Yuhan's Lung Cancer Drug 'Leclaza', Global Sales Handled by Janssen... Yuhan Remains with Milestones and Royalties

Yuhan Corporation's newly developed lung cancer drug, lazertinib, is being sold as an anticancer drug in the U.S. and Europe, but the development, production, and sales of this drug were entirely transferred to the U.S. company Johnson & Johnson (J&J) through a technology export in 2018. Yuhan does not sell the drug directly; instead, it receives an upfront payment, milestones, and sales royalties.

The clinical trial Yuhan won and the one that opened up the global market were different

The core clinical trial 'LASER301' directly conducted by Yuhan was a study pitting lazertinib against an earlier lung cancer drug, gefitinib. The trial compared the efficacy of the two drugs as a first-line treatment on 393 non-small cell lung cancer patients with EGFR gene mutations. Patients treated with lazertinib survived without their cancer worsening for 20.6 months, more than double that of gefitinib (9.7 months). As a result of this outcome, lazertinib was approved in South Korea under the name 'Leclaza', becoming the 31st domestically developed new drug. However, the scope that Yuhan directly proved was limited to domestic approval.

The basis for the U.S. and Europe approving lazertinib as a first-line treatment was not LASER301, but rather a separate large-scale clinical trial called 'MARIPOSA' conducted by Janssen. MARIPOSA did not use lazertinib alone; it directly compared a combination therapy of lazertinib and Janssen's anticancer drug amivantamab against the global standard lung cancer drug osimertinib. As a result, the period patients survived without their cancer worsening was 23.7 months, surpassing osimertinib (16.6 months), and in January 2025, results confirming that patients lived longer were also verified. The U.S. approved this combination therapy in August 2024, and Europe in January 2025. Neither the form in which it is sold globally nor the data that served as the basis for its approval belonged to Yuhan.

After transferring the rights, there are no ongoing clinical trials conducted by Yuhan

This structure was set in November 2018 when Yuhan transferred the rights for the development, production, and sales of lazertinib to Janssen. It was a deal worth up to 1.25 billion dollars (about 1.4 trillion won), including an upfront payment of 50 million dollars and milestone payments, and it became entirely Janssen's responsibility to decide how to develop the drug outside of South Korea and where to sell it. Having handed over the development rights, there was no reason for Yuhan to continue leading clinical trials, and the only clinical trial that Yuhan directly held onto until the end was LASER301, which also concluded in April of this year.

This is also confirmed in the clinical data. All lazertinib clinical trials registered with Yuhan as a sponsor have been completed, and none are currently ongoing. On the other hand, clinical trials expanding the drug's use through combinations with other drugs or targeting new patient groups are still underway, and these are being handled by domestic hospitals, researchers, and Janssen.

What the technology export left for Yuhan

Lazertinib is considered a representative success story of a South Korean new drug that has completed the full journey from development to technology export, U.S. and European approval, and domestic authorization. The path for a South Korean company to bring a new drug to the global market is usually not by selling it directly, but by transferring the rights to a major pharmaceutical company, from which point both the clinical trials and sales become the partner's responsibility.

How much the technology export actually earns is now revealed not through clinical trials, but through Yuhan's financial performance. Following the upfront payment, Yuhan received milestones at each commercialization stage in the U.S., Japan, China, and Europe, receiving a cumulative 300 million dollars (approximately 450 billion won) by May 2026, and starting from 2024, royalties linked to Janssen's sales amounts are being added to its quarterly performance. Although the royalty rate itself is not disclosed, the share that the technology export has left for Yuhan is now confirmed every quarter through these figures in the books.

This article was written by News Epoch by gathering lazertinib clinical trials from the U.S. clinical trial registration system (ClinicalTrials.gov) using The Proxy collection pipeline, and verifying the sponsors and progress status. The clinical result figures, U.S., European, and domestic approvals, as well as the details of the Yuhan-Janssen contract and milestones, followed the Journal of Clinical Oncology, FDA, European Commission, Ministry of Food and Drug Safety, and disclosures by J&J and Yuhan Corporation.