Researchers reported a number of important findings in breast cancer treatment at the 2019 Annual Meeting of the American Society of Clinical Oncology:

Investigational drug evaluated in treatment of advanced breast cancer with PIK3CA mutation

In treatment of advanced breast cancer with the PIK3CA mutation, data from the phase III SOLAR-1 trial showed that the investigational drug alpelisib, used in combination with the hormone therapy fulvestrant, prolongs progression-free survival (PFS), compared with fulvestrant alone.

What Patients Need to Know

PIK3CA mutations are present in approximately 40 percent of ER-positive metastatic breast cancers. These mutations result in the PI3K pathway being hyper-active, which drives cancer cell growth and increases resistance to hormonal therapies.

Combination of targeted therapy and standard-of-care endocrine therapy studied in advanced HR-positive breast cancer

The international phase III MONALEESA-7 trial found that adding the targeted therapy ribociclib to endocrine therapy significantly improved overall survival for premenopausal women with advanced hormone receptor (HR)-positive, HER2-negative breast cancer, compared with endocrine therapy alone.

After 42 months of follow-up, the survival rate was 70 percent for women treated with the combination therapy, compared with 46 percent for women who received endocrine therapy alone.

What Patients Need to Know

MONALEESA-7 is the first trial to focus exclusively on premenopausal women with advanced breast cancer that had not previously been treated with endocrine therapy.

Global trial shows combination of neratinib and capecitabine increased PFS in women with metastatic HER2-positive breast cancer

In the global phase III NALA trial, the treatment of metastatic HER2-positive breast cancer with the targeted therapy neratinib plus the chemotherapy capecitabine significantly improved progression-free survival as compared with the combination of lapatinib (a targeted therapy) and capecitabine.

The results of the trial also showed a trend toward improved overall survival.

What Patients Need to Know

In the trial, the novel (new) regimen of neratinib plus capecitabine was given to 662 women who had received at least two prior HER2-directed treatments for metastatic breast cancer.

Phase III trial shows combination of margetuximab and chemotherapy has

clinical benefit in pretreated HER2-positive metastatic breast cancer

Compared to the combination of trastuzumab and chemotherapy, the results of the phase III SOPHIA trial showed margetuximab plus chemotherapy led to significant improvements in progression-free survival in the treatment of HER2-positive metastatic breast cancer that had progressed after treatment with trastuzumab, pertuzumab and chemotherapy.

What Patients Need to Know

Margetuximab is a novel anti-HER2 antibody. The improved clinical benefit of margetuximab plus chemotherapy was enhanced in women with the low-affinity CD16A-158F gene. This gene is known to prevent treatment with trastuzumab from being effective.

Immunotherapy evaluated as first-line treatment of triple-negative breast cancer in phase III trial

In previously untreated women with locally advanced or metastatic triple-negative breast cancer, the phase III IMpassion130 trial showed the immunotherapy atezolizumab, in combination with the chemotherapy nab-paclitaxel, resulted in improved median survival compared to placebo plus nab-paclitaxel.

What Patients Need to Know

IMpassion130 is the first phase III trial to show the clinical benefit of immunotherapy as a first-line treatment for metastatic triple-negative breast cancer.