Avastin, a drug given conditional FDA approval for the treatment of metastatic breast cancer last February, is now one step closer to becoming a fully approved breast cancer drug. And that’s good news for women with metastatic breast cancer: both because Avastin enhances the quality of a survivor’s life, and because FDA approval of this very expensive drug would make coverage under most health plans much more likely.

Results of the so-called RIBBON 1 study, released early this week, indicate...