Intranasal delivery of insulin shows promise

Bentley Pharmaceuticals has successfully delivered insulin to type 1 diabetics using its novel intranasal formulation, throwing its hat into the ring of companies seeking to replace insulin injections with more patient-friendly options.

The specialty pharmaceutical and drug delivery company, which has a growing branded and generic product line in Europe, reported the results of a Phase II trial of the formulation, called CPE-215, at the end of last week.

This study was the first intranasal insulin trial conducted in a target population of diabetic patients and was intended to assess absorption of insulin and timing of dosing.

Seven diabetic patients received up to four doses of intranasal insulin spray, subcutaneous insulin or placebo. The total dose of intranasal insulin spray ranged from 25 to 100 International Units. Preliminary results indicate that the intranasal insulin was well absorbed and that there was partial suppression of the postprandial glucose elevation in the two hours after a standard breakfast, similar to that seen with subcutaneous insulin.

Pharmaceutical companies are queuing up to deliver an alternative to injections for insulin, with inhaled, intranasal and oral alternatives already in the clinic.

And with the number of patients with diabetes currently estimated at about 25 million in Europe alone - and escalating every year - the rewards for a company that can come up with a safe alternative to injections look assured. Analysts have predicted that the first inhaled insulin product to reach the market could achieve sales upwards of $1.5 billion a year.

Bentley is a little behind the game with its intranasal version, as inhaled products are already in late-stage clinic and one, Pfizer and Sanofi-Aventis' Exubera, is already under regulatory review. However, fear of side effects seen with inhaled products - the result of lung function testing in animals - could limit the use of these products and leave room for other delivery approaches.

James Murphy, Bentley's chairman and CEO, said: "These preliminary results are very encouraging. After full analysis of all data, we plan to design further studies in patients to better define the entire profile of our formulation."

He added that the company is seeking a development partner as it progresses further into Phase II and then Phase III development.

Scientists have known for years that the intranasal route of administration of therapeutic agents was a highly efficient route, but success in this route of administration has been difficult due to low delivery payload, poor reproducibility and/or mucosal irritation.

"We are particularly encouraged by these results because they reinforce the potential for the intranasal delivery of other peptides as well,"said Murphy.