Oral semaglutide improves postprandial glucose and lipid metabolism, and delays gastric emptying, in subjects with type 2 diabetes.

AIM: To assess the effects of oral semaglutide on postprandial glucose and lipid metabolism, and gastric emptying, in subjects with type 2 diabetes (T2D). MATERIALS AND METHODS: In this randomized, double-blind, single-centre, crossover trial, subjects with T2D received once-daily oral semaglutide (escalated to 14 mg) followed by placebo, or vice versa, over two consecutive 12-week periods. Glucose and lipid metabolism, and gastric emptying (paracetamol absorption) were assessed before and after two types of standardized meals (standard and/or fat-rich) at the end of each treatment period. The primary endpoint was area under the glucose 0-5-h curve (AUC0-5h ) after the standard breakfast. RESULTS: Fifteen subjects were enrolled (mean age 58.2 years, HbA1c 6.9%, body weight 93.9 kg, diabetes duration 3.1 years; 13 [86.7%] males). Fasting concentrations of glucose were significantly lower, and C-peptide significantly greater, with oral semaglutide versus placebo. Postprandial glucose (AUC0-5h ) was significantly lower with oral semaglutide versus placebo (estimated treatment ratio, 0.71; 95% CI, 0.63, 0.81; p < .0001); glucose incremental AUC (iAUC0-5h/5h ) and glucagon AUC0-5h were also significantly reduced, with similar results after the fat-rich breakfast. Fasting concentrations of triglycerides, very low-density lipoprotein (VLDL) and apolipoprotein B48 (ApoB48) were significantly lower with oral semaglutide versus placebo. AUC0-8h for triglycerides, VLDL and ApoB48, and triglycerides iAUC0-8h/8h , were significantly reduced after oral semaglutide versus placebo. During the first postprandial hour, gastric emptying was delayed (a 31% decrease in paracetamol AUC0-1h ) with oral semaglutide versus placebo. One serious adverse event (acute myocardial infarction) occurred during oral semaglutide treatment. CONCLUSION: Oral semaglutide significantly improved fasting and postprandial glucose and lipid metabolism, and delayed gastric emptying.

Ex vivo mRNA expression of toll-like receptors during latent tuberculosis infection.

BACKGROUND: Understanding immune mechanisms, particularly the role of innate immune markers during latent TB infection remains elusive. The main objective of this study was to evaluate mRNA gene expression patterns of toll-like receptors (TLRs) as correlates of immunity during latent TB infection and further infer their roles as potential diagnostic biomarkers. METHODS: Messenger RNA (mRNA) levels were analysed in a total of 64 samples collected from apparently healthy children and adolescents latently infected with tuberculosis (n = 32) or non-infected (n = 32). Relative expression in peripheral blood of selected genes encoding TLRs (TLR-1, TLR-2, TLR-4, TLR-6 and TLR-9) was determined with a quantitative real-time polymerase chain reaction (qRT-PCR) using specific primers and florescent labelled probes and a comparative threshold cycle method to define fold change. Data were analysed using Graph-Pad Prism 7.01 for Windows and a p-value less than 0.05 was considered statistically significant. RESULTS: An increased mean fold change in the relative expression of TLR-2 and TLR-6 mRNA was observed in LTBI groups relative to non-LTBI groups (p < 0.05), whereas a slight fold decrease was observed for TLR-1 gene. CONCLUSIONS: An increased mRNA expression of TLR-2 and TLR-6 was observed in latently infected individuals relative to those non-infected, possibly indicating the roles these biomarkers play in sustenance of the steady state interaction between the dormant TB bacilli and host immunity.

Effects of oral semaglutide on energy intake, food preference, appetite, control of eating and body weight in subjects with type 2 diabetes.

AIM: To evaluate the effect of oral semaglutide on energy intake and appetite in subjects with type 2 diabetes (T2D). MATERIALS AND METHODS: In this randomized, double-blind, placebo-controlled, two-period cross-over trial, 15 subjects with T2D received 12 weeks of treatment with once-daily oral semaglutide (4-week dose escalation from 3 to 7 to 14 mg) followed by placebo, or vice versa. Energy intake was measured during an ad libitum lunch, evening meal and snack box after a standard breakfast. Appetite ratings were measured using a visual analogue scale after standard and fat-rich breakfasts. Other assessments included eating and craving control (using the Control of Eating Questionnaire), and changes in body weight and composition. RESULTS: Following a standard breakfast, total daily ad libitum energy intake was significantly lower (38.9%) with oral semaglutide versus placebo in 13 evaluable subjects (estimated treatment difference, -5096.0 kJ; 95% CI -7000.0, -3192.1; P = .0001). After a fat-rich breakfast, there were significant differences in favour of oral semaglutide versus placebo for measures of satiety, hunger and for overall appetite score, with no significant differences following a standard breakfast. Fewer food cravings and better eating control were seen with oral semaglutide versus placebo. Overall, mean body weight decreased by 2.7 kg with oral semaglutide and 0.1 kg with placebo, mostly attributable to body fat mass loss. CONCLUSION: After 12 weeks of treatment, ad libitum energy intake was lower with oral semaglutide versus placebo, resulting in reduced body fat mass, and was associated with increased satiety and fullness after a fat-rich breakfast, and improved eating control. TRIAL REGISTRATION NUMBER: NCT02773381.

Efficacy, Safety, and Tolerability of Oral Semaglutide Versus Placebo Added to Insulin With or Without Metformin in Patients With Type 2 Diabetes: The PIONEER 8 Trial.

OBJECTIVE: To investigate the efficacy, safety, and tolerability of oral semaglutide added to insulin with or without metformin. RESEARCH DESIGN AND METHODS: Patients with type 2 diabetes uncontrolled on insulin with or without metformin were randomized to oral semaglutide 3 mg (N = 184), 7 mg (N = 182), or 14 mg (N = 181) or to placebo (N = 184) in a 52-week, double-blind trial. End points were change from baseline to week 26 in HbA1c (primary) and body weight (confirmatory secondary). Two estimands were defined: treatment policy (effect regardless of trial product discontinuation or rescue medication) and trial product (effect assuming trial product continuation without rescue medication) in randomized patients. RESULTS: Oral semaglutide was superior to placebo in reducing HbA1c (estimated treatment difference [ETD] -0.5% [95% CI -0.7, -0.3], -0.9% [-1.1, -0.7], and -1.2% [-1.4, -1.0] for 3, 7, and 14 mg, respectively; P < 0.001) and body weight (ETD -0.9 kg [95% CI -1.8, -0.0], -2.0 kg [-3.0, -1.0], and -3.3 kg [-4.2, -2.3]; P = 0.0392 for 3 mg, P ≤ 0.0001 for 7 and 14 mg) at week 26 (treatment policy estimand). Significantly greater dose-dependent HbA1c and body weight reductions versus placebo were achieved with oral semaglutide at weeks 26 and 52 (both estimands). The most frequent adverse event with oral semaglutide was nausea (11.4-23.2% of patients vs. 7.1% with placebo; mostly mild to moderate). CONCLUSIONS: Oral semaglutide was superior to placebo in reducing HbA1c and body weight when added to insulin with or without metformin in patients with type 2 diabetes. The safety profile was consistent with other glucagon-like peptide 1 receptor agonists.

Oral semaglutide versus subcutaneous liraglutide and placebo in type 2 diabetes (PIONEER 4): a randomised, double-blind, phase 3a trial.

BACKGROUND: Glucagon-like peptide-1 (GLP-1) receptor agonists are effective treatments for type 2 diabetes, lowering glycated haemoglobin (HbA1c) and weight, but are currently only approved for use as subcutaneous injections. Oral semaglutide, a novel GLP-1 agonist, was compared with subcutaneous liraglutide and placebo in patients with type 2 diabetes. METHODS: In this randomised, double-blind, double-dummy, phase 3a trial, we recruited patients with type 2 diabetes from 100 sites in 12 countries. Eligible patients were aged 18 years or older, with HbA1c of 7·0-9·5% (53-80·3 mmol/mol), on a stable dose of metformin (≥1500 mg or maximum tolerated) with or without a sodium-glucose co-transporter-2 inhibitor. Participants were randomly assigned (2:2:1) with an interactive web-response system and stratified by background glucose-lowering medication and country of origin, to once-daily oral semaglutide (dose escalated to 14 mg), once-daily subcutaneous liraglutide (dose escalated to 1·8 mg), or placebo for 52 weeks. Two estimands were defined: treatment policy (regardless of study drug discontinuation or rescue medication) and trial product (assumed all participants were on study drug without rescue medication) in all participants who were randomly assigned. The treatment policy estimand was the primary estimand. The primary endpoint was change from baseline to week 26 in HbA1c (oral semaglutide superiority vs placebo and non-inferiority [margin: 0·4%] and superiority vs subcutaneous liraglutide) and the confirmatory secondary endpoint was change from baseline to week 26 in bodyweight (oral semaglutide superiority vs placebo and liraglutide). Safety was assessed in all participants who received at least one dose of study drug. This trial is registered on Clinicaltrials.gov, number NCT02863419, and the European Clinical Trials registry, number EudraCT 2015-005210-30. FINDINGS: Between Aug 10, 2016, and Feb 7, 2017, 950 patients were screened, of whom 711 were eligible and randomly assigned to oral semaglutide (n=285), subcutaneous liraglutide (n=284), or placebo (n=142). 341 (48%) of 711 participants were female and the mean age was 56 years (SD 10). All participants were given at least one dose of study drug, and 277 (97%) participants in the oral semaglutide group, 274 (96%) in the liraglutide group, and 134 (94%) in the placebo group completed the 52-week trial period. Mean change from baseline in HbA1c at week 26 was -1·2% (SE 0·1) with oral semaglutide, -1·1% (SE 0·1) with subcutaneous liraglutide, and -0·2% (SE 0·1) with placebo. Oral semaglutide was non-inferior to subcutaneous liraglutide in decreasing HbA1c (estimated treatment difference [ETD] -0·1%, 95% CI -0·3 to 0·0; p<0·0001) and superior to placebo (ETD -1·1%, -1·2 to -0·9; p<0·0001) by use of the treatment policy estimand. By use of the trial product estimand, oral semaglutide had significantly greater decreases in HbA1c than both subcutaneous liraglutide (ETD -0·2%, 95% CI -0·3 to -0·1; p=0·0056) and placebo (ETD -1·2%, -1·4 to -1·0; p<0·0001) at week 26. Oral semaglutide resulted in superior weight loss (-4·4 kg [SE 0·2]) compared with liraglutide (-3·1 kg [SE 0·2]; ETD -1·2 kg, 95% CI -1·9 to -0·6; p=0·0003) and placebo (-0·5 kg [SE 0·3]; ETD -3·8 kg, -4·7 to -3·0; p<0·0001) at week 26 (treatment policy). By use of the trial product estimand, weight loss at week 26 was significantly greater with oral semaglutide than with subcutaneous liraglutide (-1·5 kg, 95% CI -2·2 to -0·9; p<0·0001) and placebo (ETD -4·0 kg, -4·8 to -3·2; p<0·0001). Adverse events were more frequent with oral semaglutide (n=229 [80%]) and subcutaneous liraglutide (n=211 [74%]) than with placebo (n=95 [67%]). INTERPRETATION: Oral semaglutide was non-inferior to subcutaneous liraglutide and superior to placebo in decreasing HbA1c, and superior in decreasing bodyweight compared with both liraglutide and placebo at week 26. Safety and tolerability of oral semaglutide were similar to subcutaneous liraglutide. Use of oral semaglutide could potentially lead to earlier initiation of GLP-1 receptor agonist therapy in the diabetes treatment continuum of care. FUNDING: Novo Nordisk A/S.

Dose Optimization of H56:IC31 Vaccine for Tuberculosis-Endemic Populations. A Double-Blind, Placebo-controlled, Dose-Selection Trial.

RATIONALE: Global tuberculosis (TB) control requires effective vaccines in TB-endemic countries, where most adults are infected with Mycobacterium tuberculosis (M.tb). OBJECTIVES: We sought to define optimal dose and schedule of H56:IC31, an experimental TB vaccine comprising Ag85B, ESAT-6, and Rv2660c, for M.tb-infected and M.tb-uninfected adults. METHODS: We enrolled 98 healthy, HIV-uninfected, bacillus Calmette-Guérin-vaccinated, South African adults. M.tb infection was defined by QuantiFERON-TB (QFT) assay. QFT-negative participants received two vaccinations of different concentrations of H56 in 500 nmol of IC31 to enable dose selection for further vaccine development. Subsequently, QFT-positive and QFT-negative participants were randomized to receive two or three vaccinations to compare potential schedules. Participants were followed for safety and immunogenicity for 292 days. MEASUREMENTS AND MAIN RESULTS: H56:IC31 showed acceptable reactogenicity profiles irrespective of dose, number of vaccinations, or M.tb infection. No vaccine-related severe or serious adverse events were observed. The three H56 concentrations tested induced equivalent frequencies and functional profiles of antigen-specific CD4 T cells. ESAT-6 was only immunogenic in QFT-negative participants who received three vaccinations. CONCLUSIONS: Two or three H56:IC31 vaccinations at the lowest dose induced durable antigen-specific CD4 T-cell responses with acceptable safety and tolerability profiles in M.tb-infected and M.tb-uninfected adults. Additional studies should validate applicability of vaccine doses and regimens to both QFT-positive and QFT-negative individuals. Clinical trial registered with www.clinicaltrials.gov (NCT01865487).

C-Tb skin test to diagnose Mycobacterium tuberculosis infection in children and HIV-infected adults: A phase 3 trial.

BACKGROUND: C-Tb, an ESAT-6/CFP-10-based skin test, has similar sensitivity for active TB compared to tuberculin skin test (TST) and QuantiFERON-TB-Gold-In-Tube (QFT). However, data are limited in children and HIV-infected persons. METHODS: Asymptomatic South African contacts <5 years (n = 87; HIV-uninfected), or symptomatic individuals of all ages presenting to clinics with suspected TB (n = 1003; 30% HIV-infected) were recruited from eight South African centres. C-Tb and TST were allocated to either forearm double blinded. Samples for QFT were collected in parallel, and test-positivity rates were compared. RESULTS: In participants with microbiologically confirmed TB (n = 75; 45% HIV-infected) sensitivity of C-Tb, TST and QFT were similar (72% versus 75% versus 73%; p>0.5). All 3 tests had similar positivity rates in HIV-infected participants with active TB, however, positivity rates were reduced when CD4 counts were <100 cells/µL. In participants where active TB was excluded (n = 920), C-Tb (41%), TST (43%), and QFT (44%) also had similar test-positivity rates. Among asymptomatic contacts aged below five, 32% (28/87) tested positive with C-Tb and 32% (28/87) with TST (concordance 89%). Overall, C-Tb and TST showed a similar safety profile. CONCLUSION: C-Tb was safe and showed similar test-positivity rates, compared to TST and QFT, in children and HIV-infected persons with active or latent M. tuberculosis infection. These data inform the utility of C-Tb in clinical practice. TRIAL REGISTRATION: ClinicalTrials.gov NCT01642888. EudraCT 2011-005078-40.

A phase I, open-label trial on the safety and immunogenicity of the adjuvanted tuberculosis subunit vaccine H1/IC31® in people living in a TB-endemic area.

BACKGROUND: H1/IC31® is a tuberculosis (TB) subunit vaccine candidate consisting of the fusion protein of Ag85B and ESAT-6 (H1) formulated with the IC31® adjuvant. Previous trials have reported on the H1/IC31® vaccine in M. tuberculosis (Mtb)-naïve, BCG-vaccinated and previously Mtb-infected individuals. In this trial, conducted between December 2008 and April 2010, the safety and immunogenicity of H1/IC31® was assessed in participants living in Ethiopia - a highly TB-endemic area. METHODS: Healthy male participants aged 18-25 years were recruited into four groups. Participants in group 1 (N = 12) and group 2 (N = 12) were Tuberculin Skin Test (TST) negative and QuantiFERON-TB Gold in-tube test (QFT) negative (Mtb-naïve groups), participants in group 3 (N = 3) were TST positive and QFT negative (BCG group), and participants in group 4 (N = 12) were both TST and QFT positive (Mtb-infected group). H1 vaccine alone (group 1) or H1 formulated with the adjuvant IC31® (groups 2, 3 and 4) was administered intramuscularly on day 0 and day 56. Safety and immunogenicity parameters were evaluated for up to 32 weeks after day 0. RESULTS: The H1/IC31®vaccine was safe and generally well tolerated. There was little difference among the four groups, with a tendency towards a higher incidence of adverse events in Mtb-infected compared to Mtb-naïve participants. Two serious adverse events were reported in the Mtb-infected group where a relationship to the vaccine could not be excluded. In both cases the participants recovered without sequelae within 72 h. Immunogenicity assays, evaluated in the 29 participants who received both vaccinations, showed a stronger response to TB antigens in the Mtb-naïve group vaccinated with the adjuvant. CONCLUSION: The trial confirmed the need for an adjuvant for the vaccine to be immunogenic and highlighted the importance of early phase testing of a novel TB vaccine candidate in TB-endemic areas. TRIAL REGISTRATION: ClinicalTrials.gov, ID: NCT01049282. Retrospectively registered on 14 January 2010.

Antigen Availability Shapes T Cell Differentiation and Function during Tuberculosis.

CD4 T cells are critical for protective immunity against Mycobacterium tuberculosis (Mtb), the cause of tuberculosis (TB). Yet to date, TB vaccine candidates that boost antigen-specific CD4 T cells have conferred little or no protection. Here we examined CD4 T cell responses to two leading TB vaccine antigens, ESAT-6 and Ag85B, in Mtb-infected mice and in vaccinated humans with and without underlying Mtb infection. In both species, Mtb infection drove ESAT-6-specific T cells to be more differentiated than Ag85B-specific T cells. The ability of each T cell population to control Mtb in the lungs of mice was restricted for opposite reasons: Ag85B-specific T cells were limited by reduced antigen expression during persistent infection, whereas ESAT-6-specific T cells became functionally exhausted due to chronic antigenic stimulation. Our findings suggest that different vaccination strategies will be required to optimize protection mediated by T cells recognizing antigens expressed at distinct stages of Mtb infection.

The dynamics of immune responses to Mycobacterium tuberculosis during different stages of natural infection: A longitudinal study among Greenlanders.

OBJECTIVE: Understanding human immunity to Mycobacterium tuberculosis (Mtb) during different stages of infection is important for development of an effective tuberculosis (TB) vaccine. We aimed to evaluate immunity to Mtb infection by measuring immune responses to selected Mtb antigens expressed during different stages of infection over time and to observe sustainability of immunity. METHODS: In a cohort study comprising East Greenlanders aged 17-22 years (2012 to 2014) who had either; undetectable Mtb infection, ongoing or prior Mtb infection at enrolment, we measured immunity to 15 antigens over a one-year period. Quantiferon-TB Gold testing (QFT) defined Mtb infection status (undetected/detected). The eligible study population of East Greenlanders aged 17-22 years was identified from the entire population using the Civil Registration System. From the source population 65 participants were selected by stratified random sampling according to information on Mtb infection stage. Retrospective and prospective information on notified TB (including treatment) was obtained through the mandatory TB notification system and was used to characterise Mtb infection stage (ongoing/prior). Immunity to 15 antigens including two QFT antigens, PPD and 12 non-QFT antigens (representing early, constitutive and latent Mtb infection) was assessed by measuring immune responses using whole-blood antigen stimulation and interferon gamma measurement. RESULTS: Of 65 participants, 54 were considered Mtb-infected. Immunity to Mtb infection fluctuated with high annual risk of conversion (range: 6-69%) and reversion (range: 5-95%). During follow-up, five (8%) participants were notified with TB; neither conversion nor reversion was associated with an increased risk of progressing to TB. CONCLUSIONS: Our findings suggest that human immunity to natural Mtb infection over time is versatile with fluctuations, resulting in high levels of conversion and reversion of immunity, thus human immunity to Mtb is much more dynamic than anticipated. The study findings suggest future use of longitudinal assessment of immune responses when searching for TB vaccine candidate antigens.

Introducing the ESAT-6 free IGRA, a companion diagnostic for TB vaccines based on ESAT-6.

There is a need for an improved vaccine for tuberculosis. ESAT-6 is a cardinal vaccine antigen with unique properties and is included in several vaccine candidates in development. ESAT-6 is also the core antigen in the IFN-γ release assays (IGRA) used to diagnose latent infection, rendering IGRA tests unspecific after vaccination. This challenge has prompted the development of a companion diagnostic for ESAT-6 based vaccines, an ESAT-6 free IGRA. We screened a panel of seven potential new diagnostic antigens not recognized in BCG vaccinated individuals. Three highly recognized antigens EspC, EspF and Rv2348c were identified and combined with CFP10 in an ESAT-6 free antigen cocktail. The cocktail was prepared in a field-friendly format, lyophilized with heparin in ready-to-use vacutainer tubes. The diagnostic performance of the ESAT-6 free IGRA was determined in a cross-validation study. Compared IGRA, the ESAT-6 free IGRA induced a comparable magnitude of IFN-γ release, and the diagnostic performance was on par with Quantiferon (sensitivity 84% vs 79%; specificity 99% vs 97%). The comparable performance of the ESAT-6 free IGRA to IGRA suggests potential as companion diagnostic for ESAT-6 containing vaccines and as adjunct test for latent infection.

Safety and efficacy of the C-Tb skin test to diagnose Mycobacterium tuberculosis infection, compared with an interferon γ release assay and the tuberculin skin test: a phase 3, double-blind, randomised, controlled trial.

BACKGROUND: Targeted screening and treatment of Mycobacterium tuberculosis infection substantially reduces the risk of developing active tuberculosis. C-Tb (Statens Serum Institute, Copenhagen, Denmark) is a novel specific skin test based on ESAT-6 and CFP10 antigens. We investigated the safety and diagnostic potential of C-Tb compared with established tests in the contact-tracing setting. METHODS: Negative controls, close contacts, occasional contacts, and patients with active pulmonary tuberculosis were enrolled at 13 centres in Spain. We compared C-Tb with the QuantiFERON-TB Gold In-Tube ([QFT] Qiagen, Hilden, Germany) interferon γ release assay (IGRA) and the purified protein derivative (PPD) RT 23 tuberculin skin test ([TST] Statens Serum Institute). All participants older than 5 years were tested with QFT. Some participants in the negative control group received C-Tb without the TST to test for potential interactions between C-Tb and PPD RT 23. The rest were randomly assigned in blocks of ten and tested with both C-Tb and TST, with five in each block receiving injection of C-Tb in the right arm and the TST in the left arm and five vice versa. The primary and safety analyses were done in all participants randomly assigned to a group who received any test. This trial is registered with ClinicalTrials.gov, number NCT01631266, and with EudraCT, number 2011-005617-36. FINDINGS: From July 24, 2012, to Oct 2, 2014, 979 participants were enrolled, of whom 263 were negative controls, 299 were occasional contacts, 316 were close contacts, and 101 were patients with tuberculosis. 970 (99%) participants completed the trial. Induration sizes were similar for C-Tb and TST, but TST positivity was affected by BCG vaccination status. We found a strong positive trend towards C-Tb test positivity with increasing risk of infection, from 3% in negative controls to 16% in occasional contacts, to 43% in close contacts. C-Tb and QFT results were concordant in 785 (94%) of 834 participants aged 5 years and older, and results did not differ significantly between exposure groups. The safety profile of C-Tb was similar to that for the TST. INTERPRETATION: C-Tb delivered IGRA-like results in a field-friendly format. Being unaffected by BCG vaccination status, the C-Tb skin test might provide more accurate treatment guidance in settings where the TST is commonly used. FUNDING: Statens Serum Institut.

Safety and immunogenicity of the novel H4:IC31 tuberculosis vaccine candidate in BCG-vaccinated adults: Two phase I dose escalation trials.

BACKGROUND: Novel vaccine strategies are required to provide protective immunity in tuberculosis (TB) and prevent development of active disease. We investigated the safety and immunogenicity of a novel TB vaccine candidate, H4:IC31 (AERAS-404) that is composed of a fusion protein of M. tuberculosis antigens Ag85B and TB10.4 combined with an IC31® adjuvant. METHODS: BCG-vaccinated healthy subjects were immunized with various antigen (5, 15, 50, 150µg) and adjuvant (0, 100, 500nmol) doses of the H4:IC31 vaccine (n=106) or placebo (n=18) in two randomized, double-blind, placebo-controlled phase I studies conducted in a low TB endemic setting in Sweden and Finland. The subjects were followed for adverse events and CD4+ T cell responses. RESULTS: H4:IC31 vaccination was well tolerated with a safety profile consisting of mostly mild to moderate self-limited injection site pain, myalgia, arthralgia, fever and post-vaccination inflammatory reaction at the screening tuberculin skin test injection site. The H4:IC31 vaccine elicited antigen-specific CD4+ T cell proliferation and cytokine production that persisted 18weeks after the last vaccination. CD4+ T cell expansion, IFN-γ production and multifunctional CD4+ Th1 responses were most prominent after two doses of H4:IC31 containing 5, 15, or 50µg of H4 in combination with the 500nmol IC31 adjuvant dose. CONCLUSIONS: The novel TB vaccine candidate, H4:IC31, demonstrated an acceptable safety profile and was immunogenic, capable of triggering multifunctional CD4+ T cell responses in previously BCG-vaccinated healthy individuals. These dose-escalation trials provided evidence that the optimal antigen-adjuvant dose combinations are 5, 15, or 50µg of H4 and 500nmol of IC31. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02066428 and NCT02074956.

H1:IC31 vaccination is safe and induces long-lived TNF-α+IL-2+CD4 T cell responses in M. tuberculosis infected and uninfected adolescents: A randomized trial.

BACKGROUND: Control of the tuberculosis epidemic requires a novel vaccine that is effective in preventing tuberculosis in adolescents, a key target population for vaccination against TB. METHODS: Healthy adolescents, stratified by M. tuberculosis-infection status, were enrolled into this observer-blinded phase II clinical trial of the protein-subunit vaccine candidate, H1:IC31, comprising a fusion protein (H1) of Ag85B and ESAT-6, formulated with the IC31 adjuvant. Local and systemic adverse events and induced T cell responses were measured after one or two administrations of either 15µg or 50µg of the H1 protein. RESULTS: Two hundred and forty participants were recruited and followed up for 224days. No notable safety events were observed regardless of H1 dose or vaccination schedule. H1:IC31 vaccination induced antigen-specific CD4 T cells, co-expressing IFN-γ, TNF-α and/or IL-2. H1:IC31 vaccination of M.tb-uninfected individuals preferentially drove the emergence of Ag85B and ESAT-6 specific TNF-α+IL-2+CD4 T cells, while H1:IC31 vaccination of M.tb-infected individuals resulted in the expansion of Ag85B-specific but not ESAT-6-specific TNF-α+IL-2+CD4 T cells. CONCLUSIONS: H1:IC31 was safe and immunogenic in uninfected and M.tb-infected adolescents. Two administrations of the 15µg H1:IC31 dose induced the greatest magnitude immune response, and was considered optimal (South African National Clinical Trials Register, DoH-27-0612-3947; Pan African Clinical Trial Registry, PACTR201403000464306).

Host immunity to Mycobacterium tuberculosis and risk of tuberculosis: A longitudinal study among Greenlanders.

BACKGROUND: Human immune responses to latent Mycobacterium tuberculosis (Mtb) infection (LTBI) may enable individuals to control Mtb infection and halt progression to tuberculosis (TB), a hypothesis applied in several novel TB vaccines. We aimed to evaluate whether immune responses to selected LTBI antigens were associated with subsequent reduced risk of progression to TB. METHODS: We conducted a population-based cohort study in East Greenland (2012-2014) including individuals aged 5-31years. A personal identifier allowed follow-up in national registers including the TB notification register. Mtb infection was defined by a positive Quantiferon test. Immune responses to LTBI antigens were assessed by whole blood antigen stimulation and interferon gamma measurement. RESULTS: Among 978 participants, 67 previously had TB. LTBI antigen (Rv1284, Rv2659, Rv2660c) immune response prevalence was 18%, 50%, 2% among Mtb-infected and 7%, 40%, 4% among non-infected (Quantiferon negative) participants. Among 911 participants without prior notified TB, 31 were notified with TB during study follow-up. Immune responses to LTBI antigens were not associated with reduced risk of subsequent TB; Rv1284 HR 0.92 (95%CI 0.28-3.04), Rv2659 HR 1.05 (95%CI 0.51-2.13), Rv2660c HR 3.06 (95%CI 0.70-13.37). CONCLUSION: In this large population-based study, human immune responses to selected LTBI antigens were not found to be strongly associated with reduced risk of subsequent TB.

Ex-vivo characterization of regulatory T cells in pulmonary tuberculosis patients, latently infected persons, and healthy endemic controls.

BACKGROUND: Regulatory T cells (Treg) are an essential arm of adaptive immunity not only in tolerance and autoimmunity but also in infectious diseases. In Tuberculosis (TB), it has been suggested that the frequency of Tregs is higher in the blood of TB patients when compared to healthy controls with subsequent decline after treatment. However, with the discovery that FOXP3, the hallmark marker of Tregs, is not exclusive to Tregs and the lack of specific markers for Tregs, it has been a challenge to fully understand the role of Tregs in TB. METHOD: We isolated PBMC from smear positive TB patients (TB, N = 13) before and after treatment, latent TB infected participants (LTBI, N = 8), and healthy endemic controls (EC, N = 9) and evaluated the frequency of different populations of Tregs and expression of FOXP3 by flowcytometry using six markers. RESULTS: The findings in this study showed that the association of Treg frequency with TB disease depends on the phenotypic markers used. While the frequency of CD4(+)CD25(+/hi) T cells was higher in TB patients compared to LTBI individuals, there was no difference in the frequency of CD4(+)CD25(+)FOXP3(+)CD127(lo) Treg among TB, LTBI, or EC. However, delineation of Tregs into active and naïve subsets revealed a significant increase in FOXP3 expression in active primed Tregs (CD4(+)CD25(+)FOXP3(+)CD127(lo)CD45RO(+)Ki-67(+)) of TB patients compared to LTBI and EC; and a significantly higher frequency of resting primed (CD45RO(+)Ki-67(-)) Treg in QuantiFERON negative EC compared to TB patients. After treatment completion, there was a significant decline in the frequency of active primed Treg, median (IQR) from 12.4% (9.5-21.9) of Tregs to 9.3% (7.0-12.2); P = 0.003 Wilcoxon signed rank test. We conclude that Treg subsets may be differentially regulated and expressed in TB disease, cure, and infection.

Sensitivity of C-Tb: a novel RD-1-specific skin test for the diagnosis of tuberculosis infection.

C-Tb, a novel Mycobacterium tuberculosis and 6-kDa early secretory antigenic target/10-kDa culture filtrate protein (ESAT-6/CFP-10)-specific skin test, has high specificity in bacille Calmette-Guerin-vaccinated healthy controls. However, the sensitivity of C-Tb has hitherto not been determined. The objective was to determine the sensitivity of C-Tb in patients with active tuberculosis (TB) in comparison with the tuberculin skin test (TST) and QuantiFERON-TB Gold In-Tube (QFT-GIT).C-Tb and TST were randomly administered in a double-blinded fashion to one or the other forearm in 253 patients with active TB with or without HIV co-infection. QFT-GIT testing was performed prior to skin testing.Using a receiver operating characteristic curve-derived cut-point of 5 mm, C-Tb sensitivity was similar to QFT-GIT (73.9 (95% CI 67.8-79.3) versus 75.1 (95% CI 69.3-80.2)), and similar in HIV-infected and HIV-uninfected patients (76.7 (95% CI 69.0-83.3) versus 69.5 (95% CI 59.2-78.5)). However, sensitivity was significantly diminished in HIV-infected patients with CD4 counts <100 cells·mm(-3). C-Tb and QFT-GIT combined had significantly higher sensitivity than C-Tb alone (p<0.0001). C-Tb was safe with no significant adverse events. The 5 mm cut-point corresponded to that found in the previously published specificity study (TESEC-04).C-Tb has similar sensitivity compared with QFT-GIT for the diagnosis of M. tuberculosis infection. Sensitivity was reduced only in HIV-infected patients with severe immunosuppression. Further studies in different settings are required to validate the proposed 5 mm cut-point.

First-in-human trial of the post-exposure tuberculosis vaccine H56:IC31 in Mycobacterium tuberculosis infected and non-infected healthy adults.

BACKGROUND: H56:IC31 is a candidate tuberculosis vaccine comprising a fusion protein of Ag85B, ESAT-6 and Rv2660c, formulated in IC31 adjuvant. This first-in-human, open label phase I trial assessed the safety and immunogenicity of H56:IC31 in healthy adults without or with Mycobacterium tuberculosis (M.tb) infection. METHODS: Low dose (15 µg H56 protein in 500 nmol IC31) or high dose (50 µg H56, 500 nmol IC31) vaccine was administered intramuscularly thrice, at 56-day intervals. Antigen-specific T cell responses were measured by intracellular cytokine staining and antibody responses by ELISA. RESULTS: One hundred and twenty-six subjects were screened and 25 enrolled and vaccinated. No serious adverse events were reported. Nine subjects (36%) presented with transient cardiovascular adverse events. The H56:IC31 vaccine induced antigen-specific IgG responses and Th1 cytokine-expressing CD4(+) T cells. M.tb-infected vaccinees had higher frequencies of H56-induced CD4(+) T cells than uninfected vaccinees. Low dose vaccination induced more polyfunctional (IFN-γ(+)TNF-α(+)IL-2(+)) and higher frequencies of H56-specific CD4(+) T cells compared with high dose vaccination. A striking increase in IFN-γ-only-expressing CD4(+) T cells, displaying a CD45RA(-)CCR7(-) effector memory phenotype, emerged after the second high-dose vaccination in M.tb-infected vaccinees. TNF-α(+)IL-2(+) H56-specific memory CD4(+) T cells were detected mostly after low-dose H56 vaccination in M.tb-infected vaccinees, and predominantly expressed a CD45RA(-)CCR7(+) central memory phenotype. Our results support further clinical testing of H56:IC31.

The tuberculosis vaccine H4:IC31 is safe and induces a persistent polyfunctional CD4 T cell response in South African adults: A randomized controlled trial.

BACKGROUND: New, more effective vaccines to prevent tuberculosis (TB) disease are needed urgently. H4:IC31 is an investigational vaccine that contains a fusion protein of the immunodominant antigens TB10.4 and Ag85B, formulated in IC31 adjuvant. We assessed the safety and immunogenicity of H4:IC31 in South African adults from a TB endemic setting. METHODS: In this double blind, placebo controlled, phase I trial, Mycobacterium tuberculosis-uninfected, HIV-uninfected, healthy adults with a history of childhood BCG vaccination were randomly allocated to two intramuscular vaccinations with 5, 15, 50 or 150 µg H4 formulated in 500nmol IC31, two months apart. Vaccinees were followed for six months to assess safety; immunogenicity was measured by ELISpot and intracellular cytokine staining assays. RESULTS: Thirty-two participants received H4:IC31 and 8 received placebo. Injection site adverse events were common but mild; mild fatigue was the most common systemic adverse event. Frequencies of adverse events did not differ between dosage groups. Detectable antigen-specific CD4 T cell responses were induced by all doses of H4:IC31, but doses below 50 µg induced the highest frequencies of CD4 T cells, comprised predominantly of IFN-γ(+)TNF-α(+)IL-2(+) or TNF-α(+)IL-2(+) cells. These memory responses persisted up to the end of follow up, on study day 182. CONCLUSIONS: H4:IC31 demonstrated an acceptable safety profile and was immunogenic in South African adults. In this trial, the 15 µg dose appeared to induce the most optimal immune response.

Antiviral Innate Immune Activation in HIV-Infected Adults Negatively Affects H1/IC31-Induced Vaccine-Specific Memory CD4+ T Cells.

Tuberculosis (TB) remains a global health problem, with vaccination being a necessary strategy for disease containment and elimination. A TB vaccine should be safe and immunogenic as well as efficacious in all affected populations, including HIV-infected individuals. We investigated the induction and maintenance of vaccine-induced memory CD4(+) T cells following vaccination with the subunit vaccine H1/IC31. H1/IC31 was inoculated twice on study days 0 and 56 among HIV-infected adults with CD4(+) lymphocyte counts of >350 cells/mm(3). Whole venous blood stimulation was conducted with the H1 protein, and memory CD4(+) T cells were analyzed using intracellular cytokine staining and polychromatic flow cytometry. We identified high responders, intermediate responders, and nonresponders based on detection of interleukin-2 (IL-2), tumor necrosis factor alpha (TNF-α), and gamma interferon (IFN-γ) expressing central (TCM) and effector memory CD4(+) T cells (TEM) 182 days after the first immunization. Amplicon-based transcript quantification using next-generation sequencing was performed to identify differentially expressed genes that correlated with vaccine-induced immune responses. Genes implicated in resolution of inflammation discriminated the responders from the nonresponders 3 days after the first inoculation. The volunteers with higher expression levels of genes involved in antiviral innate immunity at baseline showed impaired H1-specific TCM and TEM maintenance 6 months after vaccination. Our study showed that in HIV-infected volunteers, expression levels of genes involved in the antiviral innate immune response affected long-term maintenance of H1/IC31 vaccine-induced cellular immunity. (The clinical trial was registered in the Pan African Clinical Trials Registry [PACTR] with the identifier PACTR201105000289276.).