Pharma groups to tackle greenhouse gases from asthma inhalers

Pharmaceutical groups GSK and AstraZeneca are vying to be the first to finally upgrade their popular inhalers which deliver a life-saving puff of medicine but damage the planet.

GSK plans to start final trials to improve the gas propellant in its 55-year- old Ventolin inhaler used by tens of millions of people with asthma worldwide. This could cut the company’s entire carbon footprint by more than 40 per cent.

The extraordinary predicted effect of a single change to one product highlights the healthcare industry’s contribution to the global carbon footprint, and the growing internal, consumer and regulatory pressure to reduce it.

GSK’s medicine development leader, Laura Clow, said the development was “absolutely single-handedly the biggest carbon saving we can make”.

Rival AstraZeneca also said this week it would file for regulatory approval of a low-carbon version of its Breztri inhaler in the UK, EU and China by the end of the year. This development could trim almost a fifth of its greenhouse gas emissions.

“We might be first [to market] but time will tell,” said Pablo Panella, vice-president of AstraZeneca’s global respiratory and immunology franchise. “What’s more important is that this is not happening in isolation.”

Both companies’ plans to switch out their existing hydrofluorocarbon propellants follow the introduction of international rules to curb their use.

Other pharmaceutical companies, including Italy’s Chiesi Group, are also developing pressurised inhalers based on less polluting propellants.

The chunky two-tone blue inhalers that gasify re-loadable bottles of Ventolin, based on the muscle relaxant salbutamol, have become a familiar sight in homes, schools and workplaces since being first sold in 1969.

The treatment eases breathing difficulties by opening the airways to the lungs. Ventolin is used by 35mn people in more than 100 countries, according to GSK, and achieved £749mn ($980mn) in sales last year.

This long-running success has come in tandem with a decades-old struggle to curb its environmental impact. Even the current HFC propellants were designed to replace a previous generation of synthetic gas, the chlorofluorocarbons which can damage Earth’s protective atmospheric ozone layer.

But HFCs are also culprits. The HFC-134a propellant now used in Ventolin has a 100-year global warming potential 1,430 times greater than that of CO₂, according to a 2016 amendment to the international Montreal Protocol.

GSK calculates that Ventolin accounted for 48 per cent of its global carbon footprint in 2022, equivalent to 4.6mn tonnes of CO₂, and the existing propellant accounts for almost all of Ventolin’s impact.

An inhaler based on the alternative HFC propellant that GSK is investigating, or HFC-152a, would have a 90 per cent lower carbon footprint, according to UN projections. If all patients moved to the proposed, less environmentally damaging version of Ventolin, GSK estimates its total corporate emissions would fall by 4.1mn tonnes, or 42 per cent.

AstraZeneca’s Breztri inhaler, meanwhile, approved in 2020 to treat chronic obstructive pulmonary disease and in trials for asthma, made $677mn in sales last year. The company aims to switch out its propellant for the medical-grade alternative HFO-1234ze, developed by US tech company Honeywell, that it says will reduce emissions to near zero.

The move would cut 1.3mn tonnes of CO₂ equivalent emissions annually, amounting to about 20 per cent of AstraZeneca’s 6.7mn tonnes of so-called scope 3 emissions, or those resulting from supply or use of its products. Its total emissions were 6.9mn tonnes in CO₂ equivalent terms.

GSK’s last clinical trials of the replacement gas are scheduled to start later this year, which it hopes will clear the way for an application for regulatory approval in 2025.

On the question of why it had taken so long to make the upgrade, GSK said regulations and standards had evolved, while the understanding of inhalers had improved. Development had proved a “lengthy process”, it added, because of the need to work with the propellant manufacturer and gather non-clinical and clinical data.

The healthcare industry has been estimated to account for about 4 per cent of global greenhouse gas emissions — slightly greater than aviation — reflecting its reliance on diverse, complex and sometimes single-use resources.

Michaela Hegglin, a University of Reading professor in atmospheric chemistry, said that while it might seem a small figure by comparison with other industries such as transport, the healthcare sector was a “climate change concern”.

HFCs have been more heavily regulated since the Kigali amendment to the 1987 Montreal Protocol started coming into force in 2019, obliging the industry to find new propellant technologies.

An EU agreement in 2023 to phase out all consumption of HFCs by 2050 has also hastened the pace of change.

A quota system before that is intended to drive a steep reduction in the amount of HFCs that importers and producers can sell in the EU.

The regulation will affect makers of refrigerant devices, including air conditioning systems, with fluorinated gases estimated to be responsible for 2.5 per cent of the bloc’s greenhouse gas emissions.

Another driver is the climate targets that health services themselves are being pushed to meet as part of national goals. The UK’s National Health Service, for example, has estimated that inhaler-related emissions account for about 3 per cent of its carbon footprint.

Greener alternatives to older propellant, metered-dose inhalers exist already in the form of dry-powder inhalers, although usage shows wide regional variations.

Dry powder products can be difficult for some patients to use, said AstraZeneca’s Panella, meaning a pressurised metered-dose inhaler was still needed, he added.

More than two-thirds of UK inhalers were metered dose, compared with less than 30 per cent in most other European countries, according to a 2021 paper.

While Ventolin remains important for many with asthma, GSK’s business strategy focuses on developing innovative medicines it can sell at higher prices.

This week, the company said an experimental drug given by injection twice a year for severe asthma could reduce attacks by more than half and hospitalisation by more than 70 per cent, when used in conjunction with inhalers. Depemokimab could reach £3bn in annual sales, it estimated.