Hamburg, Dec. 2 (Reuters): Makers of anti-impotence drugs traded claim and counter-claim today in preparation for a $4-billion battle over a market so far dominated by Viagra.
Pfizer Inc’s famous little blue pill will face its first real competition next year when two new drugs, Levitra and Cialis, go on sale in Europe and the US.
GlaxoSmithKline Plc and Bayer AG, the makers of Levitra, presented data at a medical conference here showing their new impotence drug could boost men’s chances of being able to have sex more than five-fold.
Pfizer hit back with results from a clinical study rebutting claims that Viagra was slower-acting than the newcomers.
Viagra has been a huge commercial success for Pfizer, raking in 2001 sales of $1.5 billion and establishing itself as the world’s most famous pharmaceutical brand.
But analysts at Merrill Lynch believe there is considerable room for new entrants, since more than 50 per cent of patients on Viagra fail to ask for a repeat prescription and up to 25 per cent do not achieve an adequate erection.
GSK and Bayer, presenting long-term data for Levitra for the first time at the Congress of the European Society for Sexual and Impotence Research in Hamburg, said their drug had demonstrated excellent efficacy and safety.
A clinical study involving 1,020 men with impaired erectile function given Levitra for up to one year found they were nearly five-and-a-half times more likely to report success in maintaining an erection after taking the pill than those on placebo.
Five per cent of patients on the lower dose and six per cent of those on the higher dose stopped taking the drug because of adverse events. Headaches, flushing and rhinitis were the most side-effects reported but none were serious.
“This is an important study for two reasons,” said Dr Inigo Saenz de Tejada, the lead investigator and president of the Fundacion para la Investigacion y el Desarrollo en Andrologia in Madrid.
“First, patients reported sustained, improved erectile function with Levitra over a one-year period. Secondly, on average, men were successful more than eight out of 10 times in maintaining an erection sufficient for sexual intercourse with Levitra.”
Pfizer, meanwhile, shot down suggestions that Viagra was slower-acting than the newcomers, citing new data showing half the men taking Viagra could have sex within 20 minutes.
Eli Lilly and Co’s drug Cialis, developed with US biotechnology company Icos Corp, in particular, has been widely reported to work faster than Viagra but Pfizer said results of the new study showed its pill can also work fast.
In the study, 228 men previously successfully treated for mild, moderate or severe erectile dysfunction for at least two months were armed with stopwatches and told to record the time needed to obtain an erection hard enough for sexual intercourse.
Pfizer said results showed that within 14 minutes of taking Viagra, 35 per cent of men achieved an erection that resulted in successful sexual intercourse. A majority of men, 51 percent, achieved this within 20 minutes.