FDA Panel Considers HPV Vaccine Cervarix
If Approved, Cervarix Would Become Second Vaccine to Target Human Papillomavirus
Sept. 8, 2009 -- A second vaccine against human papillomavirus (HPV) is up
for the FDA's consideration to help prevent cervical cancer.
An FDA advisory panel will meet Wednesday to decide whether to recommend
approval of that vaccine, called Cervarix, in females ages 10 to 25.
Cervarix targets two HPV strains, HPV 16 and HPV 18, which are leading
causes of cervical cancer. It also contains an adjuvant, which is designed to
enhance the immune system's response against those HPV strains.
HPV infection is common; the virus is sexually transmitted. Most women who
get infected don't develop cervical cancer, and there are other possible causes
of cervical cancer.
On its web site, the FDA states that Cervarix has been shown to be effective
at preventing cervical cancer associated with HPV 16 and HPV 18 in teens and
women up to age 25 who hadn't been exposed to those HPV strains.
In the vaccine's clinical trials, participants got three doses of Cervarix
or a placebo over six months. Both groups had similar rates of serious adverse
events or death, the FDA notes. "No patterns indicating a potential safety
signal were discernible among the serious adverse outcomes," the FDA
However, the FDA has asked for a pregnancy registry to track miscarriage in
women who get Cervarix around the time of conception, due to an "imbalance" in
the proportion of those women who miscarried.
There is no proof that those miscarriages were due to the vaccine. Some of
those miscarriages took place in countries where abortion is illegal, and the
FDA notes that it's not clear if those were actually elective abortions that
were reported as miscarriage.
The FDA also wants post-marketing studies to track any cases of autoimmune
diseases (such as multiple sclerosis) and musculoskeletal conditions (including
arthritis and fibromyalgia) in patients who get Cervarix. Again, there is no
proof showing the vaccine caused rare cases of those conditions in clinical
After the FDA advisory panel makes its recommendations, it's up to the FDA
to make the final decision on whether to approve Cervarix. The FDA often
follows the recommendations of its advisory panels but is not required to do
The FDA approved the first HPV vaccine, Gardasil, in June 2006 for use in
girls and women ages 9 to 26. Gardasil targets four strains of HPV: HPV
6, HPV 11, HPV 16, and HPV 18.
Cervarix and Gardasil are both given by a series of three shots spread over
six months. No head-to-head studies have been done comparing the effectiveness
of Cervarix and Gardasil.