Biotech stocks were rocked last week when Dendreon, which makes the only approved cancer vaccine, reported that sales of Provenge significantly missed their mark. Dendreon lost two-thirds of its market value and dragged the rest of the market down with it.
One of the casualties was Needham, MA-based Celldex. The developer's experimental brain cancer vaccine--called rindopepimut (CDX-110)--recently completed a Phase II trial. The company's stock hit a 52-week low despite a Journal of Clinical Oncology article which showed for the first time that rindopepimut had an effect on brain tumors in patients.
Seeking Alpha explains that it can be very difficult for cancer vaccine developers to prove that their experimental products are clinically active, particularly in early-stage trials. Because rindopepimut is administered to patients who've had their tumor removed and are undergoing radiation and chemotherapy, it's hard for researchers to know whether patient outcomes are the result of the experimental vaccine, or standard care. So Celldex examined a databased of patients whose tumors were EGFRvIII-positive--rindopepimut's target. They found that 16 EGFRvIII-positive patients in the trial who'd received the vaccine became EGFRvIII-negative when they experienced disease recurrence. This "is unequivocal proof that the vaccine is doing something to tumors that express its target," explains Seeking Alpha.
The results will have to be confirmed in a larger trial. The developer plans to start a late-stage trial of rindopepimut this year, with results expected in 2013.
- here's the Seeking Alpha article