Efbemalenograstim joins other agents already on the U.S. market, including pegfilgrastim (Neulasta), that aim to reduce the incidence of chemotherapy-induced febrile neutropenia.
The approval of efbemalenograstim was based on two randomized trials. The first included 122 women with either metastatic or nonmetastatic breast cancer who were receiving doxorubicin and docetaxel. These patients were randomly assigned to receive either one subcutaneous injection of efbemalenograstim or placebo on the second day of their first chemotherapy cycle. All patients received efbemalenograstim on the second day of cycles two through four.
The mean duration of grade 4 neutropenia in the first cycle was 1.4 days with efbemalenograstim versus 4.3 days with placebo. Only 4.8% of patients who received efbemalenograstim experienced chemotherapy-induced febrile neutropenia, compared with 25.6% who received the placebo.
The new agent went up against pegfilgrastim in the second trial, which included 393 women who received docetaxel and cyclophosphamide as treatment for nonmetastatic breast cancer. These patients were randomly assigned to receive either a single subcutaneous injection of efbemalenograstim or pegfilgrastim on the second day of each cycle.
During the first cycle, patients in both arms of the trial experienced a mean of 0.2 days of grade 4 neutropenia.
The most common side effects associated with efbemalenograstim were nausea, anemia, and thrombocytopenia. Similar to pegfilgrastim’s label, efbemalenograstim’s label warns of possible splenic rupture, respiratory distress syndrome, sickle cell crisis, and other serious adverse events.
The FDA recommends a dose of 20 mg subcutaneous once per chemotherapy cycle.
A version of this article first appeared on Medscape.com.