Genentech Submits Application to FDA for Trastuzumab-DM1 in Previously Treated Advanced HER2-Positive Breast Cancer

Genentech Submits Application to FDA for Trastuzumab-DM1 in Previously Treated Advanced HER2-Positive Breast Cancer

-- T-DM1 is the First Antibody-Drug Conjugate in Genentech's Pipeline to Be Submitted to the FDA -- 

SOUTH SAN FRANCISCO, Calif., Jul 07, 2010 (BUSINESS WIRE) -- Genentech, a member of the Roche Group (SIX: RO, ROG; OTCQX: RHHBY), today announced that the company submitted a Biologics License Application (BLA) to the U.S. Food and Drug Administration (FDA) for trastuzumab-DM1 (T-DM1) in people with advanced HER2-positive breast cancer who have previously received multiple HER2-targeted medicines and chemotherapies. This submission is based on the results of a Phase II study, which showed T-DM1 shrank tumors in one-third of women who had received on average seven prior medicines for advanced HER2-positive breast cancer.

"While we've made great strides in treating HER2-positive breast cancer, there is a group of people whose breast cancer will come back after many treatments, leaving them with very limited options," said Hal Barron, M.D., executive vice president, Global Development and chief medical officer. "Data from studies have shown that T-DM1 shrank tumors in these people, so we are excited to have submitted this application to the FDA in hopes of offering a potential new medicine to people with this type of breast cancer."

T-DM1 is an antibody-drug conjugate (ADC), also known as an armed antibody, being studied for advanced HER2-positive breast cancer. T-DM1 attaches trastuzumab and the chemotherapy DM1 together using a stable linker, which is designed to keep T-DM1 in one piece until it reaches specific cancer cells. The antibody (trastuzumab) binds to the HER2-positive cancer cells, and is thought to block out-of-control signals that make the cancer grow while also calling on the body's immune system to attack the cells. Then, once T-DM1 is absorbed into those cancer cells, it is designed to destroy them by releasing the DM1.

About T-DM1 Studies

The FDA submission is based on a Phase II study known as TDM4374g, a single-arm, multi-center trial designed to assess single-agent T-DM1 in 110 women with HER2-positive advanced breast cancer whose disease had worsened after receiving at least two prior HER2-targeted treatments (Herceptin(R) [trastuzumab] and lapatinib) in the metastatic setting, as well as an anthracycline, a taxane and capecitabine. The primary endpoint of the study was objective response rate (a complete or partial tumor shrinkage of at least 30 percent, determined by two tumor assessments at least 28 days apart), as measured by an independent review facility.

Results from the study were presented at the 2009 San Antonio Breast Cancer Symposium and demonstrated that T-DM1 shrank tumors in 33 percent of women with advanced HER2-positive breast cancer that had worsened following treatment with an average of seven prior medicines for metastatic disease. In the study, most side effects were mild (Grade 1-2) and similar to those observed in previous clinical trials of T-DM1. The most common adverse events of any grade were fatigue (62 percent) and nausea (37 percent). The most common severe adverse events (Grade 3 or higher) were a low level of platelets in the blood (7 percent), fatigue (5 percent) and cellulitis (4 percent). No severe cardiac-specific side effects were observed. One patient with pre-existing, non-alcoholic fatty liver disease died with liver failure. The safety results were consistent with data from earlier studies, including a proof-of-concept Phase II study (TDM4258g), which also was included in the submission to the FDA.

Several Phase II and III trials of T-DM1, either alone or in combination with other medicines, are planned or ongoing:

-- An ongoing Phase III trial, known as EMILIA, is comparing T-DM1 to lapatinib in combination with capecitabine in people with advanced HER2-positive breast cancer whose disease has worsened after receiving initial treatment.

-- A planned Phase III study, MARIANNE, will compare both T-DM1 alone and T-DM1 in combination with pertuzumab to Herceptin in combination with a taxane chemotherapy in people with advanced HER2-positive breast cancer who have not been previously treated for advanced disease.

-- Preliminary results from a Phase II study (TDM4450g) comparing T-DM1 to Herceptin in combination with docetaxel chemotherapy in people with advanced HER2-positive breast cancer who have not been previously treated for advanced disease have been submitted for presentation at a future medical meeting.

-- Genentech also has opened a T-DM1 Patient Access Study in the United States to provide a specific group of people with advanced HER2-positive breast cancer access to T-DM1 while Genentech seeks U.S. approval.

Genentech licenses technology for T-DM1 under an agreement with ImmunoGen, Inc. Building on successes with T-DM1, Genentech has approximately 50 ADCs in early stages of research and development for multiple tumor types.

About Advanced HER2-Positive Breast Cancer

According to the American Cancer Society, breast cancer is the second leading cause of cancer death among women in the U.S. Women diagnosed with advanced (metastatic) disease have a poor prognosis, and only 23 percent survive five years.

Approximately 15 to 30 percent of breast cancers are HER2-positive. When HER2-positive breast cancer is advanced, the disease has spread to other parts of the body, most commonly to the lungs, bones, liver and brain. There are no treatment guidelines or FDA-approved treatment options for women with advanced HER2-positive breast cancer if the disease worsens following treatment with Herceptin and lapatinib.

About Herceptin

Herceptin is approved for one year of adjuvant treatment for HER2-overexpressing node-positive or node-negative (ER/PR-negative or with one high-risk feature) breast cancer:

-- As part of a treatment regimen containing doxorubicin, cyclophosphamide, and either paclitaxel or docetaxel

-- With docetaxel and carboplatin

-- As a single agent following multi-modality anthracycline-based therapy

Herceptin is also approved for metastatic breast cancer:

-- In combination with paclitaxel for the first-line treatment of HER2-overexpressing metastatic breast cancer

-- As a single agent for treatment of HER2-overexpressing breast cancer in patients who have received one or more chemotherapy regimens for metastatic disease

Boxed WARNINGS and Additional Safety Information

Herceptin treatment can result in heart problems, including those without symptoms (reduced heart function) and those with symptoms (congestive heart failure). Some patients have had serious infusion reactions and lung problems; fatal infusion reactions have been reported. Worsening of low white blood cell counts associated with chemotherapy has also occurred. Herceptin can cause low amniotic fluid levels and harm to the fetus when taken by a pregnant woman. The most common side effects associated with Herceptin were fever, nausea, vomiting, infusion reactions, diarrhea, infections, increased cough, headache, fatigue, shortness of breath, rash, low white and red blood cells, and muscle pain. Because everyone is different, it is not possible to predict what side effects any one person will have. Patients with questions or concerns about side effects should talk to their doctor.

For Herceptin full prescribing information, including Boxed WARNINGS and additional important safety information, please visit http://www.herceptin.com.

About Genentech

Founded more than 30 years ago, Genentech is a leading biotechnology company that discovers, develops, manufactures and commercializes medicines to treat patients with serious or life-threatening medical conditions. The company, a member of the Roche Group, has headquarters in South San Francisco, California. For additional information about the company, please visit http://www.gene.com.

SOURCE: Genentech