Sebetralstat

EKTERLY® is indicated for the treatment of acute attacks of hereditary angioedema (HAE) in adult and pediatric patients aged 12 years and older. EKTERLY ® is a plasma kallikrein inhibitor indicated for the treatment of acute attacks of hereditary angioedema (HAE) in adult and pediatric patients aged 12 years and older. ( 1 )

Tablets: 300 mg, yellow, oval, biconvex, film-coated tablets debossed with on one side and “300” on the other side. Tablets: 300 mg ( 3 ) tab logo

None. None ( 4 )

The most common adverse reaction (incidence ≥2%) is headache. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact KalVista Pharmaceuticals, Inc. at 1-855-258-4782 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 safety of EKTERLY is based on data from a double-blind, randomized, placebo-controlled, three-way, crossover clinical trial (KONFIDENT) [see Clinical Studies ( 14 )] . In KONFIDENT, a total of 110 patients aged 12 years and older with HAE treated 264 attacks. In the safety population, 93 patients received EKTERLY 600 mg, 86 patients received EKTERLY 300 mg, and 83 patients received placebo. While EKTERLY 300 mg was included in KONFIDENT, the safety data is based on the recommended dosage of EKTERLY 600 mg. Table 3 displays adverse reaction(s) with an incidence of ≥2% in the EKTERLY 600 mg treated patients and more common than placebo. Table 3: Adverse Reaction(s) with EKTERLY with Incidence ≥2% and More Common than Placebo in Patients with Hereditary Angioedema (KONFIDENT) a One (1) patient assigned to administer placebo actually received EKTERLY 600 mg. Safety results are presented by actual treatment received. Adverse Reaction EKTERLY 600 mg (N = 93) Placebo (N = 83) a n (%) n (%) Headache 3 (3.2) 1 (1.2)

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 safety of EKTERLY is based on data from a double-blind, randomized, placebo-controlled, three-way, crossover clinical trial (KONFIDENT) [see Clinical Studies ( 14 )] . In KONFIDENT, a total of 110 patients aged 12 years and older with HAE treated 264 attacks. In the safety population, 93 patients received EKTERLY 600 mg, 86 patients received EKTERLY 300 mg, and 83 patients received placebo. While EKTERLY 300 mg was included in KONFIDENT, the safety data is based on the recommended dosage of EKTERLY 600 mg. Table 3 displays adverse reaction(s) with an incidence of ≥2% in the EKTERLY 600 mg treated patients and more common than placebo. Table 3: Adverse Reaction(s) with EKTERLY with Incidence ≥2% and More Common than Placebo in Patients with Hereditary Angioedema (KONFIDENT) a One (1) patient assigned to administer placebo actually received EKTERLY 600 mg. Safety results are presented by actual treatment received. Adverse Reaction EKTERLY 600 mg (N = 93) Placebo (N = 83) a n (%) n (%) Headache 3 (3.2) 1 (1.2)

Strong and Moderate CYP3A4 Inhibitors : Avoid use with strong CYP3A4 inhibitors. In patients taking moderate CYP3A4 inhibitors, take one dose of 300 mg. A second dose of 300 mg may be taken at least 3 hours after the first dose if response is inadequate, or if symptoms worsen or recur. ( 2.2 , 7.1 , 12.3 ) CYP3A4 Inducers : Avoid use with moderate or strong CYP3A4 inducers. ( 2.2 , 7.1 , 12.3 )

7.1 Effect of Other Drugs on EKTERLY Strong CYP3A4 Inhibitors Avoid use of EKTERLY with strong CYP3A4 inhibitors [see Clinical Pharmacology ( 12.3 )] . Sebetralstat is a substrate of CYP3A4. Concomitant use of sebetralstat with a strong CYP3A4 inhibitor increases sebetralstat exposure, which may increase the risk of sebetralstat adverse reactions. Moderate and Weak CYP3A4 Inhibitors Reduce dose of EKTERLY to one dose of 300 mg (one tablet) orally at the earliest recognition of an HAE attack when used concomitantly with moderate CYP3A4 inhibitors. A second dose of 300 mg (one tablet) may be taken at least 3 hours after the first dose if response is inadequate, or if symptoms worsen or recur [see Dosage and Administration ( 2.2 ) and Clinical Pharmacology ( 12.3 )] . Sebetralstat is a substrate of CYP3A4. Concomitant use of sebetralstat with a moderate CYP3A4 inhibitor increases sebetralstat exposure, which may increase the risk of sebetralstat adverse reactions. No dose modification is recommended when EKTERLY is used concomitantly with a weak CYP3A4 inhibitor [see Dosage and Administration ( 2.1 ) and Clinical Pharmacology ( 12.3 )] . Strong and Moderate CYP3A4 Inducers Use of EKTERLY with strong or moderate CYP3A4 inducers is not recommended. Sebetralstat is a substrate of CYP3A4. Concomitant use of sebetralstat with a strong or moderate CYP3A4 inducer decreases sebetralstat exposure, which may decrease efficacy. Weak CYP3A4 Inducers No dose modification is recommended when EKTERLY is used concomitantly with weak CYP3A4 inducers [see Clinical Pharmacology ( 12.3 )] .

7.1 Effect of Other Drugs on EKTERLY Strong CYP3A4 Inhibitors Avoid use of EKTERLY with strong CYP3A4 inhibitors [see Clinical Pharmacology ( 12.3 )] . Sebetralstat is a substrate of CYP3A4. Concomitant use of sebetralstat with a strong CYP3A4 inhibitor increases sebetralstat exposure, which may increase the risk of sebetralstat adverse reactions. Moderate and Weak CYP3A4 Inhibitors Reduce dose of EKTERLY to one dose of 300 mg (one tablet) orally at the earliest recognition of an HAE attack when used concomitantly with moderate CYP3A4 inhibitors. A second dose of 300 mg (one tablet) may be taken at least 3 hours after the first dose if response is inadequate, or if symptoms worsen or recur [see Dosage and Administration ( 2.2 ) and Clinical Pharmacology ( 12.3 )] . Sebetralstat is a substrate of CYP3A4. Concomitant use of sebetralstat with a moderate CYP3A4 inhibitor increases sebetralstat exposure, which may increase the risk of sebetralstat adverse reactions. No dose modification is recommended when EKTERLY is used concomitantly with a weak CYP3A4 inhibitor [see Dosage and Administration ( 2.1 ) and Clinical Pharmacology ( 12.3 )] . Strong and Moderate CYP3A4 Inducers Use of EKTERLY with strong or moderate CYP3A4 inducers is not recommended. Sebetralstat is a substrate of CYP3A4. Concomitant use of sebetralstat with a strong or moderate CYP3A4 inducer decreases sebetralstat exposure, which may decrease efficacy. Weak CYP3A4 Inducers No dose modification is recommended when EKTERLY is used concomitantly with weak CYP3A4 inducers [see Clinical Pharmacology ( 12.3 )] .

Hepatic Impairment : Avoid use of EKTERLY in patients with severe hepatic impairment (Child-Pugh Class C). In patients with moderate hepatic impairment (Child-Pugh Class B) take one dose of 300 mg. A second dose of 300 mg may be taken at least 3 hours after the first dose if response is inadequate, or if symptoms worsen or recur. ( 2.3 , 8.6 , 12.3 )

8.1 Pregnancy Risk Summary There are no available data on EKTERLY in pregnant women to evaluate for a drug-associated risk of major birth defects, miscarriage or other adverse maternal or fetal outcomes. In animal reproduction studies, oral administration of sebetralstat to pregnant rats and rabbits during organogenesis produced no evidence of fetal harm with dose exposures up to approximately 15 and 11 times, respectively, the human exposure at the maximum recommended human dose (MRHD) of up to 1,200 mg (on an area under the curve [AUC] basis). Sebetralstat produced an increase in embryofetal losses and fetal malformations in rats at an exposure that was 60 times the MRHD (see Data) . The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriages in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. Data Animal Data In an embryofetal development study with pregnant rats dosed by the oral route during the period of organogenesis from gestation days 6 to 17, sebetralstat caused a dose-related increase in the incidence of external and visceral malformations, described as cleft palates and ventricular septal defects and an increase in embryofetal losses (early and late fetal deaths, mean number of live fetuses, and post-implantation loss at an exposure that was 60 times the MRHD (on an AUC basis with a maternal dose of 600 mg/kg/day)). Maternal toxicity, as evidenced by decreased body weight gains, was observed at exposures 60 times the MRHD (on an AUC basis with a maternal oral dose of 600 mg/kg/day). No fetal or maternal toxicities were observed at exposures up to 15 times the MRHD (on an AUC basis with a maternal oral dose of 300 mg/kg/day). In an embryofetal development study with pregnant rabbits dosed by the oral route during the period of organogenesis from gestation days 6 to 18, maternal toxicity was evidenced by a decrease in body weight gain at an exposure that was 11 times the MRHD (on an AUC basis with a maternal dose of 300 mg/kg/day). No adverse effects on maternal toxicity were observed at an exposure that was 2 times the MRHD (on an AUC basis with a maternal dose of 100 mg/kg/day). No adverse effects on fetal toxicity were observed at an exposure that was 11 times the MRHD (on an AUC basis with a maternal oral dose of 300 mg/kg/day). In a prenatal and postnatal development study with pregnant rats dosed by the oral route during the periods of gestation and lactation from gestation day 6 to lactation day 20, sebetralstat had no effects on the growth and development of offspring at an exposure that was 40 times the MRHD (on an AUC basis with a maternal oral dose of 450 mg/kg/day).

8.2 Lactation Risk Summary There are no data on the presence of sebetralstat or its metabolites in human milk, the effects on the breastfed infant, or the effects on milk production. Radioactivity is present in animal milk after dosing with radiolabeled sebetralstat. When a drug is present in animal milk, it is likely that the drug will be present in human milk. Data in the rat have shown excretion of sebetralstat and/or its metabolites in milk (see Data) . The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for EKTERLY and any potential adverse effects on the breastfed child from EKTERLY or from the underlying maternal condition. Data Animal Data In a single dose placental transfer and milk secretion study in lactating rats dosed with radiolabeled sebetralstat by the oral route, total radioactivity was detected in fetal plasma at 1 hour post dose. Similar concentrations of total radioactivity were observed in the milk and plasma of lactating females, with the maximum radioactive concentration observed at 1 hour post dose that returned to background levels by 24 hours post dose. The concentration of total radioactivity in animal milk does not necessarily predict the concentration of drug in human milk.

8.4 Pediatric Use The safety and effectiveness of EKTERLY for treatment of acute attacks of hereditary angioedema (HAE) have been established in pediatric patients aged 12 years and older. Use of EKTERLY for this indication is supported by evidence from an adequate and well-controlled study (KONFIDENT) in adults and pediatric patients aged 12 years and older with additional population pharmacokinetic (PK) analysis from adults and pediatric patients aged 12 years and older, which showed no clinically significant differences in PK based on body weight or age. Results of the subgroup analysis for pediatric patients aged 12 years and older were consistent with study results for adult patients [see Adverse Reactions ( 6.1 ), Clinical Pharmacology ( 12.3 ), and Clinical Studies ( 14 )] . The safety and effectiveness of EKTERLY in pediatric patients aged <12 years of age have not been established.

8.5 Geriatric Use Clinical studies of EKTERLY did not include sufficient numbers of patients 65 years of age and older to determine whether they respond differently from younger adult patients.

8.6 Hepatic Impairment No dose adjustment of EKTERLY is recommended for patients with mild hepatic impairment (Child-Pugh Class A). For patients with moderate hepatic impairment (Child-Pugh Class B), the recommended dose of EKTERLY is one dose of 300 mg (one tablet) orally at the earliest recognition of an HAE attack. A second dose of 300 mg (one tablet) may be taken at least 3 hours after the first dose if response is inadequate, or if symptoms worsen or recur. Avoid use of EKTERLY in patients with severe hepatic impairment (Child-Pugh Class C) [see Dosage and Administration ( 2.3 ) and Clinical Pharmacology ( 12.3 )] .

Sebetralstat is a competitive, reversible inhibitor of plasma kallikrein. Plasma kallikrein is a serine protease that cleaves high molecular weight kininogen (HK) releasing bradykinin which increases vascular permeability through activation of bradykinin receptors causing edema. Sebetralstat inhibits the cleavage of HK and reduces production of bradykinin, thereby treating the clinical symptoms of an acute, episodic attack of HAE. Sebetralstat also inhibits the positive feedback mechanism of the kallikrein kinin system by plasma kallikrein, thereby reducing factor XIIa and additional plasma kallikrein generation.