nice.org.uk/advice/esnm34/c...
Asthma: fluticasone furoate/vilanterol (Relvar Ellipta) combination inhaler
Relvar Ellipta is licensed for the regular treatment of asthma in adults and adolescents aged 12 years and older where use of a combination medicinal product (LABA and ICS) is appropriate, that is patients not adequately controlled with ICS and 'as needed' inhaled short-acting beta‑2 agonists. It is not licensed for use in patients who are already adequately controlled on both an ICS and a LABA, unlike the other 4 ICS/LABA combination inhalers that are licensed in the UK for the treatment of asthma (summaries of product characteristics: Seretide, Flutiform, Symbicort and Fostair).
This is taken from the UK NICE guidance. If symbicort or seretide isn't helping might be worth a try if available in each persons country. Just a newer inhaler.
I'm always looking for new one as symbicort 400, although it's best for me doesn't control my asthma well, and I've tried all the others including some bronchodilator inhalers for COPD.