LOS ANGELES, Aug. 31, 2018 (GLOBE NEWSWIRE) -- National securities litigation law firm Glancy Prongay & Murray LLP (“GPM”) announces that a class action lawsuit has been filed on behalf of investors that purchased or otherwise acquired the securities of Prothena Corporation plc (“Prothena” or the “Company”) (NASDAQ:  PRTA ) securities between  October 15, 2015 and April 20, 2018 , inclusive (the “Class Period”). Prothena investors now have until  September 17, 2018 to file a lead plaintiff motion.

If you are a shareholder who suffered a loss, click here to participate.

Investors that suffered losses on their Prothena investments are encouraged to contact Lesley Portnoy of GPM to discuss their legal rights in this class action at 310-201-9150 or by email to shareholders@glancylaw.com .

On October 15, 2015, Prothena disclosed its late-stage Phase 2b “PRONTO” study and expansion of its Phase 1/2 clinical trial for the antibody NEOD001. On April 23, 2018, Prothena announced it was ending development of NEOD001 after its Phase 2b PRONTO trial failed to reach either its primary or secondary endpoints. On this news, shares of Prothena fell $25.34, or nearly 69%, to close at $11.50 on April 23, 2018, thereby injuring investors.

The complaint filed in this class action alleges that, Defendants during the Class Period violated the federal securities laws by: (1) withholding relevant trial data showing that Prothena’s NEOD001, an antibody designed to treat amyloid light chain amyloidosis (“AL amyloidosis”), was not an effective treatment for AL amyloidosis; (2) making misleading comparisons of NEOD001’s “best response” rates against certain prior studies; and (3) touting that Prothena’s ongoing Phase 1/2 study of NEOD001 provided a strong basis for late-stage Phase 2b and Phase 3 studies of NEOD001, even though the full Phase 1/2 study data demonstrated that NEOD001 was not an effective treatment for AL amyloidosis.

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If you purchased shares of Prothena during the Class Period you may move the Court no later than  September 17, 2018 to ask the Court to appoint you as lead plaintiff. To be a member of the Class you need not take any action at this time; you may retain counsel of your choice or take no action and remain an absent member of the Class. If you wish to learn more about this action, or if you have any questions concerning this announcement or your rights or interests with respect to these matters, please contact Lesley Portnoy, Esquire, of GPM, 1925 Century Park East, Suite 2100, Los Angeles California 90067 at 310-201-9150, Toll-Free at 888-773-9224, by email to shareholders@glancylaw.com , or visit our website at www.glancylaw.com . If you inquire by email please include your mailing address, telephone number and number of shares purchased.

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Contacts Glancy Prongay and Murray LLP, Los Angeles Lesley Portnoy, 310-201-9150 or 888-773-9224 www.glancylaw.com   shareholders@glancylaw.com