Cell Therapeutics, Inc. Reports Final Results From Cooperative Group and NCI-Sponsored Trial of Brostallicin in Patients With Metastatic Triple-Negative Breast Cancer

CHICAGO and SEATTLE, June 1, 2013 /PRNewswire/ -- Cell Therapeutics, Inc. (CTI) (NASDAQ and MTA: CTIC) today reported on final results from a cooperative group and NCI-sponsored Phase 2 clinical trial of brostallicin in combination with cisplatin for the treatment of women with metastatic triple-negative breast cancer (mTNBC). Triple-negative breast cancer lacks progesterone and estrogen receptors and the HER2 biomarker that is present in most breast cancers, which makes standard therapy with hormone or targeted therapy ineffective. The rationale for the present study in TNBC is based on data the demonstrating that silencing of the breast cancer susceptibility gene(s) (BRCA) is associated with substantially enhanced sensitivity to brostallicin. BRCA is silenced or mutated in most patients with TNBC. In this study of 48 patients with heavily pretreated mTNBC, the 3-month progression free survival (PFS) was 51 percent with 10 confirmed responses (one complete response and nine partial responses). Among the 25 patients who received a reduced brostallicin dose, the overall response rate (ORR) was 28 percent, with 3-month progression-free survival (PFS) of 61.5 percent and median overall survival (OS) of 11.8 months. The final data are being presented during a poster session at the 2013 American Society for Clinical Oncology (ASCO) Meeting being held May 31 to June 4, 2013 in Chicago, Illinois.

Abstract #1059: Final clinical results and correlative data from the phase II trial of cisplatin (C) and the novel agent brostallicin (B) in patients with metastatic triple negative breast cancer (mTNBC). Poster session, Saturday, June 1, 1:15 to 5:00 p.m. CDT in S Hall A2.

About the Study

The study enrolled women with confirmed measurable metastatic disease and triple-negative subtype breast cancer. A total of 48 women were enrolled in the study and 47 were evaluable for efficacy. Approximately half of the patients had received between two and four prior chemotherapy regimens in the metastatic setting. The primary endpoint of the trial was 3-month PFS. Secondary endpoints included ORR, duration of response, 6-month PFS, OS and safety. In this study, patients received cisplatin on Day 1, brostallicin on Day 2, and GCSF or pegylated-GCSF on Day 3, with the cycle repeated every 21 days. The study was led by investigators at the Mayo Clinic in Florida. Key findings include:

• As of this analysis, 10 of 47 evaluable patients achieved a confirmed tumor response. One patient had a complete response (CR) and nine patients had a partial response (PR),

• 3-month PFS was 51 percent and 6-month PFS was 28 percent; median time to progression was 3.2 months, and

• Adverse events were mostly hematologic (75 percent) and consistent with other treatments in this setting.

In an exploratory analysis, patients who received a reduced dose of brostallicin had an apparent increase in efficacy (ORR= 28 percent; 3-month PFS=61.5 percent; median OS=11.8 months) with a significant decrease in febrile neutropenia compared to cycle 1.

The authors concluded that in this study the combination of brostallicin and cisplatin was an active regimen in heavily pre-treated metastatic triple-negative breast cancer patients. A follow-up randomized Phase 2 trial using the reduced dosing regimen is in development.

The poster is available at www.celltherapeutics.com.

About Triple-Negative Breast Cancer

This term is used to describe breast cancers (usually invasive ductal carcinomas) whose cells lack estrogen and progesterone receptors, and do not express HER2. Breast cancers with these characteristics occur more often in younger women and African-American women. Triple-negative breast cancers are diagnosed at a later stage and spread more quickly than most other types of breast cancer. Because the tumor cells lack receptors, neither hormone therapy nor drugs that target HER2 are effective.¹ Patients with TNBC may respond to chemotherapy but responses are generally short and no therapy has been shown to be effective in patients who have more than one relapse.² About 10 to 20 percent of breast cancers are triple-negative.³

About Brostallicin

Brostallicin, a novel synthetic second-generation DNA minor groove binder, has shown potent cancer killing activity, and has demonstrated synergism in combination with standard cytotoxic agents as well as with newer targeted therapies, in preclinical experimental tumor models. Brostallicin binds covalently to DNA within the DNA minor groove, interfering with DNA division and leading to tumor cell death. More than 200 patients have been treated with brostallicin in single-agent and combination studies.

About Cell Therapeutics, Inc.

Cell Therapeutics (Nasdaq and MTA: CTIC) is a biopharmaceutical company committed to the development and commercialization of an integrated portfolio of oncology products aimed at making cancer more treatable. CTI is headquartered in Seattle, WA. For additional information and to sign up for email alerts and get RSS feeds, please visit www.CellTherapeutics.com.

Safe Harbor Statement

This press release includes forward-looking statements that involve a number of risks and uncertainties the outcome of which could materially and/or adversely affect actual future results and the market price of CTI's securities. Specifically, the risks and uncertainties that could affect the development of brostallicin include risks associated with preclinical and clinical developments in the biopharmaceutical industry in general, and with brostallicin in particular, including, without limitation, the potential failure of brostallicin to prove safe and effective for the treatment of women with metastatic triple-negative breast cancer, either alone or in combination with cisplatin, as determined by the U.S. Food and Drug Administration and/or the European Medicines Agency; that additional clinical trials of brostallicin may not occur as planned; CTI's ability to continue to raise capital as needed to fund its operations; and competitive factors, technological developments, costs of developing, producing and selling CTI's product candidates, and the risk factors listed or described from time to time in CTI's filings with the Securities and Exchange Commission including, without limitation, CTI's most recent filings on Forms 10-K, 10-Q and 8-K. Except as may be required by law, CTI does not intend to update or alter its forward-looking statements whether as a result of new information, future events, or otherwise.

References

1. American Cancer Society. Available at http://www.cancer.org/cancer/breastcancer/detailedguide/breast-cancer-breast-cancer-types Accessed May 2013.
   
2. Chacon, Renaldo;Constanzo Maria. "Triple-negative breast cancer." Breast Cancer Research. 12(suppl 2):S3 (2010). Available at http://breast-cancer-research.com/content/12/S2/S3. Accessed May 2013.
   
3. Living Beyond Breast Cancer: Guide to Understanding Triple-Negative Breast Cancer 2nd Edition 2012. Available at http://www.lbbc.org/Understanding-Breast-Cancer/Guides-to-Understanding-Breast-Cancer/Guide-to-Understanding-Triple-Negative-Breast-Cancer. Accessed May 2013.

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SOURCE Cell Therapeutics, Inc.