Hunder, Naomi

Abstract Abstract 955 Background: Hodgkin lymphoma (HL) is a lymphoid neoplasm defined by the presence of CD30-positive Hodgkin Reed-Sternberg (HRS) cells in a background of inflammatory cells. Frontline treatment is generally ABVD alone or in combination with other chemotherapy regimens or radiation. Although a standard ABVD regimen is curative for the majority of patients with advanced stage HL, up to 30% of patients will require a second-line therapy. Brentuximab vedotin (SGN-35) comprises an anti-CD30 antibody conjugated by a protease-cleavable linker to the potent antimicrotubule agent, monomethyl auristatin E (MMAE). In a phase 2 study, an objective response rate of 75% and multiple durable complete remissions (CRs) (34%) were obtained with single-agent brentuximab vedotin in highly treatment-refractory patients with HL. Methods: A phase 1, open-label, multicenter study is being conducted to evaluate the safety of brentuximab vedotin when administered in combination with standard therapy (ABVD) or a modified standard (AVD) (ClinicalTrials.gov #NCT01060904). Patients received doses of 0.6, 0.9, or 1.2 mg/kg brentuximab vedotin with standard doses of ABVD or 1.2 mg/kg brentuximab vedotin with AVD, depending upon cohort assignment. The combination regimens were administered on Days 1 and 15 of each 28-day cycle for up to 6 cycles of therapy. Each regimen evaluated a dose limiting toxicity (DLT) period, defined as any Cycle 1 toxicity requiring a delay of ≥7 days in standard ABVD or AVD therapy. Determination of antitumor activity is based on investigator assessment of objective response according to the Revised Response Criteria for Malignant Lymphoma (Cheson 2007). Results: Interim data are presented for the first 31 patients treated. Six patients received 0.6 mg/kg, 13 received 0.9 mg/kg, and 6 received 1.2 mg/kg with ABVD; 6 patients received 1.2 mg/kg with AVD. Baseline characteristics included: Stage IV, 55%; IPI score ≥4, 29%; male, 77%; median age, 35 years (range, 19–59). Combination treatment was generally well tolerated, with no DLT observed up to 1.2 mg/kg in either regimen. Overall, AEs reported in ≥45% of patients, regardless of severity, were nausea and neutropenia (77% each); peripheral sensory neuropathy (48%); and fatigue (45%). Infusion-related reactions occurred in 23% of patients. Grade 3/4 AEs observed in >10% of patients were neutropenia (74%), febrile neutropenia (16%), and anemia (13%). No Grade 5 events were observed. Overall, 6 patients discontinued combination treatment due to an AE. In the ABVD cohorts (n=25), AEs of pulmonary toxicity, dyspnea, and interstitial lung disease that could not be distinguished from bleomycin toxicity led to discontinuation of bleomycin in 7 patients. Five of these 7 patients continued treatment with AVD and brentuximab vedotin. All 10 patients who had a response assessment available after completion of frontline therapy achieved CR. Currently, an expansion cohort of approximately 20 patients is enrolling to explore 1.2 mg/kg brentuximab vedotin combined with AVD therapy. Conclusions: In this interim analysis of 31 patients with newly diagnosed HL, the maximum tolerated dose in combination with ABVD or AVD was not reached; no DLT was observed up to 1.2 mg/kg, the maximum planned dose. Brentuximab vedotin treatment was associated with manageable AEs; the most frequent AEs in the study were nausea and neutropenia. The safety profile observed thus far in this study suggests that brentuximab vedotin has potential for combination therapy with ABVD or AVD. Updated safety and response data will be presented at the meeting. Disclosures: Younes: Seattle Genetics, Inc.: Consultancy, Honoraria, Research Funding, Speakers Bureau, Travel Expenses; Novartis: Honoraria, Research Funding, Speakers Bureau; Sanofi-Aventis: Honoraria, Research Funding, Speakers Bureau; Genentech: Research Funding; SBIO: Research Funding; Syndax: Research Funding; Celgene: Speakers Bureau; Gilead: Honoraria; Pharmacyclic: Honoraria. Off Label Use: Brentuximab vedotin (SGN-35) comprises an anti-CD30 antibody conjugated by a protease-cleavable linker to the potent antimicrotubule agent, monomethyl auristatin E (MMAE). It is an investigational agent that is being studied in CD30+ malignancies. Connors:Seattle Genetics, Inc.: Research Funding. Park:Seattle Genetics, Inc.: Research Funding. Hunder:Seattle Genetics, Inc.: Employment, Equity Ownership. Ansell:Seattle Genetics, Inc.: Research Funding.

Giant cell arteritis (GCA) is a spontaneous vasculitic syndrome that specifically targets the walls of medium and large arteries. Vascular lesions are characterized by patchy granulomatous infiltrates composed of T cells, macrophages, histiocytes, and giant cells. To test the hypothesis that a locally residing antigen recruits T cells into the vessel walls, we have analyzed T cell receptor (TCR) molecules of tissue infiltrating T cells. A total of 638 CD4+ T cell clones were isolated from temporal artery specimens of three patients with GCA. Analysis of TCR molecules for the usage of V beta 1-V beta 20 revealed that all TCR V beta elements were represented, demonstrating that interleukin 2 (IL-2)-responsive T cells infiltrating the tissue are highly diverse. To detect expanded T cell specificities, we made use of the patchy character of the inflammatory disease and compared the TCR repertoire of T cells established from independent vasculitic foci of the same artery. Sequence analysis of TCR V beta chains documented that individual TCR specificities were present in multiple copies, indicating clonal expansion. T cells with identical beta chains were isolated from distinct inflammatory foci of the same patient. These specificities represented only a small fraction of tissue-infiltrating T cells and involved the V beta 5.3 gene segment in the two patients sharing the HLA-DRB1*0401 allele. The third complementarity determining region of clonally expanded TCR beta chains was characterized by a cluster of negatively and positively charged residues, suggesting that the juxtaposed antigenic peptide is charged. The sharing of identical T cell specificities by distinct and independent regions of the granulomatous inflammation suggests that these T cells are disease relevant and that their repertoire is strongly restricted. These data suggest that an antigen residing in the arterial wall is recognized by a small fraction of CD4+ T cells in the inflammatory process characteristic for GCA.