NEW YORK (TheStreet) -- Shares of GW Pharmaceuticals (GWPH) - Get Report were surging 16.13% to $124.90 in mid-afternoon trading on Monday after the company announced that its epidiolex drug had positive results in a phase III clinical trial.

Epidiolex is meant to treat seizures in patients with Lennox-Gastaut syndrome, a rare epilepsy disorder typically beginning in childhood.

In the trial, patients taking a higher dosage of the drug saw a 42% monthly reduction in seizures, while those with a lower dosage experienced a 37% monthly drop.

Patients taking a placebo had a 17% monthly decrease in seizures.

Piper Jaffray said the Cambridge, MA-based biopharmaceuticals company is "increasingly well-positioned" for FDA submission next year, the Fly reports.

The epidiolex drug has a "robust and consistent effect" in a population whose disease is typically resistant to treatment or cure, the firm added.

The firm also reiterated an "overweight" rating and $147 price target on the stock.

More than 2.42 million GW Pharmaceuticals shares have traded so far today vs. the 30-day average volume of about 689,000 shares.

Separately, TheStreet Ratings objectively rated this stock according to its "risk-adjusted" total return prospect over a 12-month investment horizon. Not based on the news in any given day, the rating may differ from Jim Cramer's view or that of this articles's author.

TheStreet Ratings rated this stock as a "sell" with a ratings score of D.

The company's weaknesses can be seen in multiple areas, such as its disappointing return on equity and feeble growth in its earnings per share.

You can view the full analysis from the report here: GWPH

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