Radioimmunotherapy for non-Hodgkin's lymphoma; positioning, safety, and efficacy of 90Y-Ibritumomab. 10 years of experience and follow-up

Update in Diagnosis and Management of Primary Cutaneous B-Cell Lymphomas

Primary cutaneous lymphomas are a rare group of diseases, with an estimated incidence of 0.5-1 case per 100,000 people per year. Primary cutaneous B-cell lymphomas (pCBCLs) represent 25-30% of all primary cutaneous lymphomas. There are three main subtypes of pCBCL: primary cutaneous marginal zone lymphoma, primary cutaneous follicle center lymphoma, and primary cutaneous diffuse large B-cell lymphoma, leg type. Cutaneous B-cell lymphomas have a broad spectrum of clinical presentations, which makes diagnostic and therapeutic strategies challenging. To date, treatment recommendations for cutaneous B-cell lymphomas have been largely based on small retrospective studies and institutional experience. Recently, the pharmacotherapeutic landscape has expanded to include drugs that may modify the underlying disease pathology of pCBCLs, representing new therapeutic modalities for this rare group of diseases. Novel therapies used for other systemic B-cell lymphomas show promise for the treatment of pCBCLs and are being increasingly considered. These new therapies are divided into five main groups: monoclonal antibodies, immune checkpoint inhibitors, small-molecule inhibitors, bispecific T-cell engaging, and chimeric antigen receptor T cell. In this review, we discuss the clinical, histopathological, molecular, and cytogenetic features of the most common pCBCL subtypes with a focus on current and innovative therapeutic developments in their management. These emerging treatment strategies for B-cell lymphomas and cutaneous B-cell lymphomas may represent novel first-line options for the management of these rare diseases.

ImmunoPET in Multiple Myeloma-What? So What? Now What?

Despite constant progress over the past three decades, multiple myeloma (MM) is still an incurable disease, and the identification of new biomarkers to better select patients and adapt therapy is more relevant than ever. Recently, the introduction of therapeutic monoclonal antibodies (mAbs) (including direct-targeting mAbs and immune checkpoint inhibitors) appears to have changed the paradigm of MM management, emphasizing the opportunity to cure MM patients through an immunotherapeutic approach. In this context, immuno-positron emission tomography (immunoPET), combining the high sensitivity and resolution of a PET camera with the specificity of a radiolabelled mAb, holds the capability to cement this new treatment paradigm for MM patients. It has the potential to non-invasively monitor the distribution of therapeutic antibodies or directly monitor biomarkers on MM cells, and to allow direct observation of potential changes over time and in response to various therapeutic interventions. Tumor response could, in the future, be anticipated more effectively to provide individualized treatment plans tailored to patients according to their unique imaging signatures. This work explores the important role played by immunotherapeutics in the management of MM, and focuses on some of the challenges for this drug class and the significant interest of companion imaging agents such as immunoPET.

131I-labeled Anti-HER2 Camelid sdAb as a Theranostic Tool in Cancer Treatment

Purpose: Camelid single-domain antibody-fragments (sdAb) have beneficial pharmacokinetic properties, and those targeted to HER2 can be used for imaging of HER2-overexpressing cancer. Labeled with a therapeutic radionuclide, they may be used for HER2-targeted therapy. Here, we describe the generation of a ¹³¹I-labeled sdAb as a theranostic drug to treat HER2-overexpressing cancer.Experimental Design: Anti-HER2 sdAb 2Rs15d was labeled with ¹³¹I using [¹³¹I]SGMIB and evaluated in vitro Biodistribution was evaluated in two HER2⁺ murine xenograft models by micro-SPECT/CT imaging and at necropsy, and under challenge with trastuzumab and pertuzumab. The therapeutic potential of [¹³¹I]SGMIB-2Rs15d was investigated in two HER2⁺ tumor mouse models. A single-dose toxicity study was performed in mice using unlabeled [¹²⁷I]SGMIB-sdAb at 1.4 mg/kg. The structure of the 2Rs15d-HER2 complex was determined by X-ray crystallography.Results: [¹³¹I]SGMIB-2Rs15d bound specifically to HER2⁺ cells (K_d = 4.74 ± 0.39 nmol/L). High and specific tumor uptake was observed in both BT474/M1 and SKOV-3 tumor xenografted mice and surpassed kidney levels by 3 hours. Extremely low uptake values were observed in other normal tissues at all time points. The crystal structure revealed that 2Rs15d recognizes HER2 Domain 1, consistent with the lack of competition with trastuzumab and pertuzumab observed in vivo [¹³¹I]SGMIB-2Rs15d alone, or in combination with trastuzumab, extended median survival significantly. No toxicity was observed after injecting [¹²⁷I]SGMIB-2Rs15d.Conclusions: These findings demonstrate the theranostic potential of [¹³¹I]SGMIB-2Rs15d. An initial scan using low radioactive [*I]SGMIB-2Rs15d allows patient selection and dosimetry calculations for subsequent therapeutic [¹³¹I]SGMIB-2Rs15d and could thereby impact therapy outcome on HER2⁺ breast cancer patients. Clin Cancer Res; 23(21); 6616-28. ©2017 AACR.