Celldex scores upbeat data for breast cancer drug

Celldex Therapeutics ($CLDX) has provided positive data for its targeted drug against tough-to-treat breast tumors, and executives expect to seek a nod from regulators to advance the experimental treatment into a late-stage study required for approval.

The Needham, MA-based company's CDX-011 consists of an antibody targeted to the GPNMB protein and an attached chemotherapy agent that is supposed to hit tumor cells with a killer punch. In a 122-patient study, 19% of patients on Celldex's drug had a response compared with 14% among patients who got standard chemotherapy. And investigators found that response rates were higher in patients with increased levels of GPNMB, a protein on tumor cells that enables cancer to mobilize and spread. Prior to the study, all participants had received previous treatments.

The data from the mid-stage trial are preliminary and don't shed much light on the survival benefit of the treatment, yet Celldex is planning to release further details late this year. Executives aim to get the FDA to sign off on an advanced study of the drug to combat breast tumors that express GPNMB and fall into the triple-negative category, TheStreet reported. These difficult-to-treat tumors account for about a third of cases of breast cancer, according to the company, which acquired the drug in its 2009 buyout of CuraGen. Celldex has a license to antibody linking technology and cell-killing agent for CDX-011 from Seattle Genetics ($SGEN), which uses the same tech for its approved lymphoma drug Adcetris.

"GPNMB helps the tumor cell to move around," said Dr. Linda Vahdat, director of the breast cancer research program at Weill Cornell Medical College and the lead investigator of the study, as quoted by Reuters. "It almost seems like this drug puts the brakes on that process by taking away its legs."

As Adam Feuerstein at TheStreet noted, however, Celldex hasn't provided any proof that CDX-011 prolongs survival or stymies re-growth of tumors for a significant period of time. And those are the types of endpoints that regulators in the U.S. and Europe like to see programs reach before green-lighting cancer drugs. 

- here's the release
- read Reuters' article
- and TheStreet's piece