Final Analysis of a Trial of M72/AS01E Vaccine to Prevent Tuberculosis.

BACKGROUND: Results of an earlier analysis of a trial of the M72/AS01E candidate vaccine against Mycobacterium tuberculosis showed that in infected adults, the vaccine provided 54.0% protection against active pulmonary tuberculosis disease, without evident safety concerns. We now report the results of the 3-year final analysis of efficacy, safety, and immunogenicity. METHODS: From August 2014 through November 2015, we enrolled adults 18 to 50 years of age with M. tuberculosis infection (defined by positive results on interferon-γ release assay) without evidence of active tuberculosis disease at centers in Kenya, South Africa, and Zambia. Participants were randomly assigned in a 1:1 ratio to receive two doses of either M72/AS01E or placebo, administered 1 month apart. The primary objective was to evaluate the efficacy of M72/AS01E to prevent active pulmonary tuberculosis disease according to the first case definition (bacteriologically confirmed pulmonary tuberculosis not associated with human immunodeficiency virus infection). Participants were followed for 3 years after the second dose. Participants with clinical suspicion of tuberculosis provided sputum samples for polymerase-chain-reaction assay, mycobacterial culture, or both. Humoral and cell-mediated immune responses were evaluated until month 36 in a subgroup of 300 participants. Safety was assessed in all participants who received at least one dose of M72/AS01E or placebo. RESULTS: A total of 3575 participants underwent randomization, of whom 3573 received at least one dose of M72/AS01E or placebo, and 3330 received both planned doses. Among the 3289 participants in the according-to-protocol efficacy cohort, 13 of the 1626 participants in the M72/AS01E group, as compared with 26 of the 1663 participants in the placebo group, had cases of tuberculosis that met the first case definition (incidence, 0.3 vs. 0.6 cases per 100 person-years). The vaccine efficacy at month 36 was 49.7% (90% confidence interval [CI], 12.1 to 71.2; 95% CI, 2.1 to 74.2). Among participants in the M72/AS01E group, the concentrations of M72-specific antibodies and the frequencies of M72-specific CD4+ T cells increased after the first dose and were sustained throughout the follow-up period. Serious adverse events, potential immune-mediated diseases, and deaths occurred with similar frequencies in the two groups. CONCLUSIONS: Among adults infected with M. tuberculosis, vaccination with M72/AS01E elicited an immune response and provided protection against progression to pulmonary tuberculosis disease for at least 3 years. (Funded by GlaxoSmithKline Biologicals and Aeras; ClinicalTrials.gov number, NCT01755598.).

Phase 2b Controlled Trial of M72/AS01E Vaccine to Prevent Tuberculosis.

BACKGROUND: A vaccine to interrupt the transmission of tuberculosis is needed. METHODS: We conducted a randomized, double-blind, placebo-controlled, phase 2b trial of the M72/AS01E tuberculosis vaccine in Kenya, South Africa, and Zambia. Human immunodeficiency virus (HIV)-negative adults 18 to 50 years of age with latent M. tuberculosis infection (by interferon-γ release assay) were randomly assigned (in a 1:1 ratio) to receive two doses of either M72/AS01E or placebo intramuscularly 1 month apart. Most participants had previously received the bacille Calmette-Guérin vaccine. We assessed the safety of M72/AS01E and its efficacy against progression to bacteriologically confirmed active pulmonary tuberculosis disease. Clinical suspicion of tuberculosis was confirmed with sputum by means of a polymerase-chain-reaction test, mycobacterial culture, or both. RESULTS: We report the primary analysis (conducted after a mean of 2.3 years of follow-up) of the ongoing trial. A total of 1786 participants received M72/AS01E and 1787 received placebo, and 1623 and 1660 participants in the respective groups were included in the according-to-protocol efficacy cohort. A total of 10 participants in the M72/AS01E group met the primary case definition (bacteriologically confirmed active pulmonary tuberculosis, with confirmation before treatment), as compared with 22 participants in the placebo group (incidence, 0.3 cases vs. 0.6 cases per 100 person-years). The vaccine efficacy was 54.0% (90% confidence interval [CI], 13.9 to 75.4; 95% CI, 2.9 to 78.2; P=0.04). Results for the total vaccinated efficacy cohort were similar (vaccine efficacy, 57.0%; 90% CI, 19.9 to 76.9; 95% CI, 9.7 to 79.5; P=0.03). There were more unsolicited reports of adverse events in the M72/AS01E group (67.4%) than in the placebo group (45.4%) within 30 days after injection, with the difference attributed mainly to injection-site reactions and influenza-like symptoms. Serious adverse events, potential immune-mediated diseases, and deaths occurred with similar frequencies in the two groups. CONCLUSIONS: M72/AS01E provided 54.0% protection for M. tuberculosis-infected adults against active pulmonary tuberculosis disease, without evident safety concerns. (Funded by GlaxoSmithKline Biologicals and Aeras; ClinicalTrials.gov number, NCT01755598 .).

Induction and regulation of T-cell immunity by the novel tuberculosis vaccine M72/AS01 in South African adults.

RATIONALE: Tuberculosis (TB) is a major cause of morbidity and mortality worldwide, thus there is an urgent need for novel TB vaccines. OBJECTIVES: We investigated a novel TB vaccine candidate, M72/AS01, in a phase IIa trial of bacille Calmette-Guérin-vaccinated, HIV-uninfected, and Mycobacterium tuberculosis (Mtb)-infected and -uninfected adults in South Africa. METHODS: Two doses of M72/AS01 were administered to healthy adults, with and without latent Mtb infection. Participants were monitored for 7 months after the first dose; cytokine production profiles, cell cycling, and regulatory phenotypes of vaccine-induced T cells were measured by flow cytometry. MEASUREMENTS AND MAIN RESULTS: The vaccine had a clinically acceptable safety profile, and induced robust, long-lived M72-specific T-cell and antibody responses. M72-specific CD4 T cells produced multiple combinations of Th1 cytokines. Analysis of T-cell Ki67 expression showed that most vaccination-induced T cells did not express Th1 cytokines or IL-17; these cytokine-negative Ki67(+) T cells included subsets of CD4 T cells with regulatory phenotypes. PD-1, a negative regulator of activated T cells, was transiently expressed on M72-specific CD4 T cells after vaccination. Specific T-cell subsets were present at significantly higher frequencies after vaccination of Mtb-infected versus -uninfected participants. CONCLUSIONS: M72/AS01 is clinically well tolerated in Mtb-infected and -uninfected adults, induces high frequencies of multifunctional T cells, and boosts distinct T-cell responses primed by natural Mtb infection. Moreover, these results provide important novel insights into how this immunity may be appropriately regulated after novel TB vaccination of Mtb-infected and -uninfected individuals.Clinical trial registered with www.clinicaltrials.gov (NCT 00600782).

A randomized, controlled dose-finding Phase II study of the M72/AS01 candidate tuberculosis vaccine in healthy PPD-positive adults.

PURPOSE: In this dose-finding Phase II study (NCT00621322), we evaluated the safety and immunogenicity of different formulations of the candidate tuberculosis vaccine containing the M72 antigen (10/20/40 µg doses) and the liposome-based AS01 Adjuvant System. We aimed to select the lowest-dose combination of M72 and AS01 that was clinically well tolerated with immunogenicity comparable to that of the previously tested M72/AS01B (40 µg) candidate vaccine. METHODS: Healthy PPD-positive (induration 3-10 mm) adults (18-45 years) in The Philippines were randomized (4:4:4:4:1:1) to receive 2 injections, 1 month apart, of M72/AS01B (40 µg), M72/AS01E (10 µg), M72/AS01E (20 µg), M72/AS02D (10 µg), M72/Saline (40 µg) or AS01B alone, and were followed up for 6 months. AS01E and AS02D contain half the quantities of the immunostimulants present in AS01B. AS02D is an oil-in-water emulsion. Vaccine selection was based on the CD4(+) T-cell responses at 1 month post vaccination. RESULTS: All formulations had a clinically acceptable safety profile with no vaccine-related serious adverse events reported. Two vaccinations of each adjuvanted M72 vaccine induced M72-specific CD4(+) T-cell and humoral responses persisting at 6 months post vaccination. No responses were observed with AS01B alone. One month post second vaccination, CD4(+) T-cell responses induced by each of the three M72/AS01 vaccine formulations were of comparable magnitudes, and all were significantly higher than those induced by M72/AS02D (10 µg) and M72/Saline. CONCLUSIONS: The formulation with the lowest antigen and adjuvant dose, M72/AS01E (10 µg), fulfilled our pre-defined selection criteria and has been selected for further clinical development.

Non-clinical evaluation of local and systemic immunity induced by different vaccination strategies of the candidate tuberculosis vaccine M72/AS01.

A new efficacious tuberculosis vaccine targeting adolescents/adults represents an urgent medical need. The M72/AS01E vaccine candidate protected half of the latently-infected adults against progression to pulmonary tuberculosis in a Phase IIb trial (NCT01755598). We report that three immunizations of mice, two weeks apart, with AS01-adjuvanted M72 induced polyfunctional, Th1-cytokine-expressing M72-specific CD4+/CD8+ T cells in blood and lungs, with the highest frequencies in lungs. Antigen-dose reductions across the three vaccinations skewed pulmonary CD4+ T-cell profiles towards IL-17 expression. In blood, reducing antigen and adjuvant doses of only the third injection (to 1/5th or 1/25th of those of the first injections) did not significantly alter CD4+ T-cell/antibody responses; applying a 10-week delay for the fractional third dose enhanced antibody titers. Delaying a full-dose booster enhanced systemic CD4+ T-cell and antibody responses. Cross-reactivity with PPE and non-PPE proteins was assessed, as Mycobacterium tuberculosis (Mtb) virulence factors and evasion mechanisms are often associated with PE/PPE proteins, to which Mtb39a (contained in M72) belongs. In silico/in vivo analyses revealed that M72/AS01 induced cross-reactive systemic CD4+ T-cell responses to epitopes in a non-vaccine antigen (putative latency-associated Mtb protein PPE24/Rv1753c). These preclinical data describing novel mechanisms of M72/AS01-induced immunity could guide future clinical development of the vaccine.

Validation of an enzyme-linked immunosorbent assay for the quantification of human IgG directed against the repeat region of the circumsporozoite protein of the parasite Plasmodium falciparum.

BACKGROUND: Several pre-erythrocytic malaria vaccines based on the circumsporozoite protein (CSP) antigen of Plasmodium falciparum are in clinical development. Vaccine immunogenicity is commonly evaluated by the determination of anti-CSP antibody levels using IgG-based assays, but no standard assay is available to allow comparison of the different vaccines. METHODS: The validation of an anti-CSP repeat region enzyme-linked immunosorbent assay (ELISA) is described. This assay is based on the binding of serum antibodies to R32LR, a recombinant protein composed of the repeat region of P. falciparum CSP. In addition to the original recombinant R32LR, an easy to purify recombinant His-tagged R32LR protein has been constructed to be used as solid phase antigen in the assay. Also, hybridoma cell lines have been generated producing human anti-R32LR monoclonal antibodies to be used as a potential inexhaustible source of anti-CSP repeats standard, instead of a reference serum. RESULTS: The anti-CSP repeats ELISA was shown to be robust, specific and linear within the analytical range, and adequately fulfilled all validation criteria as defined in the ICH guidelines. Furthermore, the coefficient of variation for repeatability and intermediate precision did not exceed 23%. Non-interference was demonstrated for R32LR-binding sera, and the assay was shown to be stable over time. CONCLUSIONS: This ELISA, specific for antibodies directed against the CSP repeat region, can be used as a standard assay for the determination of humoral immunogenicity in the development of any CSP-based P. falciparum malaria vaccine.

Subsequent AS01-adjuvanted vaccinations induce similar transcriptional responses in populations with different disease statuses.

Transcriptional responses to adjuvanted vaccines can vary substantially among populations. Interindividual diversity in levels of pathogen exposure, and thus of cell-mediated immunological memory at baseline, may be an important determinant of population differences in vaccine responses. Adjuvant System AS01 is used in licensed or candidate vaccines for several diseases and populations, yet the impact of pre-existing immunity on its adjuvanticity remains to be elucidated. In this exploratory post-hoc analysis of clinical trial samples (clinicalTrials.gov: NCT01424501), we compared gene expression patterns elicited by two immunizations with the candidate tuberculosis (TB) vaccine M72/AS01, between three groups of individuals with different levels of memory responses to TB antigens before vaccination. Analyzed were one group of TB-disease-treated individuals, and two groups of TB-disease-naïve individuals who were (based on purified protein derivative [PPD] skin-test results) stratified into PPD-positive and PPD-negative groups. Although TB-disease-treated individuals displayed slightly stronger transcriptional responses after each vaccine dose, functional gene signatures were overall not distinctly different between groups. Considering the similarities with the signatures found previously for other AS01-adjuvanted vaccines, many features of the response appeared to be adjuvant-driven. Across groups, cell proliferation-related signals at 7 days post-dose 1 were associated with increased anti-M72 antibody response magnitudes. These early signals were stronger in the TB-disease-treated group as compared to both TB-disease-naïve groups. Interindividual homogeneity in gene expression levels was also higher for TB-disease-treated individuals post-dose 1, but increased in all groups post-dose 2 to attain similar levels between the three groups. Altogether, strong cell-mediated memory responses at baseline accelerated and amplified transcriptional responses to a single dose of this AS01-adjuvanted vaccine, resulting in more homogenous gene expression levels among the highly-primed individuals as compared to the disease-naïve individuals. However, after a second vaccination, response heterogeneity decreased and was similar across groups, irrespective of the degree of immune memory acquired at baseline. This information can support the design and analysis of future clinical trials evaluating AS01-adjuvanted vaccines.

An adjuvanted polyprotein HIV-1 vaccine induces polyfunctional cross-reactive CD4+ T cell responses in seronegative volunteers.

BACKGROUND: This phase I/II partially blinded, randomized, dose-ranging study assessed the safety and immunogenicity of a novel human immunodeficiency virus type 1 (HIV-1) vaccine candidate consisting of a recombinant fusion protein (F4) containing 4 HIV-1 clade B antigens (Gag p24, Pol reverse transcriptase, Nef, and Gag p17) adjuvanted with AS01 in HIV-seronegative volunteers. Methods. Two doses of the recombinant F4 protein (10, 30, or 90 µg/dose), adjuvanted with AS01 or reconstituted with water for injection, were administered 1 month apart to 180 healthy volunteers aged 18-40 years. F4-specific CD4(+) T cell responses were measured using intracellular cytokine staining after in vitro stimulation by overlapping peptide pools covering the 4 individual antigens. Results. Reactogenicity was higher during the 7-day period after each vaccine dose in the adjuvanted than in the nonadjuvanted groups. In the adjuvanted groups, the overall immune response rate was high after the second vaccine dose, with highest responder rates seen in the 10-µg F4/AS01 group (100% to 3 HIV-1 antigens and 80% to all 4 HIV-1 antigens). High and long-lasting CD4(+) T cell frequencies were observed (up to a median value of 1.2% F4-specific CD4(+) T cells at day 44), with strongest responses directed against reverse transcriptase. Antigen-specific CD4(+) T cells exhibited a polyfunctional phenotype, expressing at least CD40 ligand and interleukin 2, often in combination with tumor necrosis factor α and/or interferon γ. Vaccine-induced CD4(+) T cell responses were broadly cross-reactive to all 4 antigens derived from HIV-1 clades A and C. Conclusions. These results support further clinical investigation of this HIV-1 vaccine candidate both in a prophylactic setting (alone, in conjunction with an envelope-based antigen or in combination with other vaccine approaches in a heterologous prime-boost regimen) and as a potentially disease-modifying therapeutic vaccine in HIV-1-infected subjects. CLINICAL TRIALS REGISTRATION: NCT00434512.

Safety and immunogenicity of RTS,S/AS02D malaria vaccine in infants.

BACKGROUND: The RTS,S/AS malaria vaccine is being developed for delivery through the World Health Organization's Expanded Program on Immunization (EPI). We assessed the feasibility of integrating RTS,S/AS02D into a standard EPI schedule for infants. METHODS: In this phase 2B, single-center, double-blind, controlled trial involving 340 infants in Bagamoyo, Tanzania, we randomly assigned 340 infants to receive three doses of either the RTS,S/AS02D vaccine or the hepatitis B vaccine at 8, 12, and 16 weeks of age. All infants also received a vaccine containing diphtheria and tetanus toxoids, whole-cell pertussis vaccine, and conjugated Haemophilus influenzae type b vaccine (DTPw/Hib). The primary objectives were the occurrence of serious adverse events during a 9-month surveillance period and a demonstration of noninferiority of the responses to the EPI vaccines (DTPw/Hib and hepatitis B surface antigen) with coadministration of the RTS,S/AS02D vaccine, as compared with the hepatitis B vaccine. The detection of antibodies against Plasmodium falciparum circumsporozoite and efficacy against malaria infection were secondary objectives. RESULTS: At least one serious adverse event was reported in 31 of 170 infants who received the RTS,S/AS02D vaccine (18.2%; 95% confidence interval [CI], 12.7 to 24.9) and in 42 of 170 infants who received the hepatitis B vaccine (24.7%; 95% CI, 18.4 to 31.9). The results showed the noninferiority of the RTS,S/AS02D vaccine in terms of antibody responses to EPI antigens. One month after vaccination, 98.6% of infants receiving the RTS,S/AS02D vaccine had seropositive titers for anticircumsporozoite antibodies on enzyme-linked immunosorbent assay (ELISA). During the 6-month period after the third dose of vaccine, the efficacy of the RTS,S/AS02D vaccine against first infection with P. falciparum malaria was 65.2% (95% CI, 20.7 to 84.7; P=0.01). CONCLUSIONS: The use of the RTS,S/AS02D vaccine in infants had a promising safety profile, did not interfere with the immunologic responses to coadministered EPI antigens, and reduced the incidence of malaria infection. (ClinicalTrials.gov number, NCT00289185.)

Efficacy of RTS,S/AS01E vaccine against malaria in children 5 to 17 months of age.

BACKGROUND: Plasmodium falciparum malaria is a pressing global health problem. A previous study of the malaria vaccine RTS,S (which targets the circumsporozoite protein), given with an adjuvant system (AS02A), showed a 30% rate of protection against clinical malaria in children 1 to 4 years of age. We evaluated the efficacy of RTS,S given with a more immunogenic adjuvant system (AS01E) in children 5 to 17 months of age, a target population for vaccine licensure. METHODS: We conducted a double-blind, randomized trial of RTS,S/AS01E vaccine as compared with rabies vaccine in children in Kilifi, Kenya, and Korogwe, Tanzania. The primary end point was fever with a falciparum parasitemia density of more than 2500 parasites per microliter, and the mean duration of follow-up was 7.9 months (range, 4.5 to 10.5). RESULTS: A total of 894 children were randomly assigned to receive the RTS,S/AS01E vaccine or the control (rabies) vaccine. Among the 809 children who completed the study procedures according to the protocol, the cumulative number in whom clinical malaria developed was 32 of 402 assigned to receive RTS,S/AS01E and 66 of 407 assigned to receive the rabies vaccine; the adjusted efficacy rate for RTS,S/AS01E was 53% (95% confidence interval [CI], 28 to 69; P<0.001) on the basis of Cox regression. Overall, there were 38 episodes of clinical malaria among recipients of RTS,S/AS01E, as compared with 86 episodes among recipients of the rabies vaccine, with an adjusted rate of efficacy against all malarial episodes of 56% (95% CI, 31 to 72; P<0.001). All 894 children were included in the intention-to-treat analysis, which showed an unadjusted efficacy rate of 49% (95% CI, 26 to 65; P<0.001). There were fewer serious adverse events among recipients of RTS,S/AS01E, and this reduction was not only due to a difference in the number of admissions directly attributable to malaria. CONCLUSIONS: RTS,S/AS01E shows promise as a candidate malaria vaccine. (ClinicalTrials.gov number, NCT00380393.)

Evaluation of the safety and immunogenicity of the RTS,S/AS01E malaria candidate vaccine when integrated in the expanded program of immunization.

BACKGROUND: The RTS,S/AS01(E) malaria candidate vaccine is being developed for immunization of African infants through the Expanded Program of Immunization (EPI). METHODS: This phase 2, randomized, open, controlled trial conducted in Ghana, Tanzania, and Gabon evaluated the safety and immunogenicity of RTS,S/AS01(E) when coadministered with EPI vaccines. Five hundred eleven infants were randomized to receive RTS,S/AS01(E) at 0, 1, and 2 months (in 3 doses with diphtheria, tetanus, and whole-cell pertussis conjugate [DTPw]; hepatitis B [HepB]; Haemophilus influenzae type b [Hib]; and oral polio vaccine [OPV]), RTS,S/AS01(E) at 0, 1, and 7 months (2 doses with DTPwHepB/Hib+OPV and 1 dose with measles and yellow fever), or EPI vaccines only. RESULTS: The occurrences of serious adverse events were balanced across groups; none were vaccine-related. One child from the control group died. Mild to moderate fever and diaper dermatitis occurred more frequently in the RTS,S/AS01(E) coadministration groups. RTS,S/AS01(E) generated high anti-circumsporozoite protein and anti-hepatitis B surface antigen antibody levels. Regarding EPI vaccine responses upon coadministration when considering both immunization schedules, despite a tendency toward lower geometric mean titers to some EPI antigens, predefined noninferiority criteria were met for all EPI antigens except for polio 3 when EPI vaccines were given with RTS,S/AS01(E) at 0, 1, and 2 months. However, when antibody levels at screening were taken into account, the rates of response to polio 3 antigens were comparable between groups. CONCLUSION: RTS,S/AS01(E) integrated in the EPI showed a favorable safety and immunogenicity evaluation. Trial registration. ClinicalTrials.gov identifier: NCT00436007 . GlaxoSmithKline study ID number: 106369 (Malaria-050).

Safety of the RTS,S/AS02D candidate malaria vaccine in infants living in a highly endemic area of Mozambique: a double blind randomised controlled phase I/IIb trial.

BACKGROUND: Malaria remains a leading global health problem that requires the improved use of existing interventions and the accelerated development of new control methods. We aimed to assess the safety, immunogenicity, and initial efficacy of the malaria vaccine RTS,S/AS02D in infants in Africa. METHODS: We did a phase I/IIb double-blind randomised trial of 214 infants in Mozambique. Infants were randomly assigned to receive three doses either of RTS,S/AS02D or the hepatitis B vaccine Engerix-B at ages 10 weeks, 14 weeks, and 18 weeks of age, as well as routine immunisation vaccines given at 8, 12, and 16 weeks of age. The primary endpoint was safety of the RTS,S/AS02D during the first 6 months of the study, and analysis was by intention to treat. Secondary endpoints included immunogenicity and analysis of new Plasmodium falciparum infections during a 3-month follow up after the third dose. Time to new infections in the per-protocol cohort were compared between groups using Cox regression models. This study is registered with ClinicalTrials.gov, number NCT00197028. FINDINGS: There were 17 children (15.9%; 95% CI 9.5-24.2) with serious adverse events in each group. In the follow-up which ended on March 6, 2007, there were 31 serious adverse events in the RTS,S/AS02D group and 30 serious adverse events in the Engerix-B group, none of which were reported as related to vaccination. There were four deaths during this same follow-up period; all of them after the active detection of infection period had finished at study month 6 (two in RTSS/AS02D group and two in the Engerix-B group). RTS,S/AS02D induced high titres of anti-circumsporozoite antibodies. 68 first or only P falciparum infections were documented: 22 in the RTS,S/AS02D group and 46 in the control group. The adjusted vaccine efficacy was 65.9% (95% CI 42.6-79.8%, p<0.0001). INTERPRETATION: The RTS,S/AS02D malaria vaccine was safe, well tolerated, and immunogenic in young infants. These findings set the stage for expanded phase III efficacy studies to confirm vaccine efficacy against clinical malaria disease.

Long-term safety and immunogenicity of the M72/AS01E candidate tuberculosis vaccine in HIV-positive and -negative Indian adults: Results from a phase II randomized controlled trial.

OBJECTIVES: To assess the long-term safety and immunogenicity of the M72/ Adjuvant System (AS01E) candidate tuberculosis (TB) vaccine up to 3 years post-dose 2 (Y3) in human immunodeficiency virus (HIV)-positive (HIV+) and HIV-negative (HIV-) Indian adults. METHODS: This phase II, double-blind, randomised, controlled clinical trial (NCT01262976) was conducted at YRG CARE Medical Centre, in Chennai, India, between January 2011 and June 2015.Three cohorts (HIV+ participants stable on antiretroviral therapy [ART; HIV+ART+], HIV+ ART-naïve [HIV+ART-], and HIV- participants) were randomised (1:1) to receive 2 doses of M72/AS01E (M72/AS01E groups) or saline (control groups) 1 month apart and were followed up toY3. Latent TB infection was assessed at screening using an interferon-gamma (IFN-γ) release assay (IGRA). Safety and immunogenicity results up to Y1 post-vaccination were reported elsewhere. Here, we report serious adverse events (SAEs), humoral and cell-mediated immune (CMI) responses to M72 recorded at Y2 and Y3. RESULTS: Of 240 enrolled and vaccinated participants, 214 completed the long-term follow-up part of the study.In addition to SAEs previously described, between Y1 and Y2 1 M72/AS01E recipient in the HIV+ART+ cohort reported 2 SAEs (sinus cavernous thrombosis and gastroenteritis) that were not considered as causally related to the study vaccine.Vaccination elicited persistent humoral immune responses against M72. At Y3, seropositivity rates were 97.1%, 66.7%, and 97.3% and geometric mean concentrations (GMCs) were 22.0  ELISA units (EU)/mL, 4.9 EU/mL, and 24.3 EU/mL in the HIV+ART+, HIV+ART-, and HIV- cohorts, respectively. Humoral immune response was lowest in the HIV+ART- cohort.In M72/AS01E recipients, no notable decrease in the frequency of M72-specific CD4 T-cells expressing ≥2 immune markers among interleukin-2 (IL-2), IFN-γ, tumour necrosis factor alpha (TNF-α) and CD40 ligand (CD40L) was observed at Y3 post-vaccination. Median values (interquartile range) of 0.35% (0.13-0.49), 0.05% (0.01-0.10), and 0.15% (0.09-0.22) were recorded in the HIV+ART+, HIV+ART- and HIV- cohorts, respectively. CD4 T-cell response was lowest in the HIV+ART- cohort.No CD8 T-cell response was observed. CONCLUSION: The cellular and humoral immune responses induced by M72/AS01E in HIV+ and HIV- adults persisted up to Y3 post-vaccination. No safety concerns were raised regarding administration of M72/AS01E to HIV+ adults. CLINICAL TRIAL REGISTRATION: NCT01262976 (www.clinicaltrials.gov).

A Randomized, Controlled Safety, and Immunogenicity Trial of the M72/AS01 Candidate Tuberculosis Vaccine in HIV-Positive Indian Adults.

Human immunodeficiency virus (HIV)-associated tuberculosis is a major public health threat. We evaluated the safety and immunogenicity of the candidate tuberculosis vaccine M72/AS01 in HIV-positive and HIV-negative Indian adults.Randomized, controlled observer-blind trial (NCT01262976).We assigned 240 adults (1:1:1) to antiretroviral therapy (ART)-stable, ART-naive, or HIV-negative cohorts. Cohorts were randomized 1:1 to receive M72/AS01 or placebo following a 0, 1-month schedule and followed for 12 months (time-point M13). HIV-specific and laboratory safety parameters, adverse events (AEs), and M72-specific T-cell-mediated and humoral responses were evaluated.Subjects were predominantly QuantiFERON-negative (60%) and Bacille Calmette-Guérin-vaccinated (73%). Seventy ART-stable, 73 ART-naive, and 60 HIV-negative subjects completed year 1. No vaccine-related serious AEs or ART-regimen adjustments, or clinically relevant effects on laboratory parameters, HIV-1 viral loads or CD4 counts were recorded. Two ART-naive vaccinees died of vaccine-unrelated diseases. M72/AS01 induced polyfunctional M72-specific CD4 T-cell responses (median [interquartile range] at 7 days postdose 2: ART-stable, 0.9% [0.7-1.5]; ART-naive, 0.5% [0.2-1.0]; and HIV-negative, 0.6% [0.4-1.1]), persisting at M13 (0.4% [0.2-0.5], 0.09% [0.04-0.2], and 0.1% [0.09-0.2], respectively). Median responses were higher in the ART-stable cohort versus ART-naive cohort from day 30 onwards (P ≤ 0.015). Among HIV-positive subjects (irrespective of ART-status), median responses were higher in QuantiFERON-positive versus QuantiFERON-negative subjects up to day 30 (P ≤ 0.040), but comparable thereafter. Cytokine-expression profiles were comparable between cohorts after dose 2. At M13, M72-specific IgG responses were higher in ART-stable and HIV-negative vaccinees versus ART-naive vaccinees (P ≤ 0.001).M72/AS01 was well-tolerated and immunogenic in this population of ART-stable and ART-naive HIV-positive adults and HIV-negative adults, supporting further clinical evaluation.

Safety and immunogenicity of the M72/AS01E candidate tuberculosis vaccine in adults with tuberculosis: A phase II randomised study.

Previous studies have shown that the M72/AS01E candidate tuberculosis vaccine is immunogenic with a clinically acceptable safety profile in healthy and Mycobacterium tuberculosis-infected adults. This phase II, observer-blind, randomised study compared the safety, reactogenicity, and immunogenicity of M72/AS01E in 3 cohorts: tuberculosis-naïve adults (n = 80), adults previously treated for tuberculosis (n = 49), and adults who have completed the intensive phase of tuberculosis treatment (n = 13). In each cohort, 18-59-year-old adults were randomised (1:1) to receive two doses of M72/AS01E (n = 71) or placebo (n = 71) and followed-up until six months post-dose 2. Safety and reactogenicity were assessed as primary objective. Recruitment in the study ended prematurely because of a high incidence of large injection site redness/swelling reactions in M72/AS01E-vaccinated adults undergoing tuberculosis treatment. No additional clinically relevant adverse events were observed, except one possibly vaccine-related serious adverse event (hypersensitivity in a tuberculosis-treated-M72/AS01E participant). Robust and persistent M72-specific humoral and polyfunctional CD4(+) T-cell-mediated immune responses were observed post-M72/AS01E vaccination in each cohort. In conclusion, the M72/AS01E vaccine was immunogenic in adults previously or currently treated for tuberculosis, but further analyses are needed to explain the high local reactogenicity in adults undergoing tuberculosis treatment. ClinicalTrials.gov: NCT01424501.

Efficacy of the RTS,S/AS02A vaccine against Plasmodium falciparum infection and disease in young African children: randomised controlled trial.

BACKGROUND: Development of an effective malaria vaccine could greatly contribute to disease control. RTS,S/AS02A is a pre-erythrocytic vaccine candidate based on Plasmodium falciparum circumsporozoite surface antigen. We aimed to assess vaccine efficacy, immunogenicity, and safety in young African children. METHODS: We did a double-blind, phase IIb, randomised controlled trial in Mozambique in 2022 children aged 1-4 years. The study included two cohorts of children living in two separate areas which underwent different follow-up schemes. Participants were randomly allocated three doses of either RTS,S/AS02A candidate malaria vaccine or control vaccines. The primary endpoint, determined in cohort 1 (n=1605), was time to first clinical episode of P falciparum malaria (axillary temperature > or =37.5 degrees C and P falciparum asexual parasitaemia >2500 per microL) over a 6-month surveillance period. Efficacy for prevention of new infections was determined in cohort 2 (n=417). Analysis was per protocol. FINDINGS: 115 children in cohort 1 and 50 in cohort 2 did not receive all three doses and were excluded from the per-protocol analysis. Vaccine efficacy for the first clinical episodes was 29.9% (95% CI 11.0-44.8; p=0.004). At the end of the 6-month observation period, prevalence of P falciparum infection was 37% lower in the RTS,S/AS02A group compared with the control group (11.9% vs 18.9%; p=0.0003). Vaccine efficacy for severe malaria was 57.7% (95% CI 16.2-80.6; p=0.019). In cohort 2, vaccine efficacy for extending time to first infection was 45.0% (31.4-55.9; p<0.0001). INTERPRETATION: The RTS,S/AS02A vaccine was safe, well tolerated, and immunogenic. Our results show development of an effective vaccine against malaria is feasible.

Safety and immunogenicity of candidate vaccine M72/AS01E in adolescents in a TB endemic setting.

BACKGROUND: Vaccination that prevents tuberculosis (TB) disease, particularly in adolescents, would have the greatest impact on the global TB epidemic. Safety, reactogenicity and immunogenicity of the vaccine candidate M72/AS01E was evaluated in healthy, HIV-negative adolescents in a TB endemic region, regardless of Mycobacterium tuberculosis (M.tb) infection status. METHODS: In a phase II, double-blind randomized, controlled study (NCT00950612), two doses of M72/AS01E or placebo were administered intramuscularly, one month apart. Participants were followed-up post-vaccination, for 6 months. M72-specific immunogenicity was evaluated by intracellular cytokine staining analysis of T cells and NK cells by flow cytometry. RESULTS: No serious adverse events were recorded. M72/AS01E induced robust T cell and antibody responses, including antigen-dependent NK cell IFN-γ production. CD4 and CD8 T cell responses were sustained at 6 months post vaccination. Irrespective of M.tb infection status, vaccination induced a high frequency of M72-specific CD4 T cells expressing multiple combinations of Th1 cytokines, and low level IL-17. We observed rapid boosting of immune responses in M.tb-infected participants, suggesting natural infection acts as a prime to vaccination. CONCLUSIONS: The clinically acceptable safety and immunogenicity profile of M72/AS01E in adolescents living in an area with high TB burden support the move to efficacy trials.

Safety and immunogenicity of the M72/AS01 candidate tuberculosis vaccine when given as a booster to BCG in Gambian infants: an open-label randomized controlled trial.

UNLABELLED: We evaluated the candidate tuberculosis vaccine M72/AS01 in Bacille-Calmette-Guérin (BCG)-vaccinated infants after or concomitantly with Expanded-Programme-on-Immunization (EPI) vaccines. METHODS: In a Phase-II study in The Gambia (NCT01098474), 2 cohorts of 150 BCG-vaccinated infants each were randomized 1:1:1. The 'Outside-EPI' cohort received one or two M72/AS01 doses, or meningitis vaccine, 1-2 months after primary EPI vaccination. The 'Within-EPI' cohort received one or two M72/AS01 doses concomitantly with the third or last two doses of their primary EPI-regimen, respectively, or EPI vaccines alone. Safety, M72-specific humoral (ELISA) and cell-mediated (whole-blood ICS) responses, and humoral responses to EPI vaccines were assessed. RESULTS: M72/AS01 was acceptably tolerated with no vaccine-related serious adverse events reported. Seropositivity/seroprotection rates against EPI antigens in the Within-EPI cohort were comparable between groups, irrespective of M72/AS01 co-administration. Up to one year post M72/AS01 vaccination, M72-specific humoral and CD4(+) T-cell responses were higher after 2 doses versus 1 dose in both cohorts (p < 0.0001), and comparable between cohorts after either 1 or 2 doses (p > 0.05). CONCLUSION: M72/AS01 given to infants after or concomitantly with EPI vaccines had an acceptable safety profile. Our results suggest no interference of immunogenicity profiles occurred following co-administration of M72/AS01 and EPI vaccines. Two M72/AS01 doses elicited higher immune responses than one dose.

Safety and immunogenicity of the M72/AS01 candidate tuberculosis vaccine in HIV-infected adults on combination antiretroviral therapy: a phase I/II, randomized trial.

OBJECTIVE: Tuberculosis (TB) is highly prevalent among HIV-infected people, including those receiving combination antiretroviral therapy (cART), necessitating a well tolerated and efficacious TB vaccine for these populations. We evaluated the safety and immunogenicity of the candidate TB vaccine M72/AS01 in adults with well controlled HIV infection on cART. DESIGN: A randomized, observer-blind, controlled trial (NCT00707967). METHODS: HIV-infected adults on cART in Switzerland were randomized 3 : 1 : 1 to receive two doses, 1 month apart, of M72/AS01, AS01 or 0.9% physiological saline (N = 22, N = 8 and N = 7, respectively) and were followed up to 6 months postdose 2 (D210). Individuals with CD4⁺ cell counts below 200 cells/µl were excluded. Adverse events (AEs) including HIV-specific and laboratory safety parameters were recorded. Cell-mediated (ICS) and humoral (ELISA) responses were evaluated before vaccination, 1 month after each dose (D30, D60) and D210. RESULTS: Thirty-seven individuals [interquartile range (IQR) CD4⁺ cell counts at screening: 438-872 cells/µl; undetectable HIV-1 viremia] were enrolled; 73% of individuals reported previous BCG vaccination, 97.3% tested negative for the QuantiFERON-TB assay. For M72/AS01 recipients, no vaccine-related serious AEs or cART-regimen adjustments were recorded, and there were no clinically relevant effects on laboratory safety parameters, HIV-1 viral loads or CD4⁺ cell counts. M72/AS01 was immunogenic, inducing persistent and polyfunctional M72-specific CD4⁺ T-cell responses [medians 0.70% (IQR 0.37-1.07) at D60] and 0.42% (0.24-0.61) at D210, predominantly CD40L⁺IL-2⁺TNF-α⁺, CD40L⁺IL-2⁺ and CD40L⁺IL-2⁺TNF-α⁺IFN-γ⁺]. All M72/AS01 vaccines were seropositive for anti-M72 IgG after second vaccination until study end. CONCLUSION: M72/AS01 was clinically well tolerated and immunogenic in this population, supporting further clinical evaluation in HIV-infected individuals in TB-endemic settings.

Improved CD4⁺ T cell responses to Mycobacterium tuberculosis in PPD-negative adults by M72/AS01 as compared to the M72/AS02 and Mtb72F/AS02 tuberculosis candidate vaccine formulations: a randomized trial.

BACKGROUND: The Bacille Calmette-Guérin (BCG) tuberculosis (TB) vaccine provides incomplete protection, necessitating development of an effective vaccine against TB disease. The Mtb72F/AS02 candidate vaccine was previously shown to be clinically well tolerated and immunogenic in Purified Protein Derivative (PPD)-negative adults. To improve the stability of Mtb72F, a point mutation was introduced into a putative serine protease site to give the final M72 construct. AS01 is an Adjuvant System that can potentially improve both humoral and cellular immune responses compared to the AS02 Adjuvant System or unadjuvanted vaccine. This study evaluated the safety and immunogenicity in Mtb-naïve adults of vaccines containing 40 µg of the M72 antigen with AS02 or AS01 and compared the results with Mtb72F/AS02 vaccine (40 µg dose), M72 in saline (40 µg dose) and AS01 alone. METHODS: In this Phase I/II observer-blind controlled trial, 110 participants were randomized (4:4:1:1:1) to receive M72/AS01, M72/AS02, Mtb72F/AS02, M72/saline or AS01, following a 0, 1-month schedule. Subjects receiving the adjuvanted M72 vaccines were followed up until 3 years post vaccination. Evaluation of the immune response and safety/reactogenicity was performed. RESULTS: For all vaccines, solicited adverse events (AEs) were predominantly mild to moderate and transient. No vaccine-related serious AEs occurred and no subject withdrew due to an AE. Immune responses induced by Mtb72F and M72 antigens combined with AS02 were similar. M72/AS01 and M72/AS02 induced robust polyfunctional M72-specific CD4(+) T cell and antibody responses persisting at 3 years, with the highest CD4(+) T cell responses found with M72/AS01. CONCLUSION: This first clinical study with M72/AS01 and M72/AS02 showed that both vaccines were clinically well tolerated and induced high magnitude and persistent cell-mediated and humoral immune responses. The Mtb72F/AS02 and M72/AS02 vaccines were comparably immunogenic with significantly higher immune responses compared to the M72/saline control. Of the formulations tested, M72/AS01 demonstrated significantly higher vaccine specific Th1 CD4(+) T cell responses supporting its further clinical evaluation.