Numerous recombinant
therapies are being investigated for the treatment of
asthma. This report reviews the current status of several of these novel agents. Anti-
immunoglobulin (Ig)E (
omalizumab,
Xolair) markedly inhibits all aspects of the
allergen challenge in subjects who have reduction of free serum
IgE to undetectable levels. Several clinical studies in atopic
asthma have demonstrated benefit by improved symptoms and lung function and a reduction in
corticosteroid requirements. Early use in atopic asthmatics may be even more effective. Several approaches target
interleukin (IL)-4. Soluble
IL-4 receptor has been shown to effectively replace inhaled
corticosteroid; further studies are under way. Recombinant anti-IL-5 and recombinant
IL-12 inhibit blood and sputum eosinophils and
allergen-induced
eosinophilia without any effect on airway responsiveness,
allergen-induced airway responses, or
allergen-induced
airway hyperresponsiveness.
Efalizumab, a recombinant antibody that inhibits lymphocyte trafficking, is effective in
psoriasis. A bronchoprovocation study showed a reduction in
allergen-induced late asthmatic response and
allergen-induced
eosinophilia, which suggests that it should be effective in clinical
asthma. These exciting novel
therapies provide not only promise of new
therapies for
asthma but also valuable tools for investigation of
asthma mechanisms.