The company is the latest facing historic losses as pharmaceutical firms compete to develop a weight-loss pill.

Shares of Viking Therapeutics fell 40% on Tuesday after the company released mid-stage trial data on its obesity pill that disappointed investors.  While the weight loss caused by Viking's pill was roughly comparable to that of other oral drugs,

Viking Therapeutics Inc. plunged in early trading on Tuesday after its experimental obesity pill disappointed in a mid-stage study, marking another weaker-than-expected result for an oral alternative to popular weight-loss injections.