Lonapegsomatropin

12.1 Mechanism of Action SKYTROFA is a pegylated human growth hormone (somatropin) for once-weekly subcutaneous injection [see Clinical Pharmacology (12.3) ] . Somatropin binds to the growth hormone (GH) receptor in the cell membrane of target cells resulting in intracellular signal transduction and a host of pharmacodynamic effects. Somatropin has direct tissue and metabolic effects, and indirect effects mediated by insulin-like growth factor-1 (IGF-1), including stimulation of chondrocyte differentiation and proliferation, stimulation of hepatic glucose output, protein synthesis and lipolysis. Somatropin stimulates skeletal growth in pediatric patients with growth hormone deficiency (GHD) as a result of effects on the growth plates (epiphyses) of long bones.

1 INDICATIONS AND USAGE SKYTROFA (lonapegsomatropin-tcgd) is a human growth hormone indicated for the: Treatment of pediatric patients 1 year and older who weigh at least 11.5 kg and have growth failure due to inadequate secretion of endogenous growth hormone (GH). Replacement of endogenous growth hormone in adults with growth hormone deficiency (GHD). SKYTROFA is a human growth hormone indicated for: Pediatric Patients: Treatment of pediatric patients 1 year and older who weigh at least 11.5 kg and have growth failure due to inadequate secretion of endogenous growth hormone (GH) ( 1 ). Adults: Replacement of endogenous growth hormone in adults with growth hormone deficiency (GHD) ( 1 ).

2 DOSAGE AND ADMINISTRATION SKYTROFA should be administered subcutaneously once weekly into the abdomen, buttock, or thigh with regular rotation of the injection sites ( 2.7 ). Pediatric Patients: Recommended dose is 0.24 mg/kg body weight once weekly ( 2.2 ). Adults: Recommended starting dose is based on age and concomitant use of oral estrogen. Titrate monthly until the desired clinical response and/or weekly average IGF-1 concentration are achieved ( 2.3 ). See Full Prescribing Information for instructions on preparation and administration of drug ( 2.5 , 2.6 , 2.7 ). 2.1 General Dosing Information For subcutaneous injection, once weekly. Therapy with SKYTROFA should be supervised by a healthcare provider who is experienced in the diagnosis and management of patients with growth hormone deficiency (GHD). Perform fundoscopic examination before initiating treatment with SKYTROFA to exclude preexisting papilledema. If papilledema is identified, evaluate the etiology and treat the underlying cause before initiating treatment with SKYTROFA [see Warnings and Precautions (5.5) ] . 2.2 Recommended Dosage for Pediatric Patients The recommended dose of SKYTROFA for treatment-naïve patients and patients switching from another growth hormone product is 0.24 mg/kg body weight, given once weekly. Individualize and titrate the dosage of SKYTROFA based on response. When changing from daily somatropin therapy to once-weekly SKYTROFA, wait at least 8 hours between the final dose of daily somatropin and the first dose of SKYTROFA. When changing from another once-weekly growth hormone therapy to once-weekly SKYTROFA, wait at least 7 days between the final dose of the previous growth hormone therapy and the first dose of SKYTROFA. Assess compliance and evaluate other causes of poor growth, such as hypothyroidism, under-nutrition, advanced bone age and antibodies to recombinant human growth hormone if patients experience failure to increase height velocity, particularly during the first year of treatment. Patients who were treated with SKYTROFA for GH deficiency in childhood and whose epiphyses are closed should be reevaluated before continuing SKYTROFA. 2.3 Recommended Dosage for Adults The recommended starting dose of SKYTROFA in adults with GHD is based on age and concomitant use of oral estrogen [see Dosage Forms and Strengths (3) ] . For treatment-naïve patients or for patients switching from another growth hormone product, start SKYTROFA as described below: 1.4 mg once weekly for adults 30 to 60 years old, with no oral estrogen intake 2.1 mg once weekly for adults under 30 years old, or adults of any age intaking oral estrogen 0.7 mg once weekly for adults over 60 years old, with no oral estrogen intake When changing from daily somatropin therapy to once-weekly SKYTROFA, wait at least 8 hours between the final dose of daily somatropin and the first dose of SKYTROFA. When changing from another once-weekly growth hormone therapy to once-weekly SKYTROFA, wait at least 7 days between the final dose of the previous growth hormone therapy and the first dose of SKYTROFA. Increase the dose monthly to a higher strength cartridge based on the clinical response and/or IGF-1 concentration. Draw IGF-1 serum sample 4 to 5 days after the prior dose. Decrease the dose to a lower strength cartridge as needed based on adverse reactions or a weekly average IGF-1 concentration above the age- and sex-specific normal range. The maximum recommended dose is 6.3 mg once weekly. 2.4 Missed Doses Administer a missed dose as soon as possible and not more than 2 days after the missed dose. To avoid missed doses, SKYTROFA can be taken 2 days before or 2 days after the scheduled dosing day. Resume once-weekly dosing for the next dose at the previously scheduled dosing day. If more than 2 days have passed from the scheduled day, skip the dose and administer the next dose on the regularly scheduled day. At least 5 days should elapse between doses. 2.5 Administration Instructions for Pediatric Patients SKYTROFA is available in 9 cartridges (dosage strengths in somatropin equivalents) for pediatric patients. Selection of the appropriate cartridge (mg) is based on the prescribed dose (mg/kg) and the patient's body weight (kg) [see Dosage Forms and Strengths (3) ] . If prescribing a dose of 0.24 mg/kg/week and the patient's weight is 11.5 to 100 kg, follow the recommended dosing in Table 1. If prescribing a dose other than 0.24 mg/kg/week, calculate the total weekly dose (in mg) and select the appropriate cartridge as follows: Total weekly dose (mg) = prescribed weekly dose (mg/kg) × patient's body weight (kg). Round the total weekly dose (mg) to the closest cartridge dose while also considering treatment goals and clinical response. Table 1: Recommended Dosing for Pediatric Patients Prescribed Doses of 0.24 mg/kg/week Weight (kg) Dose (mg) 11.5 – 13.9 3 14 – 16.4 3.6 16.5 – 19.9 4.3 20 – 23.9 5.2 24 – 28.9 6.3 29 – 34.9 7.6 35 – 41.9 9.1 42 – 50.9 11 51 –

6 ADVERSE REACTIONS The following important adverse reactions are described elsewhere in the labeling: Increased mortality in patients with acute critical illness [see Warnings and Precautions (5.1) ] Severe hypersensitivity [see Warnings and Precautions (5.2) ] Increased risk of neoplasms [see Warnings and Precautions (5.3) ] Glucose intolerance and diabetes mellitus [see Warnings and Precautions (5.4) ] Intracranial hypertension [see Warnings and Precautions (5.5) ] Fluid retention [see Warnings and Precautions (5.6) ] Hypoadrenalism [see Warnings and Precautions (5.7) ] Hypothyroidism [see Warnings and Precautions (5.8) ] Slipped capital femoral epiphysis in pediatric patients [see Warnings and Precautions (5.9) ] Progression of preexisting scoliosis in pediatric patients [see Warnings and Precautions (5.10) ] Pancreatitis [see Warnings and Precautions (5.11) ] Lipoatrophy [see Warnings and Precautions (5.12) ] Sudden death in pediatric patients with Prader-Willi syndrome [see Warnings and Precautions (5.13) ] Pediatric Patients: Most common adverse reactions (≥ 5%): viral infection, pyrexia, cough, nausea and vomiting, hemorrhage, diarrhea, abdominal pain, and arthralgia and arthritis ( 6.1 ). Adults: Most common adverse reaction (≥ 5%): edema peripheral ( 6.1 ). To report SUSPECTED ADVERSE REACTIONS, contact Ascendis Pharma Endocrinology, Inc., at 1-844-442-7236 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 studies of another drug and may not reflect the rates observed in clinical practice. Pediatric Patients with Growth Hormone Deficiency SKYTROFA was studied in a 52-week, open-label, active-controlled trial in 161 treatment-naïve, prepubertal pediatric patients with growth hormone deficiency (GHD) [see Clinical Studies (14.1) ] . The subjects ranged in age from 3.2 to 13.1 years with a mean of 8.5 years. One hundred thirty-two (82%) of the subjects were male and 29 (18%) were female. One subject was Asian, 3 were Black or African American, 152 were Caucasian, and 5 were categorized as "other." Table 2 shows common adverse reactions that occurred in ≥ 5% of patients treated with SKYTROFA in this trial. Table 2: Adverse Reactions Occurring in ≥ 5% SKYTROFA-Treated Pediatric Patients and More Frequently Than in Daily Somatropin-Treated Pediatric Patients (52 Weeks of Treatment) Adverse reactions Daily Somatropin (N = 56) n (%) SKYTROFA (N = 105) n (%) Adverse reactions that are medically related were grouped to a single preferred term. Infection, viral 6 (11%) 16 (15%) Pyrexia 5 (9%) 16 (15%) Cough 4 (7%) 11 (11%) Nausea and vomiting 4 (7%) 11 (11%) Hemorrhage Hemorrhage in the SKYTROFA treatment group included epistaxis (3), contusion (2), petechiae (1) and eye hemorrhage (1). 1 (2%) 7 (7%) Diarrhea 3 (5%) 6 (6%) Abdominal pain 2 (4%) 6 (6%) Arthralgia and arthritis Arthralgia and arthritis in the SKYTROFA treatment group included arthralgia (5) and reactive arthritis (1). 1 (2%) 6 (6%) Laboratory Tests More SKYTROFA-treated patients shifted from normal baseline levels to elevated phosphate and alkaline phosphatase levels at the end of the trial compared to the daily somatropin group (44.2% vs. 30.2% and 19.2% vs. 9.4%, respectively); these laboratory changes occurred intermittently [see Warnings and Precautions (5.14) ] . Adults with Growth Hormone Deficiency SKYTROFA was studied in a 38-week parallel-arm, placebo-controlled (double-blind) and active-controlled (open label) trial in 259 adults with growth hormone deficiency (GHD) [see Clinical Studies (14.2) ] . The mean (range) age at enrollment was 43 (23 to 81) years old, with 119 (46%) females (55 on oral estrogen) and 140 (54%) males. One subject was American Indian or Alaska Native, one was Black or African American, 28 were Asian, and 218 were Caucasian. Table 3 shows adverse reactions that occurred in ≥ 5% of adults treated with SKYTROFA and more frequently than in placebo-treated adults in this trial. Table 3: Adverse Reactions Occurring in ≥ 5% of SKYTROFA-Treated Adults and More Frequently Than in Placebo-treated Adults (38 Weeks of Treatment) Adverse reactions Placebo (N = 84) n (%) SKYTROFA (N = 89) n (%) Adverse reactions that are medically related were grouped to a single preferred term. Edema Edema in the SKYTROFA treatment group included edema peripheral (6) and peripheral swelling (1). 1 (1%) 7 (8%) Central (secondary) hypothyroidism Central (secondary) hypothyroidism in the SKYTROFA treatment group included thyroxine free decreased (3), central hypothyroidism (2), thyroxine decreased (1), blood thyroid stimulating hormone decreased (1), tri-iodothyronine free decreased (1). Preexisting central hypothyroidism in 5 of 6 SKYTROFA-treated patients. 1 (1%) 6 (7%) Laboratory Tests More SKYTROFA-treated patients shifted

7 DRUG INTERACTIONS Table 4 includes a list of drugs with clinically important drug interactions when administered concomitantly with SKYTROFA and instructions for preventing or managing them. Table 4: Clinically Important Drug Interactions with SKYTROFA Replacement Glucocorticoid Treatment Clinical Impact: Microsomal enzyme 11β-hydroxysteroid dehydrogenase type 1 (11βHSD-1) is required for conversion of cortisone to its active metabolite, cortisol, in hepatic and adipose tissue. Somatropin inhibits 11βHSD-1. Consequently, individuals with untreated growth hormone deficiency (GHD) have relative increases in 11βHSD-1 and serum cortisol. Initiation of SKYTROFA may result in inhibition of 11βHSD-1 and reduced serum cortisol concentrations. Intervention: Patients treated with glucocorticoid replacement for hypoadrenalism may require an increase in their maintenance or stress doses following initiation of SKYTROFA [see Warnings and Precautions (5.7) ] Examples Cortisone acetate and prednisone may be affected more than others because conversion of these drugs to their biologically active metabolites is dependent on the activity of 11βHSD-1. Pharmacologic Glucocorticoid Therapy and Supraphysiologic Glucocorticoid Treatment Clinical Impact: Pharmacologic glucocorticoid therapy and supraphysiologic glucocorticoid treatment may attenuate the growth-promoting effects of SKYTROFA in pediatric patients. Intervention: Carefully adjust glucocorticoid replacement dosing in pediatric patients receiving glucocorticoid treatments to avoid both hypoadrenalism and an inhibitory effect on growth. Cytochrome P450-Metabolized Drugs Clinical Impact: Limited published data indicate that somatropin treatment increases cytochrome P450 (CYP450)-mediated antipyrine clearance. SKYTROFA may alter the clearance of compounds known to be metabolized by CYP450 liver enzymes. Intervention: Careful monitoring is advisable when SKYTROFA is administered in combination with drugs metabolized by CYP450 liver enzymes. Oral Estrogen Clinical Impact: Oral estrogens may reduce the serum insulin-like growth factor-1 (IGF-1) response to SKYTROFA. Intervention: Patients receiving oral estrogen replacement may require higher SKYTROFA dosages. Insulin and/or Other Antihyperglycemic Agents Clinical Impact: Treatment with SKYTROFA may decrease insulin sensitivity, particularly at higher doses. Intervention: Patients with diabetes mellitus may require adjustment of their doses of insulin and/or other antihyperglycemic agents [see Warnings and Precautions (5.4) ] . Replacement Glucocorticoid Treatment: Patients treated with glucocorticoid for hypoadrenalism may require an increase in their maintenance or stress doses following initiation of SKYTROFA ( 7 ). Pharmacologic Glucocorticoid Therapy and Supraphysiologic Glucocorticoid Treatment: Adjust glucocorticoid dosing in pediatric patients to avoid both hypoadrenalism and an inhibitory effect on growth ( 7 ). Cytochrome P450-Metabolized Drugs: SKYTROFA may alter the clearance. Monitor carefully if used with SKYTROFA ( 7 ). Oral Estrogen: Larger doses of SKYTROFA may be required ( 7 ). Insulin and/or Other Antihyperglycemic Agents: Dose adjustment of insulin or antihyperglycemic agent may be required ( 7 ).