[THE INVESTOR] Shares of Hanmi Pharmaceutical, South Korea’s leading drug maker, fell more than 18 percent on Sept. 30, as its deal with a German firm over lung cancer treatment developed by the Korean firm fell through.

Hanmi shares plummet 18.06 percent to close at 508,000 won (US$461.27) following the firm’s announcement in the morning that Boehringer Ingelheim will return its license of HM61713 to Hanmi, a third-generation cancer-fighting drug for the treatment of lung cancer patients who have developed a tolerance to existing cancer-fighting drugs. 

Hanmi Science, the holding company of Hanmi Pharmaceutical, shed 18.29 percent, closing the session at 114,000 won.

“Boehringer Ingelheim decided to return its rights on HM61713 after reevaluating clinical data on the drug and recent trend on lung cancer treatment,” the Seoul-based pharmaceutical company said. The contract will be terminated on Nov. 11.

Hanmi and Boehringer signed an exclusive license and collaboration agreement for the development and global commercialization rights on the drug in a deal valued at $730 million in July 2015.

The initial payment worth US$65 million from Boehringer won’t be refunded, according to the Korean firm’s regulatory filing.

Boehringer Ingelheim -- which exclusively holds the drug’s worldwide sales rights except in Korea, China and Hong Kong -- was recently carrying out phase-III clinical trials for Hanmi’s drug, with aims to submit the drug for approval to the US Food and Drug Administration and the European Medicines Agency within this year.

The German drug giant, however, suspended its clinical trials as HM61713 seemed to be losing its competitiveness against Tagrisso, a similar lung cancer treatment developed by AstraZeneca, which was already approved by the USFDA in 2015, according to industry experts.

By Park Han-na (hnpark@heraldcorp.com)