A Study to Test if the Vaccine is Working Well in Chronic Obstructive Pulmonary Disease (COPD) Patients Aged 40 to 80 Years Old to Reduce Episodes of Worsening Symptoms and to Gather Further Information on Safety and Immune Response.

The purpose of this study is to test if the vaccine is working well in COPD patients aged 40 to 80 years old to reduce episodes of worsening symptoms ("exacerbations") and to gather further information on safety and immune response. In the current study, COPD patients with a history of acute exacerbations will receive 2 doses of the investigational vaccine or placebo intramuscularly according to a 0, 2 month vaccination schedule, in addition to standard care. The effect of vaccination against two pathogens known to cause exacerbations (Non-typeable Haemophilus influenza \[NTHi\] and Moraxella catarrhalis \[Mcat\]) will be evaluated at pre-defined timepoints (scheduled study visits). In addition to the scheduled study visits, additional study visit(s) and/ or phone contact(s) will take place for each acute exacerbation of COPD occurring from first vaccination up to study conclusion.

The purpose of this Phase IIB proof-of-concept (POC) study in moderate to very severe COPD patients (i.e. GOLD grade 2, 3 and 4) aged 40 to 80 years with a history of moderate or severe acute exacerbations of COPD (AECOPD) in the previous 12 months is to evaluate whether the NTHi-Mcat vaccine can reduce the frequency of AECOPD in this population and to assess the vaccine's safety, reactogenicity and immunogenicity. Several formulations of a vaccine containing the NTHi antigens (low or high formulation) either non-adjuvanted or combined with different adjuvants (aluminium \[Al\], adjuvant system) were already evaluated in two previous Phase I clinical trials (NTHI-002 in healthy adults aged 18 - 40 years and NTHI-003 in current and former healthy smokers of 50-70 years old). The investigational vaccines were well-tolerated, with an acceptable safety and reactogenicity profile. These studies allowed the dose selection of the NTHi antigens (low formulation) and the adjuvant system currently evaluated for the first time in moderate and severe COPD patients aged 45 - 81 years in the Phase II study NTHI-004. The safety, reactogenicity and immunogenicity of different formulations of the NTHi-Mcat investigational vaccine have been evaluated in the Phase I study in healthy adults aged 19 - 40 years and in current and former smokers aged 50 - 70 years (study NTHI MCAT-001). Based on results obtained up to 30 days post-Dose 2 from this study, the adjuvanted formulation containing NTHi proteins PD and PE-PilA and of UspA2 has been selected for evaluation in the current NTHI MCAT-002 study. Placebo will be used as a control. The NTHi-Mcat investigational vaccine and placebo will be given on top of standard of care to subjects in the respective study groups. In the current study, moderate, severe and very severe COPD patients (i.e. GOLD grade 2, 3 and 4) with a history of AECOPD will receive 2 doses of the NTHi-Mcat investigational vaccine or placebo intramuscularly (IM) according to a 0, 2 month vaccination schedule, in addition to standard care. Scheduled study visits, during which the effect of immunisation against NTHi and Mcat will be evaluated, will take place at pre-defined timepoints. In addition to the scheduled study visits, ad hoc AECOPD-driven study visit(s) and/ or phone contact(s) will take place for each AECOPD occurring from first vaccination up to study conclusion: * An AECOPD visit will be scheduled as soon as possible after the onset of the AECOPD symptoms (maximum 96 hours after the onset of the symptoms). * Follow-up visit(s) and/or phone call(s) will take place to determine the end of the AECOPD. Rationale for the protocol amendment: * CD8+ T cell component was removed from the secondary endpoint, but kept in the exploratory/tertiary endpoint. Previous clinical studies have shown that the investigational NTHi and NTHi-Mcat vaccines do not induce CD8+ T cell responses. This was observed in all studies performed with the NTHi vaccine and seen in the interim analysis of NTHi Mcat-001 study. * An exclusion criterion was updated to clarify that only subjects with clinically significant respiratory diseases other than COPD (e.g. clinically significant lung fibrosis, clinically significant pulmonary embolism) need to be excluded from study participation. * The polymerase chain reaction (PCR) assay for sputum samples was not designed to discriminate amongst Haemophilus influenzae (Hi) serotypes. Results from AERIS epidemiological study \[Wilkinson, 2017\] showed that more than 99% of these bacteria would be Non-Typeable Haemophilus influenzae (NTHi). Therefore, the protocol was updated to clarify that the presence of Hi bacteria in sputum during exacerbation will be used to determine AECOPD associated to NTHi. * The list of potential immune mediated diseases was updated (effective June 30th 2017). * The 87% confidence interval (CI) was removed from all secondary analyses. This confidence interval will only be maintained for the primary analysis because the 95% CIs are underpowered for this study. All other sensitivity analyses on different cohorts will be described using 95% CIs. As the primary objective will have both 87% and 95%, the sensitivity analyses can be interpreted with 95% CIs. * A Full-Analysis Set (FAS) that corresponds to an intent-to-treat analysis was added. The FAS will include all randomized subjects who will receive at least 1 vaccine administration and, as per intention-to-treat principle, a subject in the FAS will be analysed "as randomized" (i.e. according to the vaccine a subject was planned to receive irrespectively of his/her real exposure). * Cut-off values for anti-PE, anti-PilA and anti-UspA2 antibody ELISAs were updated following the re-set up of the assays. * Additional minor updates were based on the scientific and operational experience gained from current COPD studies.