Cure of Micrometastatic B-Cell Lymphoma in a SCID Mouse Model Using Bi-Anti-CD20 Monoclonal Antibody.

We studied the feasibility of using the α-emitting Bi-anti-CD20 therapy with direct bioluminescent tracking of micrometastatic human B-cell lymphoma in a SCID mouse model. A highly lethal SCID mouse model of minimal-tumor-burden disseminated non-Hodgkin lymphoma (NHL) was established using human Raji lymphoma cells transfected to express the luciferase reporter. In vitro and in vivo radioimmunotherapy experiments were conducted.

General Method to Increase Carboxylic Acid Content on Nanodiamonds.

Carboxylic acid is a commonly utilized functional group for covalent surface conjugation of carbon nanoparticles that is typically generated by acid oxidation. However, acid oxidation generates additional oxygen containing groups, including epoxides, ketones, aldehydes, lactones, and alcohols. We present a method to specifically enrich the carboxylic acid content on fluorescent nanodiamond (FND) surfaces.

National Cancer Institute support for targeted alpha-emitter therapy.

Background: Radiopharmaceutical targeted therapy (RPT) has been studied for decades; however, recent clinical trials demonstrating efficacy have helped renewed interest in the modality.

Methods: This article reviews National Cancer Institute (NCI)'s support of RPT through communication via workshops and interest groups, through funding extramural programs in academia and small business, and through intramural research, including preclinical and clinical studies.

Results: NCI has co-organized workshops and organized interest groups on RPT and RPT dosimetry to encourage the community and facilitate rigorous preclinical and clinical studies.

Reply to the 'Comment on "Investigation of Zr(iv) and Zr(iv) complexation with hydroxamates: progress towards designing a better chelator than desferrioxamine B for immuno-PET imaging"' by A. Bianchi and M. Savastano, Chem. Commun., 2020, 56, D0CC01189D.

The alternative analysis of A. Bianchi and M. Savastano is a valuable contribution to the understanding of the complex systems at stake in the complexation chemistry of Zr by considering polynuclear species.

Y-Daclizumab (Anti-CD25), High-Dose Carmustine, Etoposide, Cytarabine, and Melphalan Chemotherapy and Autologous Hematopoietic Stem Cell Transplant Yielded Sustained Complete Remissions in 4 Patients with Recurrent Hodgkin's Lymphoma.

Despite advances in therapy of Hodgkin's lymphoma (HL), a proportion of patients will not respond or relapse. The authors had previously identified CD25, IL-2Rα, as a target for systemic radioimmunotherapy of HL since most normal cells do not express CD25, but it is expressed by a minority of Hodgkin/Reed-Sternberg (HRS) cells and most Tregs rosetting around HRS cells. This was a single institution, nonrandomized, open-label phase I/II trial of radiolabeled Y-daclizumab, an anti-CD25 monoclonal antibody, BEAM (carmustine, etoposide, cytarabine, and melphalan) conditioning treatment followed by autologous hematopoietic stem cell transplant (ASCT).

Preclinical Evaluation of Pb-Labeled Low-Molecular-Weight Compounds for Targeted Radiopharmaceutical Therapy of Prostate Cancer.

Targeted radiopharmaceutical therapy (TRT) using α-particle radiation is a promising approach for treating both large and micrometastatic lesions. We developed prostate-specific membrane antigen (PSMA)-targeted low-molecular-weight agents for Pb-based TRT of patients with prostate cancer (PC) by evaluating the matching γ-emitting surrogate, Pb. Five rationally designed low-molecular-weight ligands (L1-L5) were synthesized using the lysine-urea-glutamate scaffold, and PSMA inhibition constants were determined.

First-in-human phase 0 study of In-CHX-A"-DTPA trastuzumab for HER2 tumor imaging.

Introduction: Tumors over-expressing the human epithelial receptor 2 (HER2) or exhibiting amplification or mutation of its proto-oncogene have a poorer prognosis. Using trastuzumab and/or other HER2 targeted therapies can increase overall survival in patients with HER2(+) tumors making it critical to accurately identify patients who may benefit. We report on a Phase 0 study of the imaging agent, In-CHX-A"-DTPA trastuzumab, in patients with known HER2 status to evaluate its safety and biodistribution and to obtain preliminary data regarding its ability to provide an accurate, whole-body, non-invasive means to determine HER2 status.

Exploration of a F(ab') Fragment as the Targeting Agent of α-Radiation Therapy: A Comparison of the Therapeutic Benefit of Intraperitoneal and Intravenous Administered Radioimmunotherapy.

Refinement of treatment regimens enlisting targeted α-radiation therapy (TAT) is an ongoing effort. Among the variables to consider are the target molecule, radionuclide, dosage, and administration route. The panitumumab F(ab') fragment targeting epidermal growth factor receptor tolerated modification with the TCMC chelate as well as radiolabeling with Pb or Pb.

Bifunctional aryliodonium salts for highly efficient radioiodination and astatination of antibodies.

In this report we describe the development of an alternative approach to arylstannane chemistry for radiolabeling antibodies with radioiodine or astatine based on aryliodonium salts precursors. Bifunctional aryliodonium salts were designed and tested for the synthesis of I and At labeled prosthetic groups for bioconjugation. The nature of the electron rich aryl group was varied and its impact on the regioselectivity of radiohalogenation was evaluated.

Comparative studies on the therapeutic benefit of targeted α-particle radiation therapy for the treatment of disseminated intraperitoneal disease.

Identification of the appropriate combination of radionuclide, target and targeting vehicle is critical for successful radioimmunotherapy. For the treatment of disseminated peritoneal diseases such as pancreatic or ovarian cancer, α-emitting radionuclides have been proposed for targeted radiation therapy. This laboratory has taken a systematic approach investigating targeted α-radiation therapy, allowing comparisons to now be made between At, Th, Bi and Pb.

Targeted α-Particle Radiation Therapy of HER1-Positive Disseminated Intraperitoneal Disease: An Investigation of the Human Anti-EGFR Monoclonal Antibody, Panitumumab.

Identifying molecular targets and an appropriate targeting vehicle, i.e., monoclonal antibodies (mAb) and their various forms, for radioimmunotherapy (RIT) remains an active area of research.

Investigation of the complexation of Zr(iv) and Zr(iv) by hydroxypyridinones for the development of chelators for PET imaging applications.

Three hydroxypyridinone (HOPO) positional isomers - 1,2-HOPO (L1H) and its water soluble analogue (L1'H), 3,2-HOPO (L2H) and 3,4-HOPO (L3H) have been investigated for the complexation of Zr(iv). Potentiometric and UV-Vis spectrometric studies show a higher thermodynamic stability for the formation of Zr(L1') in comparison with Zr(L2) and Zr(L3) as well as a higher kinetic inertness in competition studies with EDTA or Fe at a radiotracer concentration with Zr. Besides the low pK of L1H or L1'H (pK = 5.

The IDO1 selective inhibitor epacadostat enhances dendritic cell immunogenicity and lytic ability of tumor antigen-specific T cells.

Epacadostat is a novel inhibitor of indoleamine-2,3-dioxygenase-1 (IDO1) that suppresses systemic tryptophan catabolism and is currently being evaluated in ongoing clinical trials. We investigated the effects of epacadostat on (a) human dendritic cells (DCs) with respect to maturation and ability to activate human tumor antigen-specific cytotoxic T-cell (CTL) lines, and subsequent T-cell lysis of tumor cells, (b) human regulatory T cells (Tregs), and (c) human peripheral blood mononuclear cells (PBMCs) in vitro. Simultaneous treatment with epacadostat and IFN-γ plus lipopolysaccharide (LPS) did not change the phenotype of matured human DCs, and as expected decreased the tryptophan breakdown and kynurenine production.

Cell Killing Mechanisms and Impact on Gene Expression by Gemcitabine and 212Pb-Trastuzumab Treatment in a Disseminated i.p. Tumor Model.

In pre-clinical studies, combination therapy with gemcitabine and targeted radioimmunotherapy (RIT) using 212Pb-trastuzumab showed tremendous therapeutic potential in the LS-174T tumor xenograft model of disseminated intraperitoneal disease. To better understand the underlying molecular basis for the observed cell killing efficacy, gene expression profiling was performed after a 24 h exposure to 212Pb-trastuzumab upon gemcitabine (Gem) pre-treatment in this model. DNA damage response genes in tumors were quantified using a real time quantitative PCR array (qRT-PCR array) covering 84 genes.