Leclaza combo confirms OS Advantage in EGFR+ NSCLC

Shows a 26% reduction in mortality in the MARIPOSA Asian subgroup patient analysis

Three-year survival is also superior… “Firmly establishes position as a new standard of care”

The Rybrevant + Leclaza combination therapy has demonstrated clear survival benefits in Asian patients, following the overall patient population, for first-line treatment of EGFR-mutated non-small cell lung cancer (NSCLC). Such results from the Asian subgroup analysis of the global Phase III MARIPOSA study confirmed that the combination therapy improves overall survival (OS) compared to Tagrisso, reaffirming its status as the ‘new standard of care’.

Given that approximately 60% of lung cancer cases occur in Asia, and particularly considering the regional characteristic of how EGFR mutations are far more prevalent in Asia than in Western populations, the new findings have substantial implications for real-world clinical practice.

On the 6th, at ESMO ASIA 2025, the Asian subgroup analysis results from the Phase III MARIPOSA study, which evaluated the efficacy and safety of ‘Rybrevant (amivantamab) + Leclaza (lazertinib)’, were presented.

The Asian cohort analysis results from the Phase III MARIPOSA study were disclosed at ESMO ASIA 2025 on the 6th

Leclaza, developed by Yuhan Corporation, is a third-generation EGFR TKI targeting exon 19 deletions and exon 21 (L858R) mutations. Johnson & Johnson holds global rights to Leclaza and has been studying its combination with Rybrevant, a bispecific EGFR/MET antibody that targets EGFR exon 20 insertions and MET alterations.

In the trial, the Rybrevant + Leclaza combination showed a statistically significant OS improvement compared with Tagrisso (Osimertinib) monotherapy.

A total of 858 patients were enrolled, of whom 501 were Asian.

At a median follow-up of 38.7 months, the Rybrevant + Leclaza combination reduced the risk of death by 26% in Asian patients. While the median overall survival (OS) was not reached in the combination group, it was 38.4 months in the Tagrisso group. The researchers estimated that the survival benefit from combining the two drugs would be more than one year. The 36-month survival rate was also higher in the combination therapy group at 61%, compared to Tagrisso.

Given that EGFR mutations are common in Asian patients and their disease characteristics differ from those in Western populations, changes in treatment strategies have a significant impact on clinical practice. This analysis confirmed the same survival improvement effect seen in the global overall results, reaffirming that the Rybrevant + Leclaza combination demonstrates ample efficacy in real-world clinical settings among East Asians.

Professor Hidetoshi Hayashi of Kindai University in Japan, the study presenter, stated, “The combination therapy demonstrated a clear reduction in mortality risk even in Asian patients, strongly supporting its establishment as the new standard of care. It is becoming a key therapeutic strategy for achieving long-term survival in EGFR-mutated lung cancer.”

The Rybrevant + Leclaza combination is already approved as a first-line treatment in major countries, including the US, Europe, South Korea, Japan, and China. Considering the high prevalence of EGFR mutations among Korean patients, this Asian subgroup analysis is expected to significantly influence actual clinical practice guidelines and treatment choices.

Professor Hayashi explained, “The major unmet need in EGFR-mutated NSCLC is improving long-term survival. These results demonstrate that the treatment paradigm is shifting from single-agent targeted therapy toward combination approaches.” “