scholarly journals 858 TILKine-2: a novel best-in-class tumor infiltrating lymphocyte (TIL) targeting engineered IL-2 with superior pre-clinical efficacy and safety for immunotherapy of cancer

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A899-A899
Author(s):  
Sreerupa Challa ◽  
Jonathan Carnino ◽  
Andrea Umana ◽  
Yuesheng Li ◽  
Jing Xu ◽  
...  
Keyword(s):  
Nk Cells ◽  
Half Life ◽  
Intracellular Signaling ◽  
Functional Characterization ◽  
Interleukin 2 ◽  
Systemic Toxicity ◽  
Fine Tuning ◽  
Therapeutic Window ◽  
High Dose ◽  
Severe Toxicity

BackgroundHigh-dose Interleukin-2 is the earliest FDA-approved immunotherapy for metastatic melanoma and renal cell carcinoma. Unfortunately, its application is limited due to its short half-life and severe toxicity at the therapeutic dose. To limit systemic toxicity, tumor-targeting antibody-based delivery of IL-2 has been developed, however with poor outcomes. We here deploy a novel strategy to deliver IL-2 to the tumor microenvironment by binding to Tumor-Infiltrating Lymphocytes (TILs). TILKine-2 is a recombinant bifunctional protein comprised of an antibody directed against TILs (TILAb) fused to an engineered IL-2, which simultaneously revives and expands antigen-primed exhausted T cells. The IL-2 portion of TILKine-2 was engineered to have improved tolerability, slower receptor-mediated clearance, and prolonged half-life.MethodsTarget binding of TILKine-2 was evaluated by cell-free and cell-based methods. In vitro functional characterization was performed using human peripheral blood mononuclear cells (PBMCs). Pharmacokinetics (PK), pharmacodynamics (PD), and anti-tumor activity of murine TILKine-2 surrogate (TILKine-2s) were evaluated in various syngeneic models. The safety and immune cell activation of TILKine-2 were assessed in non-human primates (NHPs).ResultsStructure-based design and activity-guided fine-tuning resulted in an optimized IL-2 variant that was fused to TILAb to generate TILKine-2. TILKine-2 demonstrated TIL-target antigen binding and blocking activity with sub-nM potency. TILKine-2 has a binding activity abolished to IL-2Rα and fine-tuned to IL-2Rβγ. In PBMCs, TILKine-2 potently induced intracellular signaling and cell proliferation in IL-2Rβγ dominant effector CD8+T and NK cells along with IFN-γ secretion. In vivo, TILKine-2 displayed significantly prolonged half-life with sustained proliferation, expansion, and Granzyme B expression on CD8+T and NK cells. Notably, the effects were more pronounced in the tumor than periphery, leading to massive immune hot tumors. Consequently, TILKine-2s exhibited robust anti-tumor primary and memory response in both cold and hot tumor models (MC38, CT26, B16F10, PAN02). Furthermore, TILKine-2s demonstrated superior and synergistic anti-tumor efficacy compared to TILAb alone, engineered IL-2 alone, or their combination, with 100% tumor regression resulting in ~80% tumor free mice in MC38 and Pan02 models. In NHPs, TILKine-2 preferentially induced memory CD8+T, total CD8+T, and NK cell expansion. TILKine-2 was safe and well-tolerated in NHPs with no notable changes in body weight, temperature, clinical pathology, or signs of vascular leakage after repeated dosing.ConclusionsBy targeting TILs, TILKine-2 demonstrated robust anti-tumor efficacy by preferentially inducing proliferation, expansion, and activation of intra-tumoral lymphocytes while reducing systemic toxicity and improving therapeutic window. In conclusion, TILKine-2 is a promising therapeutic agent for clinical development.Ethics ApprovalFor mouse studies, the practices and procedures used were reviewed and approved by Brandeis University IACUC committee (Protocol #22001). For monkey studies, the practices and procedures used were in accordance with the safety and Quality Assurance guidelines set out in the Guideline for Experiments document of Kunming Biomed International (KBI--01-GEv2.0).

564 Potency-reduced and extended half-life IL12 heterodimeric Fc-fusions exhibit strong anti-tumor activity with potentially improved therapeutic index compared to native IL12 agents

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A598-A598
Author(s):  
Matthew Bernett ◽  
Rajat Varma ◽  
Ke Liu ◽  
Christine Bonzon ◽  
Rumana Rashid ◽  
...  
Keyword(s):  
Nk Cells ◽  
Half Life ◽  
Single Agent ◽  
Therapeutic Index ◽  
Immune Checkpoints ◽  
Therapeutic Window ◽  
Interleukin 12 ◽  
Severe Toxicity ◽  
Anti Tumor Activity

BackgroundInterleukin-12 (IL12) is a proinflammatory cytokine produced by activated antigen-presenting cells that induces differentiation of Th1 cells and increased proliferation and cytotoxicity of T and NK cells. Stimulation of these cells by IL12 leads to production of high levels of IFNγ. These immune-stimulating aspects of IL12 may help to establish an inflammatory tumor microenvironment critical for anti-tumor responses. Preclinical studies in mice revealed that native IL12 can dramatically shrink syngeneic tumors, however clinical studies in humans resulted in severe toxicity and a small therapeutic window, limiting response rates. Prior work at Xencor demonstrated that reduced-potency IL15/IL15Rα-Fc fusion proteins exhibited superior pharmacokinetics, pharmacodynamics, and safety in non-human primates through reduction of receptor-mediated clearance. Applying similar principles to IL12, we created IL12 heterodimeric Fc-fusions (IL12-Fc) with reduced potency to improve tolerability, slow receptor-mediated clearance, and extend half-life.MethodsIL12 is a heterodimeric protein consisting of two subunits, so we engineered IL12-Fc fusions by fusing the IL12p35 subunit to one side of a heterodimeric (and inactive) Fc domain, and the IL12p40 subunit to the other side. These Fc-fusions were tuned for optimal activity by introducing amino acid substitutions at putative receptor-interface positions and screening for reductions of in vitro potency. In vitro activity was assessed on human PBMCs by measuring signaling in a STAT4 phosphorylation assay and IFNγ production in a mixed-lymphocyte reaction (MLR). In vivo anti-tumor activity was assessed by engrafting MCF-7 cells into PBMC engrafted NSG MHC class I and II double-knockout mice and by measuring tumor volume, lymphocyte activation/proliferation, and IFNγ production over time.ResultsIL12-Fc were produced with good yield and purity. An IL12-Fc potency series was created, and variants had up to a 10,000-fold reduction in STAT4 signaling potency and IFNγ production in an MLR assay compared to native IL12-Fc. Anti-tumor activity in the huPBMC-MCF7 model was achieved with potency-reduced IL12-Fc as a single-agent and in combination with anti-PD1, with weaker variants maintaining anti-tumor activity at higher dose levels. Analysis of peripheral lymphocytes indicated increased numbers of T and NK cells as well as activation of CD8+ T cells, as evidenced by upregulation of CD25. Increased expression of immune checkpoints including PD1 was also observed. Analysis of serum indicated up to 200-fold increases in IFNγ levels.ConclusionsCombined, these data indicate that potency-reduced IL12-Fc retain strong anti-tumor activity, while potentially overcoming safety and tolerability issues related to small therapeutic index associated with recombinant native IL12 or IL12-Fc agents.

High-dose interleukin-2 (HD IL-2) in the treatment of advanced melanoma: The University of Pittsburgh experience.

2013 ◽  
Vol 31 (15_suppl) ◽  
pp. 9075-9075
Author(s):  
Diwakar Davar ◽  
Melissa Saul ◽  
Ahmad A. Tarhini ◽  
An Tran ◽  
Kerry Trent ◽  
...  
Keyword(s):  
Proportional Hazards ◽  
Interleukin 2 ◽  
Complete Response ◽  
Median Number ◽  
Cox Proportional Hazards ◽  
Advanced Melanoma ◽  
High Dose ◽  
Severe Toxicity ◽  
University Of Pittsburgh ◽  
Radiological Data

9075 Background: IL-2 is a T-cell growth factor tested in a variety of regimens for advanced melanoma (MEL) and renal cell carcinoma (RCC). High-dose IL-2 (600,000-720,000 IU/kg administered intravenously every 8 hours for up to 14 consecutive doses) was approved by FDA for advanced MEL and RCC in 1998 based upon the durability of responses observed. Early studies of HD IL-2 reported overall (OR) and complete response (CR) rates of 16% and 8% respectively. Severe toxicity limited use to specialized centers with standardized protocols, either intensive care (ICU) or oncology specialty settings. The U Pittsburgh has treated 1022 patients with IL-2 at any dosage and we here present outcomes of 550 MEL pts treated with HD IL-2 in an oncology specialty non-ICU setting. Methods: Clinical and radiological data were collected on all pts treated with IL-2 using the UPCI Cancer Registry and Medical Archival System (MARS). Pharmacy records were reviewed for dosing details. The influence of baseline characteristics on treatment outcomes was assessed using Cox proportional hazards analysis. Results: A total of 848 pts received HD IL-2, of which 298 pts had RCC while 550 had MEL. Detailed pharmacy dosing records were reviewed from 176 pts treated over the past 12 years (2000-2012) who received a total of 3738 cycles. Of 165 pts evaluable for response, OR was documented in 24 pts (14.8%) and CR in 5 pts (3.0%). Median overall survival (OS) was 10.0 mos for all patients and 21.5 mos for responders (CR+PR). Median number of doses per cycle was 7. Toxicity was consistent with prior reports. HD IL-2 required ICU transfers in 5% and 1 death was attributed to HD IL-2. Pts with higher baseline lactate dehydrogenase (LDH) had poorer OS (p < 0.05). Conclusions: In this large and uniformly treated series of recent patients treated with IL-2 OR/CR rates with HD IL-2 are 14.8% and 3.0% respectively. Higher LDH is associated with poorer outcome. Biomarkers of response are currently being evaluated in banked clinical specimens collected from patients under the SPORE in Skin Cancer (P50 CA121973).

scholarly journals Analysis of the linker for activation of T cells and the linker for activation of B cells in natural killer cells reveals a novel signaling cassette, dual usage in ITAM signaling, and influence on development of the Ly49 repertoire

Blood ◽  
2008 ◽  
Vol 112 (7) ◽  
pp. 2869-2877 ◽  
Author(s):  
Gillian C. Whittaker ◽  
Deborah N. Burshtyn ◽  
Selinda J. Orr ◽  
Laura Quigley ◽  
Deborah L. Hodge ◽  
...  
Keyword(s):  
T Cells ◽  
B Cells ◽  
Nk Cells ◽  
Natural Killer ◽  
Nk Cell ◽  
Interleukin 2 ◽  
Fine Tuning ◽  
Receptor Coupling ◽  
Integral Proteins ◽  
Activation Motif

AbstractThe linker for activation of T cells (LAT) and the linker for activation of B cells (LAB/NTAL/LAT2) are integral proteins in receptor coupling to downstream events. Both proteins are expressed in natural killer (NK) cells and LAT is phosphorylated during target cell interactions or ligation of the immunoreceptor tyrosine-based activation motif (ITAM)–coupled CD16. Regardless, Lat−/− mice exhibit normal natural and antibody-mediated killing. Here we place both LAT and LAB in the DAP12 pathway of NK cells. Moreover, we unveil a LAT-independent pathway that requires expression of Syk. Mice lacking either LAT or LAB have a skewed Ly49 repertoire, and activated NK cells from Lat−/− mice have reduced responses to the ITAM-coupled receptor NK1.1. In contrast, resting Lat−/− NK cells show intact NK1.1 responses, whereas NK cells without LAB are hyperactive. Elimination of both adaptors severely reduces NK1.1 signaling under both conditions. Together these data show that NK ITAMs preferentially use a signaling cassette regulated by interplay between LAT and LAB. Activation by interleukin-2 causes a shift to greater dependency on LAT due to suppression of Syk signaling. The overlapping use of multiple adaptors permits fine-tuning of NK-cell ITAM responses over the course of an immune response.

Methotrexate-induced renal impairment: clinical studies and rescue from systemic toxicity with high-dose leucovorin and thymidine.

1983 ◽  
Vol 1 (3) ◽  
pp. 208-216 ◽  
Author(s):  
H T Abelson ◽  
M T Fosburg ◽  
G P Beardsley ◽  
A M Goorin ◽  
C Gorka ◽  
...  
Keyword(s):  
Renal Failure ◽  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Systemic Toxicity ◽  
High Dose ◽  
Severe Toxicity ◽  
Treatment Comparison ◽  
Dose Methotrexate ◽  
Significant Difference

Four separate groups of patients have been studied: (1) The effect of high-dose methotrexate (MTX) administration on glomerular filtration rate was determined by pre- and posttreatment inulin and creatinine clearances in nine patients. Measurements were made prior to and 24-40 hr after drug administration. Inulin and creatinine clearances both decreased a mean of 43%. No signs of systemic toxicity occurred. (2) Three other patients given high-dose courses of MTX developed MTX toxicity. Their creatinine clearance decreased an average of 61%. (3) In a separate group of five patients undergoing weekly MTX treatment, comparison of serum MTX pharmacokinetics with and without alkalinization of the urine demonstrated no significant difference in peak serum MTX levels or serum MTX decay. (4) Eight additional patients with severe renal dysfunction secondary to MTX were treated with increased doses of leucovorin and a continuous infusion of thymidine (8 g/m2/day) once renal failure was recognized. When high-dose leucovorin and thymidine were begun 48-72 hr after the MTX infusion, severe toxicity in the form of leukopenia, thrombocytopenia, diffuse mucositis, stomatitis, or skin rash was averted. We concluded the following: (1) high-dose MTX causes a subclinical decrease in glomerular filtration rate with each administration, even in nontoxic courses; (2) alkalinization of the urine with sodium bicarbonate does not alter plasma MTX decay, while volume expansion (hydration) is maintained constant; and (3) rigorous monitoring of serum creatinine and serum MTX levels 24-48 hr after MTX administration allows for the institution of rescue measures, including leucovorin and thymidine, which will abort the systemic toxicity that accompanies MTX-induced renal failure.

Metastatic malignant melanoma treated with combined bolus and continuous infusion interleukin-2 and lymphokine-activated killer cells.

1990 ◽  
Vol 8 (7) ◽  
pp. 1138-1147 ◽  
Author(s):  
M H Bar ◽  
M Sznol ◽  
M B Atkins ◽  
N Ciobanu ◽  
K C Micetich ◽  
...  
Keyword(s):  
Lymph Node ◽  
Continuous Infusion ◽  
Lung Metastases ◽  
Interleukin 2 ◽  
Advanced Melanoma ◽  
Lak Cells ◽  
High Dose ◽  
Severe Toxicity ◽  
Lymphokine Activated Killer Cells

Fifty patients with advanced melanoma received high-dose bolus and continuous infusion interleukin-2 (IL-2) with lymphokine-activated killer (LAK) cells in an attempt to improve the therapeutic index of this active but toxic therapy. Treatment began with up to nine bolus doses of IL-2 administered over 3 days. After 1 day of rest, patients underwent daily leukapheresis for 4 days, and the leukocytes were cultured with IL-2 in vitro to prepare LAK cells. Continuous infusion IL-2 was begun 1 day after the last leukapheresis and continued for up to 148 hours; LAK cells were administered on days 1, 2, and 4 of the infusion. Responding patients were eligible to receive up to two additional cycles of therapy at 3-month intervals. Most patients completed each cycle without dose reduction. One patient had a complete response and six patients had partial responses (14% response rate). The complete responder and three of the partial responders (8%) remain free from disease progression with follow-up of 21 to 24 months. Of these four patients with durable remissions, one had extensive liver and lymph node metastases, one had lymph node, pleural, and parenchymal lung metastases, and two had disease limited to lymph nodes or subcutaneous tissues. Seventeen patients (34%) required pressors for hypotension, three patients (6%) developed hemodynamically significant arrhythmias, and six patients (12%) developed dyspnea at rest, but none required intubation and there were no treatment-related deaths. Unacceptable toxicity developed in two patients during bolus IL-2 administration and therapy was aborted; both returned to baseline status within 4 days of discontinuing IL-2. Fever, oliguria, and elevated creatinine or transaminase levels occurred frequently but were also transient. Despite less frequent severe toxicity with this modified regimen, these results confirm the ability of IL-2 and LAK cell therapy to induce durable remissions in some patients with advanced melanoma.

The effect of prior cisplatin therapy on the pharmacokinetics of high-dose methotrexate.

1984 ◽  
Vol 2 (6) ◽  
pp. 655-661 ◽  
Author(s):  
W R Crom ◽  
C B Pratt ◽  
A A Green ◽  
J E Champion ◽  
D B Crom ◽  
...  
Keyword(s):  
Linear Regression ◽  
Multiple Linear Regression ◽  
Half Life ◽  
Linear Regression Analysis ◽  
Multiple Linear Regression Model ◽  
High Dose ◽  
Severe Toxicity ◽  
High Dose Methotrexate ◽  
Serum Samples ◽  
Dose Methotrexate

The pharmacokinetics of high-dose methotrexate (MTX, 5-15 g/m2) were evaluated in 11 children and adolescents who had previously received two to eight doses of cisplatin (90 mg/m2) in the treatment of malignant solid tumors. The half-life for disappearance of MTX from serum during the first 24 hours after infusion was determined from serum samples obtained at the end of a six-hour infusion and six, 12, and 24 hours after infusion. These values were compared to a mean half-life of 2.83 (+/- 0.34) hours following 489 courses administered to 71 patients who had not received cisplatin. Stepwise multiple linear regression analysis of patient variables revealed cumulative cisplatin dosage and time from last cisplatin dose as the best predictors of MTX half-life (r2 = 65.4%, p less than 0.001). The best predictors of 24-hour serum concentration were cumulative cisplatin dosage and MTX dosage (r2 = 54.2%, p less than 0.001) in the multiple linear regression model. Patients with delayed MTX clearance received additional leucovorin and experienced no severe toxicity. Patients receiving up to 270 mg/m2 of cisplatin appear to have minimal increases in MTX half-life, while the likelihood of delayed clearance increases in patients who have received 360 mg/m2 or more of cisplatin. All patients who have previously received cisplatin should be treated cautiously with high-dose MTX and prospective pharmacokinetic monitoring should be routinely performed.

scholarly journals Investigation of interleukin-2-mediated changes in blood pressure, fetal growth restriction, and innate immune activation in normal pregnant rats and in a preclinical rat model of preeclampsia

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Mark W. Cunningham ◽  
Lorena M. Amaral ◽  
Nathan E. Campbell ◽  
Denise C. Cornelius ◽  
Tarek Ibrahim ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Nk Cells ◽  
Fetal Growth ◽  
Rat Model ◽  
Fetal Growth Restriction ◽  
Nk Cell ◽  
Interleukin 2 ◽  
Growth Restriction ◽  
High Dose ◽  
Fetal Survival

AbstractTwo important clinical features of preeclampsia (PE) are hypertension and fetal growth restriction. The reduced uterine perfusion pressure (RUPP) preclinical rat model of PE exhibits both of these features. Moreover, RUPP and PE women have elevated vasoconstrictor peptide endothelin-1 (ET-1) and inflammation. Interleukin-2 (IL-2) is a cytokine that regulates NK cell activity and is elevated in miscarriage, PE, and RUPP rats. The objective of this study was to examine a role for IL-2 in NK cell activation, fetal growth restriction, and hypertension during pregnancy by either infusion of IL-2 or blockade of IL-2 (basiliximab) in normal pregnant (NP) and RUPP rats. On gestational day 14, NP and RUPP rats received low (LD), middle (MD), or high dose (HD) IL-2 (0.05, 0.10, or 0.20 ng/ml) IP or basiliximab (0.07 mg per rat) by IV infusion. On day 19, blood pressure (MAP), pup weights, and blood were collected. Basiliximab had no effect on blood pressure, however, significantly lowered NK cells and may have worsened overall fetal survival in RUPP rats. However, IL-2 LD (102 ± 4 mmHg) and IL-2 HD (105 ± 6 mmHg) significantly lowered blood pressure, ET-1, and activated NK cells compared to control RUPPs (124 ± 3 mmHg, p < 0.05). Importantly, IL-2 in RUPP rats significantly reduced fetal weight and survival. These data indicate that although maternal benefits may have occurred with low dose IL-2 infusion, negative effects were seen in the fetus. Moreover, inhibition of IL-2 signaling did not have favorable outcome for the mother or fetus.

scholarly journals 568 XTX201, a protein-engineered IL-2, exhibits tumor-selective activity in mice without peripheral toxicities in non-human primates

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A602-A602
Author(s):  
Minjie Zhang ◽  
Wilson Guzman ◽  
Parker Johnson ◽  
Megan McLaughlin ◽  
Kurt Jenkins ◽  
...  
Keyword(s):  
Immune Activation ◽  
Half Life ◽  
Cell Activation ◽  
Nk Cell ◽  
Interleukin 2 ◽  
Life Extension ◽  
High Dose ◽  
2Nd Generation ◽  
Tumor Selective ◽  
Selective Activity

BackgroundHigh-dose recombinant human interleukin-2 (aldesleukin) elicits durable anti-tumor immunity and gained FDA approval two decades prior to checkpoint blockers. However, use of aldesleukin is limited due to treatment-related life-threatening toxicities. Second generation efforts to alleviate toxicities have largely focused on eliminating binding to IL-2Rα, often with half-life extension. We have determined that mice and non-human primates (NHPs) treated with a 2nd generation IL-2 surrogate that does not bind IL-2Rα still experience characteristic dose-limiting toxicities, including vascular leak syndrome (VLS), and exhibit dysregulated peripheral immune function due to reduced Treg activation. To overcome these toxicities and improve the therapeutic index of IL-2 as an anti-tumor immunotherapy, we employed protein engineering to generate XTX201, a highly potent 3rd generation IL-2 that is designed to be selectively active in tumors, stimulating cytolytic responses against tumor cells while sparing systemic immune activation.MethodsXTX201 binding interactions were measured with SPR, and bioactivity was measured using STAT-5 phosphorylation in human PBMCs and reporter cell lines. Anti-tumor efficacy and immune activation was evaluated in tumors compared to peripheral organs in syngeneic tumor mouse models. Safety and pharmacokinetics were evaluated in rodents and NHPs.ResultsNon-activated XTX201 showed no detectable binding to IL-2Rα or IL-2Rβ, and limited IL-2R-dependent STAT-5 signaling in vitro. Activation of XTX201 resulted in high-affinity binding to IL-2Rβ and no binding to IL-2Rα, leading to a ~1000-fold reduction in Treg activation as compared to WT IL-2, while retaining CD8+ T and NK cell activation. Mice and NHPs treated with a 2nd generation IL-2 surrogate experienced toxicities that are commonly observed in patients treated with aldesleukin, including pulmonary edema, VLS, fever and lethality. However, XTX201 did not induce toxicities at exposures 100-fold higher than the MTD of the activated version, and achieved similar anti-tumor efficacy in mice. Experiments in primary human solid tumors and human plasma indicated that XTX201 is preferentially activated in the tumor microenvironment.ConclusionsOur data demonstrate that 2nd generation IL-2s that are systemically active and lack binding to IL-2Rα exhibit dose-limiting toxicities unless further engineered for selective activity in tumors. XTX201, a 3rd generation, tumor-selective IL-2, exhibits a long half-life and is innocuous outside of tumors. XTX201 is activated within tumors to release an IL-2Rβ/γ biased cytokine that inhibits tumor growth in syngeneic models, and exhibits tumor-specific pharmacodynamic effects without peripheral toxicities. XTX201 has the potential to be a best-in-class IL-2 immunotherapy by expanding the curative anti-tumor activity of aldesleukin while minimizing dose-limiting toxicities.

Phase I study of interleukin 2 (IL2) maintenance after induction with weekly docetaxel and estramustine in patients with metastatic hormone refractory prostate cancer (HRPC)

2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 14526-14526
Author(s):  
P. Jiang ◽  
C. S. Higano
Keyword(s):  
Phase I ◽  
Nk Cells ◽  
Low Dose ◽  
Standard Dose ◽  
Interleukin 2 ◽  
High Dose ◽  
Weekly Docetaxel ◽  
Level 1 ◽  
Hormone Refractory ◽  
Level 2

14526 Background: Patients with HRPC commonly respond to docetaxel, but many develop asthenia and other docetaxel related toxicities that impair quality of life and hence, many clinicians prescribe a “chemotherapy vacation”. IL2 exerts its anti-tumor effect through activation of T cells and NK cells and at high dose has been shown to have efficacy (and toxicity) in men with HRPC (Maffezzini, The Prostate 1996). Low dose IL2 and 13-cis-retinoic acid given as maintenance after cytoreduction of advanced solid tumors was associated with increased numbers of circulating NK cells as well as further tumor responses (Recchia, Proc ASCO 2001). A phase I trial of low dose IL2 maintenance after chemo induction was undertaken. Methods: Chemotherapy naive pts with metastatic HRPC were induced with weekly docetaxel 35 mg/m2 on day 2 and estramustine 280 mg/M2 TID on days 1 and 2 for 3 wks followed by 1 wk off for a total of 12 doses of chemotherapy. Responding pts received maintenance IL2 for 5 days/wk for 3 wks, followed by 1 wk off. During the 3rd wk, a boost dose was administered on days 2 and 3. Level 1 maintenance was 0.5 x106 IU/m2 SC bid, level 2 was 0.75 × 106 IU/m2 SC bid. Level 1 boost was 3 × 106 IU/m2, level 2 was 4.5 × 106 IU/m2 SC bid. Cohorts of 3 patients were treated at a given dose level according to standard dose escalation schemes for toxicity. IL2 was continued until objective progression was documented. Results: 15 pts, median age of 70 (range 46–78), median PSA 32.7 (range 2.28 to 1248) were enrolled. After chemotherapy, 12 pts had > 50% (7 had > 75%) decline in PSA, 3 pts had < 50% decline. 13 pts went on to receive IL2. The MTD for maintenance IL2 was 0.5 × 106 IU/m2 SC bid (4 pts at level 1 had no toxicity but 3 of 4 at level 2 had grade 2 toxicity requiring a drop to level 1). MTD for the boost was 3 × 106 IU/m2 (4 with no toxicity at level 1, 3 of 3 with grade 2 toxicity at level 2 requiring a drop to level 1). The most common toxicities were fatigue, nausea, chills, edema. One pt has received IL2 maintenance for 25 months. Conclusions: IL2 maintenance can be safely administered at the MTD. Immunological studies before/after chemotherapy and during IL2 are pending. No significant financial relationships to disclose.

scholarly journals Dose-Dependent Activation of Lymphocytes in Endotoxin-Induced Airway Inflammation

2000 ◽  
Vol 68 (12) ◽  
pp. 6962-6969 ◽  
Author(s):  
Roland Larsson ◽  
David Rocksén ◽  
Bo Lilliehöök ◽  
Åsa Jonsson ◽  
Anders Bucht
Keyword(s):  
T Cells ◽  
Nk Cells ◽  
Airway Inflammation ◽  
Lung Tissue ◽  
Low Dose ◽  
Lymphocyte Subsets ◽  
Interleukin 2 ◽  
Γδ T Cells ◽  
High Dose ◽  
Dose Dependent

ABSTRACT Recruitment of neutrophils to lung tissue and airspaces is a hallmark of inflammatory events following inhalation of endotoxins. We studied the role of different lymphocyte subsets in this inflammation, which is assumed to primarily involve the innate immune system. Inhalation of aerosolized Escherichia colilipopolysaccharide (LPS) in mice induced a dose-dependent increase in neutrophils in bronchoalveolar lavage fluid, reaching a maximum after 12 h at a low dose and after 24 h at a high dose. Profiles of gene expression in lung tissue indicated an early (2 h) and transient onset of proinflammatory cytokines and chemokines by a low dose of LPS, while a high dose caused more delayed and sustained (6 to 12 h) activation. Gamma interferon, interleukin-2 (IL-2), RANTES, and the α chain of the IL-2 receptor were not expressed at a low dose, whereas a high dose of LPS induced a strong expression of these genes, indicating a dose-dependent activation of T cells. A similar pattern was observed for IL-17, supporting a contribution of T cells to the neutrophilic inflammation only at high-dose exposure to LPS. The involvement of lymphocytes in the inflammatory response was further studied using mice with functional deficiencies in defined lymphocyte subsets. Both γδ T-cell- and B-cell-deficient mice displayed a response similar to that of the corresponding wild-type strains. Selective depletion of NK cells by in vivo administration of the pk136 antibody did not significantly affect the recruitment of neutrophils into airspaces. Thus, neither NK cells, B cells, nor γδ T cells appeared to participate in the host response, suggesting that among the lymphocyte subsets, αβ T cells are exclusively involved in endotoxin-induced airway inflammation.

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