Merck’s human papillomavirus vaccine Gardasil could become a blockbuster 10 times over if the drugmaker can win approval for use of the treatment in men.

With Gardasil use rising faster than that of any new vaccine, administering it to boys and young men as well as girls could push annual sales potential above $10 billion, according to Lisa Kelly, an analyst at Wood Mackenzie Consultants Ltd. in Edinburgh, Scotland.

If Kelly’s estimates are correct, it would make Gardasil Merck’s best-selling product, far bypassing Singulair which had sales of $3 billion in 2006.

Merck is currently conducting studies to prove that Gardasil can prevent the spread of HPV infections in men. 

Meanwhile analysts estimate that Gardasil may generate as much as $1.4 billion in its first full year on the market as regulators across the globe endorse the vaccine as a means to prevent cervical cancer caused by the sexually transmitted human papillomavirus.