[The development of biosimilars in oncology].

With the extensive application in clinical practice, biological medicine plays a significant role in both treatment and supportive care in oncology. With the expiration of original drug patents, biosimilars emerge. The biosimilars are defined as biological drugs that are be highly similar but not identical to the biological reference. Their development and evaluation procedure are different from those of small molecular chemical generics. Biosimilars are expected to reduce the health care costs worldwide. The booming developments of biosimilars, such as rituximab, trastuzumab and bevacizumab in medical oncology can optimize the clinical strategies, offer patients more treatment options and reduce the medical expenditure. In this article, we review the advances in the field of biosimilars, especially focus on the challenges and opportunities of biosimilars in clinical oncology.