Pharmacotherapeutic group: epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors, ATC code: L01EB09.
Mechanism of action
Lazertinib is a highly potent, third generation, EGFR tyrosine kinase inhibitor (TKI). It selectively inhibits both primary activating EGFR mutations (exon 19 deletions and exon 21 L858R substitution mutations) and the EGFR T790M resistance mutation, while having less activity against wild‑type EGFR.
Pharmacodynamic effects
Based on the exposure‑response analyses for efficacy, no apparent relationship between lazertinib exposure and progression‑free survival was observed at the dose regimen of 240 mg once daily. A similar exposure‑response analyses for safety, concluded that paresthesia and stomatitis appeared to show a trend of increasing occurrence with increase in lazertinib exposure.
Cardiac electrophysiology
The QTc interval prolongation potential of lazertinib was evaluated by exposure‑response (E‑R) analysis conducted with clinical data from 243 NSCLC patients who received 20, 40, 80, 120, 160, 240 or 320 mg lazertinib once daily in a phase 1/II study. The E‑R analysis revealed no clinically relevant relationship between lazertinib plasma concentration and change in QTc interval. The 2‑sided upper bound of 90% CI at steady state Cmax from the recommended dose of 240 mg once daily and highest tested clinical dose of 320 mg once daily was 5.83 and 7.23 msec, respectively.
Clinical efficacy and safety
MARIPOSA is a randomised, open-label, active‑controlled, multicentre phase 3 study assessing the efficacy and safety of Lazcluze in combination with amivantamab as compared to osimertinib monotherapy in the first‑line treatment in patients with EGFR‑mutated locally advanced or metastatic NSCLC not amenable to curative therapy. Patient samples were required to have one of the two common EGFR mutations (exon 19 deletion or exon 21 L858R substitution mutation), as identified by local testing. Tumour tissue (94%) and/or plasma (6%) samples for all patients were tested locally to determine EGFR exon 19 deletion and/or exon 21 L858R substitution mutation status using polymerase chain reaction (PCR) in 65% and next generation sequencing (NGS) in 35% of patients.
A total of 1074 patients were randomised (2:2:1) to receive Lazcluze in combination with amivantamab, osimertinib monotherapy, or Lazcluze monotherapy until disease progression or unacceptable toxicity. Lazcluze was administered at 240 mg orally once daily. Amivantamab was administered intravenously at 1050 mg (for patients < 80 kg) or 1400 mg (for patients ≥ 80 kg) once weekly for 4 weeks, then every 2 weeks thereafter starting at week 5. Osimertinib was administered at a dose of 80 mg orally once daily. Randomisation was stratified by EGFR mutation type (exon 19 deletion or exon 21 L858R substitution mutation), race (Asian or non‑Asian), and history of brain metastasis (yes or no).
Baseline demographics and disease characteristics were balanced across the treatment arms. The median age was 63 (range: 25–88) years with 45% of patients ≥ 65 years; 62% were female; and 59% were Asian, and 38% were White. Baseline Eastern Cooperative Oncology Group (ECOG) performance status was 0 (34%) or 1 (66%); 69% never smoked; 41% had prior brain metastases; and 90% had Stage IV cancer at initial diagnosis. With regard to EGFR mutation status, 60% were exon 19 deletions and 40% were exon 21 L858R substitution mutations.
Lazcluze in combination with amivantamab demonstrated a statistically significant and clinically meaningful improvement in progression‑free survival (PFS) by BICR assessment, with a 30% reduction in the risk of progression or death compared with osimertinib (HR=0.70 [95% CI: 0.58, 0.85], p=0.0002). The corresponding median PFS was 23.72 months (95% CI: 19.12, 27.66) for the Lazcluze in combination with amivantamab arm and 16.59 months (95% CI: 14.78, 18.46) for the osimertinib arm.
The final analysis of OS demonstrated a statistically significant improvement in OS for Lazcluze in combination with amivantamab compared to osimertinib (see Table 4 and Figure 3).
With 82% of pre-specified deaths for the analysis reported, there was a favourable trend for the overall survival (OS) towards the combination of Lazcluze and amivantamab compared with osimertinib. A greater proportion of patients treated with Lazcluze in combination with amivantamab were alive at 12 months, 18 months, 24 months, 36 months and 42 months (90%, 82%,75%, 60% and 56% respectively) compared to patients treated with osimertinib (88%, 79%, 70%, 51% and 44% respectively). Lazcluze in combination with amivantamab also provided a benefit in the time to second progression or death (PFS2) (HR=0.75 [95% CI: 0.58, 0.98], p=0.0314). While the objective response rate (ORR) was comparable between the arms, the median duration of response (DOR) among confirmed responders was longer with Lazcluze in combination with amivantamab (25.76 vs 16.76 months). Lazcluze in combination with amivantamab also provided a benefit in the time to symptomatic progression (TTSP), a measure of the burden of lung cancer symptoms (HR=0.72 [95% CI: 0.57, 0.91], p=0.0049). Table 4, Figure 1 and Figure 3 summarise efficacy results for Lazcluze in combination with amivantamab.
| Table 4 Efficacy results in MARIPOSA |
| | Lazcluze + amivantamab (N=429) | Osimertinib (N=429) | Lazcluze (N=216) |
| Progression‑free survival (PFS)a |
| Number of events | 192 (45%) | 252 (59%) | 121 (56%) |
| Median, months (95% CI) | 23.72 (19.12, 27.66) | 16.59 (14.78, 18.46) | 18.46 (14.75, 20.11) |
| HR (95% CI); p‑value |
| Lazcluze + amivantamab vs osimertinib | 0.70 (0.58, 0.85); p=0.0002 | | |
| Lazcluze + amivantamab vs Lazcluze | 0.72 (0.57, 0.90); p=0.0046 | | |
| Overall survival (OS) |
| Number of events | 173 (40%) | 217 (51%) | 100 (46%) |
| Median, months (95% CI) | NE (42.9, NE) | 36.7 (33.4, 41.0) | 38.5 (36.5, 45.4) |
| Hazard ratio (95% CI); p‑value |
| Lazcluze + amivantamab vs osimertinib | 0.75 (0.61, 0.92); p=0.0048 | | |
| Lazcluze + amivantamab vs Lazcluze | 0.83 (0.65, 1.06); p=0. 1416 | | |
| 12‑month event‑free rate, % (95% CI) | 90 (86, 92) | 88 (84, 91) | 85 (80, 89) |
| 18‑month event‑free rate, % (95% CI) | 82 (78, 86) | 79 (75, 83) | 77 (71, 82) |
| 24‑month event‑free rate, % (95% CI) | 75 (71, 79) | 70 (65, 74) | 72 (65, 77) |
| Objective response rate (ORR)a |
| ORR % (95% CI) | 86.2 (82.6, 89.4) | 84.5 (80.7, 87.9) | 82.7 (77.0, 87.5) |
| Odds ratio (95% CI); p‑value |
| Lazcluze + amivantamab vs osimertinib | 1.15 (0.78, 1.70); p=0.4714 | | |
| Lazcluze + amivantamab vs Lazcluze | 1.31 (0.83, 2.06); p=0.2409 | | |
| Complete response, % | 6.9 | 3.6 | 4.2 |
| Partial response, % | 79.3 | 80.9 | 78.5 |
| Duration of response (DOR)b |
| Median, months (95% CI) | 25.76 (20.14, NE) | 16.76 (14.75, 18.53) | 16.56 (14.75, 20.21) |
| Patients with DOR ≥ 6 months, % | 86.3 | 85.0 | 82.5 |
| Patients with DOR ≥ 12 months, % | 67.9 | 57.6 | 58.8 |
| BICR = blinded independent central review; CI = confidence interval; NE = not estimable. PFS, ORR and DOR results are from data cut‑off 11 August 2023. OS results are from data cut-off 04 December 2024 with a median follow-up of 37.8 months. a BICR by RECIST v1.1. b BICR by RECIST v1.1 in confirmed responders. |
Figure 1: Kaplan‑Meier curve of PFS in previously untreated patients with NSCLC by BICR assessment

The PFS benefit of Lazcluze in combination with amivantamab as compared to osimertinib was generally consistent across prespecified, clinically relevant subgroups, including age group, sex, race, weight, mutation type, ECOG performance status, history of smoking, and history of brain metastasis at study entry (see figure 2).
Figure 2: Forest plot of PFS in previously untreated patients with NSCLC by BICR assessment
The MARIPOSA study included protocol‑mandated brain magnetic resonance imaging (MRIs), which have historically not been used in trials evaluating EGFR‑mutated NSCLC. This may have led to earlier detection of recurrences and associated shorter median values for PFS. To account for this, a sensitivity analysis was done whereby patients with brain‑only progression as the site of first progression were censored. Extracranial PFS based on BICR assessment was consistent with the treatment benefit observed in the primary analysis. The median extracranial PFS was 27.5 months with Lazcluze in combination with amivantamab, as compared to 18.37 months with osimertinib (HR=0.68 [95% CI: 0.55, 0.83], nominal p=0.0001).
The stratified analysis of investigator‑assessed PFS shows that the improved treatment effect of the combination of Lazcluze and amivantamab relative to osimertinib was also observed when assessed by investigator. Results for the analysis of ORR based on investigator assessment for comparison of the Lazcluze in combination with amivantamab arm versus the osimertinib arm were consistent with results for ORR based on BICR assessment.
Figure 3: Kaplan‑Meier curve of OS in previously untreated patients with NSCLC
Results of pre‑specified analyses of intracranial ORR and DOR by BICR in the subset of patients with intracranial lesions at baseline for the combination of Lazcluze and amivantamab demonstrated similar intracranial ORR to the control. Per protocol, all patients in MARIPOSA had serial brain MRIs to assess intracranial response and duration. Results are summarised in Table 5.
| Table 5 Intracranial ORR and DOR by BICR assessment in subjects with intracranial lesions at baseline |
| | Lazcluze + amivantamab (N=180) | Osimertinib (N=186) | Lazertinib (N=93) |
| Intracranial tumour response assessment |
| Intracranial ORR (CR+PR), % (95% CI) | 77.8 (71.0, 83.6) | 77.4 (70.7, 83.2) | 75.0 (64.9, 83.4) |
| Complete response % | 63.9 | 58.6 | 54.3 |
| Intracranial DOR |
| Number or responders | 140 | 144 | 69 |
| Median, months (95% CI) | 35.0 (20.4, NE) | 25.1 (22.1, 31.2) | 22.5 (18.8, 31.1) |
| Response duration ≥ 6 months, % | 78.6 | 79.9 | 81.2 |
| Response duration ≥ 12 months, % | 63.6 | 61.1 | 60.9 |
| Response duration ≥ 18 months, % | 52.1 | 41.0 | 40.6 |
| CI = confidence interval Intracranial ORR and DOR results are from data cut off 04 December 2024 with a median follow up of 37.8 months. |
Paediatric population
The Licensing Authority has waived the obligation to submit the results of studies with Lazcluze in all subsets of the paediatric population in non‑small cell lung cancer (see section 4.2 for information on paediatric use).