European Journal of Nuclear Medicine and Molecular Imaging
Purpose 177Lu-lilotomab satetraxetan targets the CD37 antigen and has been investigated in a firs... more Purpose 177Lu-lilotomab satetraxetan targets the CD37 antigen and has been investigated in a first-in-human phase 1/2a study for relapsed non-Hodgkin lymphoma (NHL). Tumor dosimetry and response evaluation can be challenging after radioimmunotherapy (RIT). Changes in FDG PET/CT parameters after RIT and correlations with tumor-absorbed doses has not been examined previously in patients with lymphoma. Treatment-induced changes were measured at FDG PET/CT and ceCT to evaluate response at the lesion level after treatment, and correlations with tumor-absorbed doses were investigated. Methods Forty-five tumors in 16 patients, with different pre-treatment and pre-dosing regimens, were included. Dosimetry was performed based on multiple SPECT/CT images. FDG PET/CT was performed at baseline and at 3 and 6 months. SUVmax, MTV, TLG, and changes in these parameters were calculated for each tumor. Lesion response was evaluated at 3 and 6 months (PET3months and PET6months) based on Deauville crit...
Arne Kolstad,* Tim Illidge,* Nils Bolstad, Signe Spetalen, Ulf Madsbu, Caroline Stokke, Johan Bla... more Arne Kolstad,* Tim Illidge,* Nils Bolstad, Signe Spetalen, Ulf Madsbu, Caroline Stokke, Johan Blakkisrud, Ayca Løndalen, Noelle O’Rourke, Matthew Beasley, Wojciech Jurczak, Unn-Merete Fagerli, Michal Kaščák, Mike Bayne, Aleš Obr, Jostein Dahle, Lisa Rojkjaer, Veronique Pascal, and Harald Holte Department of Oncology, Oslo University Hospital, Radiumhospitalet, Oslo, Norway; University of Manchester, National Institutes of Health Research Manchester Biomedical Research Centre, Christie Hospital, Manchester, United Kingdom; Department of Medical Biochemistry, Oslo University Hospital, Radiumhospitalet, Oslo, Norway; Department of Pathology, Oslo University Hospital, Radiumhospitalet, Oslo, Norway; Department of Radiology and Nuclear Medicine, Department of Diagnostic Physics, and Department of Nuclear Medicine, Oslo University Hospital, Radiumhospitalet, Oslo, Norway; BeatsonWest of Scotland Cancer Centre, Glasgow, United Kingdom; Bristol Cancer Institute, Bristol, United Kingdom; Mar...
Arne Kolstad & Caroline Stokke (2021) Myelosuppression in patients treated with 177 Lutetiumlilot... more Arne Kolstad & Caroline Stokke (2021) Myelosuppression in patients treated with 177 Lutetiumlilotomab satetraxetan can be predicted with absorbed dose to the red marrow as the only variable,
Relapse of chronic lymphocytic leukaemia and non-Hodgkin's lymphoma after standard of care treatm... more Relapse of chronic lymphocytic leukaemia and non-Hodgkin's lymphoma after standard of care treatment is common and new therapies are needed. The targeted alpha therapy with 212 Pb-NNV003 presented in this study combines cytotoxic α-particles from 212 Pb, with the anti-CD37 antibody NNV003, targeting B-cell malignancies. The goal of this study was to explore 212 Pb-NNV003 for treatment of CD37 positive chronic lymphocytic leukaemia and non-Hodgkin's lymphoma in preclinical mouse models.An anti-proliferative effect of 212 Pb-NNV003 was observed in both chronic lymphocytic leukaemia (MEC-2) and Burkitt's lymphoma (Daudi) cells in vitro. In biodistribution experiments, accumulation of 212 Pb-NNV003 was 23%ID/g and 16%ID/g in Daudi and MEC-2 tumours 24 h post injection. In two intravenous animal models 90% of the mice treated with a single injection of 212 Pb-NNV003 were alive 28 weeks post cell injection. Median survival times of control groups were 5-9 weeks. There was no significant difference between different specific activities of 212 Pb-NNV003 with regards to therapeutic effect or toxicity. For therapeutically effective activities, a transient haematological toxicity was observed. This study shows that 212 Pb-NNV003 is effective and safe in preclinical models of CD37 positive chronic lymphocytic leukaemia and non-Hodgkin's lymphoma, warranting future clinical testing.
Background: Patients with NHL who are treated with rituximab may develop resistant-disease, often... more Background: Patients with NHL who are treated with rituximab may develop resistant-disease, often associated with changes in expression of CD20. The next generation -particle emitting radioimmunoconjugate 177 Lu-lilotomab-satetraxetan (Betalutin ®) was shown to up-regulate CD20 expression in different rituximab-sensitive NHL cell lines and to act synergistically with rituximab in a rituximab-sensitive NHL animal model. We hypothesized that 177 Lu-lilotomabsatetraxetan may be used to reverse rituximab-resistance in NHL. Methods: The rituximab-resistant Raji2R and the parental Raji cell lines were used. CD20 expression was measured by flow cytometry. ADCC was measured by a bioluminescence reporter assay. The efficacies of combined treatments with 177 Lu-lilotomab-satetraxetan (150MBq/kg or 350MBq/kg) and rituximab (4×10mg/kg) were compared with those of single agents or saline in a Raji2R-xenograft model. Cox-regression and the Bliss independence model were used to assess synergism. Results: Rituximab-binding in Raji2R cells was 36±5% of that in the rituximab-sensitive Raji cells. 177 Lu-lilotomab-satetraxetan treatment of Raji2R cells increased the binding to 53±3% of the parental cell line. Rituximab ADCC-induction in Raji2R cells was 20±2% of that induced in Raji cells, while treatment with 177 Lu-lilotomab-satetraxetan increased the ADCC-induction to 30±3% of Raji cells, representing a 50% increase (p<0.05). The combination of rituximab with 350MBq/kg 177 Lu-lilotomab-satetraxetan synergistically suppressed Raji2R tumor growth in athymic Foxn1 nu mice. Conclusion: 177 Lu-lilotomab-satetraxetan has the potential to reverse rituximab-resistance; it can increase rituximab-binding and ADCC-activity in-vitro and can synergistically improve antitumor efficacy in-vivo.
Some patients with B-cell non-Hodkin lymphoma Lymphoma (NHL) become refractory to rituximab (anti... more Some patients with B-cell non-Hodkin lymphoma Lymphoma (NHL) become refractory to rituximab (anti-CD20 antibody) therapy associated with chemotherapy. Here, the effect of the anti-CD37 antibody-radionuclide conjugate lutetium-177 (177Lu)-lilotomab (Betalutin®) was investigated in preclinical models of NHL. In SCID mice bearing DOHH2 (transformed follicular lymphoma, FL) cell xenografts, 177Lu-lilotomab significantly delayed tumor growth, even at low activity (100 MBq/kg). In athymic mice bearing OCI-Ly8 (diffuse large B-cell lymphoma, DLBCL) or Ramos (Burkitt’s lymphoma) cell xenografts, 177Lu-lilotomab activity had to be increased to 500 MBq/kg to show a significant tumor growth delay. Clonogenic and proliferation assays showed that DOHH2 cells were highly sensitive to 177Lu-lilotomab, while Ramos cells were the least sensitive, and U2932 (DLBCL), OCI-Ly8, and Rec-1 (mantle cell lymphoma) cells displayed intermediate sensitivity. The strong 177Lu-lilotomab cytotoxicity observed in ...
The CD37 targeting radioimmunoconjugate 177Lu-lilotomab satetraxetan (Betalutin®) is currently be... more The CD37 targeting radioimmunoconjugate 177Lu-lilotomab satetraxetan (Betalutin®) is currently being evaluated as monotherapy in a clinical phase 2b trial for patients with follicular lymphoma (FL) and in a phase 1 trial for patients with diffuse large B-cell lymphoma (DLBCL), as well as in a phase 1b trial in combination with rituximab for patients with relapsed/refractory FL. Herein we have investigated the effect of 177Lu-lilotomab satetraxetan in seven activated B-cell like (ABC) DLBCL cell lines. Although the radioimmunoconjugate showed anti-tumor activity, primary resistance was observed in a subset of cell lines: U-2932 and RIVA. Both cell lines are representative for TP53 deficient Double Expressor (DE) DLBCL. Importantly, resistance was not a consequence of reduced binding of the radioimmunoconjugate to cell surface expressed CD37. Thus, we set out to identify drugs able to overcome the resistance to 177Lu-lilotomab satetraxetan in both resistant ABC-DLBCL cell lines. We pe...
3732 The monoclonal anti-CD20 antibody rituximab alone or as part of combination therapy, is cons... more 3732 The monoclonal anti-CD20 antibody rituximab alone or as part of combination therapy, is considered standard therapy for…
European Journal of Nuclear Medicine and Molecular Imaging, 2019
The aim of this study was to explore the β-emitting lutetium-177 labelled anti-CD37 antibody NNV0... more The aim of this study was to explore the β-emitting lutetium-177 labelled anti-CD37 antibody NNV003 (177 Lu-NNV003, Humalutin®) for the treatment of non-Hodgkin's lymphoma in in vitro studies and in animal models. Methods Cytotoxicity of 177 Lu-NNV003 was measured in REC-1 (mantle cell lymphoma) and DOHH-2 (diffuse large B cell lymphoma) cell lines. Biodistribution was studied in mice bearing subcutaneous DOHH-2 or MEC-2 (chronic lymphocytic leukaemia) xenografts. The therapeutic effect of a single injection of 177 Lu-NNV003 was measured in mice intravenously or subcutaneously injected with REC-1 cells. Haematological and histopathological assessments were used to evaluate the toxic effect of 177 Lu-NNV003. The immunotherapeutic effect of NNV003 was assessed by measuring binding to Fcγ receptors, activation of ADCC and ADCP. NNV003's immunogenicity potential was assessed using in silico immunogenicity prediction tools. Results 177 Lu-NNV003 showed an activity dependent antiproliferative effect in all cell lines. Maximum tumour uptake in vivo was 45% of injected activity/g in MEC-2 tumours and 15% injected activity/g in DOHH-2 tumours. In mice injected intravenously with REC-1 cells, 177 Lu-NNV003 (50-100 MBq/kg) improved survival compared to control groups (p < 0.02). In mice with subcutaneous REC-1 xenografts, 500 MBq/kg 177 Lu-NNV003 extended survival compared to the control treatments (p < 0.005). Transient haematological toxicity was observed in all mice treated with radioactivity. NNV003 induced ADCC and ADCP and was predicted to have a lower immunogenicity potential than its murine counterpart. Conclusion 177 Lu-NNV003 had a significant anti-tumour effect and a favourable toxicity profile. These results warrant further clinical testing in patients with CD37-expressing B cell malignancies.
European Journal of Nuclear Medicine and Molecular Imaging, 2018
Purpose 177 Lu-lilotomab satetraxetan is a novel anti-CD37 antibody radionuclide conjugate for th... more Purpose 177 Lu-lilotomab satetraxetan is a novel anti-CD37 antibody radionuclide conjugate for the treatment of non-Hodgkin lymphoma (NHL). Four arms with different combinations of pre-dosing and pre-treatment have been investigated in a first-inhuman phase 1/2a study for relapsed CD37+ indolent NHL. The aim of this work was to determine the tumor and normal tissue absorbed doses for all four arms, and investigate possible variations in the ratios of tumor to organs-at-risk absorbed doses. Methods Two of the phase 1 arms included cold lilotomab pre-dosing (arm 1 and 4; 40 mg fixed and 100 mg/m 2 BSA dosage, respectively) and two did not (arms 2 and 3). All patients were pre-treated with different regimens of rituximab. The patients received either 10, 15, or 20 MBq 177 Lu-lilotomab satetraxetan per kg body weight. Nineteen patients were included for dosimetry, and a total of 47 lesions were included. The absorbed doses were calculated from multiple SPECT/CT-images and normalized by administered activity for each patient. Two-sided Student's t tests were used for all statistical analyses. Results Organs with distinct uptake of 177 Lu-lilotomab satetraxetan, in addition to tumors, were red marrow (RM), liver, spleen, and kidneys. The mean RM absorbed doses were 0.94, 1.55, 1.44, and 0.89 mGy/MBq for arms 1-4, respectively. For the patients not pre-dosed with lilotomab (arms 2 and 3 combined) the mean RM absorbed dose was 1.48 mGy/MBq, which was significantly higher than for both arm 1 (p = 0.04) and arm 4 (p = 0.02). Of the other organs, the highest uptake was found in the spleen, and there was a significantly lower spleen absorbed dose for arm-4 patients than for the patient group without lilotomab pre-dosing (1.13 vs. 3.20 mGy/MBq; p < 0.01). Mean tumor absorbed doses were 2.15, 2.31, 1.33, and 2.67 mGy/MBq for arms 1-4, respectively. After averaging the tumor absorbed dose for each patient, the patient mean tumor absorbed dose to RM absorbed dose ratios were obtained, given mean values of 1.07 for the patient group not pre-dosed with lilotomab, of 2.16 for arm 1, and of 4.62 for arm 4. The ratios were significantly higher in both arms 1 and 4 compared to the group without pre-dosing (p = 0.05 and p = 0.02). No statistically significant difference between arms 1 and 4 was found. Conclusions RM is the primary dose-limiting organ for 177 Lu-lilotomab satetraxetan treatment, and pre-dosing with lilotomab has a mitigating effect on RM absorbed dose. Increasing the amount of lilotomab from 40 mg to 100 mg/m 2 was found to slightly decrease the RM absorbed dose and increase the ratio of tumor to RM absorbed dose. Still, both pre-dosing amounts resulted in significantly higher tumor to RM absorbed dose ratios. The findings encourage continued use of pre-dosing with lilotomab.
Lutetium (177Lu) lilotomab satetraxetan (177Lu-lilotomab) is a novel anti-CD37 radioimmunoconjuga... more Lutetium (177Lu) lilotomab satetraxetan (177Lu-lilotomab) is a novel anti-CD37 radioimmunoconjugate (RIC) currently in Phase 2b clinical trial for treatment of non-Hodgkin lymphoma (NHL). The aim of the current study was to investigate tolerability and anti-tumor efficacy of multiple dosing of 177Lu-lilotomab in vivo. Nude mice with subcutaneous (s.c.) NHL (Ramos) xenografts were given 2, 3 or 4 weekly injections of 300 MBq/kg 177Lu-lilotomab or NaCl. Treatment tolerability was assessed by body weight, hematology and histopathological evaluation. A separate experiment in mice without xenografts was performed to collect long term toxicity data. Mice in this study were dosed more conservatively with the intention that all mice should survive until end of experiment and were administered 2 or 4 weekly injections of 200 MBq/kg 177Lu-lilotomab or NaCl. Total accumulated activity of 900 MBq/kg 177Lu-lilotomab given as three weekly injections was tolerated by nude mice with s.c. Ramos xeno...
To investigate the therapeutic potential of the next generation anti-CD37 radioimmunoconjugate Lu... more To investigate the therapeutic potential of the next generation anti-CD37 radioimmunoconjugate Lu-lilotomab satetraxetan ( Lu-lilotomab) in combination with the anti-CD20 antibody rituximab for treatment of mice with non-Hodgkin's lymphoma (NHL) xenografts. Nude mice with subcutaneous (s.c.) Burkitt's lymphoma Daudi xenografts and SCID mice intravenously (i.v.) injected with Mantle cell lymphoma Rec-1 cells were treated with either Lu-lilotomab or rituximab alone or with the combination of both treatments. Tumour volume, body weight, blood counts and clinical status were monitored. CD20 expression was measured using flow cytometry with fluorescence-labelled rituximab. The combination of Lu-lilotomab and rituximab was synergistic for treatment of nude mice with s.c. Daudi xenografts while it was additive for treatment of SCID mice with i.v. injected Rec-1 cells. Binding of rituximab to NHL cells in-vitro was increased by pre-treatment with Lu-lilotomab satetraxetan. Treatment...
Journal of nuclear medicine : official publication, Society of Nuclear Medicine, 2016
Red bone marrow (RM) is often the primary organ at risk in radioimmunotherapy; irradiation of mar... more Red bone marrow (RM) is often the primary organ at risk in radioimmunotherapy; irradiation of marrow may induce short and long term hematological toxicity. (177)Lu-lilotomab satetraxetan is a novel anti-CD37 antibody-radionuclide-conjugate (ARC) currently in phase 1/2a. Two pre-dosing regimens have been investigated, one with 40 mg unlabeled lilotomab antibody (arm 1) and one without (arm 2). The aim of this work was to compare RM absorbed doses for the two arms and to correlate absorbed doses with hematological toxicity. Eight patients with relapsed CD37+ indolent B-cell non-Hodgkin's lymphoma were included for RM dosimetry. Hybrid Single Photon Emission Computed Tomography (SPECT) and Computed Tomography (CT) images were used to estimate activity concentration in the RM of lumbar L2-L4. Pharmacokinetic parameters were calculated after measurement of (177)Lu-lilotomab satetraxetan concentration in blood samples. Adverse events were graded according to Common Terminology Criteri...
Journal of nuclear medicine : official publication, Society of Nuclear Medicine, Jan 4, 2016
Lu-lilotomab satetraxetan is a novel antibody radionuclide conjugate currently tested in a phase ... more Lu-lilotomab satetraxetan is a novel antibody radionuclide conjugate currently tested in a phase 1/2a first-inhuman dosage escalation trial for patients with relapsed CD371 indolent non-Hodgkin lymphoma. The aim of this work was to develop dosimetric methods and calculate tumor-absorbed radiation doses for patients treated with 177 Lu-lilotomab satetraxetan. Methods: Patients were treated at escalating injected activities (10, 15 and 20 MBq/kg) of 177 Lulilotomab satetraxetan and with different predosing, with or without 40 mg of unlabeled lilotomab. Eight patients were included for the tumor dosimetry study. Tumor radioactivity concentrations were calculated from SPECT acquisitions at multiple time points, and tumor masses were delineated from corresponding CT scans. Tumor-absorbed doses were then calculated using the OLINDA sphere model. To perform voxel dosimetry, the SPECT/CT data and an inhouse-developed MATLAB program were combined to investigate the dose rate homogeneity. Results: Twenty-six tumors in 8 patients were ascribed a mean tumor-absorbed dose. Absorbed doses ranged from 75 to 794 cGy, with a median of 264 cGy across different dosage levels and different predosing. A significant correlation between the dosage level and tumor-absorbed dose was found. Twenty-one tumors were included for voxel dosimetry and parameters describing dose-volume coverage calculated. The investigation of intratumor voxel doses indicates that mean tumor dose is correlated to these parameters. Conclusion: Tumor-absorbed doses for patients treated with 177 Lu-lilotomab satetraxetan are comparable to doses reported for other radioimmunotherapy compounds. Although the intertumor variability was considerable, a correlation between tumor dose and patient dosage level was found. Our results indicate that mean dose may be used as the sole dosimetric parameter on the lesion level.
Lu-DOTA-HH1 (177 Lu-HH1) is a novel anti-CD37 radioimmunoconjugate developed to treat non-Hodgkin... more Lu-DOTA-HH1 (177 Lu-HH1) is a novel anti-CD37 radioimmunoconjugate developed to treat non-Hodgkin lymphoma. Mice with subcutaneous Ramos xenografts were treated with different activities of 177 Lu-HH1, 177 Lu-DOTA-rituximab (177 Lu-rituximab) and non-specific 177 Lu-DOTA-IgG 1 (177 Lu-IgG 1) and therapeutic effect and toxicity of the treatment were monitored. Significant tumor growth delay and increased survival of mice were observed in mice treated with 530 MBq/kg 177 Lu-HH1 as compared with mice treated with similar activities of 177 Lu-rituximab or non-specific 177 Lu-IgG1, 0.9% NaCl or unlabeled HH1. All mice injected with 530 MBq/kg of 177 Lu-HH1 tolerated the treatment well. In contrast, 6 out of 10 mice treated with 530 MBq/kg 177 Lu-rituximab experienced severe radiation toxicity. The retention of 177 Lu-rituximab in organs of the mononuclear phagocyte system was longer than for 177 Lu-HH1, which explains the higher toxicity observed in mice treated with 177 Lu-rituximab. In vitro internalization studies showed that 177 Lu-HH1 internalizes faster and to a higher extent than 177 Lu-rituximab which might be the reason for the better therapeutic effect of 177 Lu-HH1.
The monoclonal antibody against CD20, rituximab, alone, or as part of combination therapies, is s... more The monoclonal antibody against CD20, rituximab, alone, or as part of combination therapies, is standard therapy for non-Hodgkin's B-cell lymphoma. Despite significantly better clinical results obtained for beta-emitting radioimmunoconjugates (RICs), RICs targeting CD20 are not commonly used in medical practice, partly because of competition for the CD20 target. Therefore, novel therapeutic approaches against other antigens are intriguing. Here, the binding properties of a novel antibody against CD37 (tetulomab) were compared with those of rituximab. The therapeutic effect of (177)Lu-tetulomab was compared with (177)Lu-rituximab on Daudi cells in vitro. The biodistribution, therapeutic and toxic effects of (177)Lu-tetulomab and unlabeled tetulomab were determined in SCID mice injected with Daudi cells. The affinity of tetulomab to CD37 was similar to the affinity of rituximab to CD20, but the CD37-tetulomab complex was internalized 10-times faster than the CD20-rituximab complex...
A better understanding of the non-targeted (bystander) effects of radiation may have important im... more A better understanding of the non-targeted (bystander) effects of radiation may have important implications with regards to radiation risk assessment, radiation protection, and targeted cancer therapy. In the present study, the direct and bystander effects of α-particle irradiation in immortalized human fibroblasts (F11hTERT) and breast cancer cells (MCF-7) was investigated. To ensure a more accurate dose delivery to these different cell lines, an existing 238Pu α-particle irradiator was improved by the addition of a collimator and the development of an analytical equation for calculation of the radiation dose to cells. The mean dose rate and α-particle fluence were calculated for each cell line by taking into consideration the size of their nuclei. Bystander effect experiments were performed by transferring medium from irradiated to unirradiated cells and by measuring micronucleus formation in the cells. Both the immortalized human fibroblasts and the breast cancer cells displayed ...
European Journal of Nuclear Medicine and Molecular Imaging
Purpose 177Lu-lilotomab satetraxetan targets the CD37 antigen and has been investigated in a firs... more Purpose 177Lu-lilotomab satetraxetan targets the CD37 antigen and has been investigated in a first-in-human phase 1/2a study for relapsed non-Hodgkin lymphoma (NHL). Tumor dosimetry and response evaluation can be challenging after radioimmunotherapy (RIT). Changes in FDG PET/CT parameters after RIT and correlations with tumor-absorbed doses has not been examined previously in patients with lymphoma. Treatment-induced changes were measured at FDG PET/CT and ceCT to evaluate response at the lesion level after treatment, and correlations with tumor-absorbed doses were investigated. Methods Forty-five tumors in 16 patients, with different pre-treatment and pre-dosing regimens, were included. Dosimetry was performed based on multiple SPECT/CT images. FDG PET/CT was performed at baseline and at 3 and 6 months. SUVmax, MTV, TLG, and changes in these parameters were calculated for each tumor. Lesion response was evaluated at 3 and 6 months (PET3months and PET6months) based on Deauville crit...
Arne Kolstad,* Tim Illidge,* Nils Bolstad, Signe Spetalen, Ulf Madsbu, Caroline Stokke, Johan Bla... more Arne Kolstad,* Tim Illidge,* Nils Bolstad, Signe Spetalen, Ulf Madsbu, Caroline Stokke, Johan Blakkisrud, Ayca Løndalen, Noelle O’Rourke, Matthew Beasley, Wojciech Jurczak, Unn-Merete Fagerli, Michal Kaščák, Mike Bayne, Aleš Obr, Jostein Dahle, Lisa Rojkjaer, Veronique Pascal, and Harald Holte Department of Oncology, Oslo University Hospital, Radiumhospitalet, Oslo, Norway; University of Manchester, National Institutes of Health Research Manchester Biomedical Research Centre, Christie Hospital, Manchester, United Kingdom; Department of Medical Biochemistry, Oslo University Hospital, Radiumhospitalet, Oslo, Norway; Department of Pathology, Oslo University Hospital, Radiumhospitalet, Oslo, Norway; Department of Radiology and Nuclear Medicine, Department of Diagnostic Physics, and Department of Nuclear Medicine, Oslo University Hospital, Radiumhospitalet, Oslo, Norway; BeatsonWest of Scotland Cancer Centre, Glasgow, United Kingdom; Bristol Cancer Institute, Bristol, United Kingdom; Mar...
Arne Kolstad & Caroline Stokke (2021) Myelosuppression in patients treated with 177 Lutetiumlilot... more Arne Kolstad & Caroline Stokke (2021) Myelosuppression in patients treated with 177 Lutetiumlilotomab satetraxetan can be predicted with absorbed dose to the red marrow as the only variable,
Relapse of chronic lymphocytic leukaemia and non-Hodgkin's lymphoma after standard of care treatm... more Relapse of chronic lymphocytic leukaemia and non-Hodgkin's lymphoma after standard of care treatment is common and new therapies are needed. The targeted alpha therapy with 212 Pb-NNV003 presented in this study combines cytotoxic α-particles from 212 Pb, with the anti-CD37 antibody NNV003, targeting B-cell malignancies. The goal of this study was to explore 212 Pb-NNV003 for treatment of CD37 positive chronic lymphocytic leukaemia and non-Hodgkin's lymphoma in preclinical mouse models.An anti-proliferative effect of 212 Pb-NNV003 was observed in both chronic lymphocytic leukaemia (MEC-2) and Burkitt's lymphoma (Daudi) cells in vitro. In biodistribution experiments, accumulation of 212 Pb-NNV003 was 23%ID/g and 16%ID/g in Daudi and MEC-2 tumours 24 h post injection. In two intravenous animal models 90% of the mice treated with a single injection of 212 Pb-NNV003 were alive 28 weeks post cell injection. Median survival times of control groups were 5-9 weeks. There was no significant difference between different specific activities of 212 Pb-NNV003 with regards to therapeutic effect or toxicity. For therapeutically effective activities, a transient haematological toxicity was observed. This study shows that 212 Pb-NNV003 is effective and safe in preclinical models of CD37 positive chronic lymphocytic leukaemia and non-Hodgkin's lymphoma, warranting future clinical testing.
Background: Patients with NHL who are treated with rituximab may develop resistant-disease, often... more Background: Patients with NHL who are treated with rituximab may develop resistant-disease, often associated with changes in expression of CD20. The next generation -particle emitting radioimmunoconjugate 177 Lu-lilotomab-satetraxetan (Betalutin ®) was shown to up-regulate CD20 expression in different rituximab-sensitive NHL cell lines and to act synergistically with rituximab in a rituximab-sensitive NHL animal model. We hypothesized that 177 Lu-lilotomabsatetraxetan may be used to reverse rituximab-resistance in NHL. Methods: The rituximab-resistant Raji2R and the parental Raji cell lines were used. CD20 expression was measured by flow cytometry. ADCC was measured by a bioluminescence reporter assay. The efficacies of combined treatments with 177 Lu-lilotomab-satetraxetan (150MBq/kg or 350MBq/kg) and rituximab (4×10mg/kg) were compared with those of single agents or saline in a Raji2R-xenograft model. Cox-regression and the Bliss independence model were used to assess synergism. Results: Rituximab-binding in Raji2R cells was 36±5% of that in the rituximab-sensitive Raji cells. 177 Lu-lilotomab-satetraxetan treatment of Raji2R cells increased the binding to 53±3% of the parental cell line. Rituximab ADCC-induction in Raji2R cells was 20±2% of that induced in Raji cells, while treatment with 177 Lu-lilotomab-satetraxetan increased the ADCC-induction to 30±3% of Raji cells, representing a 50% increase (p<0.05). The combination of rituximab with 350MBq/kg 177 Lu-lilotomab-satetraxetan synergistically suppressed Raji2R tumor growth in athymic Foxn1 nu mice. Conclusion: 177 Lu-lilotomab-satetraxetan has the potential to reverse rituximab-resistance; it can increase rituximab-binding and ADCC-activity in-vitro and can synergistically improve antitumor efficacy in-vivo.
Some patients with B-cell non-Hodkin lymphoma Lymphoma (NHL) become refractory to rituximab (anti... more Some patients with B-cell non-Hodkin lymphoma Lymphoma (NHL) become refractory to rituximab (anti-CD20 antibody) therapy associated with chemotherapy. Here, the effect of the anti-CD37 antibody-radionuclide conjugate lutetium-177 (177Lu)-lilotomab (Betalutin®) was investigated in preclinical models of NHL. In SCID mice bearing DOHH2 (transformed follicular lymphoma, FL) cell xenografts, 177Lu-lilotomab significantly delayed tumor growth, even at low activity (100 MBq/kg). In athymic mice bearing OCI-Ly8 (diffuse large B-cell lymphoma, DLBCL) or Ramos (Burkitt’s lymphoma) cell xenografts, 177Lu-lilotomab activity had to be increased to 500 MBq/kg to show a significant tumor growth delay. Clonogenic and proliferation assays showed that DOHH2 cells were highly sensitive to 177Lu-lilotomab, while Ramos cells were the least sensitive, and U2932 (DLBCL), OCI-Ly8, and Rec-1 (mantle cell lymphoma) cells displayed intermediate sensitivity. The strong 177Lu-lilotomab cytotoxicity observed in ...
The CD37 targeting radioimmunoconjugate 177Lu-lilotomab satetraxetan (Betalutin®) is currently be... more The CD37 targeting radioimmunoconjugate 177Lu-lilotomab satetraxetan (Betalutin®) is currently being evaluated as monotherapy in a clinical phase 2b trial for patients with follicular lymphoma (FL) and in a phase 1 trial for patients with diffuse large B-cell lymphoma (DLBCL), as well as in a phase 1b trial in combination with rituximab for patients with relapsed/refractory FL. Herein we have investigated the effect of 177Lu-lilotomab satetraxetan in seven activated B-cell like (ABC) DLBCL cell lines. Although the radioimmunoconjugate showed anti-tumor activity, primary resistance was observed in a subset of cell lines: U-2932 and RIVA. Both cell lines are representative for TP53 deficient Double Expressor (DE) DLBCL. Importantly, resistance was not a consequence of reduced binding of the radioimmunoconjugate to cell surface expressed CD37. Thus, we set out to identify drugs able to overcome the resistance to 177Lu-lilotomab satetraxetan in both resistant ABC-DLBCL cell lines. We pe...
3732 The monoclonal anti-CD20 antibody rituximab alone or as part of combination therapy, is cons... more 3732 The monoclonal anti-CD20 antibody rituximab alone or as part of combination therapy, is considered standard therapy for…
European Journal of Nuclear Medicine and Molecular Imaging, 2019
The aim of this study was to explore the β-emitting lutetium-177 labelled anti-CD37 antibody NNV0... more The aim of this study was to explore the β-emitting lutetium-177 labelled anti-CD37 antibody NNV003 (177 Lu-NNV003, Humalutin®) for the treatment of non-Hodgkin's lymphoma in in vitro studies and in animal models. Methods Cytotoxicity of 177 Lu-NNV003 was measured in REC-1 (mantle cell lymphoma) and DOHH-2 (diffuse large B cell lymphoma) cell lines. Biodistribution was studied in mice bearing subcutaneous DOHH-2 or MEC-2 (chronic lymphocytic leukaemia) xenografts. The therapeutic effect of a single injection of 177 Lu-NNV003 was measured in mice intravenously or subcutaneously injected with REC-1 cells. Haematological and histopathological assessments were used to evaluate the toxic effect of 177 Lu-NNV003. The immunotherapeutic effect of NNV003 was assessed by measuring binding to Fcγ receptors, activation of ADCC and ADCP. NNV003's immunogenicity potential was assessed using in silico immunogenicity prediction tools. Results 177 Lu-NNV003 showed an activity dependent antiproliferative effect in all cell lines. Maximum tumour uptake in vivo was 45% of injected activity/g in MEC-2 tumours and 15% injected activity/g in DOHH-2 tumours. In mice injected intravenously with REC-1 cells, 177 Lu-NNV003 (50-100 MBq/kg) improved survival compared to control groups (p < 0.02). In mice with subcutaneous REC-1 xenografts, 500 MBq/kg 177 Lu-NNV003 extended survival compared to the control treatments (p < 0.005). Transient haematological toxicity was observed in all mice treated with radioactivity. NNV003 induced ADCC and ADCP and was predicted to have a lower immunogenicity potential than its murine counterpart. Conclusion 177 Lu-NNV003 had a significant anti-tumour effect and a favourable toxicity profile. These results warrant further clinical testing in patients with CD37-expressing B cell malignancies.
European Journal of Nuclear Medicine and Molecular Imaging, 2018
Purpose 177 Lu-lilotomab satetraxetan is a novel anti-CD37 antibody radionuclide conjugate for th... more Purpose 177 Lu-lilotomab satetraxetan is a novel anti-CD37 antibody radionuclide conjugate for the treatment of non-Hodgkin lymphoma (NHL). Four arms with different combinations of pre-dosing and pre-treatment have been investigated in a first-inhuman phase 1/2a study for relapsed CD37+ indolent NHL. The aim of this work was to determine the tumor and normal tissue absorbed doses for all four arms, and investigate possible variations in the ratios of tumor to organs-at-risk absorbed doses. Methods Two of the phase 1 arms included cold lilotomab pre-dosing (arm 1 and 4; 40 mg fixed and 100 mg/m 2 BSA dosage, respectively) and two did not (arms 2 and 3). All patients were pre-treated with different regimens of rituximab. The patients received either 10, 15, or 20 MBq 177 Lu-lilotomab satetraxetan per kg body weight. Nineteen patients were included for dosimetry, and a total of 47 lesions were included. The absorbed doses were calculated from multiple SPECT/CT-images and normalized by administered activity for each patient. Two-sided Student's t tests were used for all statistical analyses. Results Organs with distinct uptake of 177 Lu-lilotomab satetraxetan, in addition to tumors, were red marrow (RM), liver, spleen, and kidneys. The mean RM absorbed doses were 0.94, 1.55, 1.44, and 0.89 mGy/MBq for arms 1-4, respectively. For the patients not pre-dosed with lilotomab (arms 2 and 3 combined) the mean RM absorbed dose was 1.48 mGy/MBq, which was significantly higher than for both arm 1 (p = 0.04) and arm 4 (p = 0.02). Of the other organs, the highest uptake was found in the spleen, and there was a significantly lower spleen absorbed dose for arm-4 patients than for the patient group without lilotomab pre-dosing (1.13 vs. 3.20 mGy/MBq; p < 0.01). Mean tumor absorbed doses were 2.15, 2.31, 1.33, and 2.67 mGy/MBq for arms 1-4, respectively. After averaging the tumor absorbed dose for each patient, the patient mean tumor absorbed dose to RM absorbed dose ratios were obtained, given mean values of 1.07 for the patient group not pre-dosed with lilotomab, of 2.16 for arm 1, and of 4.62 for arm 4. The ratios were significantly higher in both arms 1 and 4 compared to the group without pre-dosing (p = 0.05 and p = 0.02). No statistically significant difference between arms 1 and 4 was found. Conclusions RM is the primary dose-limiting organ for 177 Lu-lilotomab satetraxetan treatment, and pre-dosing with lilotomab has a mitigating effect on RM absorbed dose. Increasing the amount of lilotomab from 40 mg to 100 mg/m 2 was found to slightly decrease the RM absorbed dose and increase the ratio of tumor to RM absorbed dose. Still, both pre-dosing amounts resulted in significantly higher tumor to RM absorbed dose ratios. The findings encourage continued use of pre-dosing with lilotomab.
Lutetium (177Lu) lilotomab satetraxetan (177Lu-lilotomab) is a novel anti-CD37 radioimmunoconjuga... more Lutetium (177Lu) lilotomab satetraxetan (177Lu-lilotomab) is a novel anti-CD37 radioimmunoconjugate (RIC) currently in Phase 2b clinical trial for treatment of non-Hodgkin lymphoma (NHL). The aim of the current study was to investigate tolerability and anti-tumor efficacy of multiple dosing of 177Lu-lilotomab in vivo. Nude mice with subcutaneous (s.c.) NHL (Ramos) xenografts were given 2, 3 or 4 weekly injections of 300 MBq/kg 177Lu-lilotomab or NaCl. Treatment tolerability was assessed by body weight, hematology and histopathological evaluation. A separate experiment in mice without xenografts was performed to collect long term toxicity data. Mice in this study were dosed more conservatively with the intention that all mice should survive until end of experiment and were administered 2 or 4 weekly injections of 200 MBq/kg 177Lu-lilotomab or NaCl. Total accumulated activity of 900 MBq/kg 177Lu-lilotomab given as three weekly injections was tolerated by nude mice with s.c. Ramos xeno...
To investigate the therapeutic potential of the next generation anti-CD37 radioimmunoconjugate Lu... more To investigate the therapeutic potential of the next generation anti-CD37 radioimmunoconjugate Lu-lilotomab satetraxetan ( Lu-lilotomab) in combination with the anti-CD20 antibody rituximab for treatment of mice with non-Hodgkin's lymphoma (NHL) xenografts. Nude mice with subcutaneous (s.c.) Burkitt's lymphoma Daudi xenografts and SCID mice intravenously (i.v.) injected with Mantle cell lymphoma Rec-1 cells were treated with either Lu-lilotomab or rituximab alone or with the combination of both treatments. Tumour volume, body weight, blood counts and clinical status were monitored. CD20 expression was measured using flow cytometry with fluorescence-labelled rituximab. The combination of Lu-lilotomab and rituximab was synergistic for treatment of nude mice with s.c. Daudi xenografts while it was additive for treatment of SCID mice with i.v. injected Rec-1 cells. Binding of rituximab to NHL cells in-vitro was increased by pre-treatment with Lu-lilotomab satetraxetan. Treatment...
Journal of nuclear medicine : official publication, Society of Nuclear Medicine, 2016
Red bone marrow (RM) is often the primary organ at risk in radioimmunotherapy; irradiation of mar... more Red bone marrow (RM) is often the primary organ at risk in radioimmunotherapy; irradiation of marrow may induce short and long term hematological toxicity. (177)Lu-lilotomab satetraxetan is a novel anti-CD37 antibody-radionuclide-conjugate (ARC) currently in phase 1/2a. Two pre-dosing regimens have been investigated, one with 40 mg unlabeled lilotomab antibody (arm 1) and one without (arm 2). The aim of this work was to compare RM absorbed doses for the two arms and to correlate absorbed doses with hematological toxicity. Eight patients with relapsed CD37+ indolent B-cell non-Hodgkin's lymphoma were included for RM dosimetry. Hybrid Single Photon Emission Computed Tomography (SPECT) and Computed Tomography (CT) images were used to estimate activity concentration in the RM of lumbar L2-L4. Pharmacokinetic parameters were calculated after measurement of (177)Lu-lilotomab satetraxetan concentration in blood samples. Adverse events were graded according to Common Terminology Criteri...
Journal of nuclear medicine : official publication, Society of Nuclear Medicine, Jan 4, 2016
Lu-lilotomab satetraxetan is a novel antibody radionuclide conjugate currently tested in a phase ... more Lu-lilotomab satetraxetan is a novel antibody radionuclide conjugate currently tested in a phase 1/2a first-inhuman dosage escalation trial for patients with relapsed CD371 indolent non-Hodgkin lymphoma. The aim of this work was to develop dosimetric methods and calculate tumor-absorbed radiation doses for patients treated with 177 Lu-lilotomab satetraxetan. Methods: Patients were treated at escalating injected activities (10, 15 and 20 MBq/kg) of 177 Lulilotomab satetraxetan and with different predosing, with or without 40 mg of unlabeled lilotomab. Eight patients were included for the tumor dosimetry study. Tumor radioactivity concentrations were calculated from SPECT acquisitions at multiple time points, and tumor masses were delineated from corresponding CT scans. Tumor-absorbed doses were then calculated using the OLINDA sphere model. To perform voxel dosimetry, the SPECT/CT data and an inhouse-developed MATLAB program were combined to investigate the dose rate homogeneity. Results: Twenty-six tumors in 8 patients were ascribed a mean tumor-absorbed dose. Absorbed doses ranged from 75 to 794 cGy, with a median of 264 cGy across different dosage levels and different predosing. A significant correlation between the dosage level and tumor-absorbed dose was found. Twenty-one tumors were included for voxel dosimetry and parameters describing dose-volume coverage calculated. The investigation of intratumor voxel doses indicates that mean tumor dose is correlated to these parameters. Conclusion: Tumor-absorbed doses for patients treated with 177 Lu-lilotomab satetraxetan are comparable to doses reported for other radioimmunotherapy compounds. Although the intertumor variability was considerable, a correlation between tumor dose and patient dosage level was found. Our results indicate that mean dose may be used as the sole dosimetric parameter on the lesion level.
Lu-DOTA-HH1 (177 Lu-HH1) is a novel anti-CD37 radioimmunoconjugate developed to treat non-Hodgkin... more Lu-DOTA-HH1 (177 Lu-HH1) is a novel anti-CD37 radioimmunoconjugate developed to treat non-Hodgkin lymphoma. Mice with subcutaneous Ramos xenografts were treated with different activities of 177 Lu-HH1, 177 Lu-DOTA-rituximab (177 Lu-rituximab) and non-specific 177 Lu-DOTA-IgG 1 (177 Lu-IgG 1) and therapeutic effect and toxicity of the treatment were monitored. Significant tumor growth delay and increased survival of mice were observed in mice treated with 530 MBq/kg 177 Lu-HH1 as compared with mice treated with similar activities of 177 Lu-rituximab or non-specific 177 Lu-IgG1, 0.9% NaCl or unlabeled HH1. All mice injected with 530 MBq/kg of 177 Lu-HH1 tolerated the treatment well. In contrast, 6 out of 10 mice treated with 530 MBq/kg 177 Lu-rituximab experienced severe radiation toxicity. The retention of 177 Lu-rituximab in organs of the mononuclear phagocyte system was longer than for 177 Lu-HH1, which explains the higher toxicity observed in mice treated with 177 Lu-rituximab. In vitro internalization studies showed that 177 Lu-HH1 internalizes faster and to a higher extent than 177 Lu-rituximab which might be the reason for the better therapeutic effect of 177 Lu-HH1.
The monoclonal antibody against CD20, rituximab, alone, or as part of combination therapies, is s... more The monoclonal antibody against CD20, rituximab, alone, or as part of combination therapies, is standard therapy for non-Hodgkin's B-cell lymphoma. Despite significantly better clinical results obtained for beta-emitting radioimmunoconjugates (RICs), RICs targeting CD20 are not commonly used in medical practice, partly because of competition for the CD20 target. Therefore, novel therapeutic approaches against other antigens are intriguing. Here, the binding properties of a novel antibody against CD37 (tetulomab) were compared with those of rituximab. The therapeutic effect of (177)Lu-tetulomab was compared with (177)Lu-rituximab on Daudi cells in vitro. The biodistribution, therapeutic and toxic effects of (177)Lu-tetulomab and unlabeled tetulomab were determined in SCID mice injected with Daudi cells. The affinity of tetulomab to CD37 was similar to the affinity of rituximab to CD20, but the CD37-tetulomab complex was internalized 10-times faster than the CD20-rituximab complex...
A better understanding of the non-targeted (bystander) effects of radiation may have important im... more A better understanding of the non-targeted (bystander) effects of radiation may have important implications with regards to radiation risk assessment, radiation protection, and targeted cancer therapy. In the present study, the direct and bystander effects of α-particle irradiation in immortalized human fibroblasts (F11hTERT) and breast cancer cells (MCF-7) was investigated. To ensure a more accurate dose delivery to these different cell lines, an existing 238Pu α-particle irradiator was improved by the addition of a collimator and the development of an analytical equation for calculation of the radiation dose to cells. The mean dose rate and α-particle fluence were calculated for each cell line by taking into consideration the size of their nuclei. Bystander effect experiments were performed by transferring medium from irradiated to unirradiated cells and by measuring micronucleus formation in the cells. Both the immortalized human fibroblasts and the breast cancer cells displayed ...
Uploads
Papers by Jostein Dahle