This means that Nerlynx is the first extended adjuvant therapy for patients suffering from this type of cancer. Adjuvant therapies are used as an addition to the primary treatment to help reach the ultimate goal, in this case to decrease even further the risk of cancer recurrence (when the cancer returns after treatment).
The new adjuvant therapy was approved for adult patients who received previous treatment with the drug Herceptin (trastuzumab), a monoclonal antibody used to treat metastatic, HER2-positive breast cancer.
“HER2-positive breast cancers are aggressive tumors and can spread to other parts of the body, making adjuvant therapy an important part of the treatment plan,” Richard Pazdur, MD, director of the FDA’s Oncology Center of Excellence and acting director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research, said in a press release. “Now, these patients have an option after initial treatment that may help keep the cancer from coming back.”
Nerlynx works by blocking the action of several special proteins (enzymes) found to promote cells’ growth. The drug irreversibly binds to epidermal growth factor receptors (EGFRs), to human epidermal growth factor receptor 2 (HER2), and to HER4.
The effectiveness and safety of Nerlynx was determined in the ongoing Phase 3 ExteNET trial (NCT00878709), a randomized, double-blind, placebo-controlled study that enrolled 2,840 patients with early-stage, HER2-positive breast cancer.
The trial compared Nerlynx to a placebo as an extended adjuvant — or post-surgery — treatment in patients who had completed Herceptin treatment within the previous two years.
The trial’s primary goal was to determine the time it took for the cancer to return, or for death to occur, a measure called progression-free survival rate. The results showed that after two years, 94.2 percent of patients assigned to Nerlynx showed no signs of cancer recurrence or death, compared to 91.9 percent of patients in the placebo arm.
One of the side effects of the treatment with Nerlynx was diarrhea, and researchers advise that Imodium (loperamide) should be included in the first 56 days of treatment with Nerlynx to help manage the symptoms (and anytime thereafter, according to patients’ needs). Patients who experience severe side effects, including liver damage or diarrhea, should stop taking Nerlynx.