Several big drug makers are in a neck-and-neck race to introduce new drugs for treating blood clots, and the prize is a piece of a market estimated to be worth about $20 billion by 2016, The Wall Street Journal writes.

Current treatments are effective and sell well but have problems - one is difficult to dose and has risks when taken with other meds and some foods, while another is an injectable, making long-term therapy difficult, the paper writes. Boehringer Ingelheim; Pfizer in a partnership with Bristol-Myers Squibb; and Bayer in a partnership with Johnson & Johnson are all in late stages of clinical trials, the Journal notes.

The new drugs are taken by mouth, which makes them easier to use, their dosing is less troublesome, and they need no laboratory monitoring, according to the paper. And these are also potentially more effective than existing meds. The drug developed by Bayer and J&J has shown superior efficacy compared with standard therapy in a recent study. But it remains to be seen whether any of these drugs can be established as the new standard treatment for blood clots.