CLEAR
生物相似劑於2006年首次獲得歐盟認可。及後，越來越多生物相似劑在世界各地獲批准上市，並在治療應用上越來越普及。1,2
生物相似劑在結構上與所參考之原廠生物製劑高度相似，在臨床意義上沒有任何差異。
生物相似劑是生物製劑的一種，透過活細胞基因工程所製造，結構上與所參考之原廠生物製劑高度相似，並證實在臨床意義上沒有任何差異。然而，生物相似劑並不是仿製藥，它的體積比主要由小分子組成的仿製藥大約1,000倍， 結構上亦更複雜，所以並不能像仿製藥般使用化學合成方法生產，把活性成分完全「仿製」。3-6
監管機構在審核生物相似劑時，會根據全面的數據作出分析，才決定是否批准生物相似劑可用於其參考生物製劑已獲批的部份或全部適應症。7
非類比生物製劑與生物相似劑之間有明確的分別。非類比生物製劑指已獲部分國家批准出售的生物製劑的複製品，而它們的監管途徑跟生物相似劑所須符合的嚴格要求不同。非類比生物製劑或其參考藥品的仿製品在獲批推出市場前，並毋須通過如生物相似劑所須的嚴格分析性、臨床和非臨床的比較性評估。8,9
因此，非類比生物製劑的品質、效用和安全與參考藥品相比，可能會出現顯著臨床差異。部分非類比生物製劑的藥效強度會較低，或者會較易出現不良反應。這些情況顯示了經嚴格監管途徑批准的生物製劑的重要性。8
世界衛生組織已向成員國發出指引，以生物製劑現時的監管準則，對非類比生物製劑進行同等嚴格的評估。10
References: 1. European Medicines Agency. Biosimilars in the EU: information guide for healthcare professionals. www.ema.europa.eu/documents/leaflet/biosimilars-euinformation-guide-healthcare-professionals_en.pdf. Accessed October 29, 2019. 2. US Food and Drug Administration. Biosimilars action plan: balancing innovation and competition. www.fda.gov/downloads/drugs/developmentapprovalprocess/howdrugsaredevelopedandapproved/approvalapplications/therapeuticbiologicapplications/biosimilars/ucm613761.pdf. Accessed October 29, 2019. 3. European Medicines Agency. Questions and answers on biosimilar medicines (similar biological medicinal products). www.medicinesforeurope.com/wpcontent/uploads/2016/03/WC500020062.pdf. Accessed October 29, 2019. 4. US Food and Drug Administration. Guidance for industry: scientific considerations in demonstrating biosimilarity to a reference product. www.fda.gov/downloads/drugs/guidances/ucm291128.pdf. Accessed October 29, 2019. 5. Mellstedt H, Niederwieser D, Ludwig H. The challenge of biosimilars. Ann Oncol. 2008;19:411-419. 6. Lee JF, Litten JB, Grampp G. Comparability and biosimilarity: considerations for the healthcare provider. Curr Med Res Opin. 2012;28:1053-1058. 7. US Food and Drug Association. Biosimilar and interchangeable products. www.fda.gov/drugs/biosimilars/biosimilarand-interchangeable-products. Accessed October 29, 2019. 8. Dörner T, Kay J. Biosimilars in rheumatology: current perspectives and lessons learnt. Nat Rev Rheumatol. 2014;11:713-724. 9. Mysler E, Pineda C, Horiuchi T, et al. Clinical and regulatory perspectives on biosimilar therapies and intended copies of biologics in rheumatology. Rheumatol Int. 2016;36:613-625. 10. World Health Organization. Guidance on scientific principles for regulatory risk assessment of biotherapeutic products. www.who.int/biologicals/ WHO_Risk_Assessment_ for_BTP_2nd_PC_10_Dec_2014.pdf. Accessed October 29, 2019.
