Jelena P. Berglund

Peanut oral immunotherapy results in increased antigen-induced regulatory T-cell function and hypomethylation of forkhead box protein 3 (FOXP3)

BACKGROUND The mechanisms contributing to clinical immune tolerance remain incompletely understood. This study provides evidence for specific immune mechanisms that are associated with a model of operationally defined clinical tolerance. OBJECTIVE Our overall objective was to study laboratory changes associated with clinical immune tolerance in antigen-induced T cells, basophils, and antibodies in subjects undergoing oral immunotherapy (OIT) for peanut allergy. METHODS In a phase 1 single-site study, we studied participants (n = 23) undergoing peanut OIT and compared them with age-matched allergic control subjects (n = 20) undergoing standard of care (abstaining from peanut) for 24 months. Participants were operationally defined as clinically immune tolerant (IT) if they had no detectable allergic reactions to a peanut oral food challenge after 3 months of therapy withdrawal (IT, n = 7), whereas those who had an allergic reaction were categorized as nontolerant (NT; n = 13). RESULTS Antibody and basophil activation measurements did not statistically differentiate between NT versus IT participants. However, T-cell function and demethylation of forkhead box protein 3 (FOXP3) CpG sites in antigen-induced regulatory T cells were significantly different between IT versus NT participants. When IT participants were withdrawn from peanut therapy for an additional 3 months (total of 6 months), only 3 participants remained classified as IT participants, and 4 participants regained sensitivity along with increased methylation of FOXP3 CpG sites in antigen-induced regulatory T cells. CONCLUSION In summary, modifications at the DNA level of antigen-induced T-cell subsets might be predictive of a state of operationally defined clinical immune tolerance during peanut OIT.

Sustained unresponsiveness to peanut in subjects who have completed peanut oral immunotherapy

BACKGROUND Although peanut oral immunotherapy (OIT) has been conclusively shown to cause desensitization, it is currently unknown whether clinical protection persists after stopping therapy. OBJECTIVE Our primary objective was to determine whether peanut OIT can induce sustained unresponsiveness after withdrawal of OIT. METHODS We conducted a pilot clinical trial of peanut OIT at 2 US centers. Subjects age 1 to 16 years were recruited and treated for up to 5 years with peanut OIT. The protocol was modified over time to permit dose increases to a maximum of 4000 mg/d peanut protein. Blood was collected at multiple time points. Clinical end points were measured with 5000-mg double-blinded, placebo-controlled food challenges once specific criteria were met. RESULTS Of the 39 subjects originally enrolled, 24 completed the protocol and had evaluable outcomes. Twelve (50%) of 24 successfully passed a challenge 1 month after stopping OIT and achieved sustained unresponsiveness. Peanut was added to the diet. At baseline and the time of challenge, such subjects had smaller skin test results, as well as lower IgE levels specific for peanut, Ara h 1, and Ara h 2 and lower ratios of peanut-specific IgE/total IgE compared with subjects not passing. There were no differences in peanut IgG₄ levels or functional activity at the end of the study. CONCLUSIONS This is the first demonstration of sustained unresponsiveness after peanut OIT, occurring in half of subjects treated for up to 5 years. OIT favorably modified the peanut-specific immune response in all subjects completing the protocol. Smaller skin test results and lower allergen-specific IgE levels were predictive of successful outcome.

Early oral immunotherapy in peanut-allergic preschool children is safe and highly effective

Background: Oral immunotherapy (OIT) is an effective experimental food allergy treatment that is limited by treatment withdrawal and the frequent reversibility of desensitization if interrupted. Newly diagnosed preschool children may have clinical and immunological characteristics more amenable to treatment. Objective: We sought to test the safety, effectiveness, and feasibility of early OIT (E‐OIT) in the treatment of peanut allergy. Methods: We enrolled 40 children aged 9 to 36 months with suspected or known peanut allergy. Qualifying subjects reacted to peanut during an entry food challenge and were block‐randomized 1:1 to receive E‐OIT at goal maintenance doses of 300 or 3000 mg/d in a double‐blinded fashion. The primary end point, sustained unresponsiveness at 4 weeks after stopping early intervention oral immunotherapy (4‐SU), was assessed by double‐blinded, placebo‐controlled food challenge either upon achieving 4 prespecified criteria, or after 3 maintenance years. Peanut‐specific immune responses were serially analyzed. Outcomes were compared with 154 matched standard‐care controls. Results: Of 40 consented subjects, 3 (7.5%) did not qualify. Overall, 29 of 37 (78%) in the intent‐to‐treat analysis achieved 4‐SU (300‐mg arm, 17 of 20 [85%]; 3000 mg, 12 of 17 [71%], P = .43) over a median of 29 months. Per‐protocol, the overall proportion achieving 4‐SU was 29 of 32 (91%). Peanut‐specific IgE levels significantly declined in E‐OIT‐treated children, who were 19 times more likely to successfully consume dietary peanut than matched standard‐care controls, in whom peanut‐specific IgE levels significantly increased (relative risk, 19.42; 95% CI, 8.7‐43.7; P < .001). Allergic side effects during E‐OIT were common but all were mild to moderate. Conclusions: At both doses tested, E‐OIT had an acceptable safety profile and was highly successful in rapidly suppressing allergic immune responses and achieving safe dietary reintroduction.

Cholinergic Augmentation of Insulin Release Requires Ankyrin-B

The scaffolding protein ankyrin-B is needed for maximal insulin release, and loss of function is a risk factor for diabetes. Risk Factor for Diabetes In addition to the glucose that enters the bloodstream, the parasympathetic nervous system also stimulates the pancreas to secrete insulin in response to eating a meal. Healy et al. show that loss of a single copy of the gene encoding ankyrin-B (ankB) in mice impaired insulin secretion in response to ingested glucose, causing glucose intolerance. In isolated pancreatic islets, ankB haploinsufficiency resulted in reduced abundance of the inositol trisphosphate receptor (IP3R), a calcium channel localized to the endoplasmic reticulum, and impaired calcium signaling in response to cholinergic stimulation. Although islets secrete insulin in response to glucose, the addition of a cholinergic agonist (to mimic parasympathetic stimulation) enhances the amount of insulin released. Islets from the ankB haploinsufficient mice failed to show this potentiation of insulin secretion. Healy et al. also found that, in humans, a loss-of-function mutation in AnkB, which is associated with heart disease, was also associated with diabetes. Thus, mutations in this scaffolding protein that cause aberrant calcium signaling may be a risk factor in multiple diseases. Parasympathetic stimulation of pancreatic islets augments glucose-stimulated insulin secretion by inducing inositol trisphosphate receptor (IP3R)–mediated calcium ion (Ca2+) release. Ankyrin-B binds to the IP3R and is enriched in pancreatic beta cells. We found that ankyrin-B–deficient islets displayed impaired potentiation of insulin secretion by the muscarinic agonist carbachol, blunted carbachol-mediated intracellular Ca2+ release, and reduced the abundance of IP3R. Ankyrin-B–haploinsufficient mice exhibited hyperglycemia after oral ingestion but not after intraperitoneal injection of glucose, consistent with impaired parasympathetic potentiation of glucose-stimulated insulin secretion. The R1788W mutation of ankyrin-B impaired its function in pancreatic islets and is associated with type 2 diabetes in Caucasians and Hispanics. Thus, defective glycemic regulation through loss of ankyrin-B–dependent stabilization of IP3R is a potential risk factor for type 2 diabetes.

Novel baseline predictors of adverse events during oral immunotherapy in children with peanut allergy

Background: Though peanut oral immunotherapy (OIT) is a promising investigational therapy, its potential is limited by substantial adverse events (AEs), which are relatively understudied. Objective: A retrospective analysis was conducted, pooling data from 3 pediatric peanut OIT trials, comprising the largest analysis of peanut OIT safety to date. Methods: We pooled data from 104 children with peanut allergy from 3 peanut OIT studies. We catalogued AEs from parental reports, daily symptom diaries, and dose escalations. We included events that were considered likely related to OIT and identified potential baseline predictors of higher AE rates using generalized linear regression models. Results: Eighty percent of subjects experienced likely related AEs during OIT (72% during buildup and 47% during maintenance). Of these AEs, over 90% occurred while at home. Approximately 42% of subjects experienced systemic reactions, and 49% experienced gastrointestinal symptoms. Twenty percent of subjects dropped out, with half (10% of the overall group) due to persistent gastrointestinal symptoms. Baseline allergic rhinitis (AR) and peanut SPT wheal size were significant predictors of higher overall AE rates. SPT wheal size predicted increased gastrointestinal AEs, and AR predicted increased systemic reactions. Over the course of OIT, 61% of subjects received treatment for likely related AEs, 59% with antihistamines and 12% with epinephrine. Conclusions: Peanut OIT is associated with frequent AEs, with rates declining over time, and most graded mild. However, systemic reactions and intolerable gastrointestinal AEs do occur and are significantly associated with AR and peanut SPT wheal size, respectively. Further study is needed of predictive biomarkers and the overall risks and benefits of OIT.

Understanding Food and Drug Administration Regulatory Requirements for an Investigational Device Exemption for Sponsor-Investigators

Clinical investigators in academic medical centers often perceive federal regulations as a significant obstacle to conducting clinical research. The regulatory authority of the Food and Drug Administration (FDA) extends to clinical studies of medical devices. Consequently, researchers wishing to conduct device research using FDA-approved as well as nonapproved devices must comply with federal regulations for investigational device exemptions (IDE) as described in Title 21 of the Code of Federal Regulations Part 812. FDA regulatory oversight is structured to match the risk to the subject to the risk of the device. Medical device studies can be categorized as follows: meeting exemption criteria, being a nonsignificant risk device, or being a significant risk device. All IDE studies must meet regulations for the protection of human subjects, but no additional federal filing on the part of the investigator is necessary for those that meet exempt criteria. Nonsignificant risk device studies require meeting abbreviated IDE regulatory requirements for the conduct of the study, but no previous FDA approval is required. Significant risk device studies require that the investigator also function as a sponsor and to file an IDE with the FDA for approval before starting. A sponsor-investigator filing an IDE follows the format and content described in 21 CFR 812.20. The study may begin 30 days after the date of submission receipt unless the FDA notifies the sponsor otherwise. While the IDE is active, the sponsor-investigator must meet the requirements for the conduct of the study and the required monitoring and reporting to the FDA.

Preparation and Analysis of Peanut Flour Used in Oral Immunotherapy Clinical Trials

BACKGROUND Oral immunotherapy (OIT) is an investigational therapeutic approach for the treatment of food allergies. Characterization of the drug product used in oral immunotherapy trials for peanut allergy has not been reported. OBJECTIVE To quantify relative amounts of the major peanut allergens and microbial load present in peanut flour used in OIT trials and assess whether these parameters change over a 12-month period. We also anticipate that this report will serve as a guide for investigators seeking to conduct OIT trials under Food and Drug Administration-approved Investigational New Drug applications. METHODS Densitometric scanning of Ara h 1 and Ara h 2 resolved on SDS-PAGE gels was used to assess allergen content in peanut flour extracts. Microbial testing was conducted on peanut flour under US Pharmacopeia guidelines for the presence of Escherichia coli, salmonella, yeast, mold, and total aerobic bacteria. In addition, aflatoxin was quantified in peanut flour. Reported results were obtained from 4 unique lots of peanut flour. RESULTS Relative amounts of the major peanut allergens were similar between different lots of peanut flour and remained stable over a 12-month period. E coli and salmonella were absent from all lots of flour. Yeast, mold, total aerobic bacteria, and aflatoxin were within established US Pharmacopeia guidelines on all lots tested and remained within the criteria over a 12-month period. CONCLUSIONS Peanut flour used as a drug product contains the major peanut allergens and has low levels of potentially harmful microbes. Both these parameters remain stable over a 12-month period.

ClinicalTrials.gov Reporting: Strategies for Success at an Academic Health Center

The Food and Drug Administration Amendments Act of 2007 (FDAAA 2007, US Public Law 110-98) mandated registration and reporting of results for applicable clinical trials. Meeting these registration and results reporting requirements has proven to be a challenge for the academic research community. Duke Medicine has made compliance with registration and results reporting a high priority. In order to create uniformity across a large institution, a written policy was created describing requirements for clinical trials disclosure. Furthermore, a centralized resource group was formed with three full time staff members. The group not only ensures compliance with FDAAA 2007, it also acts as a resource for study teams providing hands-on support, reporting, training, and ongoing education. Intensive resourcing for results reporting has been crucial for success. Due to implementation of the institutional policy and creation of centralized resources, compliance with FDAAA 2007 has increased dramatically at Duke Medicine for both registration and results reporting. A consistent centralized approach has enabled success in the face of changing agency rules and new legislation.

Access to Investigational Drugs: FDA Expanded Access Programs or "Right-to-Try" Legislation?

The Food and Drug Administration Expanded Access (EA) program and “Right‐to‐Try” legislation aim to provide seriously ill patients who have no other comparable treatment options to gain access to investigational drugs and biological agents. Physicians and institutions need to understand these programs to respond to questions and requests for access.

Recommendations From the Investigational New Drug/Investigational Device Exemption Task Force of the Clinical and Translational Science Award Consortium: Developing and Implementing a Sponsor-Investigators Training Program

Objective The objective of this study was to provide recommendations for provision of training for sponsor and investigators at Academic Health Centers. Background A subgroup of the Investigational New Drug/Investigational Device Exemption (IND/IDE) Task Force of the Clinical and Translational Science Award (CTSA) program Regulatory Knowledge Key Function Committee was assembled to specifically address how clinical investigators who hold an IND/IDE and thus assume the role of sponsor-investigators are adequately trained to meet the additional regulatory requirements of this role. Methods The participants who developed the recommendations were representatives of institutions with IND/IDE support programs. Through an informal survey, the task force determined that a variety and mix of models are used to provide support for IND/IDE holders within CTSA institutions. In addition, a CTSA consortium-wide resources survey was used. The participants worked from the models and survey results to develop consensus recommendations to address institutional support, training content, and implementation. Recommendations The CTSA IND/IDE Task Force recommendations are as follows: (1) Institutions should assess the scope of Food and Drug Administration–regulated research, perform a needs analysis, and provide resources to implement a suitable training program; (2) The model of training program should be tailored to each institution; (3) The training should specifically address the unique role of sponsor-investigators, and the effectiveness of training should be evaluated regularly by methods that fit the model adopted by the institution; and (4) Institutional leadership should mandate sponsor-investigator training and effectively communicate the necessity and availability of training.