The QDose product, developed in a joint venture between UK firm Vectura and US company MicroDose Technologies, performed impressively in the clamp study, achieving results that outshine the dominant inhalable insulin product, Exubera.
According to the study results, QDose demonstrated relative bioavailability of inhaled insulin at around 18 per cent compared to subcutaneous injection - 50-75 per cent greater than Exubera, according to Vectura director of medical affairs, Terence Chadwick.
In addition to this, the QDose system also showed dose equivalence, i.e. two 0.75mg blisters delivering the same amount of insulin to the blood as a single 1.5mg blister.
This has been a downfall of Pfizer's Exubera, which has been unable to demonstrate this dose equivalence, making titration by patients using the device more difficult.
Although further studies will be required, the dose equivalence findings also provide strong support for dose proportionality using the device, i.e. evidence that doubling the dose doubles actual blood insulin levels.
Already presenting these efficacy advantages over Exubera, the trail-blazer in inhaled insulin that was approved in the US and EU early last year, QDose has yet another trick up its sleeve making it potentially more attractive to patients and prescribers.
"Given that the QDose has a relative bioavailability that is almost twice that of the Exubera product, our insulin requirement...would be only a fraction of Exubera's," explained MicroDose co-founder Scott Fleming.
"[It] would therefore likely enable a lower cost of goods, and in turn a lower retail price."
This is not to mention the fact that no excipients are used in the insulin powder formulation, unlike Exubera which uses mannitol, glycine and sodium citrate as excipients, so the QDose device delivers " more or less pure insulin ," says Chadwick.
The QDose product comes across as next generation inhalable insulin device, doing away with some of the design issues that hampered sales of the Exubera product that generated " disappointing " revenues of $4m (€2.9m) over the second quarter this year.
The innovative device is an electronic dry powder inhaler, which uses piezo electronics to deliver the chosen compound independently of the patient's inhalation flow rate.
The insulin formulation delivered by the device is produced using a proprietary low-temperature spray-drying technique, with the resulting powder filled into a foil blister.
Within in the QDose device, the blister is positioned above and in contact with a small piezo vibrator.
Just prior to delivery the blister is pierced by small pins within the device, and when the patient takes a breath an airflow sensor automatically turns on the piezo causing it to vibrate at a high frequency, 30 to 40 times per second.
This vibration causes the insulin powder particles to disaggregate, and they become aerosolised into the air stream produced by the inspiratory flow.
The inhaler device itself is designed to be reusable, with the companies' currently foreseeing a shelf-life of around six months for the product, with blisters produced in three or four different dose strengths.
QDose has just completed its second Phase I study, and according to Fleming importantly overcomes the flaws in Exubera that caused resistance from users as well as those responsible for reimbursement: "The QDose product is smaller than Exubera, takes less steps to prepare, and fewer inhalations to deliver a broader range of doses," he explained.
"And the higher efficiency of the QDose system should enable a lower pricing of the final product, making it more palatable to reimbursement entities."
Despite bursting onto the market with a bang last year, Exubera has fallen short of expectations and is proving an unanticipated disappointment to Pfizer.
However, by being the first to wade through the regulatory rigmarole and making it to market with the first inhaled insulin product, the company has paved the way for others working in the same field.
"I take my hat off to the people who worked on Exubera," said Chadwick.
"But the problem is that it's 1990s technology - it's not discreet and it's not convenient."
The QDose device hopes to be one of the next generation of inhalable insulin products to make it to market, making use of the path beaten by Exubera and offering a more attractive, modern option to diabetic patients.
Vectura and MicroDose are now approaching companies representing potential licensing partners for the next steps in the development of the inhalable insulin product.
According to Vectura it is unlikely that the companies would continue to invest independently in the project without securing a partner, but given the positive response they have received after presenting the product to around 10 potential licensees, Vectura is hopeful that a suitable partner will be found.
With the inhaled insulin market still finding its feet, and Pfizer just kicking off direct-to-consumer print and television advertising in recent months to try and improve Exubera's sales, QDose could find a market favouring the inhaled insulin option and hungry for improved delivery devices by the time it hits the shelves in a few years time.