For Yuhan Corp. Executive Vice President Oh Se-woong, there have been few moments in his 30-year R&D career rivaled Aug. 20 2024, when the FDA approved the company’s homegrown lung cancer drug lazertinib -- marketed as Leclaza in Korea and Lazcluze in the U.S.

“I’ve worked on so many programs over the years. Many never even made it into the clinic,” said Oh, who also heads the Korean drugmaker’s R&D institute, in an interview with Korea Biomedical Review at BIO KOREA 2025 in Seoul on Thursday. “To see one go all the way through...it still doesn’t quite feel real. That was probably the most meaningful moment of my life.”

Oh, who joined Yuhan in 2011 after a career at JW Pharmaceutical, personally led the preclinical development of lazertinib, a homegrown EGFR inhibitor that has since become Korea’s flagship oncology success story.

The program began as a monotherapy, Oh said, but pivoted -- at Janssen’s suggestion -- into a combo with Johnson & Johnson’s bispecific antibody Rybrevant (amivantamab).

The shift paid off: the duo won FDA approval in August 2024 for EGFR-mutant non-small cell lung cancer, with overall survival data released in March showing a 25 percent reduction in risk of death versus AstraZeneca’s Tagrisso (osimertinib).

“Looking back, they were right,” Oh said. "We were hesitant. We didn’t know what the regulators would say. We weren’t sure what the safety profile would look like. But Janssen had a sense of the market that we didn’t.”

That experience didn’t just lead to a product. Oh said it reshaped the company. “What we learned -- on trial design, manufacturing, even how to handle the FDA -- is shaping how we approach everything now,” he said. “That’s the intellectual return. The financial one is just as important.”

“This drug will carry us for the next 10 years,” he said. “It funds the next generation. The royalties from Janssen -- those launch milestones -- are what give us the runway to keep pushing our R&D.”

That R&D engine is picking up speed. Yuhan now plans to maintain R&D spending at around 10 percent of annual revenue. The new strategy, Oh said, is focus: fewer programs, higher quality. 

Alongside its allergy antibody YH35324, which just wrapped a phase 1b trial with “very promising” early data, the company is advancing two bispecifics co-developed with ABL Bio: YH32364 and YH32367.

Preclinical data presented at AACR 2025 showed YH32364 delivered strong antitumor activity in EGFR- and KRAS-mutant models, with added benefit when paired with anti-PD-1. In vivo, it boosted immune infiltration and showed durable responses. The candidate received investigational new drug clearance in April, with phase 1/2 trials set to begin this half.

“It’s highly specific, low in toxicity, and ideal for combinations,” ABL Bio CEO Lee Sang-hoon said of the bispecific in an interview Thursday. “The potential goes well beyond existing EGFR drugs.”

YH32367, meanwhile, is being developed for HER2-positive breast cancer. The draw, Lee said, is its safety profile. “Most cancer drugs are too toxic for combinations,” he said. “This one isn’t.”

Oh said the two candidates, along with YH35324, are being positioned as potential “next Leclazas.” A global out-licensing deal for the allergy asset is expected within the year, he added.

At the same time, Yuhan is hunting externally, especially in immuno-oncology. “China is producing a lot of high-quality programs,” Oh said. “The bar is rising. Differentiation is everything.”

The company is also placing long-term bets on targeted protein degradation and funding more than 30 investigator-initiated trials across Korea, many of them exploring new real-world uses for lazertinib, Oh said.

A senior principal scientist on the drug discovery team, following the interview, described the shift as a turning point. “When I look back to my start here in September 2017, we were just starting to gain momentum,” he said. “About a year in, the company began racking up real licensing deals. From my perspective, that moment felt like the inflection point, where we began building the foundation not just for the 100th anniversary but for the century to come."

That centennial is now a year away. Founded in 1926, Yuhan had once set its sights on cracking the global top 50 by 2026. With 2024 revenue just topping 2 trillion won, Oh admits the target may need to shift. “It’s going to be difficult by revenue alone,” he said. “But it’s still a meaningful benchmark. It reminds us where we want to be.”

Yuhan, after all, plays the long game. Levonex (levonorgestrel), its first in-house small molecule, took 11 years to develop before launching in 2005. In 2013, it became the first Korean pharma to hit $100 million in API exports.

Lazertinib took a decade too, but this time, the payoff is reinvention.