are defined by their CD3 and CD5 expression. The analysis of CD4/CD8 balance and CD27/CD5 distribution are first line test when T cell clonality is suspected. There is a special gating to detect CD3-CD4+ T cell lymphoma and double negativity of CD4 and CD8 is a surrogate marker for gamma/delta T cells. NK cells are mentioned as not-T not-B lymphocytes, without specific staining. Conclusion/Discussion:This 10 colours 14 antibodies panel allows describing in one tube normal T and B cells, hematogones, memory and naives B cells plasma cells and detects T and B clonalities. This panel follows a similar logic than the Euroflow LST tube but with 10 colours and with Beckman Coulter's technology and antibodies. Moreover, this combination helps discriminating rapidly the CD5+/CD10- lymphomas while the complete characterisation of CD5 negative lymphomas only require less than 6 antibodies second tube. This is a paperless (all the process is driven and controlled by Remisol), fast and inexpensive diagnostic approach (always less than 20 antibodies required). Disclosures: Pradier: Beckman Coulter: Consultancy, Membership on an entity's Board of Directors or advisory committees.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 2613-2613
Author(s):  
Marco L Davila ◽  
Christopher Kloss ◽  
Renier J Brentjens ◽  
Michel Sadelain

Abstract Abstract 2613 Recent work by our group and others demonstrates the therapeutic potential of CD19-targeted T cells to treat patients with indolent B cell malignancies. These studies make use of T cells that are genetically engineered with chimeric antigen receptors (CARs) comprising an scFv fused to various T cell activating elements. Whereas firs-generation CARs only direct T cell activation, second-generation CARs include two signal elements, such as CD3z and CD28 signaling domains (19–28z). We and our colleagues at MSKCC are currently evaluating the safety of 19–28z-transduced T cells in patients with acute leukemia (B-ALL) in a Phase I protocol (NCT01044069). Pre-clinical studies performed to date have mostly relied on xenogeneic models utilizing immunodeficient animals, which enable the evaluation of human engineered T cells but do not recapitulate all the interactions that may affect tumor eradication by CAR-modified T cells. We have therefore developed a pre-clinical immunocompetent mouse model of B-ALL, and addressed therein the impact of conditioning and T cell dose on the eradication of leukemia by syngeneic, CAR-targeted T cells. To establish an immunocompetent mouse model of B cell leukemia, we generated a clone from the lymph node of an Eμ-myc B6 transgenic mouse. The immunophenotype and gene-expression profile of clone Eμ-ALL01 is consistent with a progenitor B cell origin. Syngeneic B6 mice inoculated with this clone develop florid acute leukemia and die approximately 2–4 weeks after injection from progressive bone marrow infiltration. We created an anti-mouse CD19 CAR comprising all murine elements, including the CD8 signal peptide, a CD19-specific single chain variable fragment, the CD8 transmembrane region, and the CD28 and CD3z signaling domains. Transduction of the murine 19–28z CAR into mouse T cells was robust and successfully retargeted the T cells to B cells. In vitro assays demonstrated that m19–28 z transduced T cells mediated effective killing of CD19-expressing target cells and the production of effector cytokines such as IFNγ and TNFα. Cyclophosphamide either alone or in combination with control syngeneic T cells is insufficient to eradicate established Eμ-ALL01 in B6 mice. However, treatment with cyclophosphamide and m19–28z-transduced T cells cured nearly all mice. Mice sacrificed six months after treatment exhibited a dramatic reduction of B cells in the bone marrow (BM), blood, and spleen. The few remaining B lineage cells found in the BM had a phenotype consistent with early pro-B cells, suggesting that endogenous reconstitution of the B cell compartment was thwarted by persisting, functional m19–28z+ T cells. Thus, T cells are retained at the site of antigen expression, which is maintained through regeneration of progenitor B cells. The persisting CD19-targeted T cells in the BM exhibited a cell surface phenotype consistent with effector and central memory cells. Using B cell aplasia as a surrogate endpoint for assessing in vivo T cell function and persistence, we evaluated how conditioning chemotherapy and T cell dose determine the level of B cell depletion induced by adoptively transferred CD19-targeted T cells. Overall, increasing the cyclophosphamide or T cell dose, increased the degree and duration of B cell depletion and the number of persisting CAR-modified T cells. Significantly, increasing the T cell dose at a set cyclophosphamide level had a lesser impact than increasing the conditioning intensity for a given T cell dose. In summary, the new Eμ-ALL01 syngeneic, immunocompetent B-ALL model we describe here is a valuable tool for modeling CD19 CAR therapies. Our results indicate that m19–28z transduced T cells are effective at eradicating B-ALL tumor cells and persist long-term, preferentially in bone marrow. Our findings further establish that conditioning intensity and T cell dose directly determine B cell elimination and long-term T cell persistence. These studies in mice will serve as an important framework to further model and perfect our studies in patients with B-ALL. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 4117-4117
Author(s):  
Sumantha Bhatt ◽  
Kathleen Brown ◽  
Feng Lin ◽  
Michael P Meyer ◽  
Margaret V. Ragni ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Gm Csf ◽  

Abstract Abstract 4117 Background: Hemophilia is an X-linked bleeding disorder resulting from a mutation in coagulation factor VIII (F.VIII). A major drawback of current plasma-derived or recombinant F.VIII therapy is the formation of F.VIII antibodies (inhibitors). Inhibitor formation is a T cell-dependent, B cell-mediated immune response to foreign infused F.VIII. Myeloid derived suppressor cells (MDSCs) are potent suppressors of T cell and B cell responses and are currently under study for therapeutic applications in transplantation and autoimmune diseases. However, the mechanisms of MDSC development and function remain unknown, and in vitro propagation of MDSCs has been a challenge. We hypothesized that MDSCs might be effective in inhibiting F.VIII inhibitor formation in the hemophilia A model. Methods: We developed a novel method for generating MDSCs in vitro by culturing bone marrow cells from hemophilia A mice with hepatic stellate cells (HSCs), hereafter referred to as HSC-conditioned myeloid cells (H-MCs). DCs were propagated from the bone marrow with GM-CSF and IL-4, whereas H-MCs were propagated from the bone marrow with GM-CSF and HSCs. Granulocyte contaminants were removed on day 2 and the remaining monocytic populations were harvested on day 5. Expression of cell surface antigens was analyzed by flow cytometry. Arginase1 and iNOS levels were compared by qPCR, with or without LPS stimulation. The in vitro suppressive capacity of the H-MCs was determined by a mixed leukocyte reaction culture. Splenic T cells from hemophilia A mice were stimulated by irradiated DCs (at a 1–20 ratio, APC to T cell) and recombinant F.VIII. Additional irradiated DCs or H-MCs were added in graded numbers as regulators. The proliferative response was determined by 3H-thymidine incorporation. The phenotype of cultured CD4+ T cells was characterized by intracellular staining for Foxp3 and IFN-gamma and analyzed by flow cytometry. Inhibition of B cells by H-MCs was determined by a CFSE dilution assay. Purified splenic B cells were labeled with CFSE and stimulated by Ig-M and IL-4. APCs (spleen cells) or H-MCs were added at a ratio of 1:10 (APC to B cell). The proportion of proliferating B cells was determined by CFSE dilution of B220 stained cells. In the COX-2 suppression assay, CFSE labeled B cells were treated with varying concentrations of the selective inhibitor of COX-2, NS398. The suppressive effect of H-MCs on B cells in vivo was determined by simultaneously administering H-MCs (I.V) and F.VIII (I.V.) to hemophila A mice on day 0 and rechallenging with recombinant F.VIII on days 2 and 4. WT B6 mice and hemophilia A mice without H-MC transfer served as controls. Plasma anti-F.VIII antibody titers were measured on day 12 by a modified ELISA assay. Results: H-MCs expressed low levels of costimulatory molecules but high levels of the inhibitory molecule B7-H1 and immunoregulatory enzyme arginase-1. In contrast, DCs expressed high levels of costimulatory molecules and MHC class II. In vitro studies demonstrated that the H-MCs markedly inhibited antigen specific T cell proliferation induced by dendritic cells in response to recombinant F.VIII (Fig. 1). H-MCs altered the T cell response in hemophilia A mice by promoting the expansion of regulatory T cells and inhibiting IFN-γ producing CD4+ T cells. When the H-MCs were cocultured with B cells isolated from hemophilia A mice, in the presence of Ig-M and IL-4, the H-MCs abrogated B cell activation and proliferation directly (Fig. 2). H-MCs may be modulating the B cell response through the Cox-2 pathway, as inhibition of Cox-2 through NS398 led to the restoration of B cell proliferation. More importantly, adoptive transfer of H-MCs into hemophilia Amice, at the time of F.VIII infusion, markedly suppressed anti-F.VIII antibody formation (Fig. 3). Conclusion: These results suggest that HSC conditioned myeloid cells may represent a potential therapeutic approach to induction of immune tolerance in patients with hemophilia A andother immune disorders. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3078-3078
Author(s):  
Diane L Rossi ◽  
Edmund A Rossi ◽  
David M Goldenberg ◽  
Chien-Hsing Chang

Abstract Background Various formats of bispecific antibodies (bsAbs) to redirect effector T cells for the targeted killing of tumor cells have shown considerable promise both pre-clinically and clinically. The scFv-based constructs, including BiTE and DART, which bind monovalently to CD3 on T cells and to the target antigen on tumor cells, exhibit fast blood clearance and neurological toxicity due to their small size (∼55 kDa). Herein, we describe the generation of novel T-cell redirecting trivalent bsAbs comprising an anti-CD3 scFv covalently conjugated to a stabilized F(ab)2. The design was initially characterized with a prototype construct designated (19)-3s, which specifically targets CD19 on B cells. A panel of trivalent bsAbs was evaluated for their potential use in targeted T-cell immunotherapy of various B-cell malignancies. Potential advantages of this design include bivalent binding to tumor cells, a larger size (∼130 kDa) to preclude rapid renal clearance and penetration of the blood-brain barrier, and potent T-cell mediated cytotoxicity. Methods The DOCK-AND-LOCKTM (DNLTM) method was used to generate a panel of B-cell targeting bsAbs, (19)-3s, (20)-3s, (22)-3s, and (C2)-3s, which target CD19, CD20, CD22, and HLA-DR, respectively. This was achieved by combining a stabilized anti-X F(ab)2 with an anti-CD3-scFv, resulting in a homogeneous covalent structure of the designed composition, as shown by LC-MS, SE-HPLC, ELISA, SDS-PAGE, and immunoblot analyses. Each construct can mediate the formation of immunological synapses between T cells and malignant B cells, resulting in T-cell activation. At an E:T ratio of 10:1, using isolated T cells as effector cells, the bsAbs induced potent T-cell-mediated cytotoxicity in various B-cell malignancies, including Burkitt lymphomas (Daudi, Ramos, Namalwa), mantle cell lymphoma (Jeko-1), and acute lymphoblastic leukemia (Nalm-6). A non-tumor binding control, (14)-3s, induced only moderate T-cell killing at >10 nM. The nature of the antigen/epitope, particularly its size and proximity to the cell surface, appears to be more important than antigen density for T-cell retargeting potency (Table 1). It is likely that (20)-3s is consistently more potent than (19)-3s and (C2)-3s, even when the expression of CD19 or HLA-DR is considerably higher than CD20, as seen with Namalwa and Jeko-1, respectively. This is likely because the CD20 epitope comprises a small extracellular loop having close proximity to the cell surface. When compared directly using Daudi, (22)-3s was the least potent. Compared to CD19 and CD20, CD22 is expressed at the lowest density, is a rapidly internalizing antigen, and its epitope is further away from the cell surface; each of these factors may contribute to its reduced potency. Finally, sensitivity to T-cell retargeted killing is cell-line-dependent, as observed using (19)-3s, where Raji (IC50 >3 nM) is largely unresponsive yet Ramos (IC50 = 2 pM) is highly sensitive, even though the former expresses higher CD19 antigen density. Conclusions (19)-3s, (20)-3s, (22)-3s, and (C2)-3s can bind T cells and target B cells simultaneously and induce T-cell-mediated killing in vitro. The modular nature of the DNL method allowed the rapid production of several related conjugates for redirected T-cell killing of various B-cell malignancies, without the need for additional recombinant engineering and protein production. The close proximity of the CD20 extracellular epitope to the cell surface results in the highest potency for (20)-3s, which is an attractive candidate bsAb for use in this platform. We are currently evaluating the in vivo activity of these constructs to determine if this novel bsAb format offers additional advantages. Disclosures: Rossi: Immunomedics, Inc.: Employment. Rossi:Immunomedics, Inc.: Employment. Goldenberg:Immunomedics: Employment, stock options, stock options Patents & Royalties. Chang:Immunomedics, Inc: Employment, Stock option Other; IBC Pharmaceuticals, Inc.: Employment, Stock option, Stock option Other.


Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 380-380 ◽  
Author(s):  
Stephan A. Grupp ◽  
Shannon L Maude ◽  
Pamela Shaw ◽  
Richard Aplenc ◽  
David M. Barrett ◽  
...  

Abstract BACKGROUND CARs combine a single chain variable fragment (scFv) of an antibody with intracellular signaling domains. We have previously reported on CTL019 cells expressing an anti-CD19 CAR. Infusion of these cells results in 100 to 100,000x in vivo proliferation, durable anti-tumor activity, and prolonged persistence in pts with B cell tumors, including sustained CRs in adults and children with ALL (Grupp et al., NEJM 2013, Maude et al., NEJM 2014). We now report on outcomes and longer follow up of the first 30 pts with relapsed, refractory ALL treated on our pilot trial in pediatric ALL. METHODS T cells were lentivirally transduced with a CAR composed of anti-CD19 scFv/4-1BB/CD3ζ, activated/expanded ex-vivo with anti-CD3/anti-CD28 beads, and then infused into children with relapsed or refractory CD19+ ALL. 26/30 pts received lymphodepleting chemotherapy the week prior to CTL019 infusion. The targeted T cell dose range was 107 to 108 cells/kg with a transduction efficiency of 11-45%. T cells for manufacturing were collected from the pt regardless of prior SCT status, not allo donors. RESULTS 30 children median age 10y (5-22y) with CD19+ ALL were treated. 25/30 pts had detectable disease on the day before CTL019 cell infusion, while 5 were MRD(-). A median of 3.6x106 CTL019 cells/kg (1.1-18x106/kg) were infused over 1-3 days. There were no infusional toxicities >grade 2, although 9 pts developed fevers within 24 hrs of infusion and did not receive a planned 2nd infusion of CTL019 cells. 27 pts (90%) achieved a CR, including a patient with T cell ALL aberrantly expressing CD19+. 3 did not respond. MRD measured by clinical flow cytometry was negative in 23 responding pts and positive at 0.1% (negative at 3 mo), 0.09%, 0.22%, and 1.1% in 4 pts. With median follow up 8 mo (1-26 mo), 16 pts have ongoing CR, with only 3 patients in the cohort receiving subsequent treatment such as donor lymphocyte infusion or SCT, 6-month EFS measured from infusion is 63% (95% CI, 47-84%), and OS is 78% (95% CI, 63-95%). CTL019 cells were detected in the CSF of 17/19 pts and 2 pts with CNS2a disease experienced a CR in CSF. 10 pts with a CR at 1 mo have subsequently relapsed, half with CD19(-) blasts. 2/5 pts who relapsed with CD19(-) disease had previously been refractory to CD19-directed blinatumomab and subsequently went into CR with CTL019. Figure 1 Figure 1. All responding pts developed grade 1-4 cytokine release syndrome (CRS) at peak T cell expansion. Detailed cytokine analysis showed marked increases of IL6 and IFNγ (both up to 1000x), and IL2R. Treatment for CRS was required for hemodynamic or respiratory instability in 37% of patients and was rapidly reversed in all cases with the IL6-receptor antagonist tocilizumab, together with corticosteroids in 5 pts. Although T cells collected from the 21 pts who had relapsed after allo SCT were median 100% donor origin, no GVHD has been seen. Grade 4 CRS was strongly associated with high disease burden prior to infusion and with elevations in IL-6, ferritin (suggesting macrophage activation syndrome) and C reactive protein after infusion. Persistence of CTL019 cells detected by flow cytometry and/or QPCR, and accompanied by B cell aplasia, continued for 1-26 months after infusion in pts with ongoing responses. QPCR showed very high levels of CTL019 proliferation, with all patients achieving peak levels >5000 copies/ug gDNA and 26 patients with peak levels >15,000 copies/ug gDNA. B cell aplasia has been treated with IVIg without significant infectious complications. Probability of 6-mo CTL019 persistence by flow was68% (95% CI, 50-92%) andrelapse-free B cell aplasia was 73% (95% CI, 57-94%). CONCLUSIONS: CTL019 cells can undergo robust in-vivo expansion and can persist for 2 years or longer in pts with relapsed ALL, allowing for the possibility of long-term disease response without subsequent therapy such as SCT. This approach also has promise as a salvage therapy for patients who relapse after allo-SCT with a low risk of GVHD. CTL019 therapy is associated with a significant CRS that responds rapidly to IL-6-targeted anti-cytokine treatment. CTL019 cells can induce potent and durable responses for patients with relapsed/refractory ALL; however, recurrence with cells that have lost CD19 is an important mechanism of CLT019 resistance. CTL019 therapy has received Breakthrough Therapy designation from the FDA in both pediatric and adult ALL, and phase II multicenter trials have been initiated. Disclosures Grupp: Novartis: Consultancy, Research Funding. Barrett:Novartis: Research Funding. Chew:Novartis: Research Funding. Lacey:Novartis: Research Funding. Levine:Novartis: Patents & Royalties, Research Funding. Melenhorst:Novartis: Research Funding. Rheingold:Novartis: Consultancy. Shen:Novartis: Employment. Wood:Novartis Pharma: Employment. Porter:Novartis: managed according to U Penn Policy Patents & Royalties, Research Funding. June:Novartis: Research Funding, Royalty income Patents & Royalties.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 151-151 ◽  
Author(s):  
James N Kochenderfer ◽  
Mark E. Dudley ◽  
Robert O. Carpenter ◽  
Sadik H Kassim ◽  
Jeremy J. Rose ◽  
...  

Abstract Progressive malignancy is a leading cause of death in patients undergoing allogeneic hematopoietic stem cell transplantation (alloHSCT). To improve treatment of B-cell malignancies that persist despite alloHSCT, we conducted a clinical trial of allogeneic T cells genetically modified to express a chimeric antigen receptor (CAR) targeting the B-cell antigen CD19. Ten patients were treated on this trial. Four patients were recipients of human-leukocyte-antigen (HLA)-matched unrelated donor (URD) transplants and 6 patients were recipients of HLA-matched sibling transplants. T cells for genetic modification were obtained from each patient’s healthy alloHSCT donor. Patients received a single infusion of anti-CD19-CAR T cells. Cell doses ranged from 1x106 to 10x106 T cells/kg. A mean of 58% of the infused cells expressed the CAR. Patients did not receive chemotherapy or other anti-malignancy therapy with the CAR-T-cell infusions, so the responses observed in these patients are not confounded by the effects of chemotherapy. In contrast to other reports of successful treatment of B-cell malignancies with anti-CD19-CAR T cells, the patients on this study were not lymphocyte-depleted at the time of the CAR-T-cell infusions. Two patients with chronic lymphocytic leukemia (CLL) refractory to standard unmanipulated allogeneic donor lymphocyte infusions (DLIs) had regressions of large malignant lymph node masses after infusion of allogeneic anti-CD19-CAR T cells. One of these CLL patients obtained a complete remission that is ongoing 9 months after treatment with allogeneic anti-CD19-CAR T cells. This patient also had complete eradication of blood B cells within 9 days after her CAR-T-cell infusion. Another patient had tumor lysis syndrome requiring rasburicase treatment as his CLL dramatically regressed in lymph nodes, bone marrow, and blood within 2 weeks of his anti-CD19-CAR-T-cell infusion. A patient with mantle cell lymphoma obtained a partial remission that is ongoing 3 months after infusion of anti-CD19-CAR T cells. A fourth patient with diffuse large B-cell lymphoma has ongoing stable disease 11 months after infusion of anti-CD19-CAR T cells. The other 6 treated patients all had short periods of stable malignancy or progressive disease after their CAR-T-cell infusions. Specific eradication of blood B cells occurred after infusion of CAR T cells in 3 of 4 patients with measurable blood B cells pretreatment. None of the patients treated on this study developed GVHD after their anti-CD19-CAR-T-cell infusions, despite the fact that 6 of 10 treated patients had experienced GVHD at earlier time-points after their most recent alloHSCT. One patient, who had a history of cardiac dysfunction with prior acute illnesses, had temporary cardiac dysfunction after infusion of anti-CD19-CAR T cells. The most prominent toxicities experienced by patients were fever and hypotension; these peaked 5 to 12 days after CAR-T-cell infusions and resolved within 14 days after the T-cell infusions. Two patients had Grade 3 fever, and 2 patients had Grade 3 hypotension. No patients experienced Grade 4 toxicities that were attributable to the CAR-T-cell infusions. Elevated levels of serum interferon gamma were detected in 3 patients at the time that they were experiencing toxicities. We detected cells containing the anti-CD19-CAR gene in the blood of 8 of 10 patients. The peak blood levels of CAR T cells varied from undetec to 2.8% of peripheral blood mononuclear cells. The persistence of the CAR T cells in the blood of patients was limited to one month or less. When we assessed T cells from the blood of patients ex vivo, we found elevated levels of the T-cell inhibitory molecule programmed cell death protein-1 (PD-1) on CAR+ T cells compared to CAR-negative T cells. These results show for the first time that small numbers of donor-derived allogeneic anti-CD19-CAR T cells can cause regression of highly treatment-resistant B-cell malignancies after alloHSCT without causing GVHD. Malignancies that were resistant to standard DLIs regressed after anti-CD19-CAR-T-cell infusions. Future goals for improving this approach include enhancing the persistence of anti-CD19-CAR T cells and reducing toxicities. Infusion of allogeneic T cells genetically modified to recognize malignancy-associated antigens is a promising approach for treating residual malignancy after alloHSCT. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 4507-4507 ◽  
Author(s):  
L. Laura Sun ◽  
Xiaocheng Chen ◽  
Yvonne Chen ◽  
Mark S. Dennis ◽  
Diego Ellerman ◽  
...  

Abstract T-cell recruiting bispecific antibodies and antibody fragments have been used to harness the cytotoxic potential of T cells for cancer treatment. As an example, encouraging clinical responses have been reported with the B cell targeting Blinatumomab, a 55-kDa fusion protein composed of two single-chain antibody fragments (scFvs). However, the therapeutic promise of many reported bispecific antibodies and fragments is often limited by unfavorable pharmacokinetics and administration schedule, immunogenicity, and a propensity towards aggregation. We have adopted a knobs-into-holes (KIH) antibody format and produced T-cell dependent bispecific antibodies (TDB), which allow one arm to target various B cell antigens while the other arm recruits T cells by binding to the CD3e subunit of the T-cell receptor. These B cell targeting TDBs are full length, humanized IgG1 antibodies with natural antibody architecture. Single dose pharmacokinetic/pharmacodynamic studies in cynomolgus monkeys show the KIH format TDBs are well tolerated in life, result in potent B cell depletion in peripheral and lymphoid tissue, and demonstrate pharmacokinetic properties resembling conventional antibody therapy. One B cell antigen targeted is CD79b, a component of the B cell receptor complex. CD79b is restricted to B cells, is highly prevalent on B cell leukemia and lymphomas, and has been clinically validated by an anti-CD79b antibody-drug conjugate as a safe and effective therapeutic target for B cell malignancies (ASCO 2014 abstract#8519). In our present work, we show that anti-CD79b/CD3 TDB can be produced and purified from E.coli, free of homodimer and aggregates. Anti-CD79b/CD3 TDB is a conditional agonist, activating CD3+T cells only in the presence of CD79b expressing B cells. In vitro, it induces potent B cell killing in a T-cell dependent manner, and is broadly active against lymphoma cell lines with a wide range of CD79b antigen levels. Compared to bispecific antibodies targeting some other B cell antigens, anti-CD79b/CD3 TDB appears to be more potent in autologous B cell killing assays with human PBMCs isolated from healthy donors. Taking advantage of antibodies with a range of binding affinities, we show that the B cell cytotoxic potency of anti-CD79b/CD3 TDB can be enhanced with increased binding affinity of either the anti-CD79b arm or the anti-CD3 arm in vitro. To assess the therapeutic potential of anti-CD79b/CD3 TDB, we further demonstrate that it is active in killing B lymphoma cells isolated from leukemia and lymphoma patients. Collectively, these preclinical data suggest anti-CD79b/CD3 TDB may be a promising agent for clinical development in B cell malignancies. Disclosures Sun: Genentech: Employment. Chen:Genentech: Employment. Chen:Genentech: Employment. Dennis:Genentech: Employment. Ellerman:Genentech: Employment. Johnson:Genentech: Employment. Mathieu:Genentech: Employment. Oldendorp:Genentech: Employment. Polson:Genentech: Employment. Reyes:Genentech: Employment. Stefanich:Genentech: Employment. Wang:Genentech: Employment. Wang:Genentech: Employment. Zheng:Genentech: Employment. Ebens:Genentech: Employment.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 681-681 ◽  
Author(s):  
Stephan A. Grupp ◽  
Shannon L Maude ◽  
Pamela A Shaw ◽  
Richard Aplenc ◽  
David M. Barrett ◽  
...  

BACKGROUND CARs combine a targeting antibody (scFv) domain with intracellular signaling domains. We have previously reported on CTL019 cells expressing an anti-CD19 CAR, which have resulted in up to 100,000x in vivo proliferation, durable anti-tumor activity, and prolonged persistence in pts with B cell tumors, including sustained CRs in adults and children with ALL (Grupp et al., NEJM 2013, Maude et al., NEJM 2014). We now report on outcomes and longer follow up of the first 53 pts with relapsed/refractory (r/r) ALL treated on our pilot trial in pediatric ALL. METHODS T cells were lentivirally transduced with a CAR composed of anti-CD19 scFv/4-1BB/CD3ζ, activated/expanded ex-vivo with anti-CD3/anti-CD28 beads, and then infused into children with r/r CD19+ ALL. 48/53 pts received lymphodepleting chemotherapy the week prior to CTL019 infusion. The targeted T cell dose range was 107 to 108 cells/kg with a transduction efficiency of 3.6-45%. T cells for manufacturing were collected from the pt regardless of prior SCT status, and not their allo donors. RESULTS We treated 53 children and young adults with CD19+ ALL, median age 11y, (4-24y). To assess disease burden after lymphodepleting chemotherapy, pts had BM aspirations performed 1D prior to 1st CTL019 infusion: 41/53 pts had detectable ALL while 12 were MRD(-). A median of 4.3x106 CTL019 cells/kg (1-17.4x106/kg) were infused over 1-2D (1 pt got cells over 3D). There were no infusional toxicities >gr2, although pts who developed fevers within 24h of infusion did not receive a planned 2nd infusion of CTL019 cells. 50 pts (94%) achieved a CR, including a patient with CD19+ T ALL, 3 did not respond. MRD measured by clinical flow cytometry was <0.01% at D28 in 45 responding pts and positive at 0.024%-1.1% in 5 pts, with 2 patients becoming negative by 3 mo with no further therapy. With median follow up 10.6 mo (1-39 mo), 29 pts have ongoing CR, with only 6 receiving subsequent treatment such as donor lymphocyte infusion or SCT, EFS is 70% at 6 mo (95% CI, 58-85%) and 45% at 12 mo (95% CI, 31-66%), RFS is 72% at 6 mo (95% CI, 59-87%) and 44% at 12 mo (95% CI, 30-65%), and OS is 78% at 12 mo (95% CI, 67-91%). CTL019 was detected by qPCR in the CSF of 46/47 pts and 4 pts with CNS2a ALL experienced a CR in CSF. 20 pts with a CR at 1 mo have subsequently relapsed, with 3 relapses occurring after subsequent therapy (i.e. SCT) and 13 with CD19(-) blasts. 4/5 pts previously refractory to CD19-directed blinatumomab went into CR with CTL019, 3 subsequently relapsed with CD19(-) disease. All but 5 (90%) of pts developed grade 1-4 cytokine release syndrome (CRS) at peak T cell expansion. Detailed cytokine analysis showed marked increases of IL6 and IFNγ (both up to 1000x), and IL2R. Treatment for CRS was required for hemodynamic or respiratory instability in 28% of patients and was reversed in all cases with the IL6-receptor antagonist tocilizumab, together with short courses of corticosteroids in 9 pts. Although T cells collected from the 35 pts who had relapsed after allo SCT were median 100% donor origin, no GVHD has been seen. Grade 4 CRS was associated with high disease burden prior to infusion and with elevations in IL-6, ferritin (suggesting macrophage activation syndrome) and C reactive protein after infusion. Persistence of CTL019 cells can be detected by flow cytometry and/or QPCR, and results in the pharmacodynamic marker of CTL019 function, B cell aplasia, which continued for 3-39 months after infusion in pts with ongoing responses. B cell aplasia has been treated with IVIg without significant infectious complications. CONCLUSIONS: CTL019 cells can undergo robust in vivo expansion and can persist for 3 years or longer in children and young adults with r/r ALL, allowing for the possibility of long-term disease control without subsequent therapy such as SCT. This approach also has promise as salvage therapy for patients who relapse after allo SCT with a low risk of GVHD. CTL019 therapy is associated with a significant CRS that responds rapidly to IL-6-targeted anti-cytokine treatment. CTL019 cells can induce potent and durable responses for patients with r/r ALL; however, recurrence with cells that have lost CD19 is an important mechanism of CTL019 resistance. Rapid loss of CTL019 cells (prior to 3 months) is associated with a high risk of CD19+ relapse. CTL019 therapy has received Breakthrough Therapy designation from the FDA in pediatric and adult ALL, and phase 2 multicenter registration trials are well underway. Disclosures Grupp: Novartis: Consultancy, Research Funding. Maude:Novartis: Consultancy, Research Funding. Shaw:Novartis: Research Funding. Aplenc:Sigma Tau: Consultancy. Lacey:Novartis: Research Funding. Levine:Novartis: Patents & Royalties, Research Funding. Melenhorst:Novartis: Research Funding. Rheingold:Novartis: Consultancy; Endo: Other: Husband's employer, has equity interest. Teachey:Novartis: Research Funding. Wood:Novartis Pharmaceuticals Corporation: Employment. Porter:Novartis: Other: IP interest, Research Funding; Genentech: Other: Spouse employment. June:University of Pennsylvania: Patents & Royalties: financial interests due to intellectual property and patents in the field of cell and gene therapy. Conflicts of interest are managed in accordance with University of Pennsylvania policy and oversight; Novartis: Research Funding.


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