Bayer’s cancer drug Xofigo is already a revenue driver for manufacturer Bayer. The company announced that the drug, approved for castration-resistant metastatic prostate cancer, earned $57 million during the quarter, and cited the drug as one of the quarter’s key sales drivers along with newish blood thinner Xarelto and wet age-related macular degeneration drug Eylea.

Consultancy Decision Resources is also taking note, reporting Wednesday that over two-thirds of surveyed oncologists have prescribed the drug since its May 2013 approval and that a significant chunk of doctors who said they had yet to prescribe the treatment indicated that they expect to by the year’s end.

Decision Resources says about a third of prescribing doctors are using the alpha-emitting radiopharmaceutical along with other drugs including Janssen’s Zytiga (aberacitone acetate) and AbbVie’s Lupron (leuprolide acetate).

Decision Resources Group Analyst Jennifer Bamford said in a statement that the drug is tripping over some basics, such as providers not being familiar with it. She also said doctors find the need for a nuclear medicine facility off-putting.

Bayer’s expectations for the drug indicate the company considers these as minor points—the drugmaker estimated last year that the cancer medication could reach $1.31 billion in annual sales.