Myriad Genetics to highlight new clinical studies on myRisk Hereditary Cancer test at ASCO 2015

Myriad myRisk Finds >60 Percent More Mutations than BRCA1/2 Testing in Multiple Studies

Myriad Genetics, Inc. (NASDAQ: MYGN) today announced it will highlight several new clinical studies on its myRisk Hereditary Cancer molecular diagnostic test at the 2015 American Society of Clinical Oncology annual meeting being held in Chicago, Ill.

The myRisk Hereditary Cancer test assesses 25 genes for mutations associated with eight hereditary cancers. Finding deleterious mutations in these genes can help patients with cancer receive appropriate medical care and reduce the risk of second cancers, while patients without cancer can take steps in consultation with their healthcare provider to lower their risk of developing cancer.

“Myriad is pioneering a new era of cancer treatment and prevention. The myRisk Hereditary Cancer test has the potential to reduce the burden of hereditary cancer in the lives of women and men for generations to come,” said Richard Wenstrup, M.D., chief medical officer, Myriad. “myRisk represents a significant new opportunity to help physicians tailor treatment to individuals based on their genetic results as well as their personal and family history of cancer.”

Below are the key myRisk Hereditary Cancer presentations being highlighted at #ASCO15.

BREAST CANCER

Podium Presentation S100BC: Predisposing Germline Mutations in High Grade ER+HER2- Breast Cancer Patients Diagnosed <50 Years of Age.

Judy Garber, M.D., (Dana-Farber Cancer Institute), presented data on pathogenic DNA mutations in 106 high grade ER+ HER2- breast cancer patients diagnosed <50 years of age. A total of 25 cancer genes were assessed using the myRisk Hereditary Cancer test and germline mutations were classified for pathogenicity. The results demonstrated that 10.4 percent of women with ER+ HER2- breast cancer who were tested had a deleterious mutation. BRCA1/2 mutations were found in 6.6 percent of patients; however, mutations also were found in other genes related to breast cancer such as ATM, CHEK2, PALB2 in 4.7 percent of patients, representing a greater than 70 percent increase in patients identified with pathogenic mutations. These finding support expanded testing with myRisk Hereditary Cancer in women with Grade III ER+/HER2- breast cancer diagnosed at age <50, which will find more mutation carriers and has the potential to improve medical management decisions.

Poster 181: A Study of Triple Negative Breast Cancer Patients Tested with a 25-Gene Panel of Hereditary Cancer Genes.

John Sandbach, M.D. (Texas Oncology Austin), highlighted data on the distribution of mutations identified with the myRisk Hereditary Cancer 25-gene panel in 3,413 patients with triple negative breast cancer (TNBC) and compared those results to 22,890 patients with other types of breast cancer. The results found that the overall prevalence of mutations in patients with TNBC was 14.7 percent, compared to 9.2 percent in patients with other types of breast cancer. In all patients with breast cancer, the myRisk Hereditary Cancer test identified 100.8 percent more mutations than BRCA1/2 testing alone. The increase in mutations identified in patients with TNBC was 43.7 percent and 121.8 percent in patients with other types of breast cancer. TNBC mutation carriers were found to have a higher occurrence of BRCA1 mutations (50.3 percent) than patients with other breast cancers (18.2 percent). Additionally, BARD1, RAD51C and PALB2 were significantly more prevalent in patients with TNBC compared to other types of breast cancer, while ATM and CHEK2 were significantly less prevalent. These data provide insight into the prevalence and diversity of deleterious mutations that may drive the development of TNBC, and highlight the importance of a 25-gene panel versus BRCA1/2 testing alone, which may allow affected patients to receive more appropriate and tailored medical management.

Poster 338: Outcomes of Clinical Testing for 76,000 Patients Utilizing a Panel of 25 Genes Associated with Increased Risk for Breast, Ovarian, Colorectal, Endometrial, Gastric, Pancreatic, Melanoma and Prostate Cancers.

Eric Rosenthal, Ph.D. (Myriad Genetic Laboratories) presented outcomes data from clinical testing of a large, diverse cohort of U.S. patients using the myRisk Hereditary Cancer test. Results are included from the first 76,564 patients tested with the myRisk Hereditary Cancer 25-gene panel. The data found that 7.4 percent of the patients tested carry one or more deleterious mutations linked to an increased risk for hereditary cancer. Importantly, in this analysis the myRisk Hereditary Cancer test resulted in a 130 percent increase in the number of individuals identified with an increased risk for inherited cancer compared with BRCA1/2 testing alone. A significant number of total mutations were found in patients with no personal or family history of cancer associated with that specific gene, suggesting panel testing identifies genetic mutations not apparent from personal and family history alone. Additionally, deleterious mutations were found in patients of all ancestries, indicating that the myRisk Hereditary Cancer test can increase mutation detection across ethnic populations. These findings may benefit patients carrying deleterious mutations in genes for which testing was not widely available previously, and/or whose personal/family histories do not fit unambiguously with a single cancer syndrome.

ENDOMETRIAL CANCER

Poster 357: Multi-Gene Panel Testing in an Unselected Endometrial Cancer Cohort.

Kari Ring, M.D., (MD Anderson Cancer Center) presented data on the prevalence of germline mutations in Lynch Syndrome (LS) and other cancer predisposition genes in 381 patients with endometrial cancer. DNA mutations in 25 cancer genes were identified using the myRisk Hereditary Cancer test. The data showed that 35 patients (9.2 percent) had a deleterious mutation. Of these 22 patients (5.8 percent) had a deleterious mutation in LS genes and 13 patients (3.4 percent) had a deleterious mutation in non-LS genes, which represents a 59 percent increase in the number of patients identified with mutations using myRisk. Results for endometrial cancer with deleterious mutation in LS genes were similar to previous findings. Using the myRisk Hereditary Cancer panel test to include non-LS genes allowed for the identification of additional genes that may be associated with serous-type endometrial cancer, the most clinically aggressive form of this cancer. This data are consistent with recent National Comprehensive Cancer Network (NCCN) guideline updates and support providing hereditary cancer testing for the approximately 50,000 patients diagnosed each year with endometrial cancer.