Etrasimod

5 WARNINGS AND PRECAUTIONS

• Infections : May increase the risk of infections. Obtain a complete blood count (CBC) before initiation of treatment. Monitor for infection during treatment and for 5 weeks after discontinuation. Consider interruption of treatment if a serious infection develops. Avoid use of live attenuated vaccines during and for up to 5 weeks after treatment. ( 5.1 )
• Bradyarrhythmia and Atrioventricular Conduction Delays : May result in a transient decrease in heart rate and AV conduction delays. Obtain an electrocardiogram (ECG) to assess for preexisting cardiac conduction abnormalities before starting treatment. Consider cardiology consultation for conduction abnormalities or concomitant use with other drugs that decrease heart rate. ( 2.1 , 5.2 , 7 )
• Liver Injury : Elevations of aminotransferases may occur. Obtain transaminase and bilirubin levels before initiating VELSIPITY. Discontinue if significant liver injury is confirmed. ( 2.1 , 5.3 )
• Macular Edema : May increase the risk of macular edema. Obtain a baseline evaluation of the fundus, including the macula, near the start of treatment with VELSIPITY. Periodically conduct an evaluation of the fundus, including the macula, while on therapy and any time there is a change in vision. Consider discontinuing VELSIPITY if macular edema develops. ( 2.1 , 5.4 )
• Increased Blood Pressure : Monitor blood pressure during treatment. ( 5.5 )
• Fetal Risk : May cause fetal harm. Advise females of reproductive potential of the potential risk to a fetus and to use effective contraception during treatment and for one week after stopping VELSIPITY. ( 5.6 , 8.3 )
• Cutaneous Malignancies : Obtain a skin examination prior to or shortly after the start of treatment and periodically during treatment, especially if risk factors. Promptly evaluate suspicious skin lesions. ( 2.1 , 5.7 )
• Posterior Reversible Encephalopathy Syndrome (PRES) : If symptoms develop, obtain a physical and neurological exam, and consider MRI. ( 5.8 )
• Respiratory Effects : May cause a decline in pulmonary function. Assess pulmonary function (e.g., spirometry) if clinically indicated. ( 5.9 )
• Unintended Additive Immune System Effects from Prior Treatment with Immunosuppressive or Immune-Modulating Drugs : Consider the half-life and mode of action of prior therapies. ( 5.10 )
• Immune System Effects After Stopping VELSIPITY : If using concomitant immunosuppressants, monitor patients for infectious complications for up to 5 weeks after the last dose of VELSIPITY. ( 5.11 )

5.1 Infections Risk of Infections VELSIPITY causes a mean reduction in peripheral blood lymphocyte count to approximately 45% of baseline values at Week 52 because of reversible sequestration of lymphocytes in lymphoid tissues [see Clinical Pharmacology (12.2) ]. VELSIPITY may, therefore, increase the susceptibility to infections. Life-threatening and rare fatal infections have been reported in association with other sphingosine 1-phosphate (S1P) receptor modulators. Before initiating treatment, obtain a recent (i.e., within 6 months or after discontinuation of prior UC therapy) CBC, including lymphocyte count. Delay initiation of VELSIPITY in patients with an active infection until the infection is resolved. In UC-1, the overall rate of infections in subjects treated with VELSIPITY was 24.9% compared to 22.2% in subjects who received placebo. In pooled data from UC-2 and UC-3, the overall rate of infections in subjects treated with VELSIPITY was 14.0% compared to 11.8% in subjects who received placebo. The most common infections were urinary tract infections and herpes viral infections in UC-1, and urinary tract infections in UC-2 and UC-3 [see Adverse Reactions (6.1) ] . The proportion of subjects treated with VELSIPITY who experienced lymphocyte counts less than 0.2 x 10 9 /L was 5.5% in UC-1 and 0.6% in UC-2 and UC-3. These events did not lead to treatment discontinuation. Peripheral blood absolute lymphocyte counts returned to the normal range in 90% of subjects within 4 to 5 weeks of stopping therapy [see Clinical Pharmacology (12.2) ]. Consider interruption of treatment with VELSIPITY if a patient develops a serious infection. Because residual pharmacodynamic effects, such as lowering effects on peripheral lymphocyte count, may persist up to 5 weeks after discontinuation of VELSIPITY, vigilance for infection should be continued throughout this period. Progressive Multifocal Leukoencephalopathy Progressive multifocal leukoencephalopathy (PML) is an opportunistic viral infection of the brain caused by the JC virus (JCV) that typically occurs in patients who are immunocompromised, and that usually leads to death or severe disability. Typical symptoms associated with PML are diverse, progress over days to weeks, and include progressive weakness on one side of the body or clumsiness of limbs, disturbance of vision, and changes in thinking, memory, and orientation leading to confusion and personality changes. PML has been reported in multiple sclerosis (MS) patients treated with S1P receptor modulators and has been associated with some risk factors (e.g., immunocompromised patients, polytherapy with immunosuppressants, and duration of use). Based on data from patients with MS, longer treatment duration increases the risk of PML in patients treated with S1P receptor modulators, and the majority of PML cases have occurred in patients treated with S1P receptor modulators for at least 18 months. VELSIPITY is not indicated for the treatment of MS. Physicians should be vigilant for clinical symptoms or unexplained neurologic findings that may be suggestive of PML. MRI findings may be apparent before clinical signs or symptoms. If PML is suspected, treatment with VELSIPITY should be suspended until PML has been excluded by an appropriate diagnostic evaluation. If PML is confirmed, discontinue treatment with VELSIPITY. Immune reconstitution inflammatory syndrome (IRIS) has been reported in MS patients treated with S1P receptor modulators who developed PML and subsequently discontinued treatment. IRIS presents as a clinical decline in the patient’s condition that may be rapid, can lead to serious neurological complications or death, and is often associated with characteristic changes on MRI. The time to onset of IRIS in patients with PML was generally within a few months after S1P receptor modulator discontinuation. Monitoring for development of IRIS and appropriate treatment of the associated inflammation should be undertaken. Herpes Viral Infections Herpes simplex encephalitis, varicella zoster meningitis, and localized herpes viral infections have been reported with S1P receptor modulators. In UC-1, herpes zoster was reported in 0.7% of subjects treated with VELSIPITY and in none of the subjects who received placebo. Patients without a healthcare professional-confirmed history of varicella (chickenpox), or without documentation of a full course of vaccination against varicella zoster virus (VZV), should be tested for antibodies to VZV before initiating VELSIPITY (see Vaccinations ) . Cryptococcal Infection Cases of fatal cryptococcal meningitis (CM) and disseminated cryptococcal infections have been reported with S1P receptor modulators. Physicians should be vigilant for clinical symptoms or signs of CM. Patients with symptoms or signs consistent with a cryptococcal infection should undergo prompt diagnostic evaluation and treatment. VELSIPITY treatment should be suspended until a cryptococcal infection has been excluded. If CM is diagnosed, appropriate treatment should be initiated. Prior and Concomitant Treatment with Anti-neoplastic, Immune-modulating, or Non-corticosteroid Immunosuppressive Therapies VELSIPITY has not been studied in combination with anti-neoplastic, immune-modulating, or non-corticosteroid immunosuppressive therapies. Avoid concomitant administration of these therapies with VELSIPITY and in the weeks following administration because of the risk of additive immunosuppressive effects [see Warnings and Precautions (5.10) ] . Vaccinations Patients without a healthcare professional-confirmed history of varicella (chickenpox) or without documentation of a full course of vaccination against varicella zoster virus (VZV) should be tested for antibodies to VZV before initiating VELSIPITY. A full course of VZV vaccination of antibody-negative patients is recommended prior to commencing treatment with VELSIPITY, following which initiation of treatment with VELSIPITY should be postponed for 4 weeks to allow the full effect of vaccination to occur. No clinical data are available on the safety and efficacy of vaccinations in patients taking VELSIPITY. Vaccinations may be less effective if administered during VELSIPITY treatment. If live attenuated vaccine immunizations are required, administer at least 4 weeks prior to initiation of VELSIPITY. Avoid the use of live attenuated vaccines during and for 5 weeks after treatment with VELSIPITY. Update immunizations in agreement with current immunization guidelines prior to initiating VELSIPITY therapy.

5.2 Bradyarrhythmia and Atrioventricular Conduction Delays Initiation of VELSIPITY may result in a transient decrease in heart rate and AV conduction delays [see Clinical Pharmacology (12.2) ]. Reduction in Heart Rate Initiation of VELSIPITY may result in a transient decrease in heart rate. After the first dose of VELSIPITY 2 mg, subjects with UC experienced the greatest mean decrease from baseline in heart rate of 7.2 bpm at Hour 3 in UC-1 and Hour 2 in UC-2. In UC-1, bradycardia was reported on the day of treatment initiation in 1% of subjects treated with VELSIPITY compared to none in subjects who received placebo. On Day 2, bradycardia was reported in 1 subject (0.3%) treated with VELSIPITY compared to none in subjects who received placebo. In UC-2 and UC-3, bradycardia was reported on the day of treatment initiation in 2.9% of subjects treated with VELSIPITY compared to none in subjects who received placebo. On Day 2, bradycardia was reported in 1 subject (0.3%) treated with VELSIPITY compared to none in subjects who received placebo. Subjects who experienced bradycardia were generally asymptomatic. Few subjects experienced symptoms, such as dizziness, and these symptoms resolved without intervention. Atrioventricular Conduction Delays Initiation of VELSIPITY may result in transient AV conduction delays. On the day of treatment initiation of VELSIPITY 2 mg, first- or second-degree Mobitz type I AV blocks were observed in 0.7% of VELSIPITY-treated subjects compared to none in placebo in UC-1, and in 0.8% of VELSIPITY-treated subjects compared to none in placebo in UC-2 and UC-3. In UC-1, UC-2, and UC-3, Mobitz type II second- or third-degree AV blocks were not reported in VELSIPITY-treated subjects. If treatment with VELSIPITY is considered, advice from a cardiologist should be sought for those individuals:

• With significant QT prolongation (QTcF ≥450 msec in males, ≥470 msec in females)
• With arrhythmias requiring treatment with Class Ia or Class III anti-arrhythmic drugs or QT prolonging drugs [see Drug Interactions (7) ]
• With unstable ischemic heart disease, Class I or II heart failure, history of cardiac arrest, cerebrovascular disease, or uncontrolled hypertension [see Contraindications (4) ]
• With resting heart rate of less than 50 bpm
• With history of symptomatic bradycardia, recurrent cardiogenic syncope, or severe untreated sleep apnea
• With history of Mobitz type I second-degree AV block, unless the patient has a functioning pacemaker [see Contraindications (4) ] 5.3 Liver Injury Elevations of aminotransferases may occur in patients receiving VELSIPITY. In UC-1, elevations of alanine transaminase (ALT) greater than 3-fold the upper limit of normal (ULN) occurred in 4.5% of subjects who received VELSIPITY and 2.1% of subjects who received placebo. In UC-2 and UC-3, elevations of ALT greater than 3-fold the ULN occurred in 2.5% of subjects who received VELSIPITY and 0.5% of subjects who received placebo. Obtain transaminase and bilirubin levels, if not recently available (i.e., within last 6 months), before initiation of VELSIPITY. Obtain transaminases and bilirubin in patients who develop symptoms suggestive of hepatic dysfunction, such as unexplained nausea, vomiting, abdominal pain, fatigue, anorexia, or jaundice and/or dark urine. Discontinue VELSIPITY if significant liver injury is confirmed.

5.4 Macular Edema S1P receptor modulators, including VELSIPITY, have been associated with an increased risk of macular edema. Obtain a baseline evaluation of the fundus, including the macula, near the start of treatment with VELSIPITY. Periodically conduct an evaluation of the fundus, including the macula, while on therapy and any time there is a change in vision. Macular edema over an extended period of time (i.e., 6 months) can lead to permanent visual loss. Consider discontinuing VELSIPITY if macular edema develops.

5.5 Increased Blood Pressure In UC-1 and UC-2 and UC-3, subjects treated with VELSIPITY had an average increase of approximately 1 to 4 mm Hg in systolic blood pressure and approximately 1 to 2 mm Hg in diastolic blood pressure compared to <1.5 mm Hg and <1 mm Hg in subjects receiving placebo, respectively. The increase was first detected after 2 weeks of treatment and remained within the specified average range of BP increases throughout treatment. Hypertension was reported as an adverse reaction in UC-1 [see Adverse Reactions (6.1) ] . Monitor blood pressure during treatment with VELSIPITY and manage appropriately.

5.6 Fetal Risk Based on animal studies, VELSIPITY may cause fetal harm when administered to a pregnant woman. In animal reproduction studies conducted in rats and rabbits, embryofetal toxicity was observed with administration of etrasimod at clinically relevant doses. Advise pregnant women and females of reproductive potential of the potential risk to a fetus. Advise females of reproductive potential to use effective contraception to avoid pregnancy during and for one week after stopping VELSIPITY [see Use in Specific Populations (8.1 , 8.3 )] .

5.7 Cutaneous Malignancies The risk of cutaneous malignancies (including basal cell carcinoma, squamous cell carcinoma, and melanoma) is increased in patients treated with S1P receptor modulators in controlled trials. Kaposi’s sarcoma and Merkel cell carcinoma have also been reported in patients treated with S1P receptor modulators in the postmarketing setting. Skin examinations are recommended prior to or shortly after the start of treatment and periodically thereafter for all patients, particularly those with risk factors for skin cancer. Providers and patients are advised to monitor for suspicious skin lesions. If a suspicious skin lesion is observed, it should be promptly evaluated. As usual for patients with increased risk for skin cancer, exposure to sunlight and ultraviolet (UV) light should be limited by wearing protective clothing and using a sunscreen with a high protection factor. Concomitant phototherapy with UV-B radiation or PUVA-photochemotherapy is not recommended in patients taking VELSIPITY.

5.8 Posterior Reversible Encephalopathy Syndrome Rare cases of posterior reversible encephalopathy syndrome (PRES) have been reported in patients receiving S1P receptor modulators. If a patient develops any neurological or psychiatric symptoms/signs (e.g., cognitive deficits, behavioral changes, cortical visual disturbances, or any other neurological cortical symptoms/signs), any symptom/sign suggestive of an increase of intracranial pressure, or accelerated neurological deterioration, the physician should promptly schedule a complete physical and neurological examination and should consider an MRI. Symptoms of PRES are usually reversible but may evolve into ischemic stroke or cerebral hemorrhage. Delay in diagnosis and treatment may lead to permanent neurological sequelae. If PRES is suspected, discontinue treatment with VELSIPITY.

5.9 Respiratory Effects Reductions in absolute forced expiratory volume over 1 second (FEV 1 ) were observed in subjects treated with VELSIPITY as early as 3 months after treatment initiation. In UC-1, the decline in absolute FEV 1 from baseline in subjects treated with VELSIPITY compared to placebo was 79 mL (95% CI: -152, -5) at 3 months. In UC-2, reductions in absolute FEV 1 were not observed. There is insufficient information to determine the reversibility of the decrease in FEV 1 after drug discontinuation. In UC-1 and UC-2, subjects with UC and asthma and/or chronic obstructive pulmonary disease were treated with VELSIPITY; however, interpretation of changes in pulmonary function test measures in this population are limited due to small sample sizes. Spirometric evaluation of respiratory function should be performed during therapy with VELSIPITY if clinically indicated.

5.10 Unintended Additive Immune System Effects from Prior Treatment with Immunosuppressive or Immune-Modulating Drugs When switching to VELSIPITY from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects [see Drug Interactions (7) ] .

5.11 Immune System Effects After Stopping VELSIPITY After stopping VELSIPITY, lymphocyte counts returned to the normal range in 90% of subjects within 4 to 5 weeks of stopping VELSIPITY [see Clinical Pharmacology (12.2) ] . Use of immunosuppressants within this period may lead to an additive effect on the immune system, and therefore monitor patients receiving concomitant immunosuppressants for infectious complications up to 5 weeks after the last dose of VELSIPITY [see Drug Interactions (7) ] .

Severe Hepatic Impairment : Use is not recommended. ( 8.6 )

8.1 Pregnancy Pregnancy Exposure Registry There is a pregnancy exposure registry that monitors pregnancy outcomes in females exposed to VELSIPITY during pregnancy. Pregnant females exposed to VELSIPITY and healthcare providers are encouraged to contact the pregnancy registry by calling 1-800-616-3791. Risk Summary Based on findings from animal studies, VELSIPITY may cause fetal harm when administered to a pregnant woman. Available data from reports of pregnancies from the clinical development program with VELSIPITY are insufficient to identify a drug-associated risk of major birth defects, miscarriage or other adverse maternal or fetal outcomes. There are risks to the mother and the fetus associated with increased disease activity in women with inflammatory bowel disease during pregnancy (see Clinical Considerations ). In animal reproduction studies, administration of etrasimod during organogenesis produced adverse effects on development, including embryolethality and fetal malformations, in both rats and rabbits at maternal exposures 5 and 6 times, respectively, the exposure at the maximum recommended human dose (MRHD). Administration of VELSIPITY to pregnant rats during organogenesis through lactation resulted in decreased pup growth and viability at maternal exposures 5 times the exposure at the MRHD, as well as impaired reproductive performance in first generation offspring, including decreased implantations and increased pre-implantation loss at maternal exposures 24 times the exposure at the MRHD (see Data ) . The 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 miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. Clinical Considerations Disease-Associated Maternal and/or Embryo/Fetal Risk Published data suggest that the risk of adverse pregnancy outcomes in women with inflammatory bowel disease is associated with increased disease activity. Adverse pregnancy outcomes include preterm delivery (before 37 weeks of gestation), low birth weight (less than 2500 g) infants, and small for gestational age at birth. Data Animal Data In an embryo-fetal development study in pregnant rats, etrasimod was orally administered at 1, 2, or 4 mg/kg/day (5, 11, and 21 times the exposure at the MRHD of 2 mg, based on AUC comparison) during the period of organogenesis, from gestation day 6 to 17. No maternal toxicity was observed up to 21 times the exposure at the MRHD. Increased post-implantation loss with a corresponding decrease in the number of viable fetuses was observed at 4 mg/kg/day (21 times the exposure at the MRHD). Etrasimod-related fetal external and/or visceral malformations were noted at all dose levels (≥5 times the exposure at the MRHD). In an embryo-fetal development study in pregnant rabbits, etrasimod was orally administered at 2, 10, or 20 mg/kg/day (0.8, 6, and 11 times the exposure at the MRHD of 2 mg, based on AUC comparison) during the period of organogenesis, from gestation day 7 to 20. Increased post-implantation loss with a corresponding decrease in the number of viable fetuses was observed at 10 and 20 mg/kg/day (6 and 11 times the exposure at the MRHD). Etrasimod-related fetal malformations including aortic arch defects and fused sternebrae were noted at 10 and/or 20 mg/kg/day (6 and 11 times the exposure at the MRHD). There were no adverse effects on embryofetal development at 2 mg/kg/day (less than the exposure at the MRHD). In a pre- and post-natal development study in rats, etrasimod was orally administered at 0.4, 2, or 4 mg/kg/day (2, 10, and 24 times the exposure at the MRHD of 2 mg, based on AUC comparison) throughout pregnancy and lactation, from gestation day 6 through lactation day 20. Mortality during delivery and impaired maternal performance including increased post-implantation loss, increased number of females with stillborn pups, increased number of stillborn pups per litter, decreased viability index, and/or decreased lactation index was observed at 2 and 4 mg/kg/day (10 and 24 times the exposure at the MRHD). Etrasimod was detected in the plasma of F1 offspring, indicating exposure from the milk of the lactating dam. Decreased pup body weights were observed during the preweaning period at all dose levels (maternal exposures ≥2 times the exposure at the MRHD), and decreased pup viability was observed at 2 and 4 mg/kg/day (maternal exposures 10 and 24 times the exposure at the MRHD). Reduced fertility and reproductive performance including reduction in implantations and increased preimplantation loss in F1 offspring occurred at the highest dose tested (maternal exposures 24 times the exposure at the MRHD).

8.2 Lactation Risk Summary There are no data on the presence of etrasimod in human milk, the effects on the breastfed infant, or the effects of the drug on milk production. When etrasimod was orally administered to female rats during pregnancy and lactation, etrasimod was detected in the plasma of the offspring, suggesting excretion of etrasimod in milk. The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for VELSIPITY and any potential adverse effects on the breastfed infant from VELSIPITY or from the underlying maternal condition.

8.3 Females and Males of Reproductive Potential Based on animal data, VELSIPITY may cause fetal harm when administered to pregnant women [see Use in Specific Populations (8.1) ]. Contraception Females Before initiation of VELSIPITY treatment, females of reproductive potential should be counseled on the potential for a serious risk to the fetus and the need for effective contraception during treatment with VELSIPITY and for one week following the last dose [see Warnings and Precautions (5.6) and Use in Specific Populations (8.1) ].

8.4 Pediatric Use The safety and effectiveness of VELSIPITY in pediatric patients have not been established.

8.5 Geriatric Use Of the 577 VELSIPITY-treated subjects in the three clinical trials (UC-1, UC-2, and UC-3), 30 subjects (5%) were 65 years of age and older, while 3 subjects (<1%) were 75 years of age and older. Clinical studies of VELSIPITY did not include sufficient numbers of subjects aged 65 and older to determine whether they respond differently from younger adult subjects. The pharmacokinetics of etrasimod are similar in subjects 65 years of age and older compared to younger adult subjects [see Clinical Pharmacology (12.3) ].

8.6 Hepatic Impairment Etrasimod undergoes extensive hepatic metabolism . Exposure to etrasimod was similar in subjects with mild and moderate hepatic impairment (Child-Pugh A and B) compared to subjects with normal hepatic function; however, etrasimod exposure was increased in subjects with severe hepatic impairment (Child‑Pugh C) compared to subjects with normal hepatic function [see Clinical Pharmacology (12.3) ] . Use of VELSIPITY in patients with severe hepatic impairment is not recommended. No dosage adjustment is needed in patients with mild to moderate hepatic impairment.

8.7 CYP2C9 Poor Metabolizers Increased exposure of etrasimod in patients who are CYP2C9 poor metabolizers is expected with concomitant use of moderate to strong inhibitors of CYP2C8 or CYP3A4. Concomitant use of VELSIPITY is not recommended in these patients [see Clinical Pharmacology (12.3 , 12.5) ] .

12.1 Mechanism of Action Etrasimod is a sphingosine 1-phosphate (S1P) receptor modulator that binds with high affinity to S1P receptors 1, 4, and 5 (S1P 1,4,5 ). Etrasimod has minimal activity on S1P 3 (25-fold lower than C max at the recommended dose) and no activity on S1P 2 . Etrasimod partially and reversibly blocks the capacity of lymphocytes to egress from lymphoid organs, reducing the number of lymphocytes in peripheral blood. The mechanism by which etrasimod exerts therapeutic effects in UC is unknown but may involve the reduction of lymphocyte migration into the intestines.

12.2 Pharmacodynamics Reduction in Blood Lymphocyte Counts VELSIPITY causes a reduction in peripheral blood lymphocyte count [see Warnings and Precautions (5.1) ]. In UC-1 and UC-2, mean lymphocyte counts decreased to approximately 50% of baseline at 2 weeks (approximate mean blood lymphocyte counts 0.9 x 10 9 /L) and the lower lymphocyte counts were maintained during treatment with VELSIPITY. Dose-response relationship analysis indicates there is a dose-dependent reduction in blood lymphocyte counts. After discontinuing VELSIPITY 2 mg once daily, the median time for peripheral blood lymphocytes to return to the normal range was 2.6 weeks, with approximately 90% of subjects in the normal range within 4.7 weeks. Reduction in Heart Rate and AV Conduction Delays VELSIPITY may result in a transient decrease in heart rate and AV conduction upon treatment initiation [see Warnings and Precautions (5.2) ]. In UC-1 and UC-2, the mean (SD) decrease in heart rate was 7.2 (8.98) bpm at 2 to 3 hours after the first dose of VELSIPITY on Day 1. Cardiac Electrophysiology At 2 times the maximum recommended dose, etrasimod does not cause clinically significant QTc interval prolongation. Pulmonary Function Reductions in absolute FEV 1 were observed in subjects treated with VELSIPITY [see Warnings and Precautions (5.9) ] . Drug Interaction Studies No clinically significant differences in heart rate reduction were observed when etrasimod was used concomitantly with stable beta blocker treatment. The effect of concomitant use of etrasimod with a calcium channel blocker on heart rate reduction is unknown [see Drug Interactions (7) ] .

12.3 Pharmacokinetics Etrasimod mean (SD) steady-state maximum plasma concentration (C max ) was 113 (27.5) ng/mL and area under the time concentration curve at the dosing interval (AUC tau ) was 2162 (488) ng*h/mL at the recommended dosage. Etrasimod C max and AUC are approximately dose proportional from 0.7 mg to 2 mg (0.35 times up to the recommended dosage). Etrasimod steady state is reached within 7 days with an accumulation of approximately 2- to 3-fold compared to the first dose. Absorption The median (range) time to reach etrasimod C max (T max ) is approximately 4 hours (range 2 to 8 hours) after oral administration. Effect of Food No clinically significant differences in the pharmacokinetics of etrasimod were observed following administration of VELSIPITY with a high-fat meal (800 to 1000 calories) [see Dosage and Administration (2.2) ] . Distribution The mean apparent volume of distribution of etrasimod is 66 (24) L. Etrasimod plasma protein binding is 97.9%. Elimination The mean plasma elimination half-life (t 1/2 ) of etrasimod is approximately 30 hours with an apparent steady-state oral clearance of approximately 1 L/h after oral administration. Metabolism Etrasimod is metabolized by oxidation and dehydrogenation mediated primarily by CYP2C8, CYP2C9, and CYP3A4, with a minor contribution by CYP2C19 and CYP2J2. Etrasimod also undergoes conjugation primarily mediated by UGTs, with a minor contribution by sulfotransferases. Unchanged etrasimod is the main circulating component in plasma. Excretion Approximately 82% of total radioactive etrasimod dose was recovered in the feces and 5% in the urine within 336 hours. Approximately 11% of administered radioactive dose was excreted as unchanged etrasimod in feces and none was excreted unchanged in urine. Specific Populations No clinically significant differences in the pharmacokinetics of etrasimod were observed based on age (>65 years), sex, body weight, race, ethnicity, disease (healthy subjects vs. subjects with ulcerative colitis), and severe renal impairment (eGFR ≤29 mL/min). Patients with Hepatic Impairment Etrasimod AUC increased by 13% in subjects with mild (Child-Pugh A), 29% in moderate (Child-Pugh B), and 57% in severe (Child-Pugh C) hepatic impairment, respectively, compared with subjects with normal liver function. No clinically significant difference in the unbound etrasimod AUC was observed [see Use in Specific Populations (8.6) ] . Drug Interaction Studies Clinical Studies Combined moderate CYP2C9 and CYP3A4 inhibitors: Concomitant use of etrasimod with steady-state fluconazole (moderate CYP2C9 and CYP3A4 inhibitor) increased etrasimod AUC by 84% [see Drug Interactions (7) ] . Combined CYP3A4 (strong), CYP2C8 (moderate) and CYP2C9 (moderate) inducers: Concomitant use of etrasimod with rifampin (strong CYP3A4, moderate CYP2C8, and CYP2C9 inducer) decreased etrasimod AUC by 49% [see Drug Interactions (7) ]. Oral Contraceptives: No clinically significant differences in the pharmacokinetics and pharmacodynamics of oral contraceptive containing 30 mcg ethinyl estradiol and 150 mcg levonorgestrel were observed when used concomitantly with etrasimod. Other Drugs: Itraconazole (a P-gp and strong CYP3A inhibitor) increased etrasimod AUC by 32%. Gemfibrozil (an inhibitor of OATP1B1 and OAT3 and a strong inhibitor of CYP2C8) increased etrasimod AUC by 36%. These effects are unlikely to be clinically significant. In Vitro Studies Based on in vitro studies, etrasimod is not an inhibitor of CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, and CYP3A4, nor an inducer of CYP1A2, CYP2B6, and CYP3A4 at clinically relevant concentrations. Etrasimod is not an inhibitor of UGT1A3, UGT1A4, UGT1A9, UGT2B7, or UGT2B17 in vitro. Etrasimod is not a substrate or an inhibitor of P-gp, BCRP, BSEP, OATP1B1, OATP1B3, OAT1, OAT3, OCT1, OCT2, MATE1, and MATE2-K transporters.

12.5 Pharmacogenomics CYP2C9 activity is decreased in individuals with genetic variants such as CYP2C9*2 and CYP2C9*3 alleles. The impact of CYP2C9 genetic variants on the pharmacokinetics of etrasimod has not been directly evaluated. CYP2C9 poor metabolizers (e.g., *2/*3, *3/*3) may have decreased clearance of etrasimod when VELSIPITY is used concomitantly with moderate to strong inhibitors of CYP2C8 or CYP3A4 [see Drug Interactions (7) and Use in Specific Populations (8.7) ] . CYP2C9 intermediate metabolizers (e.g., *1/*2, *1/*3, *2/*2) may have decreased clearance of etrasimod when VELSIPITY is used concomitantly with moderate to strong inhibitors of CYP2C8 or CYP3A4; however, the effect on VELSIPITY exposure in CYP2C9 intermediate metabolizers with concomitant CYP2C8 or CYP3A4 inhibitors is not known. The prevalence of the CYP2C9 poor metabolizer phenotype is approximately 2 to 3% in White populations, 0.5 to 4% in Asian populations, and <1% in African-American populations. Other decreased or nonfunctional CYP2C9 alleles (e.g., *5, *6, *8, *11) are more prevalent in African-American populations.