AstraZeneca's Tagrisso (Osimertinib) and Yuhan Corporation's Leclaza (Nazartinib) are positioned for consideration by the National Health Insurance Service's deliberation committee in December, following successful negotiations with the Health Insurance Review and Assessment Service (HIRA). The expansion of reimbursement criteria for EGFR mutation non-small cell lung cancer's first-line treatment marks a pivotal moment for both drugs, albeit with different trajectories.

While Tagrisso experienced a five-year journey to broaden its reimbursement criteria, Leclaza is poised for an accelerated expansion after its initial reimbursement approval. Recent industry reports from November 30th confirm that AstraZeneca and Yuhan Corporation have reached an agreement with the Health Insurance Service, paving the way for the potential expansion of reimbursement criteria for lung cancer's first-line treatment.

Leclaza, initially approved as a second-line treatment for EGFR T790M positive mutations in January 2021, swiftly navigated approval processes and secured reimbursement within the same year. Its journey began with an application for insurance registration in December 2020, followed by official approval in January 2021, and subsequent health committee evaluations culminating in reimbursement inclusion by July. The drug's pursuit for expansion gained momentum after obtaining first-line indications for lung cancer in June this year, positioning it in direct competition with the established drug, Tagrisso.

In contrast, Tagrisso faced hurdles in expanding its first-line treatment reimbursement criteria. Despite encountering setbacks in the 2019 Cancer Drug Evaluation Committee meeting and facing evaluation obstacles in 2021 and 2022, it finally established reimbursement criteria in the March 2023 evaluation.

Both drugs commenced negotiations with the HIRA, albeit with slightly different timelines. Tagrisso concluded its negotiations by late November, while Leclaza's negotiations concluded a month later in December. Pending the December decision, both medications anticipate reimbursement for first-line lung cancer treatment starting January.

Interestingly, the reimbursement expansions for both drugs coincide with the revelation of clinical results on combination therapy in first-line lung cancer treatment. Tagrisso explores combination with chemotherapy, while Leclaza is being studied in combination with Librivant.

The FLAURA2 study revealed that combining Tagrisso extended progression-free survival (PFS) by 9 to 10 months compared to monotherapy, particularly benefiting about 40% of patients with brain metastases. Professor Myung-Joo Ahn from Samsung Medical Center suggested that not all patients may require chemotherapy alongside Tagrisso, hinting at the potential benefits for patients with brain metastases and those with the L858R mutation.

In the Mariposa Phase 3 study for Leclaza, the Leclaza+Librivant combination group exhibited a 23.7-month PFS at the 22-month mark, a noteworthy improvement compared to the 16.6 months seen in the Tagrisso group. Professor Byoung-Chul Cho from Yonsei Cancer Hospital highlighted Mariposa's showcasing of PFS improvements for EGFR mutation patients in first-line treatment, while keeping the door open for standard chemotherapy as an option.