Tick-tock. Tick-tock. Every day that the Food and Drug Administration delays making a decision about Merck's (NYSE: MRK) Gardasil, a few more women turn 46, out of the expanded age range the company is hoping to get approval for.

Merck asked the FDA more than two years ago to expand the upper end of the age range of women getting vaccinated against human papillomavirus (HPV) from 26 to 45, but the agency decided it needed more data.

The drugmaker resubmitted the data last year and expected to hear about an approval by next week; instead the FDA has delayed a decision until sometime before the end of the year.

While waiting for the FDA to approve the expanded age range, sales have gone to sleep.

Metric

2007

2008

2009

U.S. Sales of Gardasil (in millions)

$1,194

$1,041

$802

Year-over-year increase (decrease)

408%

(13%)

(23%)

Source: company releases.

An approval for use in males to prevent genital warts late last year has slowed the bleeding a little -- U.S. sales fell by only 13% year over year in the first quarter -- but Gardasil also has new competition from GlaxoSmithKline's (NYSE: GSK) HPV vaccine Cervarix, and the fight will only get fiercer as Glaxo picks up marketing steam.

Expanding the age range should help sales a little, but it'll be a one-time boost. To make a real push toward mega-blockbuster status such as Pfizer's (NYSE: PFE) childhood vaccine Prevnar, Merck and its ex-U.S. marketing partner sanofi-aventis (NYSE: SNY) need to do a better job at getting the females at the young end of the age range vaccinated.

One study published in last month's American Journal of Preventive Medicine said just 34% of girls ages 13 to 17 had been vaccinated. That's a lot of untapped market that actually will be rejuvenated each year as girls enter the low end of the age range.

You'd better get busy, Merck, while you're waiting.