Shareholder rights law firm Robbins Arroyo LLP reminds shareholders that purchasers of Prothena Corporation Public Limited Company (NasdaqGS: PRTA) filed a class action complaint against the company's officers and directors for alleged violations of the Securities Exchange Act of 1934 between October 15, 2015 and April 20, 2018. Prothena develops and sells novel immunotherapy treatment. Prothena's principal asset - NEOD001 - is a monoclonal antibody designed to treat amyloid light chain amyloidosis ("AL amyloidosis"), which can lead to organ failure and death.

View this information on the law firm's Shareholder Rights Blog: https://www.robbinsarroyo.com/prothena-corporation-public-limited-company-july-2018

Prothena Accused of Misrepresenting Its Drug's Prospects for Approval

According to the complaint, Prothena officials touted the "exciting findings" of Prothena's ongoing Phase 1/2 clinical study of NEOD001 as evidence that the drug was effective. Prothena even stated that the results showed improvements in all three organ systems measured in the study and led investors to believe that NEOD001 would obtain final approval after completion of the studies. However, Prothena withheld trial data that showed NEOD001 was not an effective treatment for AL amyloidosis and created the false impression that the drug was effective. On April 23, 2018, Prothena announced it was ending all development of NEOD001 after data from its Phase 2b PRONTO trial showed that the drug failed to reach either its primary or secondary endpoints and was substantially less effective than a placebo. On this news, Prothena's stock plummeted nearly 69%, closing at $11.50 per share on April 23, 2018, and has yet to regain its lost value.

Prothena Shareholders Have Legal Options

Concerned shareholders who would like more information about their rights and potential remedies can contact attorney Leonid Kandinov at (800) 350-6003, LKandinov@robbinsarroyo.com, or via the shareholder information form on the firm's website.

Robbins Arroyo LLP is a nationally recognized leader in shareholder rights law. The firm represents individual and institutional investors in shareholder derivative and securities class action lawsuits, and has helped its clients realize more than $1 billion of value for themselves and the companies in which they have invested.

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