Reduction in All-Cause Mortality with Fluticasone Furoate/Umeclidinium/Vilanterol in COPD Patients

Rationale: The IMPACT trial demonstrated a significant reduction in all-cause mortality (ACM) risk with fluticasone furoate/umeclidinium/vilanterol (FF/UMEC/VI) versus FF/VI or UMEC/VI in patients with COPD at risk of future exacerbations. 574 patients were censored from the original analysis due to incomplete vital status information. Objective: Report ACM and impact of stepping down therapy, following collection of additional vital status data. Methods: Patients were randomized 2:2:1 to FF/UMEC/VI 100/62.5/25μg, FF/VI 100/25μg or UMEC/VI 62.5/25μg following a run-in on their COPD therapies. Time to ACM was prespecified. Additional vital status data collection and subsequent analyses were performed post hoc. Measurements and Main Results: We report vital status data for 99.6% of the intention-to-treat population (n=10,355), documenting 98(2.36%) deaths on FF/UMEC/VI, 109(2.64%) on FF/VI, and 66(3.19%) on UMEC/VI. For FF/UMEC/VI, the hazard ratio for death was 0.72 (95%CI: 0.53,0.99;P=0.042) versus UMEC/VI and 0.89 (95%CI: 0.67,1.16;P=0.387) versus FF/VI. Independent adjudication confirmed lower rates of cardiovascular and respiratory death, and death associated with the patient’s COPD. Conclusions: In this secondary analysis of an efficacy outcome from the IMPACT trial, once-daily single-inhaler FF/UMEC/VI triple therapy reduced the risk of ACM versus UMEC/VI in patients with symptomatic COPD and a history of exacerbations. Page 5 of 47 AJRCCM Articles in Press. Published March 12, 2020 as 10.1164/rccm.201911-2207OC Copyright © 2020 by the American Thoracic Society Funding: GSK(CTT116855/NCT02164513). Abstract word count: 198word count: 198


INTRODUCTION
No pharmacologic therapy to date has prospectively demonstrated a reduction in allcause mortality (ACM) in patients with chronic obstructive pulmonary disease (COPD).
Only smoking cessation (1), oxygen therapy in severely hypoxemic patients (2, 3), and lung volume reduction surgery in select individuals (4) have been shown to decrease mortality. Previous studies, such as TORCH (5), INSPIRE (6), UPLIFT (7) and SUMMIT (8) suggested a benefit for survival with pharmacologic therapy, but either did not achieve statistical significance or were limited by methodologic considerations.
The InforMing the PAthway of COPD Treatment (IMPACT) trial (NCT02164513, CTT116855) was a 52-week phase III, randomized, double-blind, parallel-group, multicenter trial that compared the efficacy, safety and tolerability of once-daily singleinhaler triple therapy containing an inhaled corticosteroid/long-acting muscarinic antagonist/long-acting IMPACT also demonstrated a potentially clinically relevant mortality difference including reduction in the risk of on-treatment all-cause mortality, and all-cause mortality including off-treatment data in the intent-to-treat (ITT) population, comparing FF/UMEC/VI with UMEC/VI. However, 574 (5.5%) subjects were censored from the original Week 52 analysis that included off-treatment data because of incomplete vital status information, as not all investigators provided vital status data for their subjects at Week 52 after discontinuation of assigned therapy or withdrawal from the study (10). Due to the amount of missing data in the previous results we felt caution was warranted in the interpretation of the all-cause mortality finding. We now report robust findings of allcause mortality following collection of additional vital status data at nominal Week 52 representing 99.6% of the study population. In addition, the IMPACT trial design allowed participants to remain on their current COPD therapies prior to randomization, rather than have an artificial "stabilization" or withdrawal of therapy during the run-in period.
This was done to mimic therapeutic switch and step down performed in routine clinical practice, thereby improving the generalizability of the trial results. This design affords the opportunity to understand outcomes for participants who entered the trial on differing therapies. We also report on outcomes of patients who entered the trial on inhaled triple therapy and on regimens containing an ICS to understand outcomes of patients who undergo step down or switch in therapy. Some of these data have been previously presented in the form of an abstract (11).

Patient population
IMPACT randomized 10,355 patients in a 2:2:1 fashion to FF/UMEC/VI 100/62.5/25µg, FF/VI 100/25µg, and UMEC/VI 62.5/25µg, respectively, and were included in the ITT population. Eligible participants had symptomatic COPD with a forced expiratory volume in 1 second (FEV 1 ) <50% of predicted and a history of ≥1 moderate or severe (hospitalized) exacerbation, or FEV 1 of 50% to <80% of predicted and ≥2 moderate or 1 severe exacerbation in the previous year. A current diagnosis of asthma was exclusionary (10).
The total study duration consisted of a 2-week run-in period where participants remained on their own medication, a 52-week treatment period, and a 1-week safety follow-up.
Patients who permanently discontinued study treatment before the end of the 52-week treatment period but agreed to continue in the study were followed by the investigator until the end of the patients' planned 52-week participation to capture important efficacy and safety assessments, including adverse events, exacerbations, and vital status.
Those who discontinued their medications and withdrew from the study were expected to have vital status recorded at the 52-week post-randomization date. All serious adverse reports and deaths within the study were independently adjudicated to determine the primary cause of death.
The study was performed in 37 countries between June 2014 and July 2017 in accordance with Good Clinical Practice and the Declaration of Helsinki. The study received local Institutional Review Board/Independent Ethics Committee approval and all participants provided signed informed consent.

Definition of all-cause mortality
Time to ACM (on-treatment and on/off treatment) were pre-specified 'Other' efficacy endpoints in the IMPACT protocol and have previously been reported (10). Here we also include post hoc analyses of time to ACM including a near complete vital status dataset following a challenging global collection of data.
A death was defined as "on-treatment" if the actual date of death occurred up to 7 days after the last day of treatment and considered to be "off-treatment" if the actual date of death occurred more than 7 days after the last day of treatment and before the projected Week 52 date (Supplement Figure E1).

Statistical considerations and tipping point analyses
To control for the Type I error in the IMPACT trial, the truncated Hochberg method was used in a closed testing hierarchy across the co-primary and key secondary treatment comparisons. Since all tests within the prespecified statistical hierarchy achieved statistical significance (P<0.001), significance is inferred for all other endpoints and treatment comparisons with a P-value <0.05 as stated in the IMPACT protocol.  Figure E2A and B) and by imputing all possible combinations of outcomes for the logistic regression methodology (Supplement Figure E2C).

RESULTS
Participants (N=10,355) with symptomatic COPD and a history of exacerbations were randomized into the ITT population and received study medication. In total, 9087 (88%) completed the trial with 7991 (77%) completing the trial on investigational therapy.
Baseline study demographics are shown in Table 1. Most participants (66%) were male, and the mean age was 65.3 years. There were no clinically relevant differences in participant characteristics between the overall treatment groups. However, participants who entered the study on a triple therapy or an ICS-containing regimen had lower lung function and greater history of hospitalization in the previous 12 months, and were less likely to be a current smoker compared with those who entered on a dual or monotherapy, or non-ICS containing regimen ( Table 2). The participants who entered on triple therapy or ICS-containing therapy also had greater rates of exacerbation during the study suggesting they carried greater risk (Table 3).

On-treatment all-cause mortality
As originally reported (10), there were 50 (1.20%) on-treatment deaths in the  Table E1).

On/off-treatment all-cause mortality including additional vital status data
Additional post hoc data collection now provides vital status at Week 52 for 99.6% of the ITT population with 42 subjects censored in the analyses because of missing data.  with censored data are imputed as alive at the end of 52 weeks the post-withdrawal hazard for FF/UMEC/VI would need to be approximately 10 times higher than the prewithdrawal hazard before losing statistical significance. Similarly, if the patients on UMEC/VI with censored data are assumed to have a post-withdrawal hazard the same as the pre-withdrawal hazard (i.e. it is assumed that the missing data for UMEC/VI is missing at random) then the post-withdrawal hazard for FF/UMEC/VI would need to be approximately 14 times higher than the pre-withdrawal hazard before losing statistical significance. These extreme assumptions are unlikely and support the conclusion that the observed survival finding is robust to missing data. (Supplement Figure E2).

Effect of step down from triple and switch of therapy
Supplement Table E2 summarizes ACM by the patients' COPD medication at study entry. Forty per-cent of participants (n=4183) entered the study on a triple therapy (ICS+LAMA+LABA) regimen. Because of the randomization scheme, approximately 40% of these patients were maintained on triple therapy, 40% were stepped down to ICS/LABA (removal of the LAMA component) and 20% were stepped down to a LAMA/LABA (removal of the ICS component).
In the analysis including the additional follow up data in participants who entered the study on a triple therapy, the study suggested a reduced risk of on/off-treatment death for patients maintained on a triple therapy compared with those who underwent step down to either dual therapy ( Figure 3a) with a HR of 0.71 (95% CI: 0.46, 1.10, P=0.124) compared with patients stepped down to ICS/LABA, and a HR of 0.62 (95% CI: 0.38, 1.00, P=0.051) compared with patients stepped down to LAMA/LABA, though these reductions did not achieve statistical significance.
In those patients who entered the study on medications other than a triple regimen, risk of all-cause mortality was numerically lower for patients who were randomized to either triple therapy or to ICS/LABA compared with those randomized to LAMA/LABA. (Figure   3b). For participants in this subgroup randomized to triple therapy the HR for risk of  Figure 3E).

Effect of previous ICS use on all-cause mortality
Most participants (76.9%, n=7960) who entered the study were on a medication regimen that contained an ICS. In these patients, mortality was lower if they were  (14). Thus, to put these data into perspective, IMPACT has now prospectively confirmed a survival benefit with ICS-containing therapy that had previously been suggested in patients with COPD.
It is likely that the finding of reduction in the risk of all-cause mortality was confirmed in IMPACT because of the clinical severity of the population in the study, and the significant efficacy observed with the addition of the ICS FF in a highly symptomatic group of patients with frequent moderate or severe exacerbations. In IMPACT we observed a 25% reduction in the rate of on-treatment moderate and severe COPD exacerbations comparing FF/UMEC/VI with UMEC/VI as well as a 34% reduction in COPD hospitalizations for this comparison (10). The reduction in recurrent exacerbation events likely led to improved patient well-being and reduced hospitalization. Reduction in hospitalization likely reduced the known morbidity and mortality associated with hospitalization in patients with COPD (15)(16)(17)(18). This is supported by the independently adjudicated findings of reduced cardiovascular death, respiratory death, and death associated with the patient's underlying COPD compared to an efficacious activecomparator.
Our time interval data refutes the premise that the difference in all-cause mortality was due to acute ICS withdrawal, as evidenced by the continued reduction in mortality throughout the trial; not only in the first 30 days when the effect of acute ICS withdrawal would be expected to be greatest. These data suggest acute step down of medication did not drive the overall findings; rather, they demonstrate the overall benefit of ICS for this population. The observation of the statistically significant and clinically relevant reduction of on-treatment mortality with FF/VI compared with UMEC/VI further supports that the ICS component drives the survival benefit. The findings of triple compared with FF/VI, and the triple step-down data, demonstrate an additional contribution of the LAMA component to survival when using triple-inhaled therapy in this population.
The survival benefit was observed in participants who entered the trial on ICS. This is not unexpected as these patients appeared at greater risk with lower lung function and higher rates of previous hospitalization at study entry, despite being on ICS. As this population is sicker, as evidenced by higher rates of exacerbations during the trial, and most likely to be hospitalized, one might expect that this is the population that would derive the greatest benefit in the study. Only a minority of patients entered the study not taking an ICS, so we are less able to determine if there is a survival benefit in this smaller subgroup with lower risk at study entry.

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Differential response based on prior treatment has been observed in other trials. For example, post hoc analyses of patients who were previously treated with ICS in the SUMMIT trial demonstrated a beneficial effect on mortality differing from those who had not been previously treated with ICS (19). Additionally, both LABA and ICS use predicted a higher rate of health-care utilized exacerbation in the TIOSPIR study (20).
Perhaps this should be expected as patients were on their previous medications for a reason, and would likely have different clinical characteristics that would have prompted their physician to use these medications in the first place (19). This also suggests that there is something inherently different about these patients, rather than an effect of withdrawal or switch of medication in IMPACT and in these trials.
The data from patients who entered the trial on an "open" triple of ICS + LAMA + LABA suggest that maintenance on a triple therapy is associated with a trend towards lower risk of death than step down to either dual therapy in a symptomatic patient population at risk for further exacerbation. This supports the benefit of both ICS and LAMA in this population, and is of importance as international treatment guidelines suggest consideration of step down of therapy in stable patients (21). However, our findings suggest that physicians should use caution when considering step down in therapy in patients with characteristics that mirror those enrolled in IMPACT.
A limitation of the study was that it was only of 52 weeks in duration. Previous mortality studies have been a minimum of 2-3 years in length to ensure enough events to demonstrate a mortality difference. However, we were able to demonstrate a difference despite being only 1 year in length, likely due to the high-risk nature of this population. generally continue to widen over time, though this is dependent on disease stage and the mode of action of a drug (5,8). The mortality finding in IMPACT would not be expected to be different from previous longer studies as there is no suggestion from the data, or the study population, that the benefit would wane over time. Strengths of the study include the large sample size of well-characterized participants with substantial follow-up information. An additional strength is that we evaluated both on-treatment mortality (vital status of subjects while taking assigned therapy), and the mortality of subjects including off-treatment data (including vital status of subjects even after discontinuation of assigned therapy, as ITT). On-treatment data is clinically relevant because it demonstrates expected outcomes related to use of a chronic therapy while the subject is taking the medication; ACM including off-treatment data is important for understanding treatment policy and the impact of differential dropout.
In summary, we have now prospectively confirmed for the first time a reduction in the risk of death using pharmacologic therapy with once-daily inhaled FF/UMEC/VI in symptomatic patients at risk for future exacerbations. We believe that these data are important to healthcare providers and to patients with COPD.