Activity Demonstrated in Advanced Breast Cancer and Melanoma

BRANFORD, CN, USA | June 2, 2009 | CuraGen Corporation (Nasdaq: CRGN) reported three data presentations from its ongoing clinical trials of CR011-vcMMAE, an antibody-drug conjugate that targets GPNMB, in patients with advanced breast cancer and melanoma at the 2009 Annual Meeting of the American Society of Clinical Oncology (ASCO) in Orlando, Florida.

The Phase I/II study of CR011-vcMMAE administered intravenously once every three weeks in patients with advanced breast cancer began with a bridging phase to confirm the maximum tolerated dose and has expanded into a Phase II open-label, multi-center study. The study is designed to assess efficacy with an endpoint of progression-free rate at 12 weeks. The principal investigator is Dr. Linda Vahdat, Medical Director of the Breast Cancer Research Program and Associate Professor of Clinical Medicine, NewYork-Presbyterian Hospital/Weill Cornell.

Preliminary data were presented on 18 evaluable patients treated at doses of 1.0 – 1.88mg/kg from the Phase I portion and the initial portion of the Phase II study. Selection for enrollment was not based on expression of GPNMB in patients’ tumors. The median number of prior chemotherapy regimens for metastatic disease was 4 (range 2-11). Triple negative disease (ER/PR/Her-2 negative) was present in 44% of patients. Partial responses were seen in 3 patients (1 confirmed), including a patient with triple negative disease. Fifty percent (50%) of patients showed tumor shrinkage. Toxicities were similar to those observed in previous studies with CR011-vcMMAE; the most common adverse events were rash, alopecia, and fatigue. Twelve patients have now been enrolled in the Phase II portion of the study at a dose of 1.88mg/kg given once every three weeks, with total Phase II enrollment planned for up to 25 patients.

"We are very encouraged by the early evidence of activity demonstrated in this trial and look forward to presenting additional data on the Phase II study in the second half of the year," commented Dr. Ronit Simantov, Chief Medical Officer of CuraGen. "The emerging role of GPNMB, which is present in 25-40% of breast cancer patients, combined with our clinical activity, suggests that GPNMB may be an important new target in breast cancer."

Also at ASCO, data from a Phase II trial of CR011-vcMMAE in patients with advanced melanoma were presented at a poster discussion session. Thirty-six patients were enrolled into this Phase II open-label, multi-center trial that evaluated the efficacy and safety of CR011-vcMMAE 1.88 mg/kg administered intravenously once every three weeks. Eligible patients had progressive disease at trial entry and may have received one prior cytotoxic regimen and any number of prior immunotherapies. Of the patients enrolled, 94% had Stage IV disease of which two-thirds were classified as M1c, the poorest risk group.

The study successfully met its primary activity endpoint, with 5 objective responses (1 unconfirmed) observed in 34 evaluable patients, and median duration of response of 5.3 months. The median overall progression-free survival (PFS) was 4.4 months. Tumor shrinkage was observed in 58% of patients, and 20 patients had best response of stable disease. Dermatologic adverse events consisting of rash, alopecia, and pruritus were the most common toxicities in this study. Other adverse events included fatigue, diarrhea, anorexia and nausea. Grade 3 or 4 neutropenia was observed in 5 patients. The absence of rash in the first cycle of treatment predicted a worse PFS. Additionally, in a subset of patients with tumor biopsies, high levels of tumor expression of GPNMB appeared to correlate with favorable outcome.

"These Phase II results show evidence of activity in patients with advanced melanoma that compares favorably to activity seen with other currently used treatments for these patients, who are in need of additional options," commented Dr. Simantov.

In addition, data from the ongoing assessment of more frequent dosing of CR011-vcMMAE in 28 patients with advanced melanoma were presented at ASCO. Thus far, a dose of 1.0 mg/kg given once every week has been identified as the maximum tolerated dose in a weekly schedule, and a dose of 1.5mg/kg is currently being explored in the two out of three week schedule. Although median duration of follow-up is only 6 weeks, objective responses have thus far been observed in 3 of 11 evaluable patients treated with weekly CR011-vcMMAE (1 confirmed) and 1 confirmed response in 8 evaluable patients treated with CR011-vcMMAE two out of every three weeks.

"This study has confirmed that CR011 is active and that more total drug can be safely given with more frequent dosing," stated Dr. Simantov. "The expansion phase of the study will be used to generate a better estimate of the response rate with these schedules to compare to the once every three week schedule."

"The results presented at ASCO are important because they expand the activity of CR011 into patients with metastatic breast cancer and open this area up as an important development opportunity in addition to the opportunity in patients with metastatic melanoma," commented Dr. Timothy Shannon, President and Chief Executive Officer of CuraGen. "The remainder of these studies will be used to better understand the breast cancer opportunity and to understand how dose, schedule and the use of biomarkers such as the presence of GPNMB and rash might be used to enhance activity in further development."

Reprints of the presentation are available on CuraGen’s website at http://www.curagen.com or can be requested by emailing info@curagen.com.

About CR011-vcMMAE

 

CR011-vcMMAE is an antibody-drug conjugate (ADC) being developed by CuraGen that consists of a fully-human monoclonal antibody, CR011, linked to a potent cell-killing drug, monomethyl-auristatin E (MMAE). The ADC technology, comprised of MMAE and a stable linker system for attaching it to CR011, was licensed from Seattle Genetics, Inc. The ADC is designed to be stable in the bloodstream. Following intravenous administration, CR011-vcMMAE targets and binds to GPNMB, a specific protein that is predominantly expressed on the surface of cancer cells, including melanoma, breast cancer and gliomas. Upon internalization into the targeted cell, CR011-vcMMAE is designed to release MMAE from CR011 to produce a cell-killing effect. CR011-vcMMAE is currently in two Phase II trials assessing the safety and efficacy in the treatment of melanoma and for the treatment of metastatic breast cancer, and in a Phase I trial to evaluate the safety and activity of alternate dosing schedules.

About Melanoma

According to the American Cancer Society, it is expected that approximately 60,000 new cases of melanoma will be diagnosed, including nearly 11,000 patients diagnosed with Stage III or Stage IV disease, and an estimated 8,000 people in the U.S. will die of the disease during 2009. The prognosis for patients with advanced melanoma is poor, and studies have shown that the median survival is less than nine months.

About Breast Cancer

Breast cancer is the most common cancer in women and a leading cause of death in the United States. According to the American Cancer Society, more than 180,000 women will be diagnosed with invasive breast cancer in 2009 with more than 40,000 deaths attributed to this disease. Despite recent advances in therapy, the median survival of patients with metastatic breast cancer is 2 to 3 years, while patients with "triple-negative" or "basal-like" breast cancer have limited treatment options and poorer outcomes. Therefore, a significant unmet need remains for novel therapeutic approaches for patients with locally advanced and metastatic breast cancer who have failed other therapies.

About CuraGenCuraGen Corporation (Nasdaq: CRGN) is a clinical-stage biopharmaceutical company developing promising approaches for the treatment of cancer. CuraGen Corporation is headquartered in Branford, Connecticut. For additional information please visit http://www.curagen.com.

SOURCE CuraGen Corporation