Yuhan Corp. is wrapping up its chemo-free phase 2 lung cancer trial just as Johnson & Johnson pushes for reimbursement of Rybrevant in Korea -- doubling down on a combo that has already shown an overall survival edge over AstraZeneca’s Tagrisso (osimertinib).

The AMAZE-lung study, backed by J&J and run through the European Thoracic Oncology Platform, pairs Yuhan's Leclaza (lazertinib) with Rybrevant (amivantamab) and Pfizer’s Zirabev, a biosimilar to Roche’s Avastin (bevacizumab). 

The single-arm trial targets EGFR-mutant non-small cell lung cancer (NSCLC) patients whose disease progressed on Tagrisso or lazertinib.

According to an updated entry on ClinicalTrials.gov as of July 1, enrollment is now closed across 18 sites in Europe, and the trial has shifted into follow-up.

Designed to evaluate the efficacy of continuing lazertinib alongside Rybrevant and bevacizumab in a second-line setting, the phase 2 study aims to inform the size and structure of a future phase 3 trial. 

Treatment with Tagrisso must have been discontinued at least eight days before enrollment, and patients must have had radiologically confirmed disease progression on prior third-gen EGFR TKIs.

The timing aligns with a reimbursement push that could reset the playing field in first-line treatment. 

After notching a regulatory nod in January for the Leclaza-Rybrevant combo, J&J has now filed for reimbursement, a spokesperson for Korea’s Health Insurance Review and Assessment Service (HIRA) confirmed to Korea Biomedical Review. 

The application is under review and covers first-line use of Rybrevant in combination with Leclaza for patients with locally advanced or metastatic EGFR-mutant NSCLC.

That filing rides on the back of MARIPOSA trial data presented in March, where Leclaza and Rybrevant together cut the risk of death by 25 percent versus Tagrisso monotherapy (HR=0.75; P<0.005). Median overall survival for the combo hadn’t been reached, while Tagrisso’s clocked in at 36.7 months. The three-year survival rate stood at 60 percent versus Tagrisso’s 51 percent.

The domestic approval earlier this year marked the first for the combination in Asia, following prior clearances in the U.S. and Europe.

Still, access remains uneven. In June, Leclaza gained partial reimbursement for combination use, but Rybrevant remains uncovered, forcing patients to shoulder a heavy financial burden. 

Under new policy updates, patients can now receive partial reimbursement for two regimens: Leclaza plus Rybrevant, and Tagrisso plus chemo. But in both cases, only the EGFR-TKI -- Leclaza or Tagrisso -- is reimbursed.

That dynamic currently favors Tagrisso, since pemetrexed and platinum-based chemo are far cheaper than Rybrevant. If J&J’s application succeeds, the playing field could tilt.

Meanwhile, both drugs are seeing strong market traction. Tagrisso brought in 90.3 billion won (roughly $65.8 million) in prescriptions in the first half of 2025, up 50 percent year over year, while Leclaza soared 94 percent to 38.2 billion won (roughly $27.8 million), according to market tracker UBIST.