More questions about Merck's Gardasil published in 'JAMA'
Aug 19th 2009 2:30PM
Updated Dec 3rd 2009 4:35PM
As if Merck & Co. (MRK) needed more scrutiny of its controversial cervical cancer vaccine, Gardasil.
One of the first cancer vaccines on the market, Gardasil combats human papillomavirus -- a sexually transmitted virus contracted by 80 percent of sexually active women by age 50 -- Gardasil was designed to immunize women before they contract the virus and was approved by the Food and Drug Administration in 2006 for girls and women between 9 and 26. The Advisory Committee on Immunization Practices recommended that girls be vaccinated at ages 11 to 12.
Some states tried to make the vaccine mandatory, but many objected for various reasons: fear of encouraging promiscuity, for one, but also out of questions on its effectiveness, safety and longterm effects. A new study could further legitimate such concerns. Some who received the vaccination fainted, and there were reports of deaths, which the FDA and the Centers for Disease Control and Prevention continued to track.
On Tuesday, CDC and FDA researchers writing in the Journal of the American Medical Association said the drug is safe and that the rate of adverse events associated with doses of Gardasil is similar to the prelicensing rate among the 21,000 girls and young women who tested it in clinical trials and to that of other vaccines.
But significantly, Gardasil was associated with higher rates of blood clots and fainting, compared with other vaccines. Researchers analyzed 12,424 reports of adverse events between June 2006 and December 2008, associated with the 23 million doses distributed. That's quite a small percentage, but six percent of those reports were classified as serious, including 32 deaths. Most of the adverse-events rates were similar to those of other vaccines, but "there was disproportional reporting" of fainting and venous thromboembolic events, FirstWord reported.
Still, the JAMA article said that there was no evidence the severe adverse events were caused by the product. To explain the higher rate of VTE, researchers said that 90 percent of the cases also involved other risk factors and therefore urged caution. At the same time, they wondered if there hasn't been possible under reporting of events.
Merck, naturally, is emphasizing the report's finding that it says proves Gardasil's safety profile. The company did not fully address the fainting or VTE events, but it has a 15-minute observation policy following each administration of the vaccine.
"The vaccine's benefits and potential to prevent cervical cancer outweigh the risks," says lead researcher Barbara Slade. And at $400 for the three-dose regimen, no doubt many would choose a vaccine, even if cervical cancer is a rare form of cancer. But not all doctors agree. "Cervical cancer takes decades to develop, and there are established methods for detecting and treating it," wrote
The questions don't stop with Gardasil's safety profile. JAMA also published an article from Columbia University, questioning Merck's marketing practices for the vaccine. It seems that the American College Health Association, the American Society for Colposcopy and Cervical Pathology, and the Society of Gynecologic Oncologists promoted Gardasil with the help of $750,000 provided by Merck. Lines seemed to have blurred between education and marketing that did not address the "full complexity of issues surrounding the vaccine" or "provide balanced recommendations" on the product's risks and benefits. The associations' officials denied this.
It's not the first time Merck has been accused of pushy marketing, and it probably won't be the last. Between question regarding Gardasil's safety and effectiveness and its marketing practices, no wonder the vaccine's sales declined 18 percent in the second quarter. GlaxoSmithKline (GSK) makes a rival vaccine called Cervarix. While it's true, as Merck says, that "no vaccine or medicine is completely without risk," these risks should at least be known ahead of time so that a proper decision can be made. At the end, it seems, taking the risk is up to the consumer.