The article reviews drugs that were approved by the US Food and Drug Administration (FDA) for the treatment of Metastatic Breast Cancer (MBC) in the last 20 years. The authors summarize the clinical studies which lead to FDA approval.
‘First-line therapy’ is the initial treatment used to reduce cancer burden. It is usually the standard therapy and is followed by other treatments (second and third lines). In the past 10 years three drugs (Trastuzumab, Gemcitabine and Bevacizumab) were approved for use in combination with another drug called Paclitaxel. A combination treatment consisting of Letrozole and Lapitinib was also approved.
Two of these new treatment combinations were given ‘accelerated FDA approval’ (approval process was shortened) as a result of very promising studies. These included a study in 2008 which looked at the effects of Bevacizumab in combination with Paclitaxel. This study included 722 women who had metastatic (spread elsewhere in the body, outside the breast), HER2 negative, breast cancer and had not previously received chemotherapy. Patients treated with the two drugs had an average of 11.3 months without disease progression, compared to 5.8 months in those treated with Paclitaxel only.
A second study in 2010 supported the accelerated approval of Lapatinib and Letrozole. This treatment was for people with hormone receptor positive cancers (cancer is positive for the estrogen and or progesterone receptor) that express the HER2 receptor. This study included 1286 women and showed that those receiving the combination treatment had an average of 35.4 weeks free from disease progression compared to 13 weeks in women treated only with Letrozole.
Second- and third-line therapies for MBC are often used in cases where first-line treatment failed, became ineffective, or had intolerable side effects. Before 1994 the only approved treatments were Doxorubicin (approved in 1974) and Paclitaxel (approved in 1994). In the past 13 years the following treatments have received FDA approval as second- and third-line treatments:
¨ Paclitaxel (Abraxane, Taxol)
¨ Docetaxel (Taxotere)
¨ Trastuzumab (Herceptin)
¨ Capecitabine (Xeloda)
¨ Capecitabine in combination with Docetaxel (Xeloda/Taxotere)
¨ Albumin-bound Paclitaxel (Abraxane)
¨ Lapatinib in combination with Capecitabine (Xeloda/ Tykerb or Tyverb)
¨ Ixabepilone (Ixempra)
¨ Ixabepilone in combination with Capecitabine (Xeloda/ Ixempra)
¨ Eribulin (Halaven)
Examples of studies that supported the approval of these treatments include a 1998 study which looked at the use of Capecitabine for the treatment of MBC that did not respond to Paclitaxel or Anthracyclines (Doxorubicin/Adriamycin; Epirubicin). This study involving 162 patients helped Capecitabine gain accelerated approval as it showed a response rate of 25%.
Further studies are presented in the article, showing the evidence used to support the approval of new drugs and drug combinations.
Published By :
Journal of clinical oncology
Mar 19, 2012
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