When GlaxoSmithKline announced that it would unveil head-to-head trial data on its HPV vaccine long after the fact and at a lesser-known meeting, folks speculated that the drugmaker might be embarrassed of the trial's outcome. Not so--emphatically not so. The company trumpeted the comparative study, saying that its Cervarix vaccine prompted a much stronger immune-system response than Merck's Gardasil did.
The Glaxo shot generated two times as many antibodies for one HPV strain than Gardasil did, the data showed, and more than six times as many for another. Plus, Cervarix patients produced 2.7 times more memory B cells for HPV than patients who received the Merck vaccine. Another study due to be presented at the same conference found that Cervarix provided sustained antibodies against HPV through more than seven years of follow-up, the company said.
"The presence of neutralising antibodies at the location of the infection (the cervix) appears to be an important part of vaccine-induced protection against HPV," said Glaxo's R&D chief Thomas Breuer in a statement. "This study offers the first evidence that these two vaccines do not generate the same immune response."
Merck was ready to rumble though; the Gardasil maker said that the comparative data isn't clinically relevant because there's no evidence a higher immune response actually made much difference to the long-term risk of developing cancer, Reuters reports. Sanofi Pasteur MSD, a joint venture between Merck and Sanofi that sells Gardasil in Europe, also got into the act: "We see no clinical relevance in the results of this study ... and we don't see the point of doing such a comparison," Bennett Lee, medical director, told the wire service. "If you want to compare vaccines, you compare clinical efficacy."
Nonetheless, it's something of a coup for Glaxo, which was betting the farm on Cervarix when it chose to pit its HPV shot against Merck's. Now if only Glaxo can get Cervarix past the FDA, then it will really have a fight with Merck on its hands.
- read the Glaxo release
- see the story from Reuters