NHS watchdog NICE recommended that the use of trastuzumab emtansine be stopped due to its £90,000 cost, even though it can add months of life to women dying of breast cancer.
It is currently available in England under the Cancer Drugs Fund, but this will end in 2016.
The drug, which attacks cancerous cells from within thus avoiding many of the side effects of chemotherapy, could potentially help a fifth of breast cancer sufferers.
NICE chief executive Andrew Dillon called on the Swiss firm to review its pricing.
"We hope the manufacturer will act in the best interests of patients and use this consultation period to look again at their evidence and consider if there is more they can do," he told the BBC.
Roche argues that the price of the drug must take into account costly research and development liabilities.