You are now leaving GSK’s website

This link will take you to a non-GSK website. GSK does not recommend, endorse or accept liability for sites controlled by third-parties.


Go back

Video player requires JavaScript enabled. You can download this video here:

Relvar Ellipta Salford Lung Study (SLS) – pioneering asthma study results

Go to Top Close

SLS asthma is the world’s first large prospective asthma effectiveness randomised controlled trial (RCT). With a patient population of 4,233, the trial measured the effectiveness and safety of Relvar Ellipta compared with usual care, which was based on GP decision (ICS or ICS/LABA). 12

What makes this trial pioneering, is that it reflected every day clinical practice and included a broad patient population. 12

A broad patient population, broad results

With broad inclusion criteria, the trial was designed to reflect the kind of patients that you see in your clinical practice:

  • Broad patient population: patients with co-morbidities, polypharmacy, smokers were allowed 13
  • Primary care setting: everyday clinical practice where most asthma patients are treated 124
  • Minimal intervention: patient monitoring and data collection via electronic records, which allowed minimal study intervention 12

A trial designed to reflect everyday clinical setting

The SLS asthma study compared the effectiveness of Relvar Ellipta with usual care based on GP decision (ICS or ICS/LABA). 3,026 and 4,233 patients comprised the PEA (primary effectiveness analysis) and ITT (intention to treat) respectively. 12

Broad population: 90% of patients screened were randomised for inclusion. 12 RCTs often have strict exclusion criteria meaning that <5% of the overall asthma population is studied. 5

Usual care as comparator: patients comprised the PEA and ITT; 34% were on ICS and 66% on ICS/LABA (PEA). 2

  • The study design

    SLS Study design

    Primary endpoint: Asthma Control Test™ (ACT) improvement of ≥3 or total ACT ≥20 in patients initiating Relvar Ellipta vs. continuing usual care* at Month 6 in the Primary Effectiveness Analysis (PEA) population. 1

Improved control by initiating Relvar Ellipta

Relvar Ellipta improved asthma control in significantly more patients, vs. continuing on ICS/LABA, in everyday clinical practice 1*

Improvements sustained at 12 months

Consistent and sustained superiority vs ICS\LABA throughout the 12 month study 1

The data shown are from the subset of patients with a pre-randomisation prescription of ICS/LABA. 1

This study represents a broad population of patients where 3,026 and 4,233 patients comprised the PEA and ITT respectively, 34% were on ICS and 66% on ICS/LABA (PEA). 1

The primary endpoint of the study was met (p<0.001). 1

Improvements offering meaningful benefits to patients 16-8

Relvar Ellipta improved asthma control vs baseline which translates into meaningful benefits for your patients 1 *†‡

Improvements that build on a wealth of Relvar Ellipta data from other key studies.

  • 24 hours of continuous efficacy with once-daily dosing 910
  • Reduction in rate of exacerbations vs ICS 11

...all in an easy-to-use inhaler 12

Discover more about Relvar Ellipta


*Patients continued to receive treatment as prescribed by their GP 2
Patients in this subset were initiated with Relvar Ellipta (637/908) or continued on ICS/LABA (511/916).
Primary endpoint was Asthma Control Test™ (ACT) improvement (responder/non responder+ (ie.the cross symbol) 637/908) or continued on ICS/LABA (responder/non responder 508/916) of ≥3 or total ACT ≥20 in patients initiating Relvar Ellipta vs. continuing usual care* at Month 6 in the Primary Effectiveness Analysis (PEA) population.
The primary endpoint of the study was met (p<0.001). 1
The PEA population consisted of all ITT patients with a total ACT <20 at baseline.
ACT is a trademark of Quality Metric Inc.


  1. Woodcock et al. Lancet 2017; 390(10109): 2247-2255
  2. Woodcock A et al. The Salford Lung Study protocol: a pragmatic, randomised phase III real-world effectiveness trial in asthma. BMC Pulm Med. 2015; 15:160.
  3. New JP et al. Obtaining real-world evidence: the Salford Lung Study. Thorax 2014; 69: 1152-4.
  4. Vermeire PA et al. Asthma control and differences in management practices across seven European countries. Resp Med 2002 Mar; 96(3): 142-9.
  5. Herland K et al. How representative are clinical study patients with asthma or COPD for a larger ‘‘real life’’ population of patients with obstructive lung disease? Respir Med 2005; 99: 11–19.
  6. Schatz M et al. The minimally important difference of the Asthma Control Test. J Allergy Clin Immunol. 2009; 124: 719–723.
  7. Schatz M et al. Asthma Control Test: Reliability, validity, and responsiveness in patients not previously followed by asthma specialists. J Allergy Clin Immunol. 2006; 117: 549–556.
  8. Nathan RA et al. Development of the Asthma Control Test: A survey for assessing asthma control. J Allergy Clin Immunol. 2004; 113: 59–65.
  9. Relvar Ellipta SmPC. GlaxoSmithKline; 2019, available at, accessed January 2020
  10. Bernstein DI et al. Fluticasone furoate (FF)/vilanterol (100/25 mcg or 200/25 mcg) or FF (100 mcg) in persistent asthma. J Asthma. 2015; 52(10): 1073–1083.
  11. Bateman ED et al. Once-daily fluticasone furoate (FF)/vilanterol reduces risk of severe exacerbations in asthma versus FF alone. Thorax. 2014; 69: 312–319.
  12. Svedsater H et al. Ease of use of the ELLIPTA™ dry powder inhaler: data from three randomised controlled trials in patients with asthma. NPJ Prim Care Resp Med. 2014; 24: 14019.

RELVAR Ellipta was developed in collaboration with INNOVIVA Inc.

Relvar and Ellipta are registered trademarks of the GlaxoSmithKline Group of Companies