Pitrakinra May Significantly Reduce Asthma Symptoms

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Main Category: Respiratory / Asthma
Also Included In: Allergy;  Clinical Trials / Drug Trials
Article Date: 19 Oct 2007 - 0:00 PDT

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Using Pitrakinra to inhibit interleukins-4 and -13 in the lungs may significantly reduce asthma symptoms, according to an article in the medical journal The Lancet, this week's issue.

The authors explain that doctors and scientists have believed for over twenty years that cytokines, such as interleukin-4 or interleukin-13 play a vital role in the onset and development of clinical asthma. However, there has been no scientific evidence that this might be so.

Dr Malinda Longphre, Aerovance Inc, Berkeley, California, USA and team carried out two separate Phase II clinical trials, where patients received Pitrakinra. In the first study 12 volunteers received 25mg of Pitrakinra by subcutaneous injection once per day. The patients in the second study were given either 60mg of Pitrakinra twice a day by nebulization, and another 16 received a placebo. In both trials the volunteers inhaled allergens before and four weeks after treatment - the allergens are designed to induce an asthma attack, the patient during an asthma attack of this type finds it harder to expel air.

The primary endpoint for the first trial was a maximum percentage drop in forced expiratory volume (FEV1)** in one second over 4-10 hours after receiving the allergen. In the second study the primary endpoint was average percentage fall in FEV1 over 4-10 hours after being given the allergen. If smaller falls in FEV1 during the asthma attack for the Pitrakinra group compared to the placebo group were detected, this would indicate that the allergic response had been reduced by Pitrakinra.

In the first study, say the researchers, the maximum percentage fall in FEV1 was 17.1% in the Pitrakinra and 23.1% in the placebo groups - a comparable difference of 26%. In the second study the average percentage drop in FEV1 was 4.4% in the Pitrakinra versus 15.9% in the placebo group - in other words, it was over three and a half times less in the Pitrakinra group.

"The effects of pitrakinra on late phase asthmatic response are promising when compared with similar studies with other successful anti-inflammatory asthma therapies...whether the effect is due to inhibition of interleukin-13 alone, or both interleukin-13 an interleukin-4, is not yet known. Future studies of this drug, as well as molecules that specifically inhibit interleukin-13, in asthmatic individuals of all levels of severity over longer periods of time are clearly warranted," the writers conclude.

*Interleukins are a group of secreted signalling molecules (cytokines) which are part of the immune system.
** FEV1 is the amount of air that you can forcibly blow out in one second, measured in liters. It is considered one of the primary indicators of lung function.

"Effect of an interleukin-4 variant on late phase asthmatic response to allergen challenge in asthmatic patients"
S Wenzel et al
The Lancet Volume 370 • Number 9596 • October 20 - 26, 2007
http://www.thelancet.com

Written by: Christian Nordqvist
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