The relentless march towards combination therapy for asthma has limited the potential of single agent asthma drugs, but the study is significant on a couple of grounds.
Firstly, it provides a validation of Inyx 's patented lipid-binding technology for enhancing the delivery of inhalation-therapy drugs. And it also puts Inyx in a position to target the potentially huge market for HFA-propelled asthma drugs afforded by the US's tardy adoption of measures to limit the use of ozone-depleting chlorofluorocarbons (CFCs).
Jack Kachkar, Inyx' CEO, said that the results of the study have prompted the company to add the HFA MDI version of salbutamol to its development portfolio
Salbutamol - also known as albuterol in the US - is the most widely prescribed short-term bronchodilator medication to treat asthma, chronic bronchitis and other breathing disorders.
HFA is the prime substitute for the CFC gas propellant used in MDI sprays, by which approximately 95 per cent of all asthma medication is administered to the approximate 100 million people worldwide who suffer from asthma. CFC use in pharmaceutical products is already banned in Europe, Canada, Japan and many other countries.
The US is expected to start implementing the ban by 2006, but in 2003, 90 per cent of the asthma inhalers sold in the U.S. contained CFC.
The conversion from CFC to CFC-free pharmaceuticals is estimated to be up to a $5 billion-plus niche market.
Inyx plans to commence scale-up studies on the salbutamol HFA formulation in early 2005, with a view to commencing clinical efficacy equivalence studies as soon as possible, said Kachkar.
"It is anticipated that these studies should be concluded in time to allow submissions to the US and European regulatory authorities in 2006," he added.
The results of the successful two-year study on the salbutamol HFA-MDI are part of the intellectual property related to the patented lipid technology that Inyx acquired this September from Phares Technology, the parent company of Phares Drug Delivery of Muttenz in Switzerland.
The novel technology uses a lipid-binding matrix that can combine drugs that would ordinarily be difficult to formulate in the same inhaler, usually because the molecules have different properties. For example, they may have different solubilities.
Combination therapy
Acknowledging that the future of asthma treatment seems to be in combination therapy, Inyx has already started feasibility studies on HFA-MDI formulations of various lipid-enhanced combinations of respiratory drugs, including: short- and long-acting bronchodilators, inhaled corticosteroids, and non-steroidal anti-inflammatory medications.
At present, drug combinations delivered by inhaler represent a $10 billion market, spearheaded by products such as GlaxoSmithKline's Advair/Seretide (salmeterol and fluticasone) and AstraZeneca's Symbicort (budesonide and formoterol), which combine a beta agonist bronchodilator with a steroid to combat inflammation.
Last month, Italian firm Zambon exited an agreement with Danish inhaler company Direct-Haler because it felt that there was limited market appeal for a single-agent product.
Kachkar noted that the delivery technology is suitable not only for respiratory treatments but also for other pharmaceutical sectors such as acute and systemic pain management.