Two new drugs have shown clinical promise in preventing a condition known as chemotherapy-induced nausea and vomiting (CINV), but they are still classified as being experimental.

According to Reuters, Tesaro Inc.'s drug rolapitant did not show enough benefit in clinical trials to beat out its competition. As a result, Tesaro's shares have taken a 24 percent dip. Merck and Co. Inc.'s drug Emend is similar and treats CINV for up to five days.

Rolapitant and Emend are both know as NK-1 receptors antagonists that block the substance in a person's brain that induces the vomiting reaction. Rolapitant did not sustain its effects past 120 hours after chemotherapy and was not helpful in reducing CINV over the first 24 hours.

As a result, patients in the clinical trials were given a two-drug combination as well as rolapitant to try and reduce chemotherapy's side effects. Other patients were given the same treatment, only with Emend instead of rolapitant.

The most common side effects for the treatments were fatigue, loss of appetite and hair loss. In a statement provided to Reuters, Tesaro said these effects were balanced in both theirs and Merck's drug.

Rolapitant is set to undergo its third and final Phase 3 trial, Tesaro announced in a press release.

"Despite the availability of preventative therapies and established treatment guidelines for CINV, a significant number of cancer patients still suffer from the debilitating side effects of delayed nausea and vomiting," said Mary Lynne Hedley, Ph.D., President of TESARO. "We are enthusiastic about the potential for this product candidate, with a profile that may include an extended half life, convenient, single-dose oral and intravenous formulations and a lack of CYP3A4-mediated drug interactions."

Tesaro is continuing to enroll patients undergoing highly emetogenic chemotherapy treatment in their final late-stage trial. Afterward, they will present their results for all three Phase 3 trials in mid-2014.

Rolapitant has not been approved by the U.S. Food and Drug Administration or any other regulatory agencies.