The drug was already approved for use in boys aged 9 to 15, and for girls and young women aged 9 to 26.
Gardasil 9 is indicated to prevent certain diseases caused by nine types of HPV. It has the potential to avoid about 90% of cervical, vulvar, vaginal and anal cancers.
Merck said the drug includes the greatest number of HPV types in any available HPV vaccine.
The safety of Gardasil 9 was evaluated in 1,106 heterosexual males and 1,101 females. The primary analyses were carried out in the per-protocol population, in which study participants received all three vaccinations within pre-defined day ranges,
They did not have major deviations from the study protocol, and were seronegative to the relevant HPV types before dose one.
Merck said the analyses found that anti-HPV GMTs at month seven among males 16 through 26 years of age were non-inferior to anti-HPV GMTs among females 16 through 26 years of age.
In the clinical trails with GARDASIL 9 in males 16 through 26 years of age, the most common local and systemic adverse reactions reported were injection-site pain, injection-site swelling and injection-site erythema.
Merck Vaccines president Jacques Cholat said: "This is an important approval that now aligns the indication for GARDASIL 9 in males and females ages 9 through 26 to that of GARDASIL, and also supports the CDC’s HPV vaccine recommendations for use in males.
"We are pleased that males 16 through 26 years of age will now have access to GARDASIL 9, which includes the most HPV types, to help further reduce the burden of HPV-related diseases."