Credit: Rhoda Baer
A biosimilar of the erythropoiesis-stimulating agent epoetin alfa can elicit responses in patients with chemotherapy-induced anemia, according to a study published in BMC Cancer.
The agent, epoetin zeta (Retacrit), produced a hemoglobin (Hb) response in more than 80% of patients at 3- and 6-month time points.
Response rates were similar in patients with hematologic malignancies and those with solid tumors.
And the rate of clinically significant adverse events was low. This included thromboembolic events, bleeding, infection, local intolerability, and increased blood pressure.
Mauricette Michallet, MD, PhD, of Centre Hospitalier Lyon in France, and her colleagues conducted this study, known as ORHEO. It was sponsored by Hospira, the makers of epoetin zeta.
The researchers evaluated 2310 adult patients with chemotherapy-induced anemia (Hb<11 g/dL). Patients had solid tumors (n=1838), lymphomas (n=301), or multiple myeloma (n=171).
Patients were taking a number of treatments aside from epoetin zeta and chemotherapy. This included intravenous iron (10%), oral iron (16%), antithrombotic agents (12%), folates (7%), vitamin B (4%), and other vitamins (2%). An additional 17% of patients were reported as being on “other treatments.”
In all, 99.9% of patients received epoetin zeta. The primary endpoint was the rate of response.
Response was defined as an increase in Hb levels to at least 10 g/dL since enrollment, an increase in Hb levels of at least 1 g/dL since enrollment, or reaching target Hb levels set at the start of study, without any blood transfusions in the 3 weeks prior to measurement. In patients with baseline Hb levels of at least 10 g/dL, only those who reached their Hb target or had an increase greater than 1 g/dL were considered responders.
Eighty-two percent of patients achieved a response at 3 months, and 87% had a response at 6 months. The overall mean change in Hb level was 1.52 ± 1.61 at 3 months and 1.72 ± 1.61 g/dL at 6 months. The rate of transfusion was 9% at 3 months and 6% at 6 months.
Between enrollment and month 6, 1202 patients discontinued epoetin zeta. Forty percent stopped because Hb levels were met, 27% stopped because they were stopping or changing chemotherapy, 15% stopped for both of the aforementioned reasons, 11% stopped because epoetin zeta was ineffective, and 2% stopped due to adverse events.
Seventeen percent of patients experienced an adverse event, including thromboembolic events (4%), infection (5%), bleeding (2%), local intolerability (0.2%), increased blood pressure (2%), and “other” events (9%).
Epoetin zeta was approved in Europe in 2007. For epoetin biosimilars to gain approval in the European Union, companies must agree to conduct post-marketing studies.
