Browsing by Author "Kanaparthi, Sai"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Alefacept provides sustained clinical and immunological effects in new-onset type 1 diabetes patients
    (American Society for Clinical Investigation, 2015-08-03) Rigby, Mark R.; Harris, Kristina M.; Pinckney, Ashley; DiMeglio, Linda A.; Rendell, Marc S.; Felner, Eric I.; Dostou, Jean M.; Gitelman, Stephen E.; Griffin, Kurt J.; Tsalikian, Eva; Gottlieb, Peter A.; Greenbaum, Carla J.; Sherry, Nicole A.; Moore, Wayne V.; Monzavi, Roshanak; Willi, Steven M.; Raskin, Philip; Keyes-Elstein, Lynette; Long, S. Alice; Kanaparthi, Sai; Lim, Noha; Phippard, Deborah; Soppe, Carol L.; Fitzgibbon, Margret L.; McNamara, James; Nepom, Gerald T.; Ehlers, Mario R.; Department of Pediatrics, IU School of Medicine
    BACKGROUND: Type 1 diabetes (T1D) results from destruction of pancreatic β cells by autoreactive effector T cells. We hypothesized that the immunomodulatory drug alefacept would result in targeted quantitative and qualitative changes in effector T cells and prolonged preservation of endogenous insulin secretion by the remaining β cells in patients with newly diagnosed T1D. METHODS: In a multicenter, randomized, double-blind, placebo-controlled trial, we compared alefacept (two 12-week courses of 15 mg/wk i.m., separated by a 12-week pause) with placebo in patients with recent onset of T1D. Endpoints were assessed at 24 months and included meal-stimulated C-peptide AUC, insulin use, hypoglycemic events, and immunologic responses. RESULTS: A total of 49 patients were enrolled. At 24 months, or 15 months after the last dose of alefacept, both the 4-hour and the 2-hour C-peptide AUCs were significantly greater in the treatment group than in the control group (P = 0.002 and 0.015, respectively). Exogenous insulin requirements were lower (P = 0.002) and rates of major hypoglycemic events were about 50% reduced (P < 0.001) in the alefacept group compared with placebo at 24 months. There was no apparent between-group difference in glycemic control or adverse events. Alefacept treatment depleted CD4+ and CD8+ central memory T cells (Tcm) and effector memory T cells (Tem) (P < 0.01), preserved Tregs, increased the ratios of Treg to Tem and Tcm (P < 0.01), and increased the percentage of PD-1+CD4+ Tem and Tcm (P < 0.01). CONCLUSIONS: In patients with newly diagnosed T1D, two 12-week courses of alefacept preserved C-peptide secretion, reduced insulin use and hypoglycemic events, and induced favorable immunologic profiles at 24 months, well over 1 year after cessation of therapy. TRIAL REGISTRATION: https://clinicaltrials.gov/ NCT00965458. FUNDING: NIH and Astellas.
  • Thumbnail Image
    Item
    IL-6 receptor blockade does not slow β cell loss in new-onset type 1 diabetes
    (American Society for Clinical Investigation, 2021) Greenbaum, Carla J.; Serti, Elisavet; Lambert, Katharina; Weiner, Lia J.; Kanaparthi, Sai; Lord, Sandra; Gitelman, Stephen E.; Wilson, Darrell M.; Gaglia, Jason L.; Griffin, Kurt J.; Russell, William E.; Raskin, Philip; Moran, Antoinette; Willi, Steven M.; Tsalikian, Eva; DiMeglio, Linda A.; Herold, Kevan C.; Moore, Wayne V.; Goland, Robin; Harris, Mark; Craig, Maria E.; Schatz, Desmond A.; Baidal, David A.; Rodriguez, Henry; Utzschneider, Kristina M.; Nel, Hendrik J.; Soppe, Carol L.; Boyle, Karen D.; Cerosaletti, Karen; Keyes-Elstein, Lynette; Long, S. Alice; Thomas, Ranjeny; McNamara, James G.; Buckner, Jane H.; Sanda, Srinath; ITN058AI EXTEND Study Team; Pediatrics, School of Medicine
    Background: IL-6 receptor (IL-6R) signaling drives development of T cell populations important to type 1 diabetes pathogenesis. We evaluated whether blockade of IL-6R with monoclonal antibody tocilizumab would slow loss of residual β cell function in newly diagnosed type 1 diabetes patients. Methods: We conducted a multicenter, randomized, placebo-controlled, double-blind trial with tocilizumab in new-onset type 1 diabetes. Participants were screened within 100 days of diagnosis. Eligible participants were randomized 2:1 to receive 7 monthly doses of tocilizumab or placebo. The primary outcome was the change from screening in the mean AUC of C-peptide collected during the first 2 hours of a mixed meal tolerance test at week 52 in pediatric participants (ages 6–17 years). Results: There was no statistical difference in the primary outcome between tocilizumab and placebo. Immunophenotyping showed reductions in downstream signaling of the IL-6R in T cells but no changes in CD4 memory subsets, Th17 cells, Tregs, or CD4+ T effector cell resistance to Treg suppression. A DC subset decreased during therapy but regressed to baseline once therapy stopped. Tocilizumab was well tolerated. Conclusion: Tocilizumab reduced T cell IL-6R signaling but did not modulate CD4+ T cell phenotypes or slow loss of residual β cell function in newly diagnosed individuals with type 1 diabetes.