Sebetralstat

1 INDICATIONS AND USAGE 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 )

2 DOSAGE AND ADMINISTRATION Recommended Dosage : one dose of 600 mg (2 tablets) taken orally at the earliest recognition of an HAE attack. ( 2.1 ) A second dose of 600 mg (2 tablets) may be taken 3 hours after the first dose if response is inadequate, or if symptoms worsen or recur. ( 2.1 ) Maximum Recommended Dosage: 1,200 mg in any 24-hour period. ( 2.1 ) See full prescribing information for dosage modification for concomitant use with CYP3A4 inhibitors and inducers. ( 2.2 ) See full prescribing information for recommended dosage for patients with hepatic impairment. ( 2.3 ) 2.1 Recommended Dosage The recommended dosage of EKTERLY is one dose of 600 mg (two tablets) orally at the earliest recognition of an acute HAE attack. A second dose of 600 mg (two tablets) may be taken at least 3 hours after the first dose if response is inadequate, or if symptoms worsen or recur. Maximum recommended dosage is 1,200 mg (four tablets) in any 24-hour period. 2.2 Dosage Modification for CYP3A4 Inhibitors and Inducers Refer to Table 1 for dosage modification of EKTERLY when used concomitantly with CYP3A4 inhibitors and inducers. Table 1: Dosage Modification of EKTERLY for Concomitant use with CYP3A4 Inhibitors and Inducers Dosage Modification for Concomitant use of EKTERLY with CYP3A4 Inhibitors Strong CYP3A4 Inhibitors Avoid concomitant use with EKTERLY. Moderate CYP3A4 Inhibitors Reduce EKTERLY dosage to 300 mg (one tablet) orally at earliest recognition of an acute HAE attack. A second dose of 300 mg (one tablet) may be taken at least 3 hours after first dose if response is inadequate or if symptoms worsen or recur [ see Drug Interactions ( 7.1 ) and Clinical Pharmacology ( 12.3 ) ] . Weak CYP3A4 Inhibitors No dosage modification of EKTERLY [ see Dosage and Administration ( 2.1 ) ] . Dosage Modification for Concomitant use of EKTERLY with CYP3A4 Inducers Strong and Moderate CYP3A4 Inducers Avoid concomitant use with EKTERLY. Weak CYP3A4 Inducers No dosage modification of EKTERLY [ see Dosage and Administration ( 2.1 ) ] . 2.3 Recommended Dosage in Patients with Hepatic Impairment Refer to Table 2 for recommended dosage of EKTERLY in patients with hepatic impairment. Table 2: Recommended Dosage of EKTERLY in Patients with Hepatic Impairment Recommended Dosage of EKTERLY in Patients with Hepatic Impairment Severe Hepatic Impairment (Child-Pugh Class C) Avoid use of EKTERLY [ see Use in Specific Populations ( 8.6 ) and Clinical Pharmacology ( 12.3 ) ] . Moderate Hepatic Impairment (Child-Pugh Class B) Recommended dosage of EKTERLY is one dose of 300 mg (one tablet) orally at the earliest recognition of an acute 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 [ see Use in Specific Populations ( 8.6 ) and Clinical Pharmacology ( 12.3 ) ] . Mild Hepatic Impairment (Child-Pugh Class A) Recommended dosage is the same as the recommended dosage in patients with normal hepatic function [ see Dosage and Administration ( 2.1 ) ] .

6 ADVERSE REACTIONS 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)

12.3 Pharmacokinetics Following a single oral dose of 600 mg sebetralstat in subjects with HAE, the geometric mean (CV%) C max is 6,080 ng/mL (40%) and AUC 0-inf is 17,600 ng•h/mL (36%). Following administration of a second oral dose of 600 mg sebetralstat 3 hours after the first dose, C max increases 10% and AUC 0-inf increases 90% when compared to those observed following a single dose. No clinically relevant differences in sebetralstat pharmacokinetics were observed between healthy subjects and patients with HAE. Absorption After a single oral dose of 600 mg sebetralstat, the median time to peak plasma concentration is approximately 1 hour. Effect of Food No clinically relevant differences in sebetralstat pharmacokinetics were observed following administration of a high-fat meal (900-1,000 calories in total – 500-600, 250 and 150 calories from fat, carbohydrate and protein respectively). Distribution The estimated typical apparent volume of distribution (Vz/F) for sebetralstat is 70.1 L (95% CI: 64.8, 75.4). Sebetralstat plasma protein binding is 77% in vitro . Elimination Following administration of a single oral dose of 600 mg sebetralstat, the mean (SD) elimination half-life of sebetralstat ranged from 5.3 (2.3) to 8.9 (5.1) hours. The estimated typical apparent clearance (CL/F) is 30.7 L/h (95% CI: 29.1, 32.2). Metabolism Sebetralstat is primarily metabolized by CYP3A4 and to a lesser extent by CYP2C8. Excretion Following administration of a single oral dose of 600 mg radiolabeled sebetralstat to healthy male subjects, approximately 63% of the dose was recovered in feces (12.5% as unchanged sebetralstat) and 32% in urine (8.7% as unchanged sebetralstat). Specific Populations No clinically relevant differences in the pharmacokinetics of sebetralstat were observed based on body weight (45-135 kg), age (19-68 years), sex, race (71% White, 17% Black, 11% Asian), and mild renal impairment (eGFR 60-89 mL/min/1.73 m 2 ). The effect of moderate and severe renal impairment (eGFR <60 mL/min/1.73 m 2 ) on sebetralstat pharmacokinetics is unknown. Patients with Hepatic Impairment The pharmacokinetics of sebetralstat were evaluated in subjects with mild (Child-Pugh Class A) and moderate (Child-Pugh Class B) hepatic impairment following administration of a single 600 mg dose. In subjects with mild hepatic impairment C max was increased by 7% and AUC increased by 16% compared to subjects with normal hepatic function. In subjects with moderate hepatic impairment C max was increased by 63% and AUC was increased by 100% compared to subjects with normal hepatic function. The effect of severe hepatic impairment (Child-Pugh Class C) on sebetralstat pharmacokinetics is unknown [ see Use in Specific Populations ( 8.6 ) ] . Drug Interaction Studies Clinical Studies and Model-Informed Approaches Strong CYP3A4 Inhibitors : Sebetralstat C max increased 2.4-fold and AUC 0-inf increased 5.2-fold following concomitant administration with itraconazole (a strong CYP3A4 inhibitor) 200 mg once daily for 6 days [see Drug Interactions ( 7.1 )] . Moderate CYP3A4 Inhibitors : Sebetralstat C max increased 1.8-fold and AUC 0-inf increased 2-fold following concomitant administration with verapamil (a moderate CYP3A4 inhibitor) 240 mg once daily for 6 days [see Drug Interactions ( 7.1 )] . Strong CYP3A4 Inducers : Sebetralstat C max decreased by 66% and AUC 0-inf decreased by 83% following concomitant administration with phenytoin (a strong CYP3A4 inducer) 100 mg three times daily for 15 days [see Drug Interactions ( 7.1 )] . Moderate CYP3A4 Inducers : Sebetralstat C max decreased by 63% and AUC 0-inf decreased by 79% following concomitant administration with efavirenz (a moderate CYP3A4 inducer) 600 mg once daily for 14 days [see Drug Interactions ( 7.1 )] . Acid-Reducing Agents : Sebetralstat C max is estimated to decrease by up to 56% and AUC 0-inf is estimated to decrease by up to 30% at pH 6 relative to pH 0.5. Other Drugs : No clinically significant differences in sebetralstat pharmacokinetics were observed when administered concomitantly with quinidine (P-gp inhibitor), eltrombopag (BCRP inhibitor), cimetidine (evaluated as a weak CYP3A4 inhibitor), or modafinil (weak CYP3A4 inducer). In Vitro Studies CYP450 Enzymes : Sebetralstat is a substrate of CYP3A4 and CYP2C8, and is not a substrate of CYP1A2, CYP2A6, CYP2B6, CYP2C9, CYP2C19, CYP2D6, or CYP2E1. Sebetralstat is an inhibitor of CYP2C9 and CYP3A4. Sebetralstat did not inhibit CYP1A2, CYP2B6, CYP2C8, CYP2C19, or CYP2D6. Transporter Systems : Sebetralstat is a substrate of P-gp and BCRP, and is not a substrate of OATP1B1, OATP1B3, OAT1, OAT3, OCT2, or MATE1. Sebetralstat is an inhibitor of BCRP, OATP1B1, OATP1B3, OAT3, OCT2, MATE1, MATE2-K, and BSEP. Sebetralstat did not inhibit P-gp or OAT1.