Perjeta safe and effective for older women with HER2-positive metastatic breast cancer

Women 65 and older received the same treatment benefit from the combination of pertuzumab (Perjeta), trastuzumab (Herceptin) and docetaxel (Taxotere) as women 64 and younger, a sub-analysis of CLEOPATRA trial data reveals.

Benefit was seen in increased progression-free survival, the time from the start of the trial to the cancer growing or spreading. Also encouraging was the finding that older women did not suffer from more, or worse, side effects when given pertuzumab — versus a placebo, or inactive substance — in combination with the other medicines.

Background

Older women have a greater risk of developing breast cancer than younger women, yet few over age 65 take part in clinical trials. This means the findings that come out of trials might not apply to women over a certain age, because the average age at diagnosis is 61 years. In addition, the majority of women who die of metastatic breast cancer are 60 years and older.

In trials testing treatments, in particular, it’s not clear whether benefits seen in younger participants are the same for those who are older.

CLEOPATRA studied the combination of pertuzumab, trastuzumab and docetaxel in treating metastatic, HER2-positive breast cancer. Researchers found the medicines increased progression-free survival by nearly 6 months when compared with a placebo, or inactive substance. Because of the significant increase in survival, the FDA approved using pertuzumab together with the other two medicines in July 2012.

Given that breast cancer is more often diagnosed at later ages and that more women are living longer after a breast cancer diagnosis, the research team wanted to see whether women over age 65 benefitted from the pertuzumab combination in the same way as younger women.

Design

CLEOPATRA enrolled 808 women age 18 or older with HER2-positive metastatic breast cancer and who had not before been treated with other anti-HER2 therapies or chemotherapy for stage IV disease.

The women were randomly assigned to one of two groups receiving:

• treatment with 1 cycle of a placebo, trastuzumab and docetaxel, followed by more cycles of the same combination in lower doses

or

• treatment with 1 cycle of pertuzumab, trastuzumab and docetaxel, followed by more cycles of the same combination in lower doses

All medicines were given by vein. Cycles of the treatment combinations were given until the disease grew or spread, or until the side effects were too severe. They recommended each woman have 6 cycles of docetaxel, if tolerated.

Of the 808 women, 127 were 65 years or older, with 67 assigned to the placebo group and 60 assigned to the pertuzumab group.

Results

The research team analyzed the data by looking at two groups: women 64 and under, and women 65 and older. The data showed:

• longer progression-free survival in both groups treated with the pertuzumab combination
• women 65 and older experienced an almost 4.5 month longer progression-free survival period than women 64 and younger, when treated with the pertuzumab combination
• Regardless of whether they were treated with pertuzumab or the placebo, women 65 and older reported more cases of diarrhea, fatigue, weakness, loss of appetite, changes in taste, and vomiting than younger women
• Age did not impact whether a woman developed heart failure while involved in the study

What This Means for You

This study suggests the use of pertuzumab in combination with trastuzumab and docetaxel is effective in treating HER2-positive metastatic breast cancer no matter what your age. If you are 65 or older, you may find comfort in knowing that the researchers know women in your age group may experience just as much benefit, if not more, from the treatment as younger women.

Though certain side effects were reported more often in older women, they were not often severe enough to stop treatment. Talk with your doctor if you’re concerned about the side effects of any medicines, and ways to prevent them before they start.

Miles, D, Baselga, J, Amadori, D, Sunpaweravong, P, Semiglazov, V, Knott, A, et al. Treatment of older patients with HER2-positive metastatic breast cancer with pertuzumab, trastuzumab, and docetaxel: subgroup analyses from a randomized, double-blind, placebo-controlled phase III trial (CLEOPATRA).  Breast Cancer Research and Treatment. (November 2013); 142 (1):89-99.