Acceleron and Collaborators Present Data on Potential Biomarkers for Metastatic Breast Cancer and Head and Neck Cancer at the "2012 Markers in Cancer" Conference

Acceleron and Collaborators Present Data on Potential Biomarkers for Metastatic Breast Cancer and Head and Neck Cancer at the "2012 Markers in Cancer" Conference

<0> Acceleron PharmaSteven Ertel, 617-649-9234Chief Business OfficerorSuda Communications LLCMaureen L. Suda, 585-387-9248 </0>

Acceleron Pharma, Inc., a biopharmaceutical company developing protein therapeutics for cancer and orphan diseases, and its collaborators are presenting data at the 2012 Markers in Cancer Conference in Hollywood, Fla., a joint meeting sponsored by ASCO, EORTC, and the NCI, that illustrate possible new biomarkers for use in metastatic breast cancer and in squamous cell carcinoma of the head and neck. The two poster presentations describe the potential role of activin A as an adverse biomarker for patients with metastatic breast cancer and of BMP9 as a biomarker for the identification and selection of patients with head and neck cancer. Acceleron is focused on developing novel medicines that regulate members of TGF-β superfamily of proteins, which include BMP9 and activin A. These proteins play fundamental roles in regulating the growth and differentiation of various cell types and are involved in diseases such as cancer.

Serum activin A was measured in 60 metastatic breast cancer patients before starting first-line trastuzumab-containing therapy. Progression-free survival (PFS) and overall survival (OS) were analyzed using the Kaplan-Meier method and Cox modeling with both continuous and dichotomous (median) serum activin A analyses. Higher serum activin A was significant on a continuous basis for predicting reduced PFS to first-line trastuzumab-containing therapy (p<0.003), and for predicting shorter OS (p<0.0001). When analyzed using a dichotomous (median) cutpoint, the elevated serum activin A cohort had a significantly reduced PFS (HR 2.79, p <0. 002) (median 6.6 mos vs.31.1 mos) and OS (HR 5.24, p <0.0001) (median 19.6 mos vs. median not reached). In multivariate analysis for PFS with other covariates (age, line of therapy, CA 15-3, and hormone receptor status), activin A was the only significant covariate (p=0.021). In multivariate analysis for OS, activin A (p=0.002) and CA 15-3 (p=0.03) remained significant as prognostic factors.

BMP9 is a ligand that binds with high affinity to activin receptor-like kinase 1 (ALK1) and regulates the maturation stage of angiogenesis. In an analysis of archived tumor samples from patients with squamous cell carcinoma of the head and neck, 79% of the samples had either medium or high expression of BMP9. Dalantercept is an ALK1 receptor fusion protein that binds to BMP9 and BMP10 and inhibits their signaling through the ALK1 receptor. Dalantercept is currently in a Phase 2 clinical trial for treatment of patients with SCCHN (clinicaltrials.gov identifier: NCT01458392).

About Acceleron

Acceleron is a privately-held biopharmaceutical company committed to discover, develop, manufacture and commercialize novel protein therapeutics for orphan diseases and cancer. Acceleron’s scientific approach takes advantage of its unique insight to discover first-in-class therapies based on the TGF-β protein superfamily. Acceleron utilizes proven biotherapeutic technologies and capitalizes on the company’s internal GMP manufacturing capability to advance its therapeutic programs rapidly and efficiently. The investors in Acceleron include Advanced Technology Ventures, Alkermes, Avalon Ventures, Bessemer Ventures, Celgene, Flagship Ventures, MPM BioEquities, OrbiMed Advisors, Polaris Ventures, QVT Financial, Sutter Hill Ventures and Venrock. For further information on Acceleron, please visit .