LAZCLUZE

1 INDICATIONS AND USAGE LAZCLUZE, in combination with amivantamab, is indicated for the first-line treatment of adult patients with locally advanced or metastatic non-small cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) exon 19 deletions or exon 21 L858R substitution mutations, as detected by an FDA-approved test [see Dosage and Administration (2.1) ] . LAZCLUZE is a kinase inhibitor indicated in combination with amivantamab for the first-line treatment of adult patients with locally advanced or metastatic non-small cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) exon 19 deletions or exon 21 L858R substitution mutations, as detected by an FDA-approved test. ( 1 )

2 DOSAGE AND ADMINISTRATION The recommended dosage of LAZCLUZE is 240 mg orally once daily with or without food, given in combination with amivantamab. ( 2.2 ) Continue treatment until disease progression or unacceptable toxicity. ( 2.2 ) Administer LAZCLUZE any time prior to amivantamab when given on the same day. ( 2.2 ) Refer to the amivantamab prescribing information for recommended amivantamab dosing information. ( 2.2 ) Administer prophylactic and concomitant medications to reduce the risk of dermatologic adverse reactions. ( 2.3 ) Administer anticoagulant prophylaxis to reduce the risk of venous thromboembolic events (VTE) for the first four months of treatment. ( 2.3 ) 2.1 Patient Selection Select patients for the first-line treatment of NSCLC with LAZCLUZE, in combination with amivantamab, based on the presence of EGFR exon 19 deletions or exon 21 L858R substitution mutations in tumor or plasma specimens [see Clinical Studies (14) ] . If these mutations are not detected in a plasma specimen, test tumor tissue. Information on FDA-approved tests is available at: http://www.fda.gov/CompanionDiagnostics . 2.2 Recommended Dosage and Administration Recommended Dosage and Administration The recommended dosage of LAZCLUZE is 240 mg orally once daily administered in combination with amivantamab, with or without food. Swallow LAZCLUZE tablets whole. Do not crush, split, or chew. Continue treatment until disease progression or unacceptable toxicity. Administer LAZCLUZE any time prior to amivantamab when given on the same day. Refer to the amivantamab prescribing information for recommended amivantamab dosing information. Missed Dose If a patient misses a dose of LAZCLUZE within 12 hours, instruct patients to take the missed dose. If more than 12 hours has passed since the dose was to be given, instruct the patient to take the next dose at its scheduled time. Vomiting If vomiting occurs any time after taking LAZCLUZE, instruct the patient to take the next dose at its next regularly scheduled time. 2.3 Prophylactic and Concomitant Medications Venous Thromboembolic Events When initiating treatment with LAZCLUZE in combination with amivantamab, administer anticoagulant prophylaxis to reduce the risk of venous thromboembolic events (VTE) for the first four months of treatment [see Warnings and Precautions (5.1) ]. If there are no signs or symptoms of VTE during the first four months of treatment, consider discontinuation of anticoagulant prophylaxis at the discretion of the healthcare provider. Dermatologic Adverse Reactions When initiating treatment with LAZCLUZE in combination with amivantamab, prophylactic and concomitant medications are recommended to reduce the risk and severity of dermatologic adverse reactions [see Warnings and Precautions (5.3) ] . Administer an oral antibiotic (doxycycline or minocycline, 100 mg orally twice daily) starting on Day 1 for the first 12 weeks of treatment. After completion of oral antibiotic treatment, administer antibiotic lotion to the scalp (clindamycin 1% topical once daily) for the next 9 months of treatment. Administer non-comedogenic skin moisturizer (ceramide-based or other formulations that provide long-lasting skin hydration and exclude drying agents) on the face and whole body (except scalp). Wash hands and feet with 4% chlorhexidine solution once daily. Limit sun exposure during and for 2 months after treatment. Advise patients to wear protective clothing and use broad-spectrum UVA/UVB sunscreen to reduce the risk of dermatologic adverse reactions. 2.4 Dosage Modifications for Adverse Reactions The recommended LAZCLUZE dose reductions for adverse reactions are presented in Table 1. Table 1: Recommended Dose Reductions for Adverse Reactions for LAZCLUZE Dose at which the adverse reaction occurred 1 st Dose Reduction 2 nd Dose Reduction 3 rd Dose Reduction 240 mg once daily (one 240 mg tablet) 160 mg once daily (two 80 mg tablets) 80 mg once daily (one 80 mg tablet) Discontinue LAZCLUZE The recommended management and dosage modifications of LAZCLUZE for specific adverse reactions are presented in Table 2. Refer to the amivantamab prescribing information for information about dosage modifications for amivantamab. Table 2: Recommended Management and Dosage Modifications for Adverse Reactions Adverse Reaction Severity Dosage Modification Venous Thromboembolic Events (VTE) [see Warnings and Precautions (5.1) ] Grade 2 or 3 Withhold LAZCLUZE and amivantamab. Administer anticoagulant treatment as clinically indicated. Once anticoagulant treatment has been initiated, resume LAZCLUZE and amivantamab at the same dose level, at the discretion of the healthcare provider. Grade 4 or recurrent Grade 2 or 3 despite therapeutic level anticoagulation Withhold LAZCLUZE and permanently discontinue amivantamab. Administer anticoagulant treatment as clinically indicated. Once anticoagulant treatment has been initiated, treatment can continue with LAZCLUZE at the same dose level at the discretion of the healthcare provider. Interstitial Lung Disease (ILD)/Pneumonitis [see Warnings and Precautions (5.2) ] Any Grade Withhold LAZCLUZE and amivantamab if ILD/pneumonitis is suspected. Permanently discontinue LAZCLUZE and amivantamab if ILD/pneumonitis is confirmed. Dermatologic Adverse Reactions (including dermatitis acneiform, pruritus, dry skin) [see Warnings and Precautions (5.3) ] Grade 1 Initiate supportive care management as clinically indicated. Grade 2 Initiate supportive care management as clinically indicated. If there is no improvement after 2 weeks, reduce amivantamab dose and continue LAZCLUZE at the same dose. Reassess every 2 weeks, if no improvement, reduce LAZCLUZE dose until ≤ Grade 1 (Table 1), then may resume previous dose of LAZCLUZE at the discretion of the healthcare provider. Grade 3 Withhold LAZCLUZE and amivantamab. Initiate supportive care management as clinically indicated. Upon recovery to ≤ Grade 2, resume LAZCLUZE at the same dose or consider dose reduction, resume amivantamab at a reduced dose. If there is no improvement within 2 weeks, permanently discontinue both LAZCLUZE and amivantamab. Grade 4 (including severe bullous, blistering or exfoliating skin conditions) Initiate supportive care management as clinically indicated. Permanently discontinue amivantamab. Withhold LAZCLUZE until recovery ≤ Grade 2 or baseline. Upon recovery to ≤ Grade 2, resume LAZCLUZE at a reduced dose at the discretion of the healthcare provider. Other Adverse Reactions [see Adverse Reactions (6.1) ] Grade 3–4 Withhold LAZCLUZE and amivantamab until the adverse reaction resolves to ≤ Grade 1 or baseline. Resume both drugs at a reduced dose or LAZCLUZE alone. Consider permanently discontinuing both LAZCLUZE and amivantamab if recovery does not occur within 4 weeks.

4 CONTRAINDICATIONS None. None. ( 4 )

5 WARNINGS AND PRECAUTIONS Venous Thromboembolic Events (VTE): Prophylactic anticoagulation is recommended for the first four months of treatment. Monitor for signs and symptoms of VTE and treat as medically appropriate. Withhold LAZCLUZE and amivantamab based on severity. Once anticoagulant treatment has been initiated, resume LAZCLUZE and amivantamab at the same dose at the discretion of the healthcare provider. Permanently discontinue amivantamab and continue LAZCLUZE for recurrent VTE despite therapeutic anticoagulation. ( 2.3 , 2.4 , 5.1 ) Interstitial Lung Disease (ILD)/Pneumonitis : Monitor for new or worsening symptoms indicative of ILD/pneumonitis. Withhold LAZCLUZE and amivantamab in patients with suspected ILD/pneumonitis and permanently discontinue if ILD/pneumonitis is confirmed. ( 2.4 , 5.2 ) Dermatologic Adverse Reactions : Can cause severe rash including acneiform dermatitis. At treatment initiation, prophylactic and concomitant medications are recommended. Withhold, reduce the dose or permanently discontinue LAZCLUZE and amivantamab based on severity. ( 2.3 , 2.4 , 5.3 ) Ocular Adverse Reactions : Promptly refer patients with new or worsening signs and symptoms of ocular adverse reactions, including keratitis, to an ophthalmologist for evaluation. Withhold, reduce the dose, or permanently discontinue amivantamab and continue LAZCLUZE based on severity. ( 5.4 ) Embryo-Fetal Toxicity : Can cause fetal harm. Advise patients of reproductive potential of the potential risk to a fetus and to use effective contraception. ( 5.5 , 8.1 , 8.3 ) 5.1 Venous Thromboembolic Events LAZCLUZE in combination with amivantamab can cause serious and fatal venous thromboembolic events (VTE), including deep venous thrombosis (DVT) and pulmonary embolism (PE). The majority of these events occurred during the first four months of therapy [see Adverse Reactions (6.1) ] . In MARIPOSA [see Adverse Reactions (6.1) ] , VTE occurred in 36% of patients receiving LAZCLUZE in combination with amivantamab, including Grade 3 in 10% and Grade 4 in 0.5% of patients. On-study VTEs occurred in 1.2% of patients (n=5) while receiving anticoagulation therapy. There were two fatal cases of VTE (0.5%), 7% of patients had VTE leading to dose interruptions of LAZCLUZE, 0.5% of patients had VTE leading to dose reductions of LAZCLUZE, and 1.9% of patients permanently discontinued LAZCLUZE due to VTE. The median time to onset of VTEs was 84 days (range: 6 to 777). Administer prophylactic anticoagulation for the first four months of treatment [see Dosage and Administration (2.3) ] . The use of Vitamin K antagonists is not recommended. Monitor for signs and symptoms of VTE and treat as medically appropriate. Withhold LAZCLUZE and amivantamab based on severity [see Dosage and Administration (2.4) ]. Once anticoagulant treatment has been initiated, resume LAZCLUZE and amivantamab at the same dose level at the discretion of the healthcare provider. In the event of VTE recurrence despite therapeutic anticoagulation, permanently discontinue amivantamab. Continue treatment with LAZCLUZE at the same dose level at the discretion of the healthcare provider [see Dosage and Administration (2.4) ] . Refer to the amivantamab prescribing information for recommended amivantamab dosage modification. 5.2 Interstitial Lung Disease (ILD)/Pneumonitis LAZCLUZE in combination with amivantamab can cause interstitial lung disease (ILD)/pneumonitis. In MARIPOSA [see Adverse Reactions (6.1) ], ILD/pneumonitis occurred in 3.1% of patients treated with LAZCLUZE in combination with amivantamab, including Grade 3 in 1.0% and Grade 4 in 0.2% of patients. There was one fatal case (0.2%) of ILD/pneumonitis and 2.9% of patients permanently discontinued LAZCLUZE and amivantamab due to ILD/pneumonitis [see Adverse Reactions (6.1) ]. Monitor patients for new or worsening symptoms indicative of ILD/pneumonitis (e.g., dyspnea, cough, fever). Immediately withhold LAZCLUZE and amivantamab in patients with suspected ILD/pneumonitis and permanently discontinue if ILD/pneumonitis is confirmed [see Dosage and Administration (2.4) ]. 5.3 Dermatologic Adverse Reactions LAZCLUZE in combination with amivantamab can cause severe rash including dermatitis acneiform, pruritus and dry skin. In MARIPOSA [see Adverse Reactions (6.1) ] , rash occurred in 86% of patients treated with LAZCLUZE in combination with amivantamab, including Grade 3 in 26% of patients. The median time to onset of rash was 14 days (range: 1 to 556 days). Rash leading to dose reduction of LAZCLUZE occurred in 19% of patients, rash leading to dose interruption of LAZCLUZE occurred in 30% of patients, and LAZCLUZE was permanently discontinued due to rash in 1.7% of patients [see Adverse Reactions (6.1) ]. When initiating treatment with LAZCLUZE in combination with amivantamab, prophylactic and concomitant medications are recommended to reduce the risk and severity of dermatologic adverse reactions [see Dosage and Administration (2.3) ]. Instruct patients to limit sun exposure during and for 2 months after treatment with LAZCLUZE in combination with amivantamab. Advise patients to wear protective clothing and use broad-spectrum UVA/UVB sunscreen. If skin reactions develop, administer supportive care including topical corticosteroids and topical and/or oral antibiotics. For Grade 3 reactions, administer oral steroids and consider dermatologic consultation. Promptly refer patients presenting with severe rash, atypical appearance or distribution, or lack of improvement within 2 weeks to a dermatologist. Withhold, reduce the dose or permanently discontinue LAZCLUZE and amivantamab based on severity [see Dosage and Administration (2.4) ] . 5.4 Ocular Toxicity LAZCLUZE, in combination with amivantamab, can cause ocular toxicity, including keratitis. In MARIPOSA [see Adverse Reactions (6.1) ] , ocular toxicity occurred in 16% of patients treated with LAZCLUZE in combination with amivantamab, including Grade 3 or 4 ocular toxicity in 0.7% of patients. Promptly refer patients presenting with new or worsening eye symptoms to an ophthalmologist. Withhold, reduce the dose or permanently discontinue amivantamab and continue LAZCLUZE based on severity [see Dosage and Administration (2.4) ] . 5.5 Embryo-Fetal Toxicity Based on findings from animal studies and its mechanism of action, LAZCLUZE can cause fetal harm when administered to a pregnant woman. In animal reproduction studies, oral administration of lazertinib to pregnant animals during the period of organogenesis resulted in reduced embryo-fetal survival and fetal body weight in rats and malformations in rabbits at exposures approximately 4 and 0.5 times, respectively, the human exposure at the recommended dose of 240 mg/day based on AUC. Advise pregnant women and females of reproductive potential of the potential risk to a fetus. Advise females of reproductive potential to use effective contraception during treatment with LAZCLUZE and for 3 weeks after the last dose. Advise male patients with female partners of reproductive potential to use effective contraception during treatment with LAZCLUZE and for 3 weeks after the last dose [see Use in Specific Populations (8.1 , 8.3) ].

7 DRUG INTERACTIONS Strong and moderate CYP3A4 inducers: Avoid concomitant use. ( 7.1 ) 7.1 Effect of Other Drugs on LAZCLUZE CYP3A4 Inducers Avoid concomitant use of LAZCLUZE with strong and moderate CYP3A4 inducers. Consider an alternate concomitant medication with no potential to induce CYP3A4. Lazertinib is a CYP3A4 substrate. Concomitant use with a strong or moderate CYP3A4 inducer decreased lazertinib concentrations [see Clinical Pharmacology (12.3) ] , which may reduce the efficacy of lazertinib. 7.2 Effect of LAZCLUZE on Other Drugs Certain CYP3A4 Substrates Monitor for adverse reactions associated with a CYP3A4 substrate where minimal concentration changes may lead to serious adverse reactions, as recommended in the approved product labeling for the CYP3A4 substrate. Lazertinib is a weak CYP3A4 inhibitor. Concomitant use of LAZCLUZE increased concentrations of CYP3A4 substrates [see Clinical Pharmacology (12.3) ] , which may increase the risk of adverse reactions related to these substrates. Certain BCRP Substrates Monitor for adverse reactions associated with a BCRP substrate where minimal concentration changes may lead to serious adverse reactions, as recommended in the approved product labeling for the BCRP substrate. Lazertinib is a BCRP inhibitor. Concomitant use of LAZCLUZE increased concentrations of BCRP substrates [see Clinical Pharmacology (12.3) ], which may increase the risk of adverse reactions related to these substrates.

6 ADVERSE REACTIONS The following adverse reactions are discussed elsewhere in the labeling: Venous Thromboembolic Events [see Warnings and Precautions (5.1) ] Interstitial Lung Disease/Pneumonitis [see Warnings and Precautions (5.2) ] Dermatologic Adverse Reactions [see Warnings and Precautions (5.3) ] Ocular Toxicity [see Warnings and Precautions (5.4) ] LAZCLUZE in Combination with Amivantamab The most common adverse reactions (≥ 20%) were rash, nail toxicity, infusion-related reaction (amivantamab), musculoskeletal pain, edema, stomatitis, VTE, paresthesia, fatigue, diarrhea, constipation, COVID-19, hemorrhage, dry skin, decreased appetite, pruritus, and nausea. ( 6.1 ) The most common Grade 3 or 4 laboratory abnormalities (≥ 2%) were decreased albumin, decreased sodium, increased ALT, decreased potassium, decreased hemoglobin, increased AST, increased GGT, and increased magnesium. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Janssen Biotech, Inc. at 1-800-526-7736 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. The data described in WARNINGS AND PRECAUTIONS and below reflect exposure to LAZCLUZE in combination with amivantamab in 421 previously untreated patients with locally advanced or metastatic NSCLC whose tumors have EGFR exon 19 deletions or exon 21 L858R substitution mutations in MARIPOSA [see Clinical Studies (14) ] . Patients received LAZCLUZE 240 mg orally once daily in combination with amivantamab intravenously at 1,050 mg (for patients < 80 kg) or 1,400 mg (for patients ≥ 80 kg) once weekly for 4 weeks, then every 2 weeks thereafter starting at week 5. Among the 421 patients who received LAZCLUZE in combination with amivantamab, 84% were exposed to LAZCLUZE for ≥ 6 months and 73% were exposed to LAZCLUZE for > 1 year. The median age of patients who received LAZCLUZE in combination with amivantamab was 64 years (25 to 88); 64% were female; 59% were Asian, 38% were White, 1.7% were American Indian or Alaska Native, 0.7% were Black or African American, 1% were of unknown or other races; 13% were Hispanic or Latino; 67% had Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 1, 33% had ECOG PS of 0; 60% had EGFR exon 19 deletions, and 40% had EGFR exon 21 L858R substitution mutations. Serious adverse reactions occurred in 49% of patients who received LAZCLUZE in combination with amivantamab. Serious adverse reactions occurring in ≥ 2% of patients included VTE (11%), pneumonia (4%), rash and ILD/pneumonitis (2.9% each), COVID-19 (2.4%), and pleural effusion and infusion-related reaction (amivantamab) (2.1% each). Fatal adverse reactions occurred in 7% of patients who received LAZCLUZE in combination with amivantamab due to death not otherwise specified (1.2%); sepsis and respiratory failure (1% each); pneumonia, myocardial infarction, and sudden death (0.7% each); cerebral infarction, pulmonary embolism (PE), and COVID-19 infection (0.5% each); and ILD/pneumonitis, acute respiratory distress syndrome (ARDS), and cardiopulmonary arrest (0.2% each). Permanent discontinuation of LAZCLUZE due to an adverse reaction occurred in 21% of patients. Adverse reactions which resulted in permanent discontinuation of LAZCLUZE in ≥ 1% of patients included ILD/pneumonitis, pneumonia, VTE, rash, respiratory failure, and sudden death. Dosage interruption of LAZCLUZE due to an adverse reaction occurred in 72% of patients. Adverse reactions which required dosage interruption in ≥ 5% of patients were rash, nail toxicity, COVID-19, VTE, increased ALT, and increased AST. Dose reductions of LAZCLUZE due to an adverse reaction occurred in 42% of patients. Adverse reactions requiring LAZCLUZE dose reductions in ≥ 5% of patients were rash and nail toxicity. The most common adverse reactions (≥ 20%) were rash, nail toxicity, infusion-related reaction (amivantamab), musculoskeletal pain, edema, stomatitis, VTE, paresthesia, fatigue, diarrhea, constipation, COVID-19, hemorrhage, dry skin, decreased appetite, pruritus, and nausea. The most common Grade 3 or 4 laboratory abnormalities (≥ 2%) were decreased albumin, decreased sodium, increased ALT, decreased potassium, decreased hemoglobin, increased AST, increased GGT, and increased magnesium. Table 3 summarizes the adverse reactions (≥ 10%) in MARIPOSA. Table 3: Adverse Reactions (≥ 10%) in Patients with NSCLC with Exon 19 Deletion or Exon 21 L858R Substitution Mutations in MARIPOSA Adverse Reaction LAZCLUZE in combination with amivantamab (N=421) Osimertinib (N=428) All Grades (%) Grade 3 or 4 (%) All Grades (%) Grade 3 or 4 (%) Skin and subcutaneous tissue disorders Rash Grouped terms 86 26 48 1.2 Nail toxicity 71 11 34 0.7 Dry skin 25 1 18 0.2 Pruritus 24 0.5 17 0.2 Injury, poisoning and procedural complications Infusion-related reaction Applicable only to amivantamab 63 6 0 0 Musculoskeletal and connective tissue disorders Musculoskeletal pain 47 2.1 39 1.9 Gastrointestinal disorders Stomatitis 43 2.4 27 0.5 Diarrhea 31 2.6 45 0.9 Constipation 29 0 13 0 Nausea 21 1.2 14 0.2 Vomiting 12 0.5 5 0 Abdominal pain 11 0 10 0 Hemorrhoids 10 0.2 2.1 0.2 General disorders and administration site conditions Edema 43 2.6 8 0 Fatigue 32 3.8 20 1.9 Pyrexia 12 0 9 0 Vascular disorders Venous thromboembolism 36 11 8 2.8 Hemorrhage 25 1 13 1.2 Nervous system disorders Paresthesia 35 1.7 10 0.2 Dizziness 14 0 10 0 Headache 13 0.2 13 0 Infections and infestations COVID-19 26 1.7 24 1.4 Conjunctivitis 11 0.2 1.6 0 Metabolism and nutrition disorders Decreased appetite 24 1 18 1.4 Respiratory, thoracic and mediastinal disorders Cough 19 0 23 0 Dyspnea 14 1.7 17 3.5 Eye disorders Ocular toxicity 16 0.7 7 0 Psychiatric disorders Insomnia 10 0 11 0 Clinically relevant adverse reactions occurring in < 10% of patients who received LAZCLUZE in combination with amivantamab included skin ulcer (applicable to amivantamab) and ILD/pneumonitis. Table 4 summarizes the laboratory abnormalities in MARIPOSA. Table 4: Select Laboratory Abnormalities (≥ 20%) That Worsened from Baseline in Patients with NSCLC with EGFR Exon 19 Deletion or Exon 21 L858R Substitution Mutations in MARIPOSA The denominator used to calculate the rate is the number of patients with a baseline value and at least one post-treatment value for the specific lab test. Laboratory Abnormality LAZCLUZE in combination with amivantamab (N=421) Osimertinib (N=428) All Grades (%) Grade 3 or 4 (%) All Grades (%) Grade 3 or 4 (%) Chemistry Decreased albumin 89 8 22 0.2 Increased ALT 65 7 29 2.6 Increased AST 52 3.8 36 1.9 Increased alkaline phosphatase 45 0.5 15 0.5 Decreased calcium (corrected) 41 1.4 27 0.7 Increased GGT 39 2.6 24 1.9 Decreased sodium 38 7 35 5 Decreased potassium 30 5 15 1.2 Increased creatinine 26 0.7 35 0.7 Decreased magnesium 25 0.7 10 0.2 Increased magnesium 12 2.6 20 4.8 Hematology Decreased platelet count 52 0.7 57 1.4 Decreased hemoglobin 47 3.8 56 1.9 Decreased white blood cell 38 1.0 66 0.7 Decreased neutrophils 15 1.4 33 1.4

8.1 Pregnancy Risk Summary Based on findings from animal studies and its mechanism of action [see Clinical Pharmacology (12.1) ] , LAZCLUZE can cause fetal harm when administered to a pregnant woman. There are no available data on the use of LAZCLUZE in pregnant women to inform a drug-associated risk. Oral administration of lazertinib to pregnant animals during the period of organogenesis resulted in reduced embryo-fetal survival and fetal body weight in rats and malformations in rabbits at exposures approximately 4 and 0.5 times, respectively, the human exposure at the recommended dose of 240 mg/day based on AUC (see Data ) . Advise pregnant women of the potential risk to a fetus. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. Data Animal Data In an embryo-fetal development study, pregnant rats received oral doses of 7.5, 30, or 60 mg/kg/day of lazertinib during the period of organogenesis (gestation day 6 to 17). Lazertinib decreased fetal body weights in association with maternal toxicity at 60 mg/kg/day (approximately 4 times the human exposure at the recommended dose of 240 mg/day based on AUC). In a dose range-finding embryo-fetal development study, oral administration of a higher dose of lazertinib (75 mg/kg/day) to pregnant rats during the period of organogenesis resulted in increased post-implantation loss. In an embryo-fetal development study in rabbits, pregnant animals received oral doses of 5, 25, or 45 mg/kg/day of lazertinib during the period of organogenesis (gestation day 7 to 19). Lazertinib caused maternal toxicity (reduced body weight and food consumption leading to moribund condition and early termination) and an increase in the incidence of skeletal malformations in the vertebra and skull (fused maxillary process/zygomatic arch) at 45 mg/kg/day (approximately 0.5 times the human exposure at the recommended dose of 240 mg/day based on AUC).