Too early to predict impact of biosimilars on utilization of hematopoietic growth factors

April 1, 2011

Overall, it would not appear that the new erythropoiesis-stimulating agents for treatment of cytopenia will add substantially to pharmacy budgets. As they are approved by FDA, each medication will need to be reviewed to understand its complete clinical advantage, and the safety profile will need to be completely understood.

Key Points

Hematopoietic growth factors are used to treat a variety of inherited or acquired cytopenias. These cytopenias can be caused by congenital diseases, idiopathic diseases, malignancies, chronic kidney disease, and myelosuppression related to chemotherapy. Thus, hematopoietic growth factors are prescribed by multiple clinicians representing many disciplines.

Currently approved products (darbepoetin alfa, romiplostim, eltrombopag, and plerixafor) are being studied for new indications. Other agents in development include an erythropoeisis-stimulating agent, Hematide; a thrombopoiesis-stimulating agent, AKR-501; the granulopoiesis-stimulating agents Neutroval and ezatiostat (Telintra); and a lymphopoiesis-stimulating agent, CYT104.

There is skepticism that the products in development, both new entities and potential new indications for products already on the market, will offer any real advantages over the currently available products. It is premature to predict the impact of biosimilars on utilization of hematopoietic growth factors; the biosimilars may not be interchangeable with currently available products and side effects may be a concern. However, we do know that because of cost and usage across multiple disciplines, appropriate use will continue to be paramount in managing cytopenias.

Several existing therapies are being tested for extended indications. Some of these agents seem to offer some end-point improvements, but more analysis of the studies to determine the significance of these improvements is needed.

The new erythropoiesis-stimulating agents would replace existing therapy; therefore, the cost impact should not be substantial. The thrombopoiesis-stimulating agents have some interesting potential, particularly if they can assist patients who have human immunodeficiency virus infection from losing antiretroviral activity. These new agents would be an additional therapy to existing regimens, so their costs would be additive in nature.

Overall, it would not appear that the new therapies will add substantially to pharmacy budgets. As they are approved by FDA, each medication will need to be reviewed to understand its complete clinical advantage, and the safety profile will need to be completely understood. New agents likely will be covered and managed on fourth tier, along with the existing medications. Prior authorization is likely to ensure that the desired use is consistent with an FDA-approved indication. Whether step therapy is used will depend on the cost of the new agent compared with that of existing drugs and the complete clinical profile.

–Steven G. Avey, MS, RPh, vice president, national sales, Regence Rx, Portland, OR

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