WOBURN, Mass. ( TheStreet) -- Arqule ( ARQL) disclosed Wednesday that patient enrollment has been suspended temporarily in a late-stage study of its lung cancer drug tivantinib being conducted in Asia due to suspected cases of a serious lung disease. Shares of Arqule were down $1.72, or 25%, to $4.99 in early trading. Kyowa Hakko Kirin, Arqule's Japanese partner, stopped enrolling patients in the phase III "ATTENTION" study due to reports of suspected cases of interstitial lung disease (ILD) that appear to be more prevalent in patients treated with tivantinib. An independent safety monitor recommended that patient enrollment be halted temporarily while additional information about the reported cases of ILD are gathered, Arqule disclosed in an 8-K regulatory filing. The ATTENTION study is being conducted in three Asian countries to determine whether the combination of tivantinib plus Tarceva can prolong survival compared to Tarceva alone in patients with non-small cell lung cancer. Tarceva is a currently approved treatment for lung cancer marketed by Roche and Astellas. ILD is a group of diseases characterized by progressive scarring of the lungs, which over time can impair a person's ability to breathe. Safety concerns about ILD have not affected a separate phase III lung cancer study of tivantinib dubbed "MARQUEE" which completed enrollment in May and enrolled 1,000 patients in the U.S. and Europe. "Incidence of ILD-related events in MARQUEE is comparable to reported experience in the West and published literature for Tarceva treatment," said Arqule spokesman Bill Boni, adding that ILD has not been reported as a safety concern in past studies of tivantinib. ILD is listed as a reported adverse event in Tarceva'a FDA-approved label and incidences of ILD were reported in 4.5% of Japanese lung cancer patients treated with Tarceva, according to an August post-marketing surveillance study published in the Journal of Thoracic Oncology. Arqule and partner Daiichi Sankyo, which is running the "MARQUEE" study of tivantinib, expect to report results from an interim survival analysis later this fall. --Written by Adam Feuerstein in Boston. >To contact the writer of this article, click here: Adam Feuerstein.