Pfizer Inc. and Celldex Therapeutics Inc.’s said 70 percent of patients getting their experimental brain tumor vaccine were alive without their cancer worsening about eight months after diagnosis, a study found.
Cancer typically progresses in about 50 percent of patients during that time period, said Tom Davis, Celldex’s chief medical officer. The finding, involving 40 patients, is from an interim analysis of a study reported today by the American Society for Clinical Oncology. The full results will be presented June 5 at the group’s annual meeting in Chicago.
New York-based Pfizer, the world’s biggest drugmaker, licensed rights to the drug last year from Needham, Massachusetts-based Celldex for as much as $440 million, plus royalties. If approved for brain cancer, the vaccine could have $450 million in peak annual sales and come on the market in 2013, said Joseph Pantginis, an analyst with Roth Capital Partners LLC.
Some investors may be disappointed because previous, smaller studies appeared to show a greater benefit with about 90 percent of patients alive without their cancer worsening after the treatment, called CDX-110, Pantginis said. That may be a misinterpretation of the data because the studies aren’t “apples-to-apples” comparisons, he said.
Celldex fell 8.9 percent to $6.99 at 7:06 p.m. New York time in extended trading after the close of the Nasdaq Stock Market. Pfizer fell 13 cents to $15.10 in extended New York trading.
More Data Needed
Further data on the vaccine’s survival benefit will be needed to draw definitive conclusions on the treatment, said Pantginis, who has a ‘buy’ rating on Celldex shares.
“There might be some disappointment out there because you have erosion to the progression rate,” he said. “This is still a positive progression number, but the data are immature.”
The treatment is designed to ramp up the body’s immune response to fight off the tumor. The vaccine targets the molecule called epidermal growth factor receptor variant III, which plays a role in cell growth. The strategy could be applied to breast, ovarian and prostate cancer as well, though none of those indications are in human testing, Celldex said.
The drug is in the second of three stages of testing required to get U.S. regulatory approval. Pfizer hasn’t announced plans to start final-stage testing. The next step likely will be a placebo-controlled study looking at about 200 patients worldwide, Davis said.
In the research, newly diagnosed patients received injections of CDX-110 along with radiation therapy and Merck & Co.’s Temodar until their tumor progressed. All patients received the experimental treatment, rather than giving the medicine to half of the participants while the other half received placebos.
Final results from 65 patients enrolled in the trial should be available by year’s end, Davis said.