October 22, 2020 - A seconded amended complaint was filed.

June 29, 2020 - An amended complaint was filed.

July 23, 2019 - An investor in shares of Karyopharm Therapeutics Inc. (NASDAQ: KPTI) filed a lawsuit in the U.S. District Court for the District of Massachusetts over alleged violations of Federal Securities Laws by Karyopharm Therapeutics Inc. in connection with certain allegedly false and misleading statements made between March 2, 2017 and February 22, 2019 .

Newton, MA based Karyopharm Therapeutics Inc., an oncology-focused pharmaceutical company, engages in the discovery, development, and commercialization of various drugs directed against nuclear export and related targets for the treatment of cancer and other diseases. Karyopharm Therapeutics Inc is developing small molecule selective inhibitor of nuclear export (SINE) compounds that inhibit the nuclear export protein exportin 1 Its lead compound is XPOVIO (selinexor), which has received approval from the Food and Drug Administration in combination with dexamethasone as a treatment for patients with heavily pretreated multiple myeloma, as well as is under review by the European Medicines Agency.

On February 22, 2019, when the Federal Drug Administration ( FDA ) released a briefing document that expressed serious concerns with selinexor. Specifically, the FDA revealed that, contrary to Karyopharm's assurances, one of the previously cancelled selinexor trials had resulted in worse overall survival for certain patients treated with selinexor, which highlight[ed] the toxicity of this drug. The FDA unambiguously concluded that [t]reatment with selinexor is associated with significant toxicity and has limited efficacy. Shares of Karyopharm Therapeutics Inc. (NASDAQ: KPTI) declined from $21.71 per share in August 2018 to as low as $3.92 per share on March 1, 2019.

According to the complaint the plaintiff alleges, that the defendants violated Federal Securities Laws. The plaintiff claims violations of Sections 10(b) and 20(a) of the Securities Exchange Act of 1934 on behalf of investors in Karyopharm Therapeutics Inc. (NASDAQ: KPTI) common stock during the time period of March 2, 2017 and February 22, 2019, and violations of Sections 11, 12(a)(2), and 15 of the Securities Act of 1933 on behalf of all persons who purchased or otherwise acquired Karyopharm Therapeutics Inc. (NASDAQ: KPTI common stock in or traceable to the Company's public offerings of common stock conducted on or around April 28, 2017 and May 7, 2018.

More specifically, the plaintiff alleges that the Defendants' material misrepresentations and omissions center on Defendants' claims regarding results from clinical trials for selinexor's treatment of patients with certain types of blood cancer, that the, Defendants claimed that selinexor studies showed that selinexor was well-tolerated by patients and explained that there were no new clinically significant adverse events in the patients receiving selinexor , and that the Company repeatedly touted the commercial prospects for selinexor and consistently described selinexor as having a predictable and manageable tolerability profile and a very nice safety profile”, while in reality, selinexor was unsafe with limited efficacy.