Merck readies FDA submission for son of Gardasil

After suffering a postlaunch trough, sales of Merck's ($MRK) human papillomavirus (HPV) vaccine Gardasil have rebounded in recent years, restoring its blockbuster status. Now, though, a competitor is threatening to chip away at sales. Fortunately for Merck, it is the company developing the rival.

Merck is presenting data from the Phase III trial of its Gardasil successor, V503, at a HPV-focused medical meeting in Florence, Italy, this week. V503 is designed to protect against the four HPV strains covered by Gardasil--two of which are thought to cause 70% of cervical cancer cases--plus a further 5 forms of the virus. Merck ran the trial to test whether V503 is comparable to Gardasil in protecting against their four shared HPV strains, and whether it is superior in preventing infection by the other 5 forms.

Measuring immune responses through blood tests showed that V503 is comparable to Gardasil. And looking at precancerous lesions demonstrated its superiority in protecting against the 5 other strains. V503 cut the incidence of lesions caused by the 5 strains by 97% compared to Gardasil. Merck believes the data is strong enough to take to the FDA and expects to file a regulatory submission by the end of the year. "The case for using V503 is even stronger than the case for using Gardasil, which was already strong," Roger Perlmutter, head of R&D at Merck, told the Wall Street Journal.

Leerink Swann analysts think V503 will be a success--with sales expected to reach $1.9 billion by 2018--but this will come at the expense of Gardasil. Sales of Merck's current HPV vaccine are predicted to slump to $525 million in 2018, down from $1.6 billion last year. So, while V503 is still expected to give a net boost to sales, its impact will be mitigated by the cannibalization of income from Gardasil.

Merck is looking to V503 to offset generic competition facing its other blockbusters, a threat that prompted its decision to lay off 8,500 people. Vaccines will largely be spared, but 500 workers at the West Point plant--which makes the bulk ingredient for shingles vaccine Zostavax--are to lose their jobs. 

- here's the WSJ article (sub. req.)
- check out FierceBiotech's take
- read news of Merck's cuts