Effects of the Toll-like receptor 7 (TLR7) agonist, AZD8848, on allergen-induced responses in patients with mild asthma: a double-blind, randomised, parallel-group study.

BACKGROUND: Although allergic asthma is a complex area with many interacting factors involved, the 'hygiene hypothesis' proposes that a lack of exposure to infection during childhood may polarise the immune system towards allergen-reactive Th2-type responses in genetically susceptible individuals. Toll-like receptors (TLRs) play a key role within the innate immune system and TLR7 agonists have previously been shown to up-regulate Th1 responses and down-regulate Th2 responses to allergens in murine models of allergic or chronic asthma. This study aimed to examine the efficacy and safety of the novel TRL7 agonist AZD8848, which has been developed as an antedrug. METHODS: In this double-blind, randomised, parallel-group study, AZD8848 60 µg or placebo was administered intranasally once-weekly for 8 weeks in patients with mild-to-moderate allergic asthma (NCT00999466). Efficacy assessments were performed at 1 and 4 weeks after the last dose. The primary outcome was the late asthmatic response (LAR) fall in forced expiratory volume in 1 s (FEV1) after allergen challenge at 1-week post-treatment. RESULTS: AZD8848 significantly reduced average LAR fall in FEV1 by 27% vs. placebo at 1 week after treatment (p = 0.035). This effect was sustained at 4 weeks post-treatment; however, it did not reach clinical significance. AZD8848 reduced post-allergen challenge methacholine-induced airway hyper-responsiveness (AHR) vs. placebo at 1 week post-dosing (treatment ratio: 2.20, p = 0.024), with no effect at 4 weeks. There was no significant difference between the two groups in plasma cytokine, sputum Th2 cytokine or eosinophil responses post-allergen challenge at 1 week after treatment. The incidence of adverse events was similar in the two groups. AZD8848 was generally well tolerated. CONCLUSIONS AND CLINICAL RELEVANCE: In patients with allergic asthma, TLR7 agonists could potentially reduce allergen responsiveness by stimulating Type 1 interferon responses to down-regulate the dominant Th2 responses. TRIAL REGISTRATION: clinicaltrials.gov identifier NCT00999466.

Bioequivalence of Canakinumab Injected Subcutaneously via an Autoinjector Device or a Prefilled Safety Syringe Device in Healthy Subjects.

Canakinumab, a high-affinity human anti-interleukin-1ß monoclonal antibody, is being used for the treatment of a broad spectrum of inflammatory diseases. This phase 1 study compared the relative bioavailability of a single dose of subcutaneous canakinumab either self-administered with an autoinjector (AI) or administered by a health care professional (HCP) with a prefilled safety syringe (SS) in healthy subjects. The study enrolled 80 subjects randomized 1:1 to receive 150 mg/mL of a liquid formulation of canakinumab via an AI or SS into either the thigh or abdomen. The geometric mean ratio (90% confidence interval [CI]) of Cmax was 1.09 (0.97-1.21), AUClast was 1.06 (0.96-1.17), and AUCinf was 1.05 (0.94-1.18) for the AI versus SS. The 2-sided 90%CIs that compared self-administration with the AI versus administration by an HCP using the SS were entirely within the bioequivalence limits of 80%-125%. Two subjects in the AI group and 1 in the SS group experienced mild injection-site reactions. No immunogenicity response was detected in the 307 samples analyzed for immunogenicity. No discontinuations because of adverse events were reported in this trial. Canakinumab administration with an AI or SS has a comparable bioavailability, meeting bioequivalence criteria.

Biological effects and clinical efficacy of a topical Toll-like receptor 7 agonist in seasonal allergic rhinitis: a parallel group controlled phase IIa study.

OBJECTIVE AND DESIGN: The purpose of the study was to examine effects of pre-treatment with a Toll-like receptor 7 (TLR7) agonist (AZD8848) in allergic rhinitis and to evaluate clinical effects of two dosing regimens. SUBJECTS: The study involved 83 patients with allergic rhinitis. Data on effects of AZD8848 on symptoms were analysed with data from a previous study (n = 68) of identical double blind, parallel group design (NCT00770003). TREATMENT: The treatment involved intranasal AZD8848 20 µg three times weekly, 60 µg once weekly, or placebo for 5 weeks. METHODS: Nasal lavage and plasma were analysed for proof-of-mechanism markers. Daily nasal allergen challenges were given for 7 days, starting 24 h after the final AZD8848 dose. Symptoms were monitored after each challenge and every morning and evening. RESULTS: Markers of TLR-activation increased following AZD8848 administration (CXCL10, TNFα, IL-6, IFNγ). Symptoms recorded soon after allergen challenge were reduced up to eight days after the final dose of AZD8848. Morning and evening symptoms were also reduced, and these changes reached statistical significance for morning observations. Adverse effects were more frequent in the 20 µg three times weekly group. CONCLUSIONS: Repeated administration of AZD8848 activated TLR7 and produced IFN-induced effects. This was associated with a sustained reduction in allergen responsiveness.