scholarly journals Effects of monoclonal antibody therapy in patients with chronic lymphocytic leukemia

Blood ◽  
1984 ◽  
Vol 64 (5) ◽  
pp. 1085-1093 ◽  
Author(s):  
KA Foon ◽  
RW Schroff ◽  
PA Bunn ◽  
D Mayer ◽  
PG Abrams ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Chronic Lymphocytic Leukemia ◽  
T Lymphocytes ◽  
Lymphocytic Leukemia ◽  
Leukemia Cells ◽  
Antigenic Modulation ◽  
Cell Counts ◽  
In Vivo Labeling ◽  
Dose Levels

A phase I clinical trial was initiated to treat patients with stage IV B-derived chronic lymphocytic leukemia (CLL) with the IgG2a murine monoclonal antibody T101. This antibody binds to a 65,000-mol wt (T65) antigen found on normal T lymphocytes, malignant T lymphocytes, and B- derived CLL cells. All of the patients had a histologically confirmed diagnosis of advanced B-derived CLL and were refractory to standard therapy, and more than 50% of their leukemia cells reacted with the T101 antibody in vitro. The patients received T101 antibody two times per week, over two to 50 hours by intravenous administration in 100 mL of normal saline containing 5% human albumin. Twelve patients were treated with a fixed dosage of 1, 10, 50, or 100 mg, and one patient was treated with 140 mg of antibody. It was demonstrated that patients given two-hour infusions of 50 mg developed pulmonary toxicity, with shortness of breath and chest tightness. This toxicity was eliminated when infusions of 50 or 100 mg of T101 were prolonged to 50 hours. All dose levels caused a rapid but transient decrease in circulating leukemia cell counts. In vivo binding to circulating and bone marrow leukemia cells was demonstrated at all dose levels with increased binding at higher dosages. Antimurine antibody responses were not demonstrated in any patients at any time during treatment. Circulating free murine antibody was demonstrated in the serum of only the two patients treated with 100 mg of antibody as a 50-hour infusion and the patient treated with 140 mg of antibody over 30 hours. Antigenic modulation was demonstrated in patients treated at all dose levels but was particularly apparent in patients treated with prolonged infusions of 50 and 100 mg of antibody. We were also able to demonstrate antigenic modulation in lymph node cells, which strongly suggests in vivo labeling of these cells. Overall, T101 antibody alone appears to have a very limited therapeutic value for patients with CLL. The observations of in vivo labeling of tumor cells, antigenic modulation, antibody pharmacokinetics, toxicity, and antimurine antibody formation may be used in the future for more effective therapy when drugs or toxins are conjugated to the antibody.

scholarly journals Effects of monoclonal antibody therapy in patients with chronic lymphocytic leukemia

Blood ◽  
1984 ◽  
Vol 64 (5) ◽  
pp. 1085-1093 ◽  
Author(s):  
KA Foon ◽  
RW Schroff ◽  
PA Bunn ◽  
D Mayer ◽  
PG Abrams ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Chronic Lymphocytic Leukemia ◽  
T Lymphocytes ◽  
Lymphocytic Leukemia ◽  
Leukemia Cells ◽  
Antigenic Modulation ◽  
Cell Counts ◽  
In Vivo Labeling ◽  
Dose Levels

Abstract A phase I clinical trial was initiated to treat patients with stage IV B-derived chronic lymphocytic leukemia (CLL) with the IgG2a murine monoclonal antibody T101. This antibody binds to a 65,000-mol wt (T65) antigen found on normal T lymphocytes, malignant T lymphocytes, and B- derived CLL cells. All of the patients had a histologically confirmed diagnosis of advanced B-derived CLL and were refractory to standard therapy, and more than 50% of their leukemia cells reacted with the T101 antibody in vitro. The patients received T101 antibody two times per week, over two to 50 hours by intravenous administration in 100 mL of normal saline containing 5% human albumin. Twelve patients were treated with a fixed dosage of 1, 10, 50, or 100 mg, and one patient was treated with 140 mg of antibody. It was demonstrated that patients given two-hour infusions of 50 mg developed pulmonary toxicity, with shortness of breath and chest tightness. This toxicity was eliminated when infusions of 50 or 100 mg of T101 were prolonged to 50 hours. All dose levels caused a rapid but transient decrease in circulating leukemia cell counts. In vivo binding to circulating and bone marrow leukemia cells was demonstrated at all dose levels with increased binding at higher dosages. Antimurine antibody responses were not demonstrated in any patients at any time during treatment. Circulating free murine antibody was demonstrated in the serum of only the two patients treated with 100 mg of antibody as a 50-hour infusion and the patient treated with 140 mg of antibody over 30 hours. Antigenic modulation was demonstrated in patients treated at all dose levels but was particularly apparent in patients treated with prolonged infusions of 50 and 100 mg of antibody. We were also able to demonstrate antigenic modulation in lymph node cells, which strongly suggests in vivo labeling of these cells. Overall, T101 antibody alone appears to have a very limited therapeutic value for patients with CLL. The observations of in vivo labeling of tumor cells, antigenic modulation, antibody pharmacokinetics, toxicity, and antimurine antibody formation may be used in the future for more effective therapy when drugs or toxins are conjugated to the antibody.

Targeting of Chronic Lymphocytic Leukemia B Cells with a Novel Monoclonal Antibody to ROR1

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 984-984
Author(s):  
Bing CUi ◽  
George F. Widhopf ◽  
Jian Yu ◽  
Daniel Martinez ◽  
Esther Avery ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
B Cells ◽  
Chronic Lymphocytic Leukemia ◽  
Adoptive Transfer ◽  
Leukemia Cell ◽  
Lymphocytic Leukemia ◽  
Leukemia Cells ◽  
Human Leukemia ◽  
Phosphorylated Akt

Abstract Abstract 984 ROR1 is an orphan receptor tyrosine kinase that is expressed on leukemia cells of patients with chronic lymphocytic leukemia (CLL), but not on most adult tissues of healthy adults, including CD5+ B cells. To generate anti-ROR1 antibodies, we immunized mice using different strategies employing vaccines comprised of recombinant ROR1 protein, polynucleotide-ROR1 vaccines and CD154 genetic adjuvants, or replication-defective adenovirus vectors encoding ROR1 and CD154. We extirpated the spleens of animals that developed high-titer serum anti-ROR1 antibodies and used these to generate monoclonal-antibody-(mAb)-producing hybridomas or antibody phage-display libraries that subsequently were screened for ROR1-binding. Over 70 unique mAbs were generated that each bound the extra-cellular domain of native ROR1. Most mAbs recognized an epitope(s) within the ROR1 Ig-like domain, which appears to represent the immune dominant epitope. Other mAb recognized epitopes within the conserved ROR1 Kringle domain. One mAb (UC D10-001) had distinctive binding to an intradomain epitope of human ROR1 (hROR1). UC D10-001 was the only mAb we found directly cytotoxic for hROR1-expressing leukemia cells cultured in media without complement for 6 hours. We found that UC D10-001 could induce significant reductions in basal levels of phosphorylated AKT in hROR1-expressing leukemia cells. Moreover, UC D10-001 significantly decreased the basal levels of phosphorylated AKT in freshly isolated human CLL cells (N=4) to levels comparable to that observed in co-cultures containing 10 mM LY294002, a broad-spectrum inhibitor of PI3K. We examined whether this mAb had cytotoxic activity for leukemia cell in vivo. For this we examined whether we could inhibit the adoptive transfer of human-ROR1-expressing leukemia cells to young, syngeneic recipient mice made transgenic for human ROR1 under control of a B-cell specific promoter. Cohorts of 5 animals per group were each given intravenous injections of antibody at a dose of at 10 mg/kg. Each cohort was treated with UC D10-001, control IgG, or 4A5, an anti-ROR1 mAb specific for a non-cross-reactive epitope located in the Ig-like domain of ROR1. Each animal received an intravenous injection of 5 × 105 ROR1-expressing leukemia cells and then was assessed weekly for circulating leukemia cells by flow cytometry. UC D10-001, but not control IgG or 4A5, significantly inhibited engraftment of the ROR1+ leukemia. Four weeks after adoptive transfer, animals treated with UC D10-001 had a 10-fold lower median number of leukemia B cells in the blood than animals treated with control IgG or 4A5. We also tested UC D10-001 for its capacity to induce clearance of human ROR1+ CLL cells engrafted into the peritoneal cavity of Rag-2−/−/γc−/− immune deficient mice. Each of these mice received intraperitoneal injections of equal numbers of human ROR1+ CLL cells prior to receiving D10-001, control IgG, or 4A5, each at 10 mg/kg. These animals were sacrificed seven days later and the human leukemia cells were harvested via peritoneal lavage. In mice treated with UC D10-001 we harvested an average of only 6 × 104 ± 3 × 104 CLL cells. This number of cells was significantly less than the average number of CLL cells harvested from control IgG or 4A5-treated mice (8 × 105 ± 4 × 105 or 7 × 105 ± 2 × 105, respectively, p <0.01). These studies indicate that the anti-ROR1 mAb UC D10-001 can be directly cytotoxic for ROR1-expressing leukemia cells in vitro and in vivo, a property that apparently is unique to this mAb among other anti-ROR1 mAbs. Because of the restricted expression of ROR1 on leukemia cells and the distinctive properties of this mAb, we propose that UC D10-001 might have potential utility in the treatment of patients with CLL. Disclosures: No relevant conflicts of interest to declare.

Selective Clearance of Chronic Lymphocytic Leukemia Cells in Vivo Following Treatment with UC99961, an Anti-ROR1 Monoclonal Antibody

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 3886-3886
Author(s):  
Eva Hellqvist ◽  
Christina C.N. Wu ◽  
George F. Widhopf ◽  
Alice Shih ◽  
Rommel Tawatao ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
T Cells ◽  
B Cells ◽  
Chronic Lymphocytic Leukemia ◽  
Cord Blood ◽  
Peritoneal Lavage ◽  
Lymphocytic Leukemia ◽  
Leukemia Cells ◽  
Human Cord Blood

Abstract Abstract 3886 ROR1 is a receptor-tyrosine kinase like protein expressed on the surface of chronic lymphocytic leukemia (CLL) B cells, but not on normal mature B cells, suggesting that it may be a promising therapeutic target. We have generated a chimeric monoclonal antibody (mAb), UC99961, which binds to an intradomain epitope of human ROR1 (hROR1). UC99961 binds the same epitope as the murine anti-hROR1 mAb, UC D10–001, which has direct cytotoxic effects on hROR1 positive CLL cells. In this study we investigated the in-vivo anti-leukemic activity and tolerability of UC99961 on ROR1+ primary patient CLL cells and human cord-blood-derived B cells and T cells, respectively. For these studies, immunodeficient RAG2−/−γc−/− neonatal mice were reconstituted with a human immune system by intrahepatic xenotransplantation of 1×105 CD34+ human cord blood progenitor cells. Eight to ten weeks post transplantation, cord blood engraftment was verified by peripheral blood screening, at which point the mice received an intraperitoneal transplantation of 2×107 primary patient ROR1+ CLL cells. Twenty-four hours after CLL transplantation, five animals per group were each treated with a single intraperitoneal injection (10mg/kg) of UC99961, UC D10–001, or control IgG. Seven days following mAb treatment, the animals were sacrificed and marrow, spleen, thymus, and peritoneal lavage samples were collected and analyzed by flow cytometry for CLL cells, as well as normal cord-blood-derived B cells and T cells. To confirm mAb administration according to the study design, serial residual ROR1 plasma antibody levels were determined by ELISA. Results from three consecutive experiments using leukemia cells from two different patients showed that the vast majority of CLL B cells remained in the peritoneal cavity of the animals and did not migrate to other hematopoietic organs. Both anti-hROR1 mAbs UC99961 and UC D10–001 significantly reduced the average number of harvested CLL cells in the peritoneal lavage compared to control IgG (99% and 71% reduction respectively), while cord-blood-derived T cells (CD45+3+) in thymus remained unaffected by the mAb treatment. For the majority of cord-blood-derived B cells in marrow and spleen, no significant reduction could be observed after UC99961 or UC D10–001 mAb treatment. A small CD19+ROR1+CD34− cord-blood-derived B cell population was identified in marrow and spleen that was reduced after UC99961 and UC D10–001 mAb treatment. This study demonstrates that the anti-human ROR1 specific mAbs have in vivo anti-leukemic activity with minimal impact on human cord-blood-derived B cells and T cells. From these results, UC99961 appears to be an excellent candidate antibody for future clinical studies for patients with CLL. Disclosures: No relevant conflicts of interest to declare.

A novel monoclonal antibody recognizing human thymocytes and B-cell chronic lymphocytic leukemia cells

1994 ◽  
Vol 39 (2) ◽  
pp. 137-146 ◽  
Author(s):  
P. Tassone ◽  
P. Bonelli ◽  
F. Tuccillo ◽  
H.M. Bond ◽  
M.C. Turco ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Chronic Lymphocytic Leukemia ◽  
B Cell ◽  
Lymphocytic Leukemia ◽  
Leukemia Cells ◽  
Cell Chronic Lymphocytic Leukemia

scholarly journals A novel adoptive transfer model of chronic lymphocytic leukemia suggests a key role for T lymphocytes in the disease

Blood ◽  
2011 ◽  
Vol 117 (20) ◽  
pp. 5463-5472 ◽  
Author(s):  
Davide Bagnara ◽  
Matthew S. Kaufman ◽  
Carlo Calissano ◽  
Sonia Marsilio ◽  
Piers E. M. Patten ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
T Lymphocytes ◽  
Adoptive Transfer ◽  
Severe Combined Immunodeficiency ◽  
Immune Surveillance ◽  
Lymphocytic Leukemia ◽  
Unknown Etiology ◽  
Lymphoid Tissues ◽  
Transfer Model

AbstractChronic lymphocytic leukemia (CLL) is an incurable adult disease of unknown etiology. Understanding the biology of CLL cells, particularly cell maturation and growth in vivo, has been impeded by lack of a reproducible adoptive transfer model. We report a simple, reproducible system in which primary CLL cells proliferate in nonobese diabetes/severe combined immunodeficiency/γcnull mice under the influence of activated CLL-derived T lymphocytes. By cotransferring autologous T lymphocytes, activated in vivo by alloantigens, the survival and growth of primary CFSE-labeled CLL cells in vivo is achieved and quantified. Using this approach, we have identified key roles for CD4+ T cells in CLL expansion, a direct link between CD38 expression by leukemic B cells and their activation, and support for CLL cells preferentially proliferating in secondary lymphoid tissues. The model should simplify analyzing kinetics of CLL cells in vivo, deciphering involvement of nonleukemic elements and nongenetic factors promoting CLL cell growth, identifying and characterizing potential leukemic stem cells, and permitting preclinical studies of novel therapeutics. Because autologous activated T lymphocytes are 2-edged swords, generating unwanted graph-versus-host and possibly autologous antitumor reactions, the model may also facilitate analyses of T-cell populations involved in immune surveillance relevant to hematopoietic transplantation and tumor cytoxicity.

scholarly journals ATR inhibition induces synthetic lethality and overcomes chemoresistance in TP53- or ATM-defective chronic lymphocytic leukemia cells

Blood ◽  
2016 ◽  
Vol 127 (5) ◽  
pp. 582-595 ◽  
Author(s):  
Marwan Kwok ◽  
Nicholas Davies ◽  
Angelo Agathanggelou ◽  
Edward Smith ◽  
Ceri Oldreive ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Synthetic Lethality ◽  
Lymphocytic Leukemia ◽  
Leukemia Cells ◽  
Selective Cytotoxicity ◽  
Key Points ◽  
Synthetically Lethal

Key PointsATR inhibition is synthetically lethal to TP53- or ATM-defective CLL cells. ATR targeting induces selective cytotoxicity and chemosensitization in TP53- or ATM-defective CLL cells in vitro and in vivo.

scholarly journals Effect of a thymic factor on T lymphocytes in B cell chronic lymphocytic leukemia: in vitro and in vivo studies

Blood ◽  
1984 ◽  
Vol 64 (3) ◽  
pp. 667-671 ◽  
Author(s):  
F Lauria ◽  
D Raspadori ◽  
S Tura
Keyword(s):  
T Cell ◽  
Chronic Lymphocytic Leukemia ◽  
T Lymphocytes ◽  
B Cell ◽  
Proliferative Response ◽  
Lymphocytic Leukemia ◽  
Before And After ◽  
Cell Chronic Lymphocytic Leukemia

Abstract Abnormalities of T lymphocytes in B cell chronic lymphocytic leukemia (B-CLL) have been extensively documented by several immunologic investigations. Following recent studies pointing to the favorable effect of TP-1, a partially purified extract of calf thymus, on the T cell-mediated immunity of several diseases, including Hodgkin's disease, we have used monoclonal antibodies and the enriched T lymphocytes of 16 untreated B-CLL patients to evaluate the proportion of T cell subsets before and after the administration of TP-1. In addition, the proliferative response to phytohemagglutinin (PHA) and the helper function in a pokeweed mitogen (PWM) system were assessed. In ten cases, the effect of TP-1 was also studied in vitro by evaluating the same parameters before and after incubation of B-CLL T cells with the drug. The study demonstrated that in vivo administration of TP-1 increases significantly (P less than .001) the proportion of the defective helper/inducer T cell population (OKT4-positive cells) in B-CLL, leading to a near normal OKT4/OKT8 ratio. Furthermore, the improved phenotypic profile was accompanied by an increased proliferative response to PHA and, in particular, by a significant increase (P less than .01) of T helper capacity; this increase was, however, insufficient to enable the normalization of the serum immunoglobulin levels. The in vitro incubation of B-CLL T lymphocytes did not succeed in producing significant modifications in distribution and function.

A Phase II, Open Label Study of AT-101 in Combination with Rituximab in Patients with Relapsed or Refractory Chronic Lymphocytic Leukemia.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2838-2838 ◽  
Author(s):  
Januario E. Castro ◽  
Loria J. Olivier ◽  
Aguillon A. Robier ◽  
James Danelle ◽  
Suarez J. Carlos ◽  
...  
Keyword(s):  
High Risk ◽  
Chronic Lymphocytic Leukemia ◽  
Adverse Events ◽  
Plasma Concentrations ◽  
Leukemia Cell ◽  
Lymphocytic Leukemia ◽  
Leukemia Cells ◽  
Pharmacokinetic Studies ◽  
Cell Counts ◽  
Grade 3

Abstract Chronic lymphocytic leukemia (CLL) cells express high-levels of Bcl-2 and related anti-apoptotic proteins that collectively can enhance leukemia-cell survival and drug-resistance. AT-101 is an orally active BH3-mimetic that can inhibit the anti-apoptotic activity of Bcl-2-family-member proteins (e.g. Bcl-2, Bcl-XL, Mcl-1) and induce CLL cells to undergo apoptosis. Furthermore, we found that AT-101 also can enhance the cytotoxicity of rituximab for CLL cells in vitro. As such we conducted a phase 2 trial to evaluate the safety and activity of AT-101 when used together with rituximab to treat 12 patients who had relapsed/refractory CLL. Patients received AT-101, at 30 mg/d, for 21 or 28 days during each of three 28-day cycles. Rituximab was administered at 375 mg/m2 for 12 doses (total dose = 4,500 mg/m2) on days 1, 3, 5, 8, 15, 22, 29, 31, 33, 40, 57, 59, 61. The first dose of rituximab was given over two days to minimize infusion-related adverse events. The patients’ median age was 61.5 years (range 43–81). Nine patients were high risk and 3 were intermediate risk based on the modified Rai classification and had received a median of 2 prior regimens (range 1–8). Six patients had leukemia cells that expressed ZAP-70 and/or unmutated immunoglobulin variable region genes and 4 patients had either 11q deletions or complex cytogenetics. Six patients interrupted treatment due to adverse events, most of which were transient and without residual complications. Grade 1–2 gastrointestinal effects (e.g., nausea, vomiting) occurred in 11 patients, 2 of whom had grade 3/4 ileus. Six patients experienced treatment-associated fatigue (grade 1–2 in 5 and grade 3 in one). Other than ileus and fatigue the only grade 3/4 event noted was neutropenia. One patient without neutropenia died while undergoing treatment from community-acquired bacterial pneumonia[j1]. Pharmacokinetic studies demonstrated that the average Cmax of AT-101 was 565 ng/ml (280 – 805 ng/ml) at a Tmax of 3.1 hours (1.7 – 5.6 hrs.). Correlative science studies performed on leukemia cells isolated at various times after treatment demonstrated leukemia-cell apoptosis in vivo, with maximum levels seen at times when we observed peak drug levels of AT-101. Eight patients had completed the study and had full response evaluation at the time of this abstract’s submission. The overall response rate was 38% [CRu (2); PR (1); SD (3); PD (2)]. Four of eight patients (50%) had significant reductions in leukemia cell counts and splenomegaly and 5 of 8 (63%) had reductions in lymphadenopathy. AT-101 in combination with Rituximab has apparent activity in patients with relapsed-refractory high-risk CLL. Additional enrollment is planned using alternate AT-101 schedules in an attempt to increase peak plasma concentrations (and potentially activity) and reduce GI toxicity.

A Phase I Study of Immune Gene Therapy for Patients with CLL Using a Membrane-Stable, Humanized CD154.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 2040-2040 ◽  
Author(s):  
William G. Wierda ◽  
J. Castro ◽  
R. Aguillon ◽  
A. Jalayer ◽  
J. McMannis ◽  
...  
Keyword(s):  
T Cell ◽  
Phase I ◽  
Death Receptor ◽  
Leukemia Cells ◽  
Cell Counts ◽  
Post Infusion ◽  
Bystander Cells ◽  
Induced Apoptosis ◽  
Dose Levels

Abstract Chronic lymphocytic leukemia (CLL) is an ideal disease for therapeutic vaccine strategies. While the leukemia cells are usually stealth-like, avoiding T cell recognition, they can be manipulated through ligation of CD40 on their surface to become very effective antigen presenting cells (APCs). Ligation of CD40 leads to expression of CD80, CD86 and upregulation of CD54. Other biochemical changes occur upon ligation of CD40, including upregulation of CD95, DR5, and expression of Bid, predisposing the leukemia cells to death-receptor-induced apoptosis. CLL cells can be made to express CD154 (CD40-ligand) using a replication-defective adenovirus. A phase I clinical trial with autologous CLL cells transduced to express murine CD154 previously demonstrated tolerability and clinical activity with this strategy (Blood96:2917, 2000). More recently, a recombinant CD154 (ISF35) was produced, based on the human CD154 backbone, incorporating murine sequences needed for expression on CLL cells and with the proteinase cleavage site removed. We evaluated this new transgene in a phase I clinical trial, expecting to have similar tolerability to the murine CD154. Transduction of CLL cells results in expression of ISF35, ligation of CD40 on transduced and bystander cells, and the resultant downstream changes needed for antigen presentation and sensitivity to death receptor-induced apoptosis. We conducted a phase I study of a single infusion of autologous CLL cells transduced to express ISF35. Three dose levels were evaluated with 3 patients (pts) each: 1×108, 3×108, & 1×109 transduced cells. Infusions were well tolerated, no acute infusion-related toxicities were observed. ISF35-related toxicities consisted of grade 1–2 flu-like symptoms that occurred several hrs after the infusion and consisted of fever, arthralgia, myalgia, nausea, vomiting, and fatigue lasting 2–4 days and resolving in all cases. There were no dose-limiting toxicities at any dose level. Biologic responses were seen at all doses, there was no dose-response relationship. There were consistent decreases in absolute lymphocyte counts at all dose levels, indicating a therapeutic effect. This was not dose-related, and ALC returned to pre-treatment level after 1–2 months post-infusion. There was consistent induction of CD95 and DR5 expression on bystander cells in vivo by 3 days following infusion, which lasted 2–3 weeks. Furthermore, consistent induction of Bid expression in bystander cells was seen by wk 1, also lasting 2–3 wks. Finally, consistent increases in absolute T cell counts (both CD4+ & CD8+) were seen, peaking 1–4 wks post infusion. These results demonstrate that ISF34-transduced autologous leukemia cells can be given safely at up to 1×109 transduced cells, without dose-limiting toxicities, and resulting in phenotypic and biochemical changes in bystander leukemia cells in vivo that render the cells able to present antigen and priming them for death-receptor-induced apoptosis. Furthermore, clinical responses were seen with reduction in leukemia counts and increases in absolute T cell counts. We expect that multiple, sequential doses will be needed for maximal therapeutic effect with this strategy. Given these results, we have developed a phase II trial of repeated doses of autologous ISF35-transduced leukemia cells for patients with CLL.

Sign in / Sign up

Export Citation Format

Share Document