NEW YORK (TheStreet) -- Transition Therapeutics (TTHI) shares are up by 8.81% to $2.10 in afternoon trading on Thursday, after the company's Alzheimer drug candidate proved to be effective in late-stage trials.

The company reported that the drug, ELND005, reduced severe agitation and aggression in Alzheimer patients.

These latest results are a reverse from the data the company provided in June showing that the drug did not reduce moderate-to-severe agitations and aggression.

That report caused the company's stock to fall as much as 20% in a single session.

"This study was originally designed as a Phase 2 study, and viewed from that perspective, it has provided TTIL with important data to select a patient population, effectively screen for these patients in a clinical setting and identify a dosing regimen with acceptable safety and tolerability. The next step will be to share these findings with regulators to discuss an ELND005 Phase 3 program in AD patients with severe agitation and aggression," CEO Dr. Tony Cruz said in a statement.

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