Newly released data from Genentech’s international phase 3 CLEOPATRA study demonstrates the efficacy of Perjeta treatment in patients with previously untreated HER2-positive metastatic breast cancer. Patient survival was extended by 15.7 months to almost five years, which is remarkable for aggressive breast cancer.
“Adding Perjeta to treatment with Herceptin and chemotherapy resulted in the longest survival observed to date in a clinical study of people with HER2-positive metastatic breast cancer,” said Sandra Horning, MD, chief medical officer and head of Global Product Development, in a news release from the company. The findings were presented at the Presidential Symposium at the European Society for Medical Oncology (ESMO) 2014 Congress in Madrid.
CLEOPATRA, or “Clinical Evaluation of Pertuzumab and Trastuzumab,” evaluated 808 patients with recurrent metastatic HER2-positive breast cancer using the primary outcome of progression-free survival assessed by an independent review committee. Treatment consisted of either Perjeta, Herceptin, and docetaxel chemotherapy or placebo, Herceptin, and docetaxel chemotherapy. Patients had a median follow-up of 50 months, at which point overall survival was calculated.
“The median survival of nearly five years for people who received the Perjeta regimen is 15.7 months longer than for people who received Herceptin and chemotherapy alone, a magnitude of improvement we rarely see in clinical trials in advanced cancer,” Dr. Horning added in the press release.
No new adverse events were incurred by patients during the study in response to Perjeta. Perjeta is specific to inhibiting the HER2 receptor, which is involved in tumor cell growth and survival. The molecule prevents HER2 from associating with other HER receptors, inhibiting proliferation.
Currently, Perjeta is approved only for patients whose cancer fits the subset studied during the trial, and it is to be used in combination with Herceptin and docetaxel. It is one more tool clinicians may be able to use to combat breast cancer, and it adds to other positive research in the field, such as vaccines that may be able to prevent recurrence of HER2-positive breast cancer.