Antibody drug conjugate targets gpNMB, a protein which promotes the migration, invasion and metastasis of breast cancer

HAMPTON, NJ, USA I December 2, 2013 I Celldex Therapeutics, Inc. (Nasdaq:CLDX) today announced that it has launched a randomized study (METRIC) of Glembatumumab vedotin (CDX-011) in patients with metastatic triple negative breast cancers that over-express glycoprotein NMB (gpNMB). Glembatumumab vedotin is an antibody-drug conjugate that targets and binds to gpNMB, a specific protein that is expressed in breast cancer which promotes the migration, invasion and metastasis of the disease. It is also highly expressed in triple negative breast cancers where it is associated with increased risk of recurrence. Initial sites are now open to screen patients in the United States. Additional sites in the United States and in Canada and Australia will open in early 2014. The study is expected to include up to 100 sites and will enroll approximately 300 patients.

“In the Phase 2 EMERGE study, Glembatumumab vedotin elicited impressive response rates that correlated with a survival benefit for patients with metastatic breast cancer that also had high levels of gpNMB on the surface of their tumor cells,” said Thomas Davis, M.D., Senior Vice President and Chief Medical Officer of Celldex. “Currently, patients with triple negative breast cancer have very limited treatment options and no targeted interventions. We believe gpNMB could be an important marker in breast cancer and that Glembatumumab vedotin holds significant potential as a possible targeted therapy for women facing this disease.”

“Given the lack of treatment options available for women with triple negative breast cancer, we are gratified that we are able to conduct the METRIC study on an accelerated approval path and are committed to enrolling the study expeditiously,” said Anthony Marucci, President and Chief Executive Officer of Celldex. “We also plan to further expand the clinical development program for Glembatumumab vedotin in 2014 by initiating additional studies in other cancers known to express gpNMB including melanoma and squamous cell lung cancer.”

About the METRIC Study

The METRIC study is a pivotal, open-label, prospectively controlled, randomized study of Glembatumumab vedotin in patients with metastatic gpNMB-expressing triple-negative breast cancer. Eligible patients must have received no more than 1 prior line of chemotherapy for advanced disease and therapy must have included a taxane and anthracycline. Patients will be randomized (2:1) to receive Glembatumumab vedotin or capecitabine. Study treatment will continue until disease progression or intolerance with tumor assessments performed at six week intervals for six months and nine week intervals thereafter. The primary objective is to evaluate the anti-cancer activity of Glembatumumab vedotin as measured by the objective response rate (ORR) and duration of progression-free survival (PFS). The study is designed to enable Celldex to apply for registration with positive results for either endpoint. Secondary endpoints include duration of response, overall survival, safety and tolerability. The Company will also assess improvements in quality of life and/or cancer-related pain as exploratory endpoints.

Patients will be stratified as follows:

  • No prior chemotherapy for advanced disease vs. 1 prior line of chemotherapy for advanced disease
     
  • “Resistant” to anthracycline therapy (i.e., progression-free interval of ≤ 6 months after completing treatment) vs. “Exposed” to anthracycline therapy (i.e., progression-free interval of > 6 months after completing treatment)

Clinical Data Supporting Glembatumumab vedotin in Triple Negative Breast Cancer

In the Phase 2 EMERGE study, final data supported an overall survival benefit in specific sub-groups of breast cancer patients with tumors that over-express gpNMB. Treatment of patients with both triple negative breast cancer and over-expression of gpNMB showed a high overall response rate (ORR) of 33% (n=12) when treated with Glembatumumab vedotin. In comparison, no responses (n=4) were seen in patients with both triple negative breast cancer and over-expression of gpNMB with standard chemotherapies. In this same patient population, the median overall survival (OS) for patients treated with Glembatumumab vedotin was 10 months vs. 5.5 months (p= 0.003) and progression free survival (PFS) was 3 months for the Glembatumumab vedotin arm vs. 1.5 months for the control arm (p=0.008), respectively. The most common adverse event was rash.

About Glembatumumab vedotin

Glembatumumab vedotin (CDX-011) is a fully-human monoclonal antibody-drug conjugate (ADC) that targets glycoprotein NMB (gpNMB). gpNMB is a protein overexpressed by multiple tumor types, including breast cancer and melanoma. gpNMB has been shown to be associated with the ability of the cancer cell to invade and metastasize and to correlate with reduced time to progression and survival in breast cancer. The gpNMB-targeting antibody, CR011, is linked to a potent cytotoxic, monomethyl auristatin E (MMAE), using Seattle Genetics’ proprietary technology. Glembatumumab vedotin is designed to be stable in the bloodstream, but to release MMAE upon internalization into gpNMB-expressing tumor cells, resulting in a targeted cell-killing effect. Glembatumumab vedotin is in development for the treatment of locally advanced or metastatic breast cancer—with an initial focus in triple negative disease. In May 2010, the U.S. Food and Drug Administration (FDA) granted Fast Track designation to Celldex’s Glembatumumab vedotin for the treatment of advanced, refractory/resistant gpNMB-expressing breast cancer. Glembatumumab vedotin is also in development for the treatment of Stage III and IV melanoma.

About Celldex Therapeutics, Inc.

Celldex is developing targeted therapeutics to address devastating diseases for which available treatments are inadequate. Our pipeline is built from a proprietary portfolio of antibodies and immunomodulators used alone and in strategic combinations to create novel, disease-specific therapies that induce, enhance or suppress the body’s immune response. Visit www.celldex.com.

SOURCE: Celldex Therapeutics