Shareholder rights law firm Robbins Arroyo LLP announces that a lawsuit was filed against Clovis Oncology, Inc. (NASDAQGS: CLVS) in the Supreme Court of the State of New York, County of New York. The complaint is brought for alleged violations of the Securities Act of 1933 by Clovis's officers and directors. Clovis, a biopharmaceutical company, focuses on acquiring, developing, and commercializing anti-cancer agents in the United States, Europe, and internationally. View this information on the law firm's Shareholder Rights Blog: www.robbinsarroyo.com/shareholders-rights-blog/clovis-oncology-inc-nov-2016Clovis Accused of Overstating the Efficacy of Its Drug According to the complaint, Clovis officials made false, incomplete, and misleading statements concerning test data which purportedly showed the efficacy and safety of Clovis's lung cancer drug - rociletinib. It was imperative for Clovis to be able to show that rociletinib was at least as safe and effective as Tagrisso—the treatment of its competitor, AstraZeneca. Shortly after AstraZeneca released data showing Tagrisso was safe and effective, Clovis released test data claiming rociletinib was just as safe and effective, causing the company's stock price to increase. Then, on May 31, 2015, at the American Society of Clinical Oncology Medical Conference, Clovis claimed that it had observed an objective response rate ("ORR") of 60% for rociletinib, which represented the percentage of patients who experienced a clinically meaningful tumor shrinkage when treated with the drug. However, on November 16, 2015, Clovis disclosed that the rociletinib ORR that it had previously reported was "based primarily on unconfirmed responses" and that rociletinib's ORR based on confirmed responses was just 30%. On April 8, 2016, the U.S. Food and Drug Administration revealed that Clovis had concealed that rociletinib was not well tolerated, and that serious adverse events were reported in 47% of patients treated with the drug. On this news, Clovis's stock fell 17% to close at $15.77 per share on April 8, 2016.