South Korean pharmaceutical giant Yuhan announced Friday it has terminated its collaboration with Janssen Biotech on the development of a next-generation targeted anticancer drug, citing the strong efficacy of its existing treatment, which has reduced the need for further development.

According to the company’s regulatory filing, Yuhan and Janssen have amended their research partnership to discontinue the further development of a fourth-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor. The treatment was intended to be prescribed to patients with non-small cell lung cancer exhibiting epidermal growth factor receptor mutations.

“Due to the significantly lower incidence of EGFR secondary resistance mutations in patients receiving combination therapy with our third-generation EGFR inhibitor, Lazertinib, and Janssen's bispecific antibody, Amivantamab, the need for further development of a fourth-generation treatment has diminished,” a Yuhan official explained.

Back in 2018, Yuhan transferred the global -- excluding Korea -- development and commercialization rights for Leclaza, the brand name of Lazertinib, to Janssen and signed a licensing agreement to jointly develop the fourth-generation EGFR inhibitor.

The termination of this development project has also resulted in a reduction in milestone payments, from $1.25 billion to $950 million. However, this decision does not affect the upfront payment of $50 million or the ongoing development of the combination therapy of Lazertinib and Amivantamab.

Following the termination, Yuhan retains the rights to Leclaza in Korea, while Janssen holds the rights to the combination therapy. Yuhan noted, "Despite the end of this research partnership, we will continue to pursue follow-up treatments for Leclaza domestically."

On the same day, Yuhan also announced a contract with US-based biopharma Gilead Sciences to supply active pharmaceutical ingredients for HIV treatments. The deal, valued at $80.9 million, accounts for nearly 6 percent of Yuhan’s revenue last year. The contract is set to last until Sept. 30, 2025.