Pharmaxis asthma treatment found safe, but is it effective?

Asthma sufferers will have to wait a little longer before they have a potential new treatment after an exploratory phase IIa trial of Pharmaxis’ (ASX:PXS) experimental treatment for allergic asthma, ASM8, was inconclusive on efficacy.

The randomised crossover trial showed a significant reduction in allergic response three to seven hours after administration of the drug at two different doses, but patients receiving a placebo also experienced a similar reduction over the same time scale.

Patients who received 3mg of ASM8 saw a 44% reduction in allergic response, and those receiving 7.8mg saw a 41% reduction.

However, patients receiving the control dose also saw a 44% reduction in allergic response three to seven hours after the dose.

The company speculates that this result could be a consequence of the trial design. Being a crossover study, patients randomly received either the 3mg, 7.8mg or control dose once a day for two weeks. They then had a four to six week washout between doses before a new dose was randomly assigned.

It’s possible that the significant control response is due to drug carryover, suggesting the washout period may have been insufficiently long.

Pharmaxis CEO Dr Alan Roberston commented that the trial results were encouraging, although acknowledged that further trials would be required.

“We remain encouraged by these new clinical data demonstrating the potential value of this approach for treating asthma,” he said.

“We now know that ASM8 is best dosed once per day and we know that 3mg is an appropriate dose for future trials.

“The statistically significant response when patients were treated with vehicle indicates that future studies with drugs of this nature should be parallel in design.”

The trial did find that ASM8 was safe, with no significant differences in adverse events between the treatment groups.

The full results of the trial are being compiled and will be presented at a future scientific conference.

ASM8 is a combination product of two RNA-silencing oglionucleotides targeting two cellular pathways involved in airway inflammation.

Pharmaxis (ASX:PXS) share price dipped by nearly 5% as of 12.30pm, dropping to $1.23 in high volume trading through the morning.

The company also announced that UBS Global Asset Management has become a substantial holder as of 12 April, with the investment company holding 15.3 million securities and taking 5.01% voting power.