By Richard Acello
Small Times Correspondent
SAN DIEGO, Dec. 28, 2001 — A group of West Coast scientists has developed an improved propellant system for use in aerosol drug delivery.
It’s a development that could allow more than 17 million Americans afflicted with asthma, and millions more with other chronic lung diseases, to breathe easier.
Using hollow, porous, perforated particles or microstructures that one inventor of the system likens to “little Wiffle balls,” scientists have discovered that drugs administered in the propellant are more likely to enter the lungs, leading to more consistent and beneficial results.
The research is described in a patent issued on Oct. 30 to San Francisco Bay area-based biotech Inhale Therapeutic Systems Inc. and a group of inventors that includes Jeffry Weers, Ernest Schutt, Luis Dellamary, Thomas Tarara, and Alexey Kabalnov.
The PulmoSphere process, first described in a 1999 paper published in Pharmaceutical Research, is currently in clinical study. The results of those tests are expected to be published in the upcoming issue of the same periodical.
From his office at Inhale, Weers, said the company is in “early negotiations” with at least one unnamed pharmaceutical firm on a development deal for PulmoSphere. “We’ve been able to form a very stable supply of propellant in that (nanosize) media,” Weers said. “It’s a more efficient dispersal system, meaning there’s less impact on the throat, so more of the drug gets into the lung.”
Currently, the most widely used devices for delivering drugs into the lungs are metered dose inhalers (pMDIs) and dry powder inhalers (DPIs). Both inhalers deliver micronized drugs in a process that has been described as equivalent to throwing a crystal ball at a steel wall.
On contact with the throat, the crystal splinters into millions of pieces with little control over the size, density and other factors that affect how the drug is dispersed into the lungs. Lacking direction, and forced to mingle with other particles, the dose that can be delivered is less than about 10 milligrams. Treatment is also undermined by cohesive forces between drug particles that also hamper powder flow.
In metered dose inhalers, the dry powder must be dispersed in a hydrofluoroalkane (HFA) propellant. But this approach to stabilizing drugs in propellants is subject to flocculation, or clotting. To combat clotting and other effects, the canister containing the drug must be shaken by the patient and used promptly.
Inhale’s line includes 21 products that have completed or are in human clinical testing.
For the quarter that ended Sept. 30, Inhale lost $26.9 million, or 49 cents a share, on revenue of $22.4 million, compared with a loss of $13.2 million, or 31 cents a share, on revenue of 14 million a year earlier. Despite the red ink, Inhale still has a war chest of about $353 million in cash and investments.
“That’s to be expected. As the value of the product you’re testing goes up, so do the expenses” associated with clinical trials.
According to McCamant, Inhale scored a recent victory when Chiron Corp. dropped the inhaled drug technology of Sunnyvale, Calif.-based Aerogen Inc. for treating infection in patients that have cystic fibrosis. Instead, Chiron went with Inhale.
Under its agreement with Inhale, Chiron will help develop a new inhaled Tobramycin powder for treating cystic fibrosis patients. This could lead to the development of other inhaled antibiotics.
“That’s a pretty strong vote for Inhale,” McCamant said. Inhale is considered one of the industry leaders in its space, McCamant added.
“You’re looking at decent-sized markets, but you have business model questions, since they don’t own the drugs outright,” McCamant said, referring to Inhale’s moves into PulmoSphere technology.
Joel Martin, a partner at San Diego-based Forward Ventures, is bullish on the role of nanotechnology for “limitless” applications in particulates, coatings and medical devices, but tempers his enthusiasm with the “pragmatic” approach of an investor.
“I always ask ‘What does it do for you?’ ” he said. “I don’t want to be on the bleeding side of technology.” Forward has more than $300 million under management.
Martin said the premise behind Inhale’s PulmoSphere technology is a “sound one, the dry powder spray is a good route of administration for certain drugs.”
He does, however, have one reservation about its commercial potential. “The hard part is getting the drug into the patient who can’t breathe well,” he explained. Patients can have varying degrees of breathing capacity, Martin said, making the metering of the dosage difficult.
Martin joined Forward in November. Previously, he founded Quantum Dot Corp. in Hayward, Calif., and is still chairman of its board of directors.