Epoetins

Epoetins, or erythropoiesis-stimulating agents (ESAs), are recombinant glycoprotein hormones that stimulate red blood cell production by activating the erythropoietin receptor on erythroid progenitor cells in the bone marrow. They mimic endogenous erythropoietin and are used to treat anemia associated with chronic kidney disease, certain cancers receiving chemotherapy, and other conditions that impair red blood cell production.

Chemical and pharmacologic properties: Common epoetins include epoetin alfa and epoetin beta; longer-acting forms include darbepoetin alfa and methoxy polyethylene glycol-epoetin beta. These products are produced in mammalian cell lines such as CHO cells to achieve human-like glycosylation. They can be administered intravenously or subcutaneously, depending on the product and indication, with dosing tailored to patient factors, hemoglobin trajectory, and iron status.

Clinical use and dosing: Epoetins reduce the need for red blood cell transfusions and can improve quality of life in some patients. Careful target hemoglobin levels are recommended, typically avoiding aiming for normal ranges in many chronic conditions; in CKD, targets are usually lower to reduce risk of adverse events.

Monitoring and iron status: Regular monitoring of hemoglobin, iron stores, and blood pressure is required. Adequate iron availability is important for response; iron supplementation is common to support efficacy.

Safety considerations: Potential adverse effects include hypertension, thromboembolic events, and, rarely, pure red cell aplasia caused by neutralizing antibodies. In cancer and other settings, higher hemoglobin targets have been associated with adverse outcomes, leading to regulatory warnings and usage guidelines. Biosimilars of epoetin alfa are available where approved.