The combination therapy of Leclaza (lazertinib), South Korea’s first domestically developed anti-cancer drug approved by the U.S. Food and Drug Administration (FDA), has demonstrated potential to significantly extend patient survival compared to AstraZeneca’s Tagrisso (osimertinib), recent clinical findings reveal. On Jan. 7, Johnson & Johnson (J&J) announced results from a Phase 3 clinical trial indicating that the combination of the oral drug Leclaza and Rybrevant (amivantamab-vmjw) injection may achieve superior overall survival (OS) compared to Tagrisso. OS, a critical metric in oncology, measures the time from treatment initiation to death. J&J researchers highlighted that the Leclaza-Rybrevant combination is expected to extend patient survival by at least one year compared to Tagrisso.
Developed by South Korea’s Yuhan Corporation, Leclaza targets non-small cell lung cancer (NSCLC) by inhibiting the epidermal growth factor receptor (EGFR), a protein that drives cancer cell growth. Lung cancer is categorized as small cell lung cancer (SCLC) when the cancer cells are small and as non-small cell lung cancer (NSCLC) when they are larger. Yuhan Corporation licensed the technology to J&J in 2018 for $1.255 billion (1.7 trillion won). Leclaza was approved by South Korea’s Ministry of Food and Drug Safety in 2021 as the country’s 31st domestically developed new drug and received FDA approval in August 2023 for its use in combination with Rybrevant. In South Korea, where Tagrisso has dominated the lung cancer treatment market, the Leclaza-Rybrevant combination poses a strong challenge to AstraZeneca’s widely prescribed drug. Industry estimates suggest Tagrisso generated approximately $6.8 billion (9.9 trillion won) in global sales last year. This has fueled optimism that Leclaza could achieve blockbuster status, defined as annual sales exceeding $685 million (1 trillion won), marking a milestone for South Korean pharmaceuticals.
Professor Cho Byoung-chul of Yonsei University College of Medicine, who leads the Lung Cancer Center at Yonsei Cancer Hospital, underscored the significance of the findings during a Jan. 10 interview. “Extending overall survival by more than 12 months compared to existing treatments is a groundbreaking achievement in oncology,” Cho remarked. He also noted J&J’s assertion that the findings may open the door to “considering the possibility of curing NSCLC.”
Cho has spearheaded clinical trials for the combination therapy from Phase 1 through Phase 3, as well as standalone trials for Leclaza and Rybrevant. Reflecting on the initial challenges, he recalled, “When we launched clinical trials in 2016, skepticism was widespread within academic and pharmaceutical circles regarding the feasibility of a South Korean-developed drug competing in this space. At the time, major global players such as Pfizer and Novartis had abandoned similar projects due to Tagrisso’s dominance.”
Despite these hurdles, Cho’s commitment to advancing the trials was driven by patient needs. Each year, approximately 30,000 new cases of lung cancer are diagnosed in South Korea, with NSCLC accounting for 80% of cases. The disease predominantly affects non-smoking women in their 40s and 50s, often diagnosed at Stage 4 due to the absence of early detection methods or distinctive symptoms, underscoring the urgent demand for innovative therapies.
Discussing the trial results, Cho explained, “The data indicates that the Leclaza-Rybrevant combination may extend survival by more than one year beyond Tagrisso’s average overall survival of approximately three years. While precise figures are still being monitored as participants remain under observation, this marks a significant milestone. For patients, gaining an additional year of survival is invaluable.” He further emphasized, “In oncology, patients who survive more than five years without further treatment are often considered cured. If the Leclaza-Rybrevant therapy achieves an overall survival of four years or longer, some patients may approach the threshold of a cure.”
