Selumetinib

1 INDICATIONS AND USAGE KOSELUGO is indicated for the treatment of adult and pediatric patients 1 year of age and older with neurofibromatosis type 1 (NF1) who have symptomatic, inoperable plexiform neurofibromas (PN) [see Dosage and Administration (2) ]. KOSELUGO is a kinase inhibitor indicated for the treatment of adult and pediatric patients 1 year of age and older with neurofibromatosis type 1 (NF1) who have symptomatic, inoperable plexiform neurofibromas (PN). ( 1 )

12.1 Mechanism of Action Selumetinib is an inhibitor of mitogen-activated protein kinase kinases 1 and 2 (MEK1/2). MEK1/2 proteins are upstream regulators of the extracellular signal-related kinase (ERK) pathway. Both MEK and ERK are critical components of the RAS-regulated RAF-MEK-ERK pathway, which is often activated in different types of cancers. In genetically modified mouse models of NF1 that generate neurofibromas that recapitulate the genotype and phenotype of human NF1, oral dosing of selumetinib inhibited ERK phosphorylation, and reduced neurofibroma numbers, volume, and proliferation.

2 DOSAGE AND ADMINISTRATION • KOSELUGO capsules: The recommended dosage is 25 mg/m 2 , swallowed whole, taken orally twice daily with or without food (see Table 1) . (2.1 , 2.2 ) • KOSELUGO oral granules: The recommended dosage is equivalent to 25 mg/m 2 , sprinkled onto or mixed with soft food and taken orally twice daily (see Table 2). ( 2.1 , 2.2 ) • Moderate hepatic impairment (Child-Pugh B): The recommended dosage is 20 mg/m 2 orally twice daily (see Tables 6 and 7) . ( 2.2 , 2.4 ) • Severe hepatic impairment (Child-Pugh C): The recommended dosage has not been established. ( 2.4 , 8.6 ) • Strong or Moderate CYP3A4 Inhibitors or Fluconazole: If coadministration with strong or moderate CYP3A4 inhibitors or fluconazole cannot be avoided, reduce the dose of KOSELUGO (see Tables 8 and 9) . ( 2.5 ) 2.1 Recommended Dosage The recommended dosage of KOSELUGO capsules ( see Table 1 ) and KOSELUGO oral granules ( see Table 2 ) for adult and pediatric patients 1 year of age and older, based on body surface area, is 25 mg/m 2 orally twice daily, until disease progression or unacceptable toxicity [see Dosage and Administration (2.2)]. Table 1 Recommended Dosage: KOSELUGO Capsules Body Surface Area The recommended dosage of KOSELUGO capsules for patients with a BSA less than 0.55 m 2 has not been established. KOSELUGO Capsules 0.55 – 0.69 m 2 20 mg in the morning and 10 mg in the evening 0.70 – 0.89 m 2 20 mg twice daily 0.90 – 1.09 m 2 25 mg twice daily 1.10 – 1.29 m 2 30 mg twice daily 1.30 – 1.49 m 2 35 mg twice daily 1.50 – 1.69 m 2 40 mg twice daily 1.70 – 1.89 m 2 45 mg twice daily ≥ 1.90 m 2 50 mg twice daily Table 2 Recommended Dosage: KOSELUGO Oral Granules Body Surface Area The recommended dosage of KOSELUGO oral granules for patients with a BSA less than 0.40 m 2 has not been established. KOSELUGO Oral Granules 0.40 – 0.59 m 2 12.5 mg twice daily 0.60 – 0.69 m 2 15 mg twice daily 0.70 – 0.89 m 2 20 mg twice daily 0.90 – 1.09 m 2 25 mg twice daily 1.10 – 1.29 m 2 30 mg twice daily 1.30 – 1.49 m 2 35 mg twice daily 1.50 – 1.69 m 2 40 mg twice daily 1.70 – 1.89 m 2 45 mg twice daily ≥ 1.90 m 2 50 mg twice daily 2.2 Administration KOSELUGO is available in two dosage forms: KOSELUGO capsules and KOSELUGO oral granules. Prescribe KOSELUGO oral granules for patients who have difficulty swallowing whole capsules. KOSELUGO Capsules • Administer KOSELUGO capsules to patients who can swallow a whole capsule. • Swallow KOSELUGO capsules whole. Do not open, chew or crush KOSELUGO capsules. • KOSELUGO capsules may be administered with or without food. KOSELUGO Oral Granules Administer KOSELUGO oral granules to patients who have difficulty swallowing a whole capsule. Sprinkle KOSELUGO oral granules on or mix with a small amount (about 1 to 3 teaspoons) of smooth yogurt, or fruit puree containing the following fruits: apple, banana, pear, or strawberry and consume within 30 minutes of preparation. If not consumed within 30 minutes of preparation, discard and prepare a new dose. If a dose has been partially consumed within 30 minutes of preparation, discard the remainder of the dose and do not prepare a new dose, aim to complete dosing within 30 minutes next time. The KOSELUGO oral granules should be free-flowing. Do NOT use if the oral granules are clumped or stuck inside the capsule shell. Instruct the patient or caregiver to contact their pharmacy if this happens. Discard the empty capsule shells after use. Do NOT swallow, chew, or dissolve the capsule shells of KOSELUGO oral granules. Do NOT chew or crush the KOSELUGO oral granules. Do NOT add oral granules to liquids. Do NOT mix KOSELUGO oral granules in grapefruit or any juice, fruit puree or jam containing Seville orange. Missed Dose If a dose of KOSELUGO capsules or KOSELUGO oral granules is missed, make up that dose unless the next dose is due within 6 hours. Vomiting If vomiting occurs after taking a dose of KOSELUGO capsules or KOSELUGO oral granules, do not take an additional dose

6 ADVERSE REACTIONS The following clinically significant adverse reactions are described elsewhere in the labeling: • Left Ventricular Dysfunction [see Warnings and Precautions (5.1) ] • Ocular Toxicity [see Warnings and Precautions (5.2) ] • Gastrointestinal Toxicity [see Warnings and Precautions (5.3) ] • Skin Toxicity [see Warnings and Precautions (5.4) ] • Increased Creatine Phosphokinase [see Warnings and Precautions (5.5) ] Most common adverse reactions in pediatric patients (≥ 40%) are: vomiting, diarrhea, increased creatine phosphokinase, dry skin, paronychia, nausea, dermatitis acneiform, and pyrexia. ( 6.1 ) Most common adverse reactions in adult patients (≥ 40%) are rash (all), dermatitis acneiform, and diarrhea. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact AstraZeneca 1-800-236-9933 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 NF1 PN pediatric safety pool described in the WARNINGS AND PRECAUTIONS reflects exposure to KOSELUGO at the recommended dosage in 134 pediatric patients in SPRINKLE (N = 36) (NCT05309668), SPRINT Phase I (N = 24) (NCT01362803), SPRINT Phase II Stratum 1 (N = 50) [see Clinical Studies (14.1) ] , and Phase I Food Effect Study (N = 24) (NCT05101148). Among pediatric patients, the duration of KOSELUGO exposure was 12 months or longer (80%), more than 2 years (44%), or more than 3 years (37%). The most common adverse reactions in pediatric patients (≥ 40%) are vomiting, diarrhea, increased creatine phosphokinase, dry skin, paronychia, nausea, dermatitis acneiform, and pyrexia. In the KOMET adult NF1 PN study, 71 adult patients received KOSELUGO at the recommended dosage [see Clinical Studies (14.1) ] . Among adult patients, the duration of KOSELUGO exposure in the randomized period was 6 months or longer (92%), and 11 months or longer (66%). The most common adverse reactions in adult patients (≥ 40%) are rash (all), dermatitis acneiform, and diarrhea. Neurofibromatosis Type 1 (NF1) with Inoperable Plexiform Neurofibromas (PN) Pediatrics 2-18 years of Age (SPRINT Phase II Stratum 1) The safety of KOSELUGO was evaluated in SPRINT Phase II Stratum 1 [see Clinical Studies (14.1) ] . Eligible patients were 2-18 years of age with neurofibromatosis type 1 (NF1) who had inoperable plexiform neurofibromas (PN) that was causing significant morbidity. Patients were excluded for abnormal LVEF, uncontrolled hypertension (blood pressure ≥ the 95th percentile for age, height, and sex), any current or past history of RVO or RPED, intraocular pressure > 21 mmHg (or upper limit of normal adjusted by age), uncontrolled glaucoma, and inability to swallow whole capsules. Patients received KOSELUGO 25 mg/m 2 orally twice daily (N = 50). Among these patients, 88% were exposed for 12 months or longer and 66% were exposed for greater than 2 years. Serious adverse reactions occurred in 24% of patients who received KOSELUGO. Serious adverse reactions that occurred in 2 or more patients were anemia, hypoxia and diarrhea. Permanent discontinuation due to an adverse reaction occurred in 12% of patients who received KOSELUGO. Adverse reactions resulting in permanent discontinuation of KOSELUGO included increased blood creatinine, increased weight, diarrhea, paronychia, malignant peripheral nerve sheath tumor, acute kidney injury, and skin ulcer. Dosage interruptions and dose reductions due to adverse reactions occurred in 80% and 24% of patients who received KOSELUGO, respectively. Adverse reactions requiring a dosage interruption or reduction in ≥ 5% of patients were vomiting, paronychia, diarrhea, nausea, abdominal pain, rash, skin infection, influenza-like illness, pyrexia and weight gain. The most common adverse rea

5 WARNINGS AND PRECAUTIONS • Left Ventricular Dysfunction : Assess ejection fraction prior to initiating treatment, every 3 months during the first year, then every 6 months thereafter and as clinically indicated. Withhold, reduce the dose, or permanently discontinue KOSELUGO based on severity of adverse reaction. ( 2.3 , 5.1 ) • Ocular Toxicity : Conduct ophthalmic assessments prior to initiating KOSELUGO, at regular intervals during treatment and for new or worsening visual changes. Permanently discontinue KOSELUGO for retinal vein occlusion (RVO). Withhold KOSELUGO for retinal pigment epithelial detachment (RPED), monitor with optical coherence tomography assessments until resolution, and resume at reduced dose. ( 2.3 , 5.2 ) • Gastrointestinal Toxicity : Advise patients to start an anti-diarrheal agent immediately after the first episode of loose stool and to increase fluid intake. Withhold, reduce the dose, or permanently discontinue KOSELUGO based on severity of adverse reaction. ( 2.3 , 5.3 ) • Skin Toxicity : Monitor for severe skin rashes. Withhold, reduce the dose, or permanently discontinue KOSELUGO based on severity of adverse reaction. ( 2.3 , 5.4 ) • Increased Creatine Phosphokinase (CPK) : Increased CPK and rhabdomyolysis can occur. Obtain serum CPK prior to initiating KOSELUGO, periodically during treatment, and as clinically indicated. If increased CPK occurs, evaluate for rhabdomyolysis or other causes. Withhold, reduce the dose, or permanently discontinue KOSELUGO based on severity of adverse reaction. ( 2.3 , 5.5 ) • Increased Vitamin E Levels and Increased Risk of Bleeding (KOSELUGO Capsules) : KOSELUGO capsules contain vitamin E and daily intake of vitamin E that exceeds the recommended or safe limits may increase the risk of bleeding. An increased risk of bleeding may occur in patients co-administered vitamin-K antagonists or anti-platelet agents. KOSELUGO oral granules do not contain vitamin E. ( 5.6 ) • Embryo-Fetal Toxicity: Can cause fetal harm. Advise patients of reproductive potential of the potential risk to a fetus and to use effective contraception ( 5.7 , 8.1 , 8.3 ). 5.1 Left Ventricular Dysfunction KOSELUGO can cause cardiomyopathy, defined as a decrease in left ventricular ejection fraction (LVEF) ≥ 10% below baseline. KOSELUGO has not been studied in patients with a history of clinically significant cardiac disease or LVEF less than 55% prior to treatment. Pediatric Patients In the NF1 PN pediatric safety pool (N = 134) [see Adverse Reactions (6.1) ], Grade 2 LVEF decrease [Grade 2 LVEF decrease (40% to 50%; 10 to 19% drop from baseline)], based on reported adverse reactions, occurred in 17% of evaluable patients. Decreased LVEF of ≥ 20% occurred in 0.7% of patients and resulted in dose interruption and dose reduction. Decreased LVEF resolved in 75% of these patients. The median time to first onset of maximum CTCAE grade LVEF decrease was approximately 12 months (median duration approximately 3 months). Adult Patients In the KOMET adult NF1 PN study (N = 71) [see Adverse Reactions (6.1) ], Grade 2 LVEF decrease [Grade 2 LVEF decrease (40% to 50%; 10 to 19% drop from baseline)], based on echocardiogram results, occurred in 14% of evaluable patients. Decreased LVEF resulted in dose interruption in 1.4% of patients. The median time to first onset of maximum CTCAE grade LVEF decrease was approximately 4 months (median duration approximately 4 months). Assess ejection fraction by echocardiogram prior to initiating treatment, every 3 months during the first year of treatment, every 6 months thereafter, and as clinically indicated. Withhold, reduce dose, or permanently discontinue KOSELUGO based on severity of adverse reaction [see Dosage and Administration (2.3)]. In patients who interrupt KOSELUGO for decreased LVEF, obtain an echocardiogram or a cardiac MRI every 3 to 6 weeks until resolution. Upon resolution of decreased LVEF to greater than or equal to the institutional LLN, obtain an echocar

4 CONTRAINDICATIONS None. None. ( 4 )

10 OVERDOSAGE Dialysis is not effective as KOSELUGO is highly protein bound and is extensively metabolized.