Marked Therapeutic Efficacy of a Novel Polyethyleneglycol-SN38 Conjugate, EZN-2208, in Xenograft Models of Non-Hodgkin’s Lymphoma.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 1397-1397
Author(s):  
Puja Sapra ◽  
Mary Mehlig ◽  
Jennifer Malaby ◽  
Patricia Kraft ◽  
Clifford Longley ◽  
...  

Abstract Background: The clinical utility of SN38 (10-hydroxy-7-ethyl-camptothecin), the active moiety of CPT-11 (Camptosar®), has been severely compromised due to its poor solubility. EZN-2208 is a novel, water-soluble, polyethyleneglycol (PEG)-SN38 conjugate generated by linking SN38 with a multi-arm high molecular weight PEG, 40k 4-arm-PEG, via a glycine linker. Here, we compare the efficacy of EZN-2208 and CPT-11 in the treatment of animals bearing non-Hodgkin’s lymphomas. Methods: The in vitro cytotoxicity of EZN-2208 and CPT-11 were tested in human lymphoma (Raji, Daudi, DoHH2) cancer cell lines using the tetrazolium assay. The pharmacokinetics and maximum tolerated dose (MTD) of EZN-2208 and CPT-11 were evaluated in tumor-free severe combined immunodeficient (SCID) mice and the therapeutic efficacy was evaluated in xenograft models of non-Hodgkin’s lymphoma (Raji and Daudi). Results: In vitro, the IC50 of EZN-2208 ranged from 2–20nM and the in vitro potency of EZN-2208 was 30 to 50-fold more than CPT-11. The MTDs of EZN-2208 and CPT-11 in SCID mice were 30 and 60 mg/kg, respectively, when injected as a single dose. When administered in a multiple dose regimen (q2d x 5), the MTDs of EZN-2208 and CPT-11 were 10- and 40 mg/kg respectively. The pharmacokinetic profile of EZN-2208 was biphasic showing a rapid distribution phase (t1/2a =0.6h) and a slow elimination phase (t1/2b =19.3h for conjugate and 14.2h for SN38). In the Raji xenograft model, treatment with a single MTD of EZN-2208 resulted in a 500% improvement in life span (ILS) and 50% cures of animals compared with 19% ILS observed for mice treated with a single MTD of CPT-11. Multiple dose treatment of EZN-2208 resulted in 90% cures of animals compared with 63% ILS and no cures observed for the CPT-11 group. In the Daudi xenograft model, a single injection of EZN-2208 given as early treatment resulted in cures of 100% of animals in contrast to 66% ILS and no cures observed for CPT-11 group. When treatment was delayed, a single MTD of EZN-2208 caused 90% cures of animals, whereas CPT-11 treatment was completely ineffective. Conclusions: EZN-2208 demonstrated excellent efficacy in preclinical models of non-Hodgkin’s lymphoma. Ongoing Phase I studies will determine the optimal dose and schedule of EZN-2208.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3289-3289
Author(s):  
Sailaja S. Vanama ◽  
Puja Sapra ◽  
Hans J. Hansen ◽  
Ivan D. Horak ◽  
David M. Goldenberg ◽  
...  

Abstract Ranpirnase (Rap), isolated from frog (Rana pipiens) oocytes, is a monomeric ribonuclease (MW 11800) that kills cells by degrading t-RNA upon internalization. Previous studies indicated that the cytotoxicity of Rap could be enhanced more than 10,000-fold when the enzyme is chemically conjugated to an internalizing antibody. Here we describe the construction and characterization of 2L-Rap-hLL1-γ4P, composed of two Rap molecules fused to hLL1, an internalizing anti-CD74 humanized monoclonal antibody. To reduce unwanted cytotoxicity, the IgG1 constant region of hLL1 was replaced with an IgG4 that contains a proline mutation in the hinge region. The Rap gene was inserted at the N-terminus of the light chain in the expression vector of hLL1 and expressed in NS0 mouse myeloma cells. The fusion protein was characterized by a variety of techniques, including SE-HPLC, SDS-PAGE, in vitro transcription translation (IVTT) assay using luciferase reporter system, and competition ELISA to measure the binding affinity for CD74. The in vitro potency was determined in non-Hodgkin’s lymphoma (Daudi) and multiple myeloma (MC/CAR) cell lines by MTS tetrazolium dye reduction assay. In vivo pharmacokinetics and biodistribution of radiolabeled 2L-Rap-hLL1- γ4P was compared to radiolabeled hLL1 mAb in naïve mice and in vivo therapeutic efficacy of 2L-Rap-hLL1- γ4P was determined in a xenograft model of Burkitt’s non-Hodgkin’s lymphoma (Daudi). Purified 2L-Rap-hLL1- γ4P was shown to be a single peak by SE-HPLC and its MW determined by MALDI-TOF to be 177,150, which is in agreement with the MW of one IgG (150,000) plus two Rap molecules (24,000). Reducing-SDS-PAGE of 2L-Rap-hLL1- γ4P revealed the presence of 3 bands, one corresponding to the heavy chain and the other two appearing to be derived from the Rap-fused light chains (38,526 and 36,700 by MS). Occurrence of the 2 light chains was shown to be due to glycosylation of Rap at the N69 residue. The binding affinity of 2L-Rap-hLL1- γ4P for CD74 was indistinguishable from that of hLL1. Both 2L-Rap-hLL1- γ4P and hLL1 bound to CD74 with subnanomolar affinity. The EC50 of RNase activity, as measured by the IVTT assay, was 300 pM for 2L-Rap-hLL1- γ4P and 30 pM for recombinant Rap (expressed in E. coil). In in vitro cytotoxicity assays, 2L-Rap-hLL1- γ4P was significantly cytotoxic against Daudi (EC50 280 pM) and the myeloma cell line, MC/CAR (EC50 50 nM). In contrast, free Rap or naked hLL1 did not demonstrate significant cytotoxicity at the concentrations tested. In vivo, the pharmacokinetic profile of 2L-Rap-hLL1- γ4P was almost identical to that of naked hLL1. Both 2L-Rap-hLL1- γ4P and hLL1 showed biphasic clearance from the circulation; the α and β half-life (t1/2) of 2L-Rap-hLL1- γ4P were 5 h and 119 h, respectively, and those of hLL1 were 4 h and 125 h, respectively. In tissue biodistribution studies, no significant difference was observed between 2L-Rap-hLL1- γ4P and hLL1 with regards to normal tissue uptake. Early efficacy results in the Daudi Burkitt’s non-Hodgkin’s lymphoma xenograft model demonstrate that treatment with a single dose of 2L-Rap-hLL1- γ4P as low as 1 μg/mouse significantly improves survival in comparison to untreated control mice (P<0.0001).


Blood ◽  
1993 ◽  
Vol 82 (1) ◽  
pp. 262-267 ◽  
Author(s):  
R Stauder ◽  
S Hamader ◽  
B Fasching ◽  
G Kemmler ◽  
J Thaler ◽  
...  

The interaction of human lymphoma cells with high endothelial venules (HEVs) on sections of lymphatic tissues was studied in 44 cases of non- Hodgkin's lymphoma (NHL) with the in vitro HEV binding assay. The relative adherence ratio (RAR) of lymphoma cells to HEVs as related to that of reactive lymphocytes was 0.29 to 4.64 in 38 cases of B chronic lymphocytic leukemia (CLL), 1.15 and 1.54 in two cases of immunocytic NHL, 1.12 and 0.70 in two cases of centrocytic NHL, 1.98 in one case of a peripheral T-NHL, whereas plasma cell leukemia cells adhered very weakly (RAR 0.1). Among the patients suffering from CLL a pronounced HEV binding ability of tumor cells correlated significantly with the more unfavorable Binet stages B and C (median 1.32) as well as with a widespread lymphatic dissemination, which strongly indicates a hematogenous, HEV-mediated spread (median 1.34). In contrast, weak adherence to HEVs was associated with Binet stage A (median 0.85; P < .05) and with a lacking or only localized clinical involvement of lymph nodes (median 0.84; P < .01). Thus, specific HEV recognition processes even operate in lymphoid neoplasms and via this mechanism seem to influence the dissemination of tumors.


2020 ◽  
Vol 6 (14) ◽  
pp. eaaz9798 ◽  
Author(s):  
Kin Man Au ◽  
Andrew Z. Wang ◽  
Steven I. Park

Overactivation of the PI3K/mTOR signaling has been identified in non-Hodgkin’s lymphoma. BEZ235 is an effective dual PI3K/mTOR inhibitor, but it was withdrawn from early-phase clinical trials owing to poor solubility and on-target/off-tumor toxicity. Here, we developed a nanoparticle (NP)–based pretargeted system for the therapeutic delivery of BEZ235 to CD20- and HLA-DR–expressing lymphoma cells for targeted therapy. The pretargeted system is composed of dibenzocyclooctyne-functionalized anti-CD20 and anti-Lym1 antibodies as the tumor-targeting components and azide-functionalized BEZ235-encapsulated NPs as the effector drug carrier. Using lymphoma cell lines with different CD20 and HLA-DR antigen densities as examples, we demonstrate that the dual antibody pretargeted strategy effectively raises the number of NPs retained on the target tumor cells and improves the in vitro and in vivo antitumor activity of BEZ235 through the inhibition of the PI3K/mTOR pathway. Our data demonstrate that the NP-based pretargeted system improves the therapeutic window of small-molecule kinase inhibitor.


Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 1388-1388
Author(s):  
Mireille Guerin ◽  
Cynthia Therien ◽  
Gorazd Krosl ◽  
Jinzi J. Wu ◽  
Helene Dulude ◽  
...  

Abstract Prostate secretory protein 94 (PSP-94) has been shown to exert anti-tumor activity against prostate cancer cells, particularly in the form of PCK3145, a synthetic peptide corresponding to amino acids 31–45 of PSP-94. Indeed, when tested in a murine model, this peptide could reduce experimental prostate tumour growth. In addition, when evaluated in a Phase I clinical study, this peptide demonstrated a particularly interesting safety profile, with almost complete lack of toxicity. In order to determine whether PCK3145 could exert cytotoxic activity against other marrow infiltrating cancers, we tested its activity both in vitro and in vivo against non-Hodgkin’s lymphoma (NHL) and other hematologic cancers. Interestingly, PCK3145 inhibited the proliferation of human NHL (SR) and myeloma (RPMI-8226) cell lines in vitro. To explore its anti-tumor activity in vivo, the impact of PCK3145 was also measured by inoculating P815 malignant cells into syngeneic DBA mice. First, four groups of 6 DBA mice were injected subcutaneously with 2x104 P815 cells and then treated with subcutaneous injections of PCK3145, and compared to a peptide with the scrambled amino acid sequence, PCK5266 (peptide derived from amino acids 52 to 66 of PSP-94), and phosphate-buffered saline (PBS). Treatment with PCK3145 significantly decreased the growth of P815 tumours in comparison to PBS (p<0.001), scrambled peptide (p<0.05) and PCK5266 (p<0.01), confirming in vivo anti-tumor activity and suggesting that tumour growth inhibition is due to the specific amino acid sequence of PCK3145. The same model was used to determine the effect of PCK3145 on metastatic dissemination following intraperitoneal administration of the peptide. PCK3145 treatment led to a decreased number of liver metastasis compared to PBS (p<0.05) and scrambled peptide (p<0.05) controls. In order to determine whether PCK3145 exerted its activity by altering metalloproteinase release, metalloproteinase MMP-9 levels were measured 3 weeks post-tumor cell exposure. MMP-9 levels, measured by ELISA, in the peripheral blood of treated P815 bearing mice were similar to those obtained with healthy animals (12.83±1.890 (mean±SD) ng/ml and 7.183±0.4070 ng/ml, respectively), while MMP-9 levels were elevated in mice treated with PBS and scrambled peptide (35.12±8.559 ng/ml and 22.60±3.944 ng/ml, respectively; p<0.05). We next tested PCK3145 treatment on human SR lymphoma cell line grown subcutaneously in NOD/SCID mice. Similarly to results obtained with murine tumors, treatment with PKC3145 resulted in significant inhibition of SR non-Hodgkin’s lymphoma growth compared to treatment with PBS (p<0.001) and scrambled peptide (p<0.01). These results demonstrate that in vivo treatment with PCK3145 can reduce tumor cell proliferation of both murine and human hematologic cancers. In addition, PCK3145 has the potential to inhibit tumor cells dissemination by lowering MMP-9 secretion. Thus, PCK3145 represents a unique peptide demonstrating sequence-specific anti-tumor activity against NHL and other hematologic malignancies. Based on these results, clinical studies are being designed to evaluate its therapeutic activity in humans.


2001 ◽  
Vol 12 (1) ◽  
pp. 57-63 ◽  
Author(s):  
Sanaa M Nabha ◽  
Ramzi M Mohammad ◽  
Nathan R Wall ◽  
Julie A Dutcher ◽  
Bashar M Salkini ◽  
...  

Blood ◽  
1981 ◽  
Vol 57 (6) ◽  
pp. 1081-1087
Author(s):  
RL Whisler ◽  
SP Balcerzak ◽  
JL Murray

Peripheral blood mononuclear cells (PBMC) from 18 untreated patients with non-Hodgkin's lymphoma (NHL) were studied to characterize the cellular mechanisms contributing to impaired in vitro lymphocyte responses after stimulation by the mitogen conconavalin A (Con-A). In vitro reactivity was quantitated by the 3H-thymidine incorporation in response to an optimal dose of Con-A. All patients demonstrated impaired in vitro reactivities compared to normal controls. These in vitro impairments were partially reversible since patient's cells precultured in media alone for 3 days demonstrated enhanced Con-A responses. In greater than half of the patients, the hyporeactive PBMC suppressed the enhanced reactivities of autologous precultured PBMC when assayed in cocultures. Suppressor activity was detected mainly in those untreated patients presenting with either constitutional symptoms or diffuse histology and in general was not marked compared to the severity of impairments. Adherent monocytes were shown to participate in the suppression of autologous lymphocyte reactivity but only appeared partially responsible for the in vitro impairments. In those patients lacking detectable suppressive activity, preculturing also enhanced Con-A reactivities and was compatible with the presence of a reversible, inhibitory mechanism differing from active suppression. Many patients' hyporeactive PBMC, however, failed to demonstrate normal responses after preculturing. This failure could not be directly attributed to aberrant regulatory populations, but rather appeared to possibly represent an additional intrinsic impairment of potentially reactive populations.


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