Treatment of metastatic, castration-resistant prostate cancer (mCRPC) remains a highly unmet medical need and current therapies ultimately result in disease progression. Immunotherapy is a rapidly growing approach for treatment of cancer but has shown limited success to date in the treatment of mCRPC. We have developed a novel humanized bispecific antibody, MOR209/ES414, built on the ADAPTIR (modular protein technology) platform, to redirect T-cell cytotoxicity toward prostate cancer cells by specifically targeting T cells through CD3e to prostate cancer cells expressing PSMA (prostate-specific membrane antigen). In vitro cross-linking of T cells with PSMAexpressing tumor cells by MOR209/ES414 triggered potent targetdependent tumor lysis and induction of target-dependent T-cell activation and proliferation. This activity occurred at low picomolar concentrations of MOR209/ES414 and was effective at low T-effector to tumor target cell ratios. In addition, cytotoxic activity was equivalent over a wide range of PSMA expression on target cells, suggesting that as few as 3,700 PSMA receptors per cell are sufficient for tumor lysis. In addition to high sensitivity and in vitro activity, MOR209/ES414 induced limited production of cytokines compared with other bispecific antibody formats. Pharmacokinetic analysis of MOR209/ES414 demonstrated a serum elimination half-life in NOD/SCID g (NSG) mice of 4 days. Administration of MOR209/ES414 in murine xenograft models of human prostate cancer significantly inhibited tumor growth, prolonged survival, and decreased serum prostate-specific antigen levels only in the presence of adoptively transferred human T cells. On the basis of these preclinical findings, MOR209/ES414 warrants further investigation as a potential therapeutic for the treatment of CRPC. Mol Cancer Ther; 15(9); 2155-65. Ó2016 AACR.

Purpose Alexithymia, defined as the inability of a person to identify, describe and express emotions, has been found to influence glycemic control in type 2 diabetes patients (D2). The characteristics and influencing factors of alexithymia and the association of this psychological construct with D2 has not yet been studied in Lebanon where 14.6% of adults are diagnosed with the disease. This study aims at evaluating the prevalence of alexithymia and its relationship with glycemic control among Lebanese adults with D2. Methods Alexithymia was assessed in 104 patients diagnosed with D2 and 100 healthy controls using the 20-item Toronto Alexithymia Scale (TAS-20). The impact of alexithymia on glycemic control was evaluated using HbA1c values, fasting blood glucose levels, number of severe hyperglycemic episodes and hospitalizations for hyperglycemia within the past months. Results Alexithymia prevalence was significantly higher in D2 patients compared to controls (35.5% vs 15%). Patients with alexithymia showed higher levels of HbA1c and glucose in comparison to those without alexithymia. Consistently, significant positive correlations were found between the TAS-20 total and subscale scores and both HbA1c and glucose levels. Alexithymic patients had three times more severe hyperglycemic episodes and five times more hospitalizations for hyperglycemia compared to those without alexithymia. According to multivariate regression analysis, lifestyle factors alone were not found predictive of alexithymia in D2 patients. Conclusion Given the impact of alexithymia on D2 regulation, screening of alexithymia in case of D2 and appropriate psychological follow-up are important for a better prognosis, management and treatment of the disease.

Purpose: CD20-directed therapy with rituximab is effective in many patients with malignant lymphoma or follicular lymphoma. However, relapse frequently occurs within 1year, and patients become increasingly refractory to retreatment. Our purpose was to produce a compact, single-chain CD20-targeting immunotherapeutic that could offer therapeutic advantages in the treatment of B-cell lymphoma. Experimental Design: Rituximab is a chimeric antibody containing two heavy chains and two light chains. Here, we describe the properties of TRU-015, a small modular immunopharmaceutical specific for CD20, encoded by a single-chain construct containing a single-chain Fv specific for CD20 linked to human IgG1hinge, CH2, and CH3 domains but devoid of CH1and CL domains. Results: TRU-015 mediates potent direct signaling and antibody-dependent cellular cytotoxicity but has reduced size and complement-mediated cytotoxicity activity compared with rituximab. TRU-015 is a compact dimer of 104 kDa that comigrates with albumin in size exclusion chromatography and retains a long half-life in vivo.TRU-015 induced growth arrest in multiple B lymphoma cell lines in vitro and showed effective antitumor activity against large, established subcutaneous Ramos or Daudi xenograft tumors in nude mice. TRU-015 also showed rapid, dose-dependent, and durable depletion of peripheral blood B cells following single-dose administration to nonhuman primates. Conclusion: These results indicate that TRU-015 may improve CD20-directed therapy by effectively depleting embedded malignant B cells and nonmalignant pathogenic B cells and do so with reduced complement activation.

Introduction: Depletion of CD123 over-expressing malignant cells provides a potential new treatment option which may improve patient outcomes in several hematological malignancies. CD123 is over-expressed in AML, MDS, ALL, CML, HCL and BPDCN and infrequently expressed by normal cells making it an attractive target which is being pursued using a number of different approaches including T-cell engaging immunotherapy. Cytokine release syndrome is a significant concern with T-cell activating therapeutics which has led to severe complications in clinical trials. We have developed APVO436, a bispecific anti-CD123 x anti-CD3 ADAPTIR molecule for redirecting T-cell cytotoxicity to CD123-expressing tumor cells. A potential advantage of the ADAPTIR platform is reduced cytokine release upon T-cell engagement compared to other formats (Mol Cancer Ther. 2016 Sep;15(9):2155-65). Here we present in vitro and in vivo activity of APVO436 and compare the activity of APVO436 to another anti-CD123 x anti-CD3 bispecific containing the amino acid sequence of MGD006.Methods: Binding, T-cell activation and proliferation were assessed using multi-color flow cytometry. Cytotoxic activity was determined using chromium release assays and flow cytometry. PBMC samples were obtained from normal donors and AML patients. In vivo studies were performed using NSG mice transplanted with human PBMC's. The CD123 and CD3 binding domain sequences for flotuzumab (MGD006) were obtained from patent W02015026892 engineered in Macrogenic's dual-affinity re-targeting format as reported in Sci Transl Med. 2015 May 27;7(289):289ra82.Results: Dose-dependent cytotoxicity of CD123 expressing tumor cell lines and primary AML cells was induced by APVO436 at low effector to target ratios, accompanied by T-cell activation and proliferation. APVO436 induced significantly lower levels of several T-cell cytokines including IFNγ, IL-2, and TNFα compared to the molecule in the dual-affinity re-targeting format. In vivo, APVO436 significantly reduced established tumor burden in xenograft murine models.Conclusions: APVO436 potently induces T-cell activation, proliferation and CD123+ cell depletion with AML and normal donor samples and CD123 expressing tumor cell lines with limited levels of T-cell cytokine release compared to another CD123 x CD3 targeting bispecific format suggesting a potential safety advantage. APVO436 inhibits tumor-growth in sub-cutaneous tumor models with IV-implanted human T cells, indicating migration and engagement of T cells at the tumor site. These data are supportive of further investigation of APVO436 as a potential treatment option for AML and other hematological malignancies. GLP toxicology studies have been completed in non-human primates and APVO436 is advancing to clinical testing. Citation Format: Michael R. Comeau, Robert E. Miller, Robert Bader, Rebecca Gottschalk, Mollie Daugherty, Toddy Sewell, Lynda Misher, Lara Parr, Melissa DeFrancesco, David Bienvenue, Catherine J. McMahan, Gabriela H. Hoyos, Jane A. Gross. APVO436, a bispecific anti-CD123 x anti-CD3 ADAPTIR™ molecule for redirected T-cell cytotoxicity, induces potent T-cell activation, proliferation and cytotoxicity with limited cytokine release [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1786.