Foundation Medicine announces discovery of high incidence of ERBB2 alterations in MPUC patients

Foundation Medicine, Inc. (NASDAQ:FMI) today announced the discovery of a high incidence of ERBB2 (HER2) extracellular domain alterations in patients with micropapillary urothelial carcinoma (MPUC), a particularly aggressive form of urinary bladder cancer, using FoundationOne™. The research was published in the current edition of Clinical Cancer Research.

"This study identifies a recurrent clinically actionable genomic alteration in an extremely aggressive subtype of urinary bladder cancer and opens the door for the use of targeted therapies to treat a significant proportion of patients with this disease," said Jeffrey S. Ross, M.D., medical director, Foundation Medicine and co-lead author of the study. "By using FoundationOne, a highly sensitive, fully informative genomic profile, we were able to identify an alteration that is not typically tested for in the routine care of these patients. We believe this discovery may enable new opportunities for treating patients with this rapidly progressive form of cancer with anti-ERBB2 targeted therapies."

In this study, Foundation Medicine researchers conducted comprehensive genomic profiling using FoundationOne on 15 MPUC and 64 non-micropapillary urothelial bladder carcinomas (non-MPUC) FFPE tumor samples. Mutations in the extracellular domain of ERBB2 were identified in six of 15 (40%) MPUC samples. All six cases of MPUC with an ERBB2 mutation were negative for ERBB2 amplification and ERBB2 overexpression. In contrast, six of 64 (9.4%) non-MPUC samples harbored an ERBB2 alteration, including base substitutions (three cases), amplifications (two cases), and gene fusion (one case), which is higher than the two of 159 (1.3%) protein-changing ERBB2 alterations reported for urinary bladder cancer in COSMIC. The enrichment of ERBB2 alterations in MPUC compared with non-MPUC is statistically significant both between this series (P < 0.0084) and for all types of urinary bladder cancer in COSMIC (P < 0.001).

MPUC is an uncommon subtype of urothelial carcinoma with an incidence of 3,000 to 4,000 cases per year in the United States.