Preclinical Targeted α- and β−-Radionuclide Therapy in HER2-Positive Brain Metastasis Using Camelid Single-Domain Antibodies

HER2-targeted therapies have drastically improved the outcome for breast cancer patients. However, when metastasis to the brain is involved, current strategies fail to hold up to the same promise. Camelid single-domain antibody-fragments (sdAbs) have been demonstrated to possess favorable properties for detecting and treating cancerous lesions in vivo using different radiolabeling methods. Here we evaluate the anti-HER2 sdAb 2Rs15d, coupled to diagnostic γ- and therapeutic α- and β−-emitting radionuclides for the detection and treatment of HER2pos brain lesions in a preclinical setting. 2Rs15d was radiolabeled with 111In, 225Ac and 131I using DTPA- and DOTA-based bifunctional chelators and Sn-precursor of SGMIB respectively and evaluated in orthotopic tumor-bearing athymic nude mice. Therapeutic efficacy as well as systemic toxicity were determined for 131I- and 225Ac-labeled sdAbs and compared to anti-HER2 monoclonal antibody (mAb) trastuzumab in two different HER2pos tumor models. Radiolabeled 2Rs15d showed high and specific tumor uptake in both HER2pos SK-OV-3-Luc-IP1 and HER2pos MDA-MB-231Br brain lesions, whereas radiolabeled trastuzumab was unable to accumulate in intracranial SK-OV-3-Luc-IP1 tumors. Administration of [131I]-2Rs15d and [225Ac]-2Rs15d alone and in combination with trastuzumab showed a significant increase in median survival in 2 tumor models that remained largely unresponsive to trastuzumab treatment alone. Histopathological analysis revealed no significant early toxicity. Radiolabeled sdAbs prove to be promising vehicles for molecular imaging and targeted radionuclide therapy of metastatic lesions in the brain. These data demonstrate the potential of radiolabeled sdAbs as a valuable add-on treatment option for patients with difficult-to-treat HER2pos metastatic cancer.

Download Full-text

Molecular and cellular mechanisms underlying brain metastasis of breast cancer

Cancer and Metastasis Reviews ◽

10.1007/s10555-020-09881-y ◽

2020 ◽

Vol 39 (3) ◽

pp. 711-720 ◽

Cited By ~ 2

Author(s):

Mari Hosonaga ◽

Hideyuki Saya ◽

Yoshimi Arima

Keyword(s):

Breast Cancer ◽

Brain Metastasis ◽

Brain Metastases ◽

Cancer Cells ◽

Metastatic Cancer ◽

Breast Cancer Patients ◽

Cellular Mechanisms ◽

Her2 Positive ◽

Cells Of The Microenvironment ◽

The Brain

Abstract Metastasis of cancer cells to the brain occurs frequently in patients with certain subtypes of breast cancer. In particular, patients with HER2-positive or triple-negative breast cancer are at high risk for the development of brain metastases. Despite recent advances in the treatment of primary breast tumors, the prognosis of breast cancer patients with brain metastases remains poor. A better understanding of the molecular and cellular mechanisms underlying brain metastasis might be expected to lead to improvements in the overall survival rate for these patients. Recent studies have revealed complex interactions between metastatic cancer cells and their microenvironment in the brain. Such interactions result in the activation of various signaling pathways related to metastasis in both cancer cells and cells of the microenvironment including astrocytes and microglia. In this review, we focus on such interactions and on their role both in the metastatic process and as potential targets for therapeutic intervention.

Download Full-text

Chronological brain lesions after SARS-CoV-2 infection in hACE2-transgenic mice

Veterinary Pathology ◽

10.1177/03009858211066841 ◽

2021 ◽

pp. 030098582110668

Author(s):

Enric Vidal ◽

Carlos López-Figueroa ◽

Jordi Rodon ◽

Mónica Pérez ◽

Marco Brustolin ◽

...

Keyword(s):

Transgenic Mice ◽

Neuronal Damage ◽

Brain Lesions ◽

Olfactory Mucosa ◽

Histopathological Analysis ◽

Post Inoculation ◽

Vacuolar Degeneration ◽

Early Entry ◽

The Central Nervous System ◽

The Brain

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes respiratory disease, but it can also affect other organs including the central nervous system. Several animal models have been developed to address different key questions related to Coronavirus Disease 2019 (COVID-19). Wild-type mice are minimally susceptible to certain SARS-CoV-2 lineages (beta and gamma variants), whereas hACE2-transgenic mice succumb to SARS-CoV-2 and develop a fatal neurological disease. In this article, we aimed to chronologically characterize SARS-CoV-2 neuroinvasion and neuropathology. Necropsies were performed at different time points, and the brain and olfactory mucosa were processed for histopathological analysis. SARS-CoV-2 virological assays including immunohistochemistry were performed along with a panel of antibodies to assess neuroinflammation. At 6 to 7 days post inoculation (dpi), brain lesions were characterized by nonsuppurative meningoencephalitis and diffuse astrogliosis and microgliosis. Vasculitis and thrombosis were also present and associated with occasional microhemorrhages and spongiosis. Moreover, there was vacuolar degeneration of virus-infected neurons. At 2 dpi, SARS-CoV-2 immunolabeling was only found in the olfactory mucosa, but at 4 dpi intraneuronal virus immunolabeling had already reached most of the brain areas. Maximal distribution of the virus was observed throughout the brain at 6 to 7 dpi except for the cerebellum, which was mostly spared. Our results suggest an early entry of the virus through the olfactory mucosa and a rapid interneuronal spread of the virus leading to acute encephalitis and neuronal damage in this mouse model.

Download Full-text

THER-03. USING SUCCESSIVE EGF RECEPTOR ANTAGONISTS TO TREAT A PATIENT WITH EXTENSIVE METASTATIC DISEASE: CASE REPORT AND REVIEW OF THE LITERATURE

Neuro-Oncology Advances ◽

10.1093/noajnl/vdz014.046 ◽

2019 ◽

Vol 1 (Supplement_1) ◽

pp. i11-i11

Author(s):

Joseph Megyesi ◽

David Macdonald

Keyword(s):

Case Report ◽

Metastatic Disease ◽

Maxillary Antrum ◽

Metastatic Cancer ◽

Brain Mri ◽

Brain Lesions ◽

Targeted Agents ◽

Disease Case ◽

Bony Lesions ◽

The Brain

Abstract INTRODUCTION: EGFR-targeted agents can be useful in the treatment of systemic metastatic cancer including that which has spread to the brain. We present the case of a patient with two different EGFR mutations that responded to receptor blockade. CASE REPORT: A 38 year old right-handed female presented with a one week history of progressive left-sided weakness and focal seizures. Neuroimaging revealed multiple enhancing brain lesions and a lesion in the left maxillary antrum. Body imaging revealed a right lung mass, hilar and mediastinal nodes and multiple bony lesions. Biopsy of the maxillary antrum lesion showed metastatic poorly differentiated adenocarcinoma, TTF-1 positive, suggesting a lung primary. ALK was not mutated but there was an EGFR mutation (exon 19 deletion). The patient underwent treatment with dexamethasone, levetiracetam, whole brain radiation and afatinib, an oral EGFR-targeted agent. Most of the brain lesions responded completely with only two small residual lesions. Seizures were controlled. There was major partial response from the systemic lesions. Two years later the patient was clinically well but the lung lesion, mediastinal nodes and bony lesions were all enlarging. A new pituitary lesion was identified on brain MRI. A liquid biopsy (blood) revealed a T790M mutation and the patient underwent stereotactic body radiation and EGFR-targeted therapy with osimertinib. All lesions responded to treatment and four years after initial diagnosis the patient is clinically well with stable disease. DISCUSSION: Successful treatment of widespread metastatic disease is possible with the use of multiple EGFR-targeted agents in certain patients.

Download Full-text

First-in-human Study of a 99mTc-Labeled Single-Domain Antibody for SPECT/CT Assessment of HER2 Expression in Breast Cancer

10.21203/rs.3.rs-356098/v1 ◽

2021 ◽

Author(s):

Lingzhou Zhao ◽

Changcun Liu ◽

Yan Xing ◽

Jin He ◽

Jim O’Doherty ◽

...

Keyword(s):

Breast Cancer ◽

Cancer Patients ◽

Radiation Dosimetry ◽

Single Domain ◽

Her2 Expression ◽

Breast Cancer Patients ◽

Single Domain Antibody ◽

Primary Tumors ◽

Non Invasive ◽

Domain Antibody

Abstract Background: Accurate determination of human epidermal growth factor receptor 2 (HER2) expression is essential for HER2-targeted therapy. HER2 expression in a complex environment, such as in a heterogenous tumor, makes precise assessment difficult using current methods. Therefore, we developed a novel 99mTc-labeled anti-HER2-single domain antibody (99mTc-NM-02) as a molecular imaging tracer for non-invasive detection of HER2 expression and investigated its safety, radiation dosimetry, biodistribution, and tumor-targeting potential in breast cancer patients.Methods: A lead compound (NM-02) was screened from a library of hexahistidine-tagged anti-HER2-single domain antibodies and labeled with 99mTc for the preparation of 99mTc-NM-02 tracer. Ten women with breast cancer were administered 99mTc-NM-02 at a mean dose of 458 ± 37 MBq (406−510 MBq), corresponding to 100 μg of NM-02. Whole-body and local SPECT/CT images were acquired at 1 and 2 h post-administration to investigate the tumor-targeting potential in primary and metastatic lesions. Additional images were acquired at 10 min, 3 h, and 24 h in three patients to calculate radiation dosimetry. Physical evaluation and blood analysis were performed for safety assessment.Results: No drug-related adverse reactions occurred. The tracer mainly accumulated in the kidneys and liver with mild uptake in the spleen, intestines, and thyroid, but only background levels were observed in other organs where primary tumors and metastases typically occurred. The mean effective dose was 6.56 × 10−3 mSv/MBq, and tracer uptake was visually observed in primary tumors and metastases. Owing to the fast clearance of the tracer, we were able to sufficiently discern uptake over normal background in both primary lesions and metastases within 2 h after injection. A maximal standard uptake value of 1.5 could be a reasonable cutoff for determining HER2 positivity using SPECT/CT imaging.Conclusions: Our 99mTc-NM-02 tracer can be safely used for imaging in breast cancer patients with reasonable radiation doses, favorable biodistribution and imaging characteristics. 99mTc-NM-02 SPECT imaging may provide an accurate and non-invasive method to detect HER2 status in breast cancer patients.Trial registration: ClinicalTrials.gov, NCT04040686. Registered 30 July 2019. https://clinicaltrials.gov/ct2/show/NCT04040686.

Download Full-text

Single domain antibody (SBT-100) crosses the blood brain barrier (BBB) and inhibits human glioblastoma by selectively targeting KRAS and P-STAT3.

Journal of Clinical Oncology ◽

10.1200/jco.2017.35.15_suppl.e13547 ◽

2017 ◽

Vol 35 (15_suppl) ◽

pp. e13547-e13547

Author(s):

Sunanda Singh ◽

Genoveva Murillo ◽

Avani Singh ◽

Samara Singh ◽

Meenakshi S Parihar ◽

...

Keyword(s):

Targeted Therapy ◽

Growth Inhibition ◽

Glial Cells ◽

Mtt Assay ◽

Single Domain ◽

Single Domain Antibody ◽

Kras Mutations ◽

Domain Antibody ◽

Established Tumor ◽

The Brain

e13547 Background: Glioblastoma is difficult to treat malignancy that has a high incidence of KRAS mutations ( > 90%) and hyper-expression of P-STAT3 ( > 90%). Most chemotherapeutic agents and large biologics (four chain heterotetrameric IgG) cannot cross the BBB. Therefore Singh Biotechnology’s (SBT) propriety technology has developed a novel targeted therapy and engineered SBT-100 a 15 kD single domain antibody (sdAb) that is bispecific for KRAS and STAT3, which can cross the BBB to target gliablastomas. Methods: Human glioblastoma (U87MG) cell line was used and obtained from ATCC. Biacore affinity assay was used to demonstrate SBT-100 binding to KRAS, KRAS (G12D), and STAT3. The glioblastoma cells were incubated with 0µg/ml to 200µg/ml of SBT-100. MTT assay was performed after 3 days of treatment with SBT-100 and the growth inhibition was calculated. Xenograft (athymic nude mouse) with a well established tumor growing for 6 weeks was injected with SBT-100 intraperitoneally (IP). After 15 minutes the brain of this animal was harvested for immunohistochemical staining. Results: Biacore studies showed SBT-100 binds KRAS with affinity constant of 10-9M, KRAS (G12D) at 10-8M, and STAT3 at 10-8M. MTT assay reveals 62% (p < 0.01) growth inhibition of U87MG within 3 days. A xenograft mouse with a well established tumor ( > 150mm3), when injected IP with 5mg/kg of SBT-100 showed localization in the brain within 15 minutes. Therefore SBT-100 (sdAb) crosses the BBB, and shows intracellular localization in the animal’s neurons and glial cells. Conclusions: SBT-100 significantly inhibits the growth of glioblastoma. KRAS mutations and/or over expression of P-STAT3 in glioblastomas are promising targets for sdAbs like SBT-100, which is bispecific for KRAS and STAT3. SBT-100 crosses the BBB and localizes within the neurons and glial cells of the brain. SBT’s proprietary single domain antibody technology platform used to engineer SBT-100 holds promise for targeting primary brain malignancies, metastatic cancers that go to the brain, and for neurologic disease amenable to targeted therapy. Many chemo-resistant and radiation-resistant cancers use STAT3 as an escape mechanism.

Download Full-text

Beyond the Barrier: Targeted Radionuclide Therapy in Brain Tumors and Metastases

Pharmaceutics ◽

10.3390/pharmaceutics11080376 ◽

2019 ◽

Vol 11 (8) ◽

pp. 376 ◽

Cited By ~ 4

Author(s):

Puttemans ◽

Lahoutte ◽

D’Huyvetter ◽

Devoogdt

Keyword(s):

Brain Tumors ◽

Radionuclide Therapy ◽

Clinical Investigation ◽

Metastatic Cancer ◽

Targeted Radionuclide Therapy ◽

Newly Diagnosed ◽

Cytotoxic Potential ◽

Therapeutic Modalities ◽

Systemic Treatments ◽

The Brain

Brain tumors are notoriously difficult to treat. The blood-brain barrier provides a sanctuary site where residual and metastatic cancer cells can evade most therapeutic modalities. The delicate nature of the brain further complicates the decision of eliminating as much tumorous tissue as possible while protecting healthy tissue. Despite recent advances in immunotherapy, radiotherapy and systemic treatments, prognosis of newly diagnosed patients remains dismal, and recurrence is still a universal problem. Several strategies are now under preclinical and clinical investigation to optimize delivery and maximize the cytotoxic potential of pharmaceuticals with regards to brain tumors. This review provides an overview of targeted radionuclide therapy approaches for the treatment of primary brain tumors and brain metastases, with an emphasis on biological targeting moieties that specifically target key biomarkers involved in cancer development.

Download Full-text

Clinical outcomes and prognostic factors in HER-2 positive breast cancer with brain metastasis: A single-center experience.

Journal of Clinical Oncology ◽

10.1200/jco.2020.38.15_suppl.e13015 ◽

2020 ◽

Vol 38 (15_suppl) ◽

pp. e13015-e13015

Author(s):

Serdar Karakaya ◽

İbrahim Karadağ ◽

Ayse Ocak Duran ◽

Omur Berna Oksuzoglu ◽

Umut Demirci

Keyword(s):

Breast Cancer ◽

Brain Metastasis ◽

Median Overall Survival ◽

De Novo ◽

Breast Cancer Patients ◽

Her2 Positive ◽

Multiple Brain Metastasis ◽

Ecog Ps ◽

The Brain ◽

Positive Breast Cancer

e13015 Background: Brain metastasis is common in HER2 positive metastatic breast cancer patients. There is limited data on the prognosis, incidence, treatment, risk factors and complications of brain metastasized breast cancer because most clinical trials excluded these patients. we aimed to determine the characteristics and prognosis of brain metastasized HER2 positive breast cancer in our patient group, retrospectively. Methods: We scanned 3100 patients retrospectively and included 105 patients who met the criteria for inclusion in the study. Patients older 18 years old, had HER2 positive breast cancer and brain metastasis with no secondary malignity participated in the study. Results: In total, 35 (33.3%) patients had de-novo metastasis. Median overall survival (OS) was found to be 50 months in all patients. Median OS was 31 and 66 months for patients with de-novo metastasis (without brain metastasis) and patients with no metastasis at the time of the diagnosis, respectively (p < 0.01). When we compared median OS between 25 patients with one brain metastasis and 80 patients with multiple brain metastasis, it was found to be 90 months in the first-mentioned group whereas it was determined to be 45 in the latter group (p < 0.01). In all patients, the median elapsed time for the occurrence of brain metastasis was 22 months (for de-novo metastasis 15 months, for no metastasis 35 months; p < 0.01). Median OS was determined to be 15 months for all patients with brain metastasis after the occurrence of the metastasis. Patients with ECOG PS score of 0-1 at the time of the brain metastasis had 19 months median OS, while patients with ECOG PS score of 2 at the time of the brain metastasis had 8 months median OS (p < 0.01). Median OS after brain metastasis was 32 and 14 months for patients with one brain metastasis and patients with multiple brain metastasis, respectively (p < 0.01). Multivariate cox regression analyses revealed that elapsed time for the occurrence of brain metastasis was shorter in patients with high-grade tumours compared to patients with low-grade tumours (p = 0.04), and in patients with de-novo metastasis compared to patients without de-novo metastasis (p < 0.01). Conclusions: Our study indicated that tumour grade and de-novo metastasis are independent predictive factors that may cause the earlier occurrence of brain metastasis and affect mortality in breast cancer patients. After the occurrence of brain metastasis, lower ECOG PS score and multiple brain metastasis at the time of the diagnosis affected median overall survival as bad prognostic factors.

Download Full-text

When Should Trastuzumab be Stopped after Achieving Complete Response in Her2-Positive Metastatic Breast Cancer Patients?

Tumori Journal ◽

10.1177/030089160709300514 ◽

2007 ◽

Vol 93 (5) ◽

pp. 491-492 ◽

Cited By ~ 14

Author(s):

Manuela Beda ◽

Umberto Basso ◽

Cristina Ghiotto ◽

Silvio Monfardini

Keyword(s):

Breast Cancer ◽

Metastatic Breast Cancer ◽

Complete Remission ◽

Randomized Trials ◽

Metastatic Breast ◽

Complete Response ◽

Breast Cancer Patients ◽

Her2 Positive ◽

Multiple Liver Metastases ◽

The Brain

We report the case of a woman with HER2-positive metastatic breast cancer who achieved prolonged complete remission of multiple liver metastases after treatment with weekly trastuzumab plus paclitaxel but relapsed in the brain soon after stopping trastuzumab maintenance therapy which had been prosecuted for almost three years. In the absence of randomized trials, the optimal duration of trastuzumab administration after achieving complete remission of metastatic breast cancer remains questionable.

Download Full-text

P14.111 Successful treatment of extensive metastatic disease with successive use of two different EGF receptor antagonists: case report and review of the literature

Neuro-Oncology ◽

10.1093/neuonc/noz126.346 ◽

2019 ◽

Vol 21 (Supplement_3) ◽

pp. iii94-iii94

Author(s):

J F Megyesi ◽

D R Macdonald

Keyword(s):

Case Report ◽

Metastatic Disease ◽

Successful Treatment ◽

Maxillary Antrum ◽

Metastatic Cancer ◽

Brain Mri ◽

Brain Lesions ◽

Targeted Agents ◽

Bony Lesions ◽

The Brain

Abstract INTRODUCTION EGFR-targeted agents can be useful in the treatment of systemic metastatic cancer including that which has spread to the brain. We present the case of a patient with two different EGFR mutations that responded to receptor blockade. CASE REPORT A 38 year old right-handed female presented with a one week history of progressive left-sided weakness and focal seizures. Neuroimaging revealed multiple enhancing brain lesions and a lesion in the left maxillary antrum. Body imaging revealed a right lung mass, hilar and mediastinal nodes and multiple bony lesions. Biopsy of the maxillary antrum lesion showed metastatic poorly differentiated adenocarcinoma, TTF-1 positive, suggesting a lung primary. ALK was not mutated but there was an EGFR mutation (exon 19 deletion). The patient underwent treatment with dexamethasone, levetiracetam, whole brain radiation and afatinib, an oral EGFR-targeted agent. Most of the brain lesions responded completely with only two small residual lesions. Seizures were controlled. There was major partial response from the systemic lesions. Two years later the patient was clinically well but the lung lesion, mediastinal nodes and bony lesions were all enlarging. A new pituitary lesion was identified on brain MRI. A liquid biopsy (blood) revealed a T790M mutation and the patient underwent stereotactic body radiation and EGFR-targeted therapy with osimertinib. All lesions responded to treatment and four years after initial diagnosis the patient is clinically well with stable disease. DISCUSSION Successful treatment of widespread metastatic disease is possible with the use of multiple EGFR-targeted agents in certain patients.

Download Full-text

Tumor-associated autoantibodies from mouse breast cancer models are found in serum of breast cancer patients

npj Breast Cancer ◽

10.1038/s41523-021-00257-1 ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Sasha E. Stanton ◽

Ekram Gad ◽

Erik Ramos ◽

Lauren Corulli ◽

James Annis ◽

...

Keyword(s):

Breast Cancer ◽

Transgenic Mouse ◽

Mammary Tumor ◽

Tumor Antigens ◽

Ductal Carcinoma ◽

Breast Tumors ◽

Breast Cancer Patients ◽

Tumor Models ◽

Her2 Positive ◽

Mouse Mammary Tumor

AbstractB cell responses to tumor antigens occur early in breast tumors and may identify immunogenic drivers of tumorigenesis. Sixty-two candidate antigens were identified prior to palpable tumor development in TgMMTV-neu and C3(1)Tag transgenic mouse mammary tumor models. Five antigens (VPS35, ARPC2, SERBP1, KRT8, and PDIA6) were selected because their decreased expression decreased survival in human HER2 positive and triple negative cell lines in a siRNA screen. Vaccination with antigen-specific epitopes, conserved between mouse and human, inhibited tumor growth in both transgenic mouse models. Increased IgG autoantibodies to the antigens were elevated in serum from women with ductal carcinoma in situ (DCIS) and invasive breast cancer (IBC). The autoantibodies differentiated women with DCIS from control with AUC 0.93 (95% CI 0.88–0.98, p < 0.0001). The tumor antigens identified early in the development of breast cancer in mouse mammary tumor models were conserved in human disease, and potentially identify early diagnostic markers in human breast tumors.

Download Full-text