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.

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.

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.

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

PURPOSE: 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. METHODS: FDA EA programs and state and federal legislative efforts to provide investigational products to patients by circumventing FDA regulations were summarized and compared. RESULTS: The FDA EA program includes Single Patient-Investigational New Drug (SP-IND), Emergency SP-IND, Intermediate Sized Population IND, and Treatment IND. Approval rates for all categories exceed 99%. Approval requires FDA and Institutional Review Board (IRB) approval, and cooperation of the pharmaceutical partner is essential. "Right-to-Try" legislation bypasses some of these steps, but provides no regulatory or safety oversight. CONCLUSION: The FDA EA program is a reasonable option for patients for whom all other therapeutic interventions have failed. The SP-IND not only provides patient access to new drugs, but also maintains a balance between immediacy and necessary patient protection. Rather than circumventing existing FDA regulations through proposed legislation, it seems more judicious to provide the knowledge and means to meet the EA requirements.

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.

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.

Warning letters to sponsor-investigators at academic health centres - the regulatory "canaries in a coal mine".

PURPOSE: This study highlights Warning Letter (WL) findings issued to sponsor-investigators (S-Is) by the Food and Drug Administration (FDA). METHODS: The online index of WLs issued from October 1, 2007 through September 30, 2012 was reviewed [1]. Through a manual screening process, letters were evaluated if specifically issued to 'clinical investigators', 'sponsors' or 'sponsor-investigators'. A particular focus was given to S-Is at Academic Health Centres (AHCs). Each letter was scored for the presence of violations in 40 general regulatory categories. RESULTS: A review of FDA WLs issued over a five-year period (FDA Fiscal Years 2008-2012) revealed that WLs to S-Is represent half of the WLs issued to all sponsors (16 of 32 letters). A review of these letters indicates that S-Is are not aware of, or simply do not meet, their regulatory responsibilities as either investigators or sponsors. In comparing total sponsor letters to those of S-Is, the most cited violation was the same: a lack of monitoring. A review of publicly available inspection data indicates that these 16 letters merely represent the tip of the iceberg. CONCLUSION: This review of the WL database reveals the potential for serious regulatory violations among S-Is at AHCs. Recent translational funding initiatives may serve to increase the number of S-Is, especially among Academic Health Centres (AHCs) [2]; thus, AHCs must become aware of this S-I role and work to support investigators who assume both roles in the course of their research.