PERTUZUMAB-TRASTUZUMAB COMBINATION ALSO IMPROVES SURVIVAL

June 22, 2012 — Dual targeted therapy blockade, including the newly approved pertuzumab (Perjeta, Genentech/Roche), has been shown for the first time to significantly improve overall survival in women with HER2-positive metastatic breast cancer, according to a company announcement.

The groundbreaking data come from a phase 3 study in which the targeted therapy combination of pertuzumab and trastuzumab (Herceptin, Genentech/Roche) plus docetaxel is compared with trastuzumab and docetaxel alone in the first-line metastatic setting.

These new overall survival data, which are from the Clinical Evaluation of Pertuzumab and Trastuzumab (CLEOPATRA) trial, will be presented at an upcoming medical meeting.

In short, the data indicate that 2 anti-HER2 drugs are better than 1.

Pertuzumab and trastuzumab are believed to target different places on the HER2 receptor, the protein that designates HER2-positive cancers, and thus work complimentarily, said the manufacturer.

"We are pleased that Perjeta helped people with HER2-positive metastatic breast cancer live longer and lengthened the time they lived without their disease worsening," said Hal Barron, MD, chief medical officer of Genentech, in a press statement.

Previously, results from the 808-patient CLEOPATRA study indicated that the 2 anti-HER2 drug combination significantly improved progression-free survival (PFS) by 6 months (18.5 months vs 12.4 months), as reported byMedscape Medical News from last year's San Antonio Breast Cancer Symposium.

At the time, the lead author was effusive about the results. "This is huge. It is very uncommon to have a clinical trial show this level of improvement in PFS," said José Baselga, MD, PhD, professor of medicine at Harvard Medical School and associate director of the Massachusetts General Hospital Cancer Center in Boston.

The US Food and Drug Administration recently approved pertuzumab in combination with trastuzumab and docetaxel chemotherapy for the treatment of people with HER2-positive metastatic breast cancer who have not received prior anti-HER2 therapy or chemotherapy for metastatic disease, based on the CLEOPATRA data.

Roche has also submitted an approval application with the European Medicines Agency for pertuzumab for previously untreated HER2-positive metastatic disease.