Larotrectinib

12.1 Mechanism of Action Larotrectinib is an inhibitor of the tropomyosin receptor kinases (TRK), TRKA, TRKB, and TRKC. In a broad panel of purified enzyme assays, larotrectinib inhibited TRKA, TRKB, and TRKC with IC 50 values between 5-11 nM. One other kinase TNK2 was inhibited at approximately 100-fold higher concentration. TRKA, B, and C are encoded by the genes NTRK1, NTRK2, and NTRK3. Chromosomal rearrangements involving in-frame fusions of these genes with various partners can result in constitutively-activated chimeric TRK fusion proteins that can act as an oncogenic driver, promoting cell proliferation and survival in tumor cell lines. In in vitro and in vivo tumor models, larotrectinib demonstrated anti-tumor activity in cells with constitutive activation of TRK proteins resulting from gene fusions, deletion of a protein regulatory domain, or in cells with TRK protein overexpression. Larotrectinib had minimal activity in cell lines with point mutations in the TRKA kinase domain, including the clinically identified acquired resistance mutation, G595R. Point mutations in the TRKC kinase domain with clinically identified acquired resistance to larotrectinib include G623R, G696A, and F617L.

1 INDICATIONS AND USAGE VITRAKVI is indicated for the treatment of adult and pediatric patients with solid tumors that: have a neurotrophic receptor tyrosine kinase ( NTRK ) gene fusion without a known acquired resistance mutation, are metastatic or where surgical resection is likely to result in severe morbidity, and have no satisfactory alternative treatments or that have progressed following treatment. Select patients for therapy based on an FDA-approved test [see Dosage and Administration (2.1) ]. VITRAKVI is a kinase inhibitor indicated for the treatment of adult and pediatric patients with solid tumors that: have a neurotrophic receptor tyrosine kinase ( NTRK ) gene fusion without a known acquired resistance mutation, are metastatic or where surgical resection is likely to result in severe morbidity, and have no satisfactory alternative treatments or that have progressed following treatment. Select patients for therapy based on an FDA-approved test. ( 1 , 2.1 )

2 DOSAGE AND ADMINISTRATION Select patients for treatment with VITRAKVI based on the presence of a NTRK gene fusion ( 2.1 , 14 ). Recommended Dosage in Adult and Pediatric Patients with Body Surface Area of 1 Meter-Squared or greater: 100 mg orally twice daily ( 2.2 ) Recommended Dosage in Pediatric Patients with Body Surface Area of Less Than 1 Meter-Squared: 100 mg/m 2 orally twice daily ( 2.2 ) 2.1 Patient Selection Select patients for treatment with VITRAKVI based on the presence of a NTRK gene fusion in tumor specimens [see Clinical Studies (14) ] . In patients with secretory breast cancer, mammary analogue secretory cancer (MASC), congenital mesoblastic nephroma (CMN), or infantile fibrosarcoma, consider treatment without confirmation of NTRK rearrangements in tumor specimens. Information on FDA-approved tests is available at http://www.fda.gov/companiondiagnostics. 2.2 Recommended Dosage Recommended Dosage in Adult and Pediatric Patients with Body Surface Area of 1 Meter-Squared or greater The recommended dosage of VITRAKVI is 100 mg orally twice daily, with or without food, until disease progression or until unacceptable toxicity. Recommended Dosage in Pediatric Patients with Body Surface Area Less Than 1 Meter-Squared The recommended dosage of VITRAKVI is 100 mg/m 2 orally twice daily, with or without food, until disease progression or until unacceptable toxicity. 2.3 Dosage Modifications for Adverse Reactions For Grade 2 and higher liver function test abnormalities, refer to Section 2.4, Table 2, Dosage Modifications for Hepatotoxicity. For all other Grade 3 or 4 adverse reactions: Withhold VITRAKVI until adverse reaction resolves or improves to baseline or Grade 1. Resume at the next dosage modification if resolution occurs within 4 weeks. Permanently discontinue VITRAKVI if an adverse reaction does not resolve within 4 weeks. The recommended dosage reductions for VITRAKVI for adverse reactions are provided in Table 1. Table 1 Recommended Dosage Reductions for VITRAKVI for Adverse Reactions Dosage Reduction Adult and Pediatric Patients with Body Surface Area of 1 m 2 or Greater Pediatric Patients with Body Surface Area Less Than 1 m 2 First 75 mg orally twice daily 75 mg/m 2 orally twice daily Second 50 mg orally twice daily 50 mg/m 2 orally twice daily Third 100 mg orally once daily 25 mg/m 2 orally twice daily Pediatric patients on 25 mg/m 2 orally twice daily should remain on this dosage even if body surface area becomes greater than 1 m 2 during the treatment. Maximum dose should be 25 mg/m 2 orally twice daily at the third dosage modification. Permanently discontinue VITRAKVI in patients who are unable to tolerate VITRAKVI after three dose modifications. 2.4 Dosage Modifications for Hepatotoxicity The recommended dosage modifications for VITRAKVI liver function test abnormalities are provided in Table 2. For CTCAE Grade 2 ALT and/or AST elevation, monitor liver function frequently as clinically indicated, to establish whether a dose interruption or reduction is required [see Warnings and Precautions (5.3) ] . Table 2 Recommended Dosage Modifications for VITRAKVI for Hepatotoxicity Severity Grading defined by National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE) version 4.03 Dosage Modification ALT = alanine aminotransferase; AST = aspartate aminotransferase; ULN = upper limit of normal AST or ALT ≥ 5 × ULN with bilirubin ≤ 2 × ULN [see Warnings and Precautions (5.3) ] Withhold VITRAKVI until recovery to ≤ Grade 1 or return to baseline. Resume VITRAKVI at the next lower dose level. Permanently discontinue if a Grade 4 AST and/or ALT elevation occurs after resuming VITRAKVI. AST or ALT > 3 × ULN with total bilirubin > 2 × ULN in the absence of alternative causes Permanently discontinue VITRAKVI. 2.5 Dosage Modifications for Coadministration with Strong CYP3A4 Inhibitors Avoid coadministration of strong CYP3A4 inhibitors with VITRAKVI. If coadministration of a strong CYP3A4 inhibitor cannot be avoided, reduce the VITRAKVI dose by 50%. After the inhibitor has been discontinued for 3 to 5 elimination half-lives, resume the VITRAKVI dose that was used prior to initiating the CYP3A4 inhibitor [see Drug Interactions (7.1) , Clinical Pharmacology (12.3) ]. 2.6 Dosage Modifications for Coadministration with Strong or Moderate CYP3A4 Inducers Avoid coadministration of strong CYP3A4 inducers with VITRAKVI. If coadministration of a strong CYP3A4 inducer cannot be avoided, double the VITRAKVI dose. Additionally, for coadministration with a moderate CYP3A4 inducer, double the VITRAKVI dose. After the inducer has been discontinued for 3 to 5 elimination half-lives, resume the VITRAKVI dose that was used prior to initiating the CYP3A4 inducer [see Drug Interactions (7.1) , Clinical Pharmacology (12.3) ]. 2.7 Dosage Modifications for Patients with Hepatic Impairment Reduce the starting dose of VITRAKVI by 50% in patients with moderate (Child-Pugh B) to severe (Child-Pugh C) hepa

6 ADVERSE REACTIONS The following clinically significant adverse reactions are described elsewhere in the labeling: Central Nervous System Effects [see Warnings and Precautions (5.1) ] Skeletal Fractures [see Warnings and Precautions (5.2) ] Hepatotoxicity [see Warnings and Precautions (5.3) ] The most common (≥ 20%) adverse reactions, including laboratory abnormalities, with VITRAKVI were increased AST, increased ALT, anemia, hypoalbuminemia, musculoskeletal pain, increased alkaline phosphatase, leukopenia, lymphopenia, neutropenia, hypocalcemia, fatigue, vomiting, cough, constipation, pyrexia, diarrhea, nausea, abdominal pain, dizziness, and rash ( 6 ). To report SUSPECTED ADVERSE REACTIONS, contact Bayer HealthCare Pharmaceuticals Inc. at 1-888-842-2937 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 Clinical Trial 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. Unless noted, data in WARNINGS AND PRECAUTIONS and below reflects exposure to VITRAKVI in 444 patients, including 62% patients exposed for greater than 6 months, 44% patients exposed for greater than 1 year, and 30% patients exposed for greater than 2 years. VITRAKVI was studied in one adult dose-finding trial [LOXO-TRK-14001 (n = 75)], one pediatric dose-finding trial [SCOUT (n = 154)], and one single arm trial [NAVIGATE (n = 215)]. All patients had an unresectable or metastatic solid tumor and no satisfactory alternative treatment options or disease progression following treatment. Across these 444 patients, the median age was 44 years (range: 18 days to 90 years); 35% were younger than 18 years; 53% were female; 59% were White, 24% were Asian and, 4% were Black; and 7% were Hispanic/Latino. Most adults (91%) received VITRAKVI 100 mg orally twice daily and 91% of pediatrics (< 18 years) received VITRAKVI 100 mg/m 2 twice daily up to a maximum dose of 100 mg twice daily. The dose ranged from 50 mg daily to 200 mg twice daily in adults and 9.6 mg/m 2 twice daily to 120 mg/m 2 twice daily in pediatrics [see Use in Specific Populations (8.4) ] . The most common serious adverse reactions (≥ 2%) were pneumonia, pyrexia, and dyspnea. Grade 3 or 4 adverse reactions occurred in 60% of patients; adverse reactions leading to dose interruption or modification occurred in 45% and 11% of patients, respectively, and 12% permanently discontinued VITRAKVI for adverse reactions. The most common adverse reactions (1% each) that resulted in permanent discontinuation of VITRAKVI were increased ALT and increased AST. The most common adverse reactions (≥ 3%) resulting in dose interruption were increased ALT (6%), increased AST (5%), neutrophil count decreased (4.7%), pyrexia (4.3%), and vomiting (3.2%). Most (64%) adverse reactions leading to dose interruption occurred during the first three months of exposure. The most common adverse reactions (≥ 20%), including laboratory abnormalities, in order of decreasing frequency were increased AST, increased ALT, anemia, hypoalbuminemia, musculoskeletal pain, increased alkaline phosphatase, leukopenia, lymphopenia, neutropenia, hypocalcemia, fatigue, vomiting, cough, constipation, pyrexia, diarrhea, nausea, abdominal pain, dizziness, and rash. Adverse reactions of VITRAKVI occurring in ≥ 10% of patients and laboratory abnormalities worsening from baseline in ≥ 20% of patients are summarized in Table 3 and Table 4, respectively. Table 3 Adverse Reactions Occurring in ≥ 10% of Patients Treated with VITRAKVI Adverse Reaction The adverse reaction identifies a composite term: VITRAKVI N = 444 All Grades National Cancer Institute-Common Terminology Criteria for Adverse Events (NCI-CTCAE) v 4.03. (%) Grade 3-4 Grade 4 adverse reaction: 1 of cognitive impairment, 1 of pyrexia. (%) Musculoskeletal and Connective Tissue Musculoskeletal Pain Includes: arthralgia, back pain, bone pain, flank pain, groin pain, growing pains, musculoskeletal chest pain, musculoskeletal discomfort, musculoskeletal pain, musculoskeletal stiffness, myalgia, neck pain, non-cardiac chest pain, pain in extremity, pain in jaw, and tendon pain 41 3.6 General Fatigue Includes: fatigue, asthenia 31 2.5 Pyrexia 26 2.3 Edema Includes: face edema, generalized edema, lip edema, localized edema, edema, edema genital, edema peripheral, periorbital edema, and swelling 17 0.7 Respiratory, Thoracic and Mediastinal Cough Includes: cough, productive cough, and upper-airway cough syndrome 29 0.5 Dyspnea Includes: dyspnea, and dyspnea exertional 17 2.7 Nasal congestion 10 0 Nervous System Dizziness Includes: dizziness, dizziness postural, and vertigo 22 0.9 Headache 17 0.9 Cognitive Impairment Includes: amnesia, aphasia, cognitive disorder, confusional state, delirium, disturbance in attention, hallucination, hallucination visual, memory impairment

7 DRUG INTERACTIONS Strong CYP3A4 Inhibitors: Avoid coadministration of strong CYP3A4 inhibitors with VITRAKVI. If coadministration cannot be avoided, reduce the VITRAKVI dose. ( 2.5 , 7.1 ) Moderate CYP3A4 Inhibitors: Monitor for adverse reactions more frequently in patients coadministered a moderate CYP3A4 inhibitor with VITRAKVI and reduce the VITRAKVI dosage based on severity of adverse reactions. ( 7.1 ) Strong CYP3A4 Inducers: Avoid coadministration of strong CYP3A4 inducers with VITRAKVI. If coadministration cannot be avoided, increase the VITRAKVI dose. ( 2.6 , 7.1 ) Moderate CYP3A4 Inducers: Increase the VITRAKVI dose. ( 2.6 , 7.1 ) Sensitive CYP3A4 Substrates: Avoid coadministration of sensitive CYP3A4 substrates with VITRAKVI. ( 7.2 ) 7.1 Effects of Other Drugs on VITRAKVI Strong and Moderate CYP3A4 Inhibitors Coadministration of VITRAKVI with a strong or moderate CYP3A4 inhibitor may increase larotrectinib plasma concentrations, which may result in a higher incidence of adverse reactions [see Clinical Pharmacology (12.3) ]. Avoid coadministration of VITRAKVI with strong CYP3A4 inhibitors, including grapefruit or grapefruit juice. If coadministration of strong CYP3A4 inhibitors cannot be avoided, modify VITRAKVI dose as recommended [see Dosage and Administration (2.5) ] . In patients coadministered a moderate CYP3A4 inhibitor with VITRAKVI, monitor for adverse reactions more frequently and reduce the VITRAKVI dosage based on the severity of emergent adverse reactions [see Dosage and Administration (2.3) ] . Strong and Moderate CYP3A4 Inducers Coadministration of VITRAKVI with a strong or moderate CYP3A4 inducer may decrease larotrectinib plasma concentrations, which may decrease the efficacy of VITRAKVI [see Clinical Pharmacology (12.3) ]. Avoid coadministration of VITRAKVI with strong CYP3A4 inducers, including St. John's wort. If coadministration of strong CYP3A4 inducers cannot be avoided, modify VITRAKVI dose as recommended. For coadministration with moderate CYP3A4 inducers, modify VITRAKVI dose as recommended [see Dosage and Administration (2.6) ]. 7.2 Effects of VITRAKVI on Other Drugs Sensitive CYP3A4 Substrates Coadministration of VITRAKVI with sensitive CYP3A4 substrates may increase their plasma concentrations, which may increase the incidence or severity of adverse reactions [see Clinical Pharmacology (12.3) ] . Avoid coadministration of VITRAKVI with sensitive CYP3A4 substrates. If coadministration of these sensitive CYP3A4 substrates cannot be avoided, monitor patients for increased adverse reactions of these drugs.