Table I.

Selection of asthma therapies undergoing clinical trials

Agent	Clinical trial status	Efficacy	References
Anti-cytokine therapies
IL-4R-α antagonist	Phase 2	Despite initial benefits in severe asthmatics, these compounds have been discontinued	27
Anti-IL-5	Phase 2	Shown to reduce the number of severe asthma exacerbations	24, 25
Anti-IL-5R-α	Phase 2	Reduces circulating eosinophils. Favourable safety, pharmacokinetic and pharmacodynamic profile. Efficacy studies using IV and SC routes of administration still ongoing	13
Anti-IL-9	Phase 2b	Modest improvements reported in patients with mild asthma undergoing allergen challenge. Larger clinical studies underway in severe asthmatics	14
Anti-IL-13	Phase 2	Five anti-IL-13 compounds investigated. Early compounds reduced both early asthmatic response (EAR) and late asthmatic response (LAR) Majority of Phase 2 results yet to be released	15, 16
Chemokine ihibitors
CCR3 antagonist	Phase 2	Orally active competitive antagonist, currently on trial for mild to moderate asthma	17
Toll-like receptor targets
TLR7, TLR9 synthetic agonists	Phase 1 and 2	Effective in animal models of asthma, efficacy in human studies yet to be determined	18
Kinase inhibitors
Syk kinase inhibitor	Phase 2 planned	In Phase 1, reported that the inhaled inhibitor is well tolerated, with an improvement in both the EAR and LAR	19
c-kit/PDGF receptor tyrosine kinase inhibitor	Phase 3	In Phase 2, generated promising efficacy data and good safety profile	20
Phosphodiesterase inhibitors
PDE 3/4 inhibitors	Phase 2	Reduced EAR and LAR in naive atopic asthmatics in response to inhaled allergen. However, orally administered drugs result in side effects such as gastro-intestinal symptoms	21