CLEOPATRA Final Results: Perjeta Extends Life Significantly
Final results from the CLEOPATRA trial were presented at the European Society for Medical Oncology, ESMO, 2014 Congress in Madrid at the end of September. The results show the combination of trastuzumab (Herceptin) and pertuzumab (Perjeta), along with chemotherapy, lengthened the lives of women with HER2-positive metastatic breast cancer by a median 15.7 months. The increase is being called unprecedented.
Background and Goals
As many as 25 percent of breast cancers grow because of too much of a protein called human epidermal growth factor receptor-2. This kind of breast cancer is called HER2-positive. Trastuzumab binds to the HER2 protein and interferes with how it works. Pertuzumab also targets the HER2 protein, but in a different way. When used together, these medicines are called dual HER2 antibody therapy or dual inhibition.
Early results of the CLEOPATRA trial were released in 2012. They showed the combination medicine plus chemotherapy improved progression-free survival, PFS, the length of time after treatment begins that breast cancer does not grow, by about 6 months. This led to pertuzumab being approved by the FDA later that year for treatment of HER2-positive metastatic breast cancer, when paired with trastuzumab and docetaxel (Taxotere), a type of chemotherapy. The final CLEOPATRA results contain information about overall survival, OS, the length of time between treatment beginning and death from any cause. This data wasn’t yet available when the trial was first presented in 2012.
Women who had HER2-positive metastatic breast cancer and hadn’t been treated in the past with other anti-HER2 therapies or chemotherapy for metastatic disease were able to participate in CLEOPATRA. The study enrolled 808 women, who were randomly assigned to one of two groups:
- The treatment group, receiving pertuzumab, trastuzumab and docetaxel
- The placebo group, receiving an inactive medicine, trastuzumab and docetaxel
Final CLEOPATRA results show that an unexpectedly high number of participants were still alive more than four years after treatment began. Researchers reported that median OS was:
- 56.5 months in the treatment group
- 40.8 months in the placebo group
That difference of 15.7 months is significant. In addition, the benefit of adding pertuzumab to a treatment regimen was seen across study subgroups, such as race and region. This means the medicine combination has the potential to work in many people.
Final results of PFS were also reported, and were similar to the earlier findings. Median PFS was 6.3 months longer in the treatment group, for a total of:
- 18.7 months in the treatment group
- 12.4 months in the placebo group
A number of side effects were seen more often in the treatment group than in the placebo group, including diarrhea, rash, headaches, dry skin and muscle spasms.
What This Means for You
This study confirms that trastuzumab and pertuzumab, when used together in combination with chemotherapy, has the potential to add more than a year to your life if you are living with metastatic HER2 disease. Ask your doctor if this kind of treatment could be right for you.
The cost for these medicines can top $10,000 a month, so it’s important that you learn about financial planning and what resources are available to help you pay for breast cancer treatment. Many companies offer financial assistance programs when the costs of the medicines they produce are high; to learn about financial assistance for pertuzumab through Genentech, its maker, visit http://www.genentech-access.com/perjeta/patients. The programs offer help with navigating health insurance and assistance to people who are uninsured or underinsured.
Swain, Sandra M.; Kim, Sung-Bae; Cortés, Javier et al. Final overall survival (OS) analysis from the CLEOPATRA study of first-line (1L) pertuzumab (Ptz), trastuzumab (T), and docetaxel (D) in patients with HER2-positive metastatic breast cancer (MBC). Presented at the European Society for Medical Oncology 2014 Congress; Sept. 26-Sept. 30, 2014; Madrid, Spain.