Objective: We previously reported that the nonpeptide tachykinin NK(2) receptor antagonist SR48968 (saredutant) significantly inhibits neurokinin A-induced bronchoconstriction in patients with asthma. MEN11420 (nepadutant) is a bicyclic peptide tachykinin NK(2) receptor antagonist. The aim of the trial was to examine the effect of nepadutant on neurokinin A-induced bronchoconstriction in man.
Methods: 12 patients with stable, mild to moderate asthma participated in a double-blind, placebo-controlled crossover trial and received, with intervals of 1 week, MEN11420 2 mg, MEN11420 8 mg and placebo (i.v.). Increasing concentrations of NKA (10(-9) to 10(-6) moles/ml) were inhaled immediately after (d1) and 24 hours after (d2) administration of treatment.
Results: On d1 both MEN11420 2 and 8 mg shifted the dose response curve for neurokinin A to the right (log PC(20) FEV(1) neurokinin A [moles/ml]; mean + or = or - SEM -6.38 + or - 0.26 after 2 mg, -6.11 + or - 0.23 after 8 mg, versus -6.95 + or - 0.27 after placebo]. On d2 MEN11420 had no effect on neurokinin A-induced bronchoconstriction.
Conclusion: In conclusion, the tachykinin NK(2) receptor antagonist nepadutant significantly inhibits bronchoconstriction induced by neurokinin A in patients with asthma.