Enteric pythiosis was diagnosed in nine dogs in Oklahoma. Eight dogs had anorexia and weight loss. Two of these dogs had diarrhea; two dogs exhibited vomiting and diarrhea; and one dog had vomiting. One dog presented with dysphagia. Seven dogs had either a palpable or radiographically visible abdominal mass. These seven dogs had localized regions of mucosal ulceration and thickened gastric or intestinal walls with some involvement of the adjacent mesentery or omentum. Two dogs had enlarged regional mesenteric lymph nodes. One dog that presented with dysphagia had an oropharyngeal mass involving the larynx and cranial esophagus. Microscopically, there was transmural chronic sclerosing and granulomatous to pyogranulomatous inflammation with arteritis. Pythium spp. were identified in all specimens by immunohistochemistry.

in the CD13+ myeloid compartment (88.3 ± 4.5%) compared to other lineages, including CD20+ lymphoid (9.1 ± 3.9%), CD235a+ erythroid (0.2 ± 0.1%) and CD41+ megakaryocytic (0.6 ± 0.2%) lineages. Interestingly, human myeloid engraftment was superior in recipient mice engrafted with human CD18+ cells (81.5 ± 4.3%) compared to animals transplanted with non-transduced (CD18-) LAD-1 cells (65.3 ± 11.3%). Integration site analysis of engrafted human cells is ongoing. Thus, FVV-mediated transduction of human LAD-1 CD34 + cells leads to clinically significant levels of CD18 expression, supporting the use of this CD18-expressing FVV in a human clinical trial.

A glycinate derivative of α-methylprednisolone (MP) was prepared and conjugated to a linear cyclodextrin polymer (CDP) with a loading of 12.4% w/w. The polymer conjugate (CDP-MP) self-assembled into nanoparticles with a size of 27 nm. Release kinetics of MP from the polymer conjugate showed a half-life (t 1/2) of 50 h in phosphate buffer solution (PBS) and 19 h in human plasma. In vitro, the proliferation of human lymphocytes was suppressed to a similar extent but with a delayed effect when CDP-MP was compared with free MP. In vivo, CDP-MP was administered intravenously to mice with collagen-induced arthritis and compared with free MP. CDP-MP was administered weekly for six weeks (0.07, 0.7, and 7 mg/kg/week) and MP was administered daily for six weeks (0.01, 0.1, and 1 mg/kg/day). Body weight changes were minimal in all animals. After 28 days, a signifi cant decrease in arthritis score was observed in animals treated weekly with an intermediate or high dose of CDP-MP. Additionally, dorsoplantar swelling was reduced to baseline in animals treated with CDP-MP at the intermediate and high dose level. Histological evaluation showed a reduction in synovitis, pannus formation and disruption of architecture at the highest dose level of CDP-MP. MP administered daily at equivalent cumulative doses showed minimal effi cacy in this model. This study demonstrates that conjugation of MP to a cyclodextrin-polymer may improve its effi cacy, leading to lower doses and less frequent administration for a safer and more convenient management of rheumatoid arthritis.

Introduction: KTE-C19 is an autologous anti-CD19 CAR T cell product that is being studied in a phase 2 multicenter trial (ZUMA-1, NCT02348216). We developed a robust and efficient manufacturing process to support this trial, and compared the characteristics of the starting lymphocytes to resultant CAR T cells. Methods: After apheresis and PBMC enrichment, cells were activated with anti-CD3 antibody and cultured in serum free medium. T cells were transduced with a retroviral vector encoding the CAR gene, expanded to achieve a target dose and cryopreserved. The product CAR T cells and the starting PBMCs were evaluated by flow cytometry. Results: 7 subjects were dosed in the phase 1 portion of the trial. KTE-C19 was successfully manufactured at a dose of 2 × 106/kg (minimum 1 × 106/kg) for all subjects. All lots contained mainly CD3+ T cells (median 97%; 94-99%). While there was inter-subject variability in PBMC and CAR T cell product characteristics, the CD8/CD4 T cell ratios in PBMC and corresponding CAR product were similar (Table 1). T cells in PBMC from patients with NHL contained a majority of effector memory (36%) and effector T cells (27%), however, T cells in KTE-C19 contained a majority of central memory (37%) and effector memory (42%) CAR+ T cells. These CAR T cells were active and objective responses occurred in 5/7 patients. Conclusions: A KTE-C19 dose was successfully produced for all subjects. The optimized manufacturing process generated clinically active CAR T cells with a less differentiated phenotype than T cells in the starting PBMC population. Less differentiated cells likely confer preferred product characteristics based on preclinical studies. This manufacturing process is robust and well suited for multicenter clinical trials. Table 1.Comparative analysis of T cells from KTE-C19 and PBMC from patients with refractory aggressive NHL.IDSampleNaïve (%)Central Memory (%)Effector Memory (%)Effector (%)CD8/CD4 ratioSubject 1KTE-C1911583014.6PBMC161246272.3Subject 2KTE-C1914473540.37PBMC26303490.27Subject 3KTE-C196345642.3PBMC4536552.9Subject 4KTE-C19111552222.0PBMC1224721.8Subject 5KTE-C1915403871.0PBMC91550261.1Subject 6KTE-C1919344252.3PBMC101359192.0Subject 7KTE-C19152645140.5PBMC121336390.5Median (Range)KTE-C1913 (6-15)37 (15-58)42 (30-56)5 (1-22)1.9 (0.4-4.6)PBMC10 (1-26)13 (2-30)36 (24-59)27 (9-72)1.9 (0.3-2.9) Citation Format: Marc Better, Vijay Chiruvolu, James Oliver, Maryam Sorkhabi, Jeff S. Aycock, Emily Lowe, Edmund Chang, Arianne Perez, Lynn Navale, John M. Rossi, Adrian Bot. Manufacturing and characterization of KTE-C19 in a multicenter trial of subjects with refractory aggressive non-Hodgkin's lymphoma (NHL) (ZUMA-1). [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2308.

14078 Background: IT-101 is a de novo designed experimental therapeutic comprised of linear, cyclodextrin(CD)-containing polymer conjugates of camptothecin(CPT) that assemble into ca. 40 nm diameter nanoparticles via polymer-polymer interactions that involve inclusion complex formation between the CPT and the CD. Particle size, near neutral surface charge and CPT release rate were specifically designed into IT-101. Published pre-clinical animal studies show extended circulation times (t1/2 of ca. 20 h in rodents), tumor accumulation, slow release of the CPT and anti-tumor efficacy that directly correlate to the properties of the nanoparticle. Release of CPT can disassemble the nanoparticle into individual polymer chains that have size ca. 10 nm that are capable of renal clearance (t1/2 of several minutes in rodents). Methods: Patients with relapsed or refractory cancer were evaluated every two cycles of therapy (90 minute IV infusions of IT- 101 in D5W on days 1, 8 and 15 of a 28 day cycle). Three dose levels of 6, 12 and 18 mg CPT eq./m2 have been tested. Results: At the time of this interim analysis, eight patients have been enrolled and five evaluated. In general, IT-101 is well tolerated and pancytopenia is the DLT. The expected MTD is 12 mg/ m2.Three out of five patients demonstrated stable disease on CT scan evaluation. One pancreatic cancer patient remains stable for 6 months. PK data are available from the first 5 patients. Total and free CPT display biphasic elimination from plasma with mean terminal elimination half lives of 38±3.7 and 61±43 hours, respectively. The mean Vd and CLsys of total CPT are 6.1±1.4 L and 0.1±0.03 L/h and are unrelated to dose over the range tested, with a mean total-to-free AUC ratio of 10.7±3.7. Conclusions: These first in human PK data for IT-101 confirm that 40 nm particles with near neutral surface charge provide favorable PK properties. The stable disease rate, although not yet conclusive, is consistent with promising efficacy. The preliminary results of this phase I study warrant continued enrollment that is ongoing. No significant financial relationships to disclose.