Evaluation of the antirhinovirus chalcone Ro 09-0415 given orally to volunteers.

Ro 09-0415, a phosphorylated 'pro-drug' of the potent antirhinovirus compound, 4' ethoxy-2'-hydroxy-4, 6' dimethoxy-chalcone (Ro 09-0410) was tested in a double-blind placebo-controlled trial for its protective effect against experimental rhinovirus infection. The maximum dose, 1200 mg bd, based on considerations of practicality and tolerance was given orally both before and after challenge with a sensitive rhinovirus, type 9. Plasma concentrations of active compound in excess of those required for the inhibition of rhinovirus type 9 in vitro were achieved, but there was no evidence to suggest that treatment with Ro 09-0415 had a beneficial effect. It is concluded that Ro 09-0415 given orally is unlikely to be of value in the prophylaxis or therapy of human rhinovirus infection.