2.1 Recommended Dosage

The recommended dosage regimen is 1 metered dose administered rectally twice daily for 2 weeks followed by 1 metered dose administered rectally once daily for 4 weeks.

2.2 Administration Instructions

Advise patients:

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Budesonide rectal foam is only to be applied rectally. It is not for oral use.

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Before using budesonide rectal foam, use the bathroom to empty your bowels.

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Each applicator is coated with a lubricant. If additional lubrication is needed, petrolatum or petroleum jelly can also be used.

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Warm the canister in the hands while shaking it vigorously for 10 to 15 seconds prior to use.

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Budesonide rectal foam can be used in a standing, lying or sitting position (e.g., while using the toilet).

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Apply budesonide rectal foam in the morning and the evening for the first 2 weeks of treatment; then once daily in the evening for the next 4 weeks. When applied in the evening, use immediately prior to bedtime. Try not to empty your bowels again until the next morning.

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Avoid concomitant use of CYP3A4 inhibitors (e.g., ketoconazole, grapefruit juice) during treatment with budesonide rectal foam.

5.1 Hypercorticism and Adrenal Axis Suppression

When glucocorticosteroids are used chronically, systemic effects such as hypercorticism and adrenal suppression may occur. Glucocorticosteroids can reduce the response of the hypothalamus-pituitary-adrenal (HPA) axis to stress. In situations where patients are subject to surgery or other stress situations, supplementation with a systemic glucocorticosteroid is recommended. Since budesonide rectal foam contains a glucocorticosteroid, general warnings concerning glucocorticoids should be followed [see Clinical Pharmacology (12.2)].

Reduced liver function affects the elimination of glucocorticosteroids, and increased systemic availability of oral budesonide has been demonstrated in patients with liver cirrhosis [see Use in Specific Populations (8.6)].

5.2 Impaired Adrenal Suppression in Patients Transferred from Other Glucocorticoids

Monitor patients who are transferred from glucocorticosteroid treatment with higher systemic effects to glucocorticosteroids with lower systemic effects, such as budesonide rectal foam, since symptoms attributed to withdrawal of steroid therapy, including those of acute adrenal suppression or benign intracranial hypertension, may develop. Adrenocortical function monitoring may be required in these patients and the dose of glucocorticosteroid treatment with high systemic effects should be reduced cautiously.

Replacement of systemic glucocorticosteroids with budesonide rectal foam may unmask allergies (e.g., rhinitis and eczema), which were previously controlled by the systemic drug.

5.3 Increased Risk of Infection

Patients who are on drugs that suppress the immune system are more susceptible to infection than healthy individuals. Chicken pox and measles, for example, can have a more serious or even fatal course in susceptible patients or patients on immunosuppressant doses of glucocorticosteroids. In patients who have not had these diseases, particular care should be taken to avoid exposure.

How the dose, route and duration of glucocorticosteroid administration affect the risk of developing a disseminated infection is not known. The contribution of the underlying disease and/or prior glucocorticosteroid treatment to the risk is also not known. If exposed, therapy with varicella zoster immune globulin (VZIG) or pooled intravenous immunoglobulin (IVIG), as appropriate, may be indicated. If exposed to measles, prophylaxis with pooled intramuscular immunoglobulin (IG) may be indicated (see prescribing information for VZIG and IG). If chicken pox develops, treatment with antiviral agents may be considered.

Glucocorticosteroids should be used with caution, if at all, in patients with active or quiescent tuberculosis infection, untreated fungal, bacterial, systemic viral or parasitic infections, or ocular herpes simplex.

5.4 Other Glucocorticosteroid Effects

Monitor patients with hypertension, diabetes mellitus, osteoporosis, peptic ulcer, glaucoma or cataracts, or with a family history of diabetes or glaucoma, or with any other condition where glucocorticosteroids may have unwanted effects.

5.5 Flammable Contents

The contents of budesonide rectal foam include n-butane, isobutane and propane as propellants which are flammable. Instruct the patient to avoid fire, flame, and smoking during and immediately following administration. Patients should temporarily discontinue use of budesonide rectal foam before initiation of bowel preparation for colonoscopy and consult their healthcare provider before resuming therapy.

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 with rates in the clinical trials of another drug and may not reflect the rates observed in practice.

The data described below reflect exposure to budesonide rectal foam in 332 patients with active mild to moderate distal ulcerative colitis extending up to 40 cm from the anal verge. The median duration of exposure was 42 days. This included 14 patients exposed for at least 6 months.

Budesonide rectal foam was studied primarily in 2 placebo-controlled, 6-week trials in patients with active disease (Study 1 and Study 2). In these trials, 268 patients received budesonide rectal foam 2 mg twice a day for 2 weeks followed by 2 mg once a day for 4 weeks [see Clinical Studies (14)].

The most common adverse reactions (≥ 2% of the budesonide rectal foam or Placebo group and at higher frequency in the budesonide rectal foam group) were decreased blood cortisol, adrenal insufficiency, and nausea (Table 1). Decreased blood cortisol was defined as a morning cortisol level of <5 mcg/dL. Adrenal insufficiency was defined as a cortisol level of <18 mcg/dL at 30 minutes post-challenge with adrenocorticotropic hormone (ACTH).

A total of 10% of budesonide rectal foam-treated patients discontinued treatment due to an adverse reaction compared with 4% of placebo-treated patients.

Table 1: Summary of Adverse Reactions in 2 Placebo-Controlled Trials* (Studies 1 and 2)

*Experienced by ≥ 2% of the budesonide rectal foam or Placebo group and at higher frequency in the budesonide rectal foam group.

#Decreased blood cortisol was defined as a morning cortisol level of <5 mcg/dL.

†Adrenal insufficiency was defined as a cortisol level of <18 mcg/dL at 30 minutes post-challenge with ACTH.

Of the 46 budesonide rectal foam treated patients with decreased blood cortisol (defined as a morning cortisol level of <5 mcg/dL) reported as an adverse event, none had adrenal insufficiency (defined as a cortisol level of <18 mcg/dL at 30 minutes post-challenge with ACTH) (see Table 2). All cases of adrenal insufficiency resolved.

Table 2 summarizes the percentages of patients reporting glucocorticoid related effects in the 2 placebo-controlled trials (Studies 1 and 2).

Table 2: Summary of Glucocorticoid Related Effects in Two Placebo-Controlled Trials (Studies 1 and 2)

*Decreases in serum cortisol levels associated with budesonide treatment were seen at Weeks 1 and 2 (twice daily treatment) in the budesonide rectal foam group, but gradually returned to baseline levels during the 4 weeks of once daily treatment.

No clinically significant differences were observed with respect to the overall percentages of patients with any glucocorticoid related effects between budesonide rectal foam and placebo after 6 weeks of therapy.

For additional details on morning cortisol levels and the response to the ACTH stimulation test, see Clinical Pharmacology (12.2).

6.2 Postmarketing Experience

In addition to adverse reactions reported from clinical trials for budesonide rectal foam, the following adverse reactions have been identified during post-approval use of other oral and rectal formulations of budesonide. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

Cardiac disorders: hypertension

Gastrointestinal disorders: pancreatitis

General disorders and administration site conditions: pyrexia, peripheral edema

Immune system disorders: anaphylactic reactions

Nervous system disorders: dizziness, benign intracranial hypertension

Psychiatric disorders: mood swings

Skin and subcutaneous tissue disorders: pruritus, maculopapular rash, allergic dermatitis

7.1 CYP3A4 Inhibitors

The active ingredient of budesonide rectal foam, budesonide, is metabolized by CYP3A4. Inhibitors of CYP3A4 activity (such as ketoconazole, itraconazole, ritonavir, indinavir, saquinavir, erythromycin, cyclosporine and grapefruit juice) can increase systemic budesonide concentrations. Avoid concomitant use of CYP3A4 inhibitors with budesonide rectal foam [see Clinical Pharmacology (12.3)].

8.1 Pregnancy

Risk Summary

Limited published studies report on the use of budesonide in pregnant women; however, the data are insufficient to inform a drug-associated risk for major birth defects and miscarriage. There are clinical considerations (see Clinical Considerations). In animal reproduction studies with pregnant rats and rabbits, subcutaneous administration of budesonide during organogenesis at doses 1.2 times and 0.12 times, respectively, the human intrarectal dose of 4 mg/day, resulted in increased fetal loss, decreased pup weights, and skeletal abnormalities. Maternal toxicity was observed in both rats and rabbits at these dose levels (see Data). Based on animal data, advise pregnant women of the potential risk to a fetus.

The estimated background risk of major birth defects and miscarriage of 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 of 2% to 4%, and 15% to 20%, respectively.

Clinical Considerations

Disease-Associated Maternal and/or Embryo/Fetal Risk

Published data suggest that increased disease activity is associated with the risk of developing adverse pregnancy outcomes in women with ulcerative colitis. 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.

Fetal/Neonatal Adverse Reactions

Hypoadrenalism may occur in infants born of mothers receiving corticosteroids during pregnancy. Infants should be carefully observed for signs of hypoadrenalism, such as poor feeding, irritability, weakness, and vomiting, and managed accordingly [see Warnings and Precautions (5.1)].

Data

Animal Data

Budesonide was teratogenic and embryolethal in rabbits and rats.

In an embryo-fetal development study in pregnant rats dosed subcutaneously with budesonide during the period of organogenesis from gestation days 6-15 there were effects on fetal development and survival at subcutaneous doses up to approximately 500 mcg/kg in rats (approximately 1.2 times the recommended human intrarectal dose on a body surface area basis). In an embryo-fetal development study in pregnant rabbits dosed during the period of organogenesis from gestation days 6-18, there was an increase in maternal abortion, and effects on fetal development and reduction in litter weights at subcutaneous doses up to approximately 25 mcg/kg in rabbits (approximately 0.12 times the recommended human intrarectal dose of 4 mg/day on a body surface area basis). Maternal toxicity, including reduction in body weight gain, was observed at subcutaneous doses of 5 mcg/kg in rabbits (approximately 0.02 times the recommended human intrarectal dose on a body surface area basis) and 500 mcg/kg in rats (approximately 1.2 times the recommended human intrarectal dose of 4 mg/day on a body surface area basis).

In a pre-and post-natal development study, rats dosed subcutaneously with budesonide during the period of Day 15 post coitum to Day 21 postpartum, budesonide had no effects on delivery but did have an effect on growth and development of offspring. In addition, offspring survival was reduced, and surviving offspring had decreased mean body weights at birth and during lactation at exposures 0.05 times the MRHD (on a mg/m2 basis at maternal subcutaneous doses of 20 mcg/kg/day and higher). These findings occurred in the presence of maternal toxicity.

8.2 Lactation

Risk Summary

Lactation studies have not been conducted with budesonide rectal foam or other rectally administered budesonide products and no information is available on the effects of budesonide on the breastfed infant or the effects of the drug on milk production. One published study reports that budesonide is present in human milk following maternal inhalation of budesonide (see Data). The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for budesonide rectal foam and any potential adverse effects on the breastfed child from budesonide rectal foam or from the underlying maternal condition.

Data

One published study reports that budesonide is present in human milk following maternal inhalation of budesonide and the milk/plasma ratio ranged between 0.4 and 0.5. Budesonide plasma concentrations were not detected, and no adverse events were noted in the breastfed infants following maternal use of inhaled budesonide. The systemic exposure (AUC0-12) following administration of 400 mcg twice a day of inhaled budesonide ranged from 1.27 to 2.26 ng*hr/mL. The estimated budesonide AUC0-12 following rectal administration of 2 mg twice a day budesonide was 4.31 ng*hr/mL [see Clinical Pharmacology (12.3)]. Budesonide exposure to the nursing child may be higher with maternal rectal administration of budesonide than with maternal inhaled administration of budesonide.

8.4 Pediatric Use

The safety and effectiveness of budesonide rectal foam has not been established in pediatric patients.

Children who are treated with corticosteroids by any route may experience a decrease in their growth velocity. This negative impact of corticosteroids on growth has been in the absence of laboratory evidence of hypothalamic-pituitary-adrenal (HPA) axis suppression. The long-term effects of this reduction in growth velocity associated with corticosteroid treatment, including the impact on final adult height, are unknown. Growth velocity may therefore be a more sensitive indicator of systemic corticosteroid exposure in children than some commonly used tests of HPA axis function. The linear growth of children treated with corticosteroids by any route should be monitored (e.g., via stadiometry), and the potential growth effects of prolonged treatment should be weighed against clinical benefits obtained and the availability of other treatment alternatives. In order to minimize the potential growth effects of corticosteroids, children should be titrated to the lowest effective dose.

8.5 Geriatric Use

Clinical studies with budesonide rectal foam did not include sufficient numbers of patients aged 65 and over to determine whether they respond differently than younger patients. Other reported clinical experience has not identified differences in responses between the elderly and younger patients. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy.

8.6 Hepatic Impairment

No dosage adjustment is needed for patients with mild (Child-Pugh Class A) hepatic impairment. Patients with moderate to severe hepatic impairment (Child-Pugh Class B or C) should be monitored for increased signs and/or symptoms of hypercorticism. Discontinuing the use of budesonide rectal foam should be considered in these patients if signs of hypercorticism are observed [see Warnings and Precautions (5.1) and Clinical Pharmacology (12.3)].

12.1 Mechanism of Action

Budesonide has glucocorticosteroid (GCS) activity.

12.2 Pharmacodynamics

Treatment with glucocorticosteroids, including budesonide rectal foam, is associated with a suppression of endogenous cortisol concentrations and an impairment of the hypothalamic-pituitary-adrenal (HPA) axis function. These effects were measured by determination of plasma cortisol concentrations and responses to adrenocorticotropin challenge (i.e., ACTH stimulation test) in 2 placebo-controlled, 6-week trials in patients with active disease [see Clinical Studies (14)]. These trials enrolled subjects with post-ACTH stimulation cortisol levels of >18 mcg/dL at baseline. Subjects received budesonide rectal foam 2 mg or a placebo twice daily for 2 weeks followed by once daily for 4 weeks. Normal morning serum cortisol levels >5 mcg/dL were maintained in 85% and 84% of budesonide rectal foam treated subjects during Weeks 1 and 2 (twice daily treatment) and 93% and 94% during Weeks 4 and 6 (once daily treatment), respectively (see Table 3).

At baseline (predose), 84% of subjects in the budesonide rectal foam group had a normal response to the ACTH challenge and at Week 6, 63% of subjects had a normal response to the ACTH challenge; in the placebo group, these values were 86% and 76%, respectively (see Table 3). ACTH stimulation test was not performed routinely during the twice daily treatment period (Weeks 1 and 2).

Table 3: Proportion of Subjects with Normal Endogenous Cortisol Levels (>5 mcg/dL) During the Study and Proportion of Subjects with Normal Response to ACTH Challenge

aThe normal response to ACTH challenge included 3 criteria, as defined in the cosyntropin label: 1) morning cortisol level >5 mcg/dL; 2) increase in cortisol level by ≥7 mcg/dL above the morning (pre-challenge) level following ACTH challenge; and cortisol level of >18 mcg/dL following ACTH challenge.

bDenominator includes 20 subjects in the budesonide rectal foam arm and 2 subjects in the placebo arm who discontinued prior to Week 6 due to adverse events related to low cortisol or abnormal response to ACTH challenge.

12.3 Pharmacokinetics

Absorption

Distal Ulcerative Colitis Patients

Based on population pharmacokinetic analysis from sparse PK samples from phase 3 studies, the estimated AUC0-12 following administration of budesonide rectal foam 2 mg twice a day was 4.31 ng*hr/mL with a CV of 64% in the target patient population.

Distribution

The volume of distribution (VSS) of budesonide varies between 2.2 and 3.9 L/kg in healthy subjects and in patients. Plasma protein binding is estimated to be 85 to 90% in the concentration range of 1 to 230 nmol/L, independent of gender. The erythrocyte/plasma partition ratio at clinically relevant concentrations is approximately 0.8.

Elimination

Metabolism

Following absorption, budesonide is subject to first-pass metabolism. In vitro experiments in human liver microsomes demonstrate that budesonide is rapidly and extensively biotransformed, mainly by CYP3A4, to its 2 major metabolites, 6β-hydroxy budesonide and 16α-hydroxy prednisolone. The glucocorticoid activity of these metabolites is negligible (<1/100) in relation to that of the parent compound.

In vivo investigations with intravenous doses in healthy subjects demonstrate that budesonide has a plasma clearance of 0.9-1.8 L/min. These plasma clearance values approach the estimated liver blood flow, suggesting that budesonide is a high hepatic clearance drug.

Excretion

Budesonide is excreted in urine and feces in the form of metabolites. After oral as well as intravenous administration of micronized [3H]-budesonide, approximately 60% of the recovered radioactivity is found in urine. The major metabolites, including 6β-hydroxybudesonide and 16α-hydroxyprednisolone, are mainly renally excreted, intact or in conjugated forms. No unchanged budesonide is detected in urine.

Specific Populations

Patients with Renal Impairment

The pharmacokinetics of budesonide in patients with renal impairment has not been studied. Intact budesonide is not renally excreted, but metabolites are to a large extent, and might therefore reach higher levels in patients with impaired renal function. However, these metabolites have negligible corticosteroid activity as compared with budesonide.

Patients with Hepatic Impairment

The effect of hepatic impairment on the pharmacokinetics of budesonide rectal foam has not been studied. In a study in patients with mild to moderate hepatic impairment (Child-Pugh Class A and Child-Pugh Class B) dosed with budesonide 4 mg oral capsules, systemic exposure was similar between patients with mild hepatic impairment (Child-Pugh Class A; n=4) and healthy subjects (n=8), and 3.5-fold higher in patients with moderate hepatic impairment (Child-Pugh Class B; n=4) than in healthy subjects. For the intravenous dose, no significant differences in CL or VSS are observed. Patients with severe liver dysfunction (Child-Pugh Class C) were not studied [see Use in Specific Populations (8.6)].

Drug Interaction Studies

Budesonide is metabolized via CYP3A4. Potent inhibitors of CYP3A4 can increase the plasma concentrations of budesonide. Co-administration of ketoconazole (inhibitor of CYP3A4) results in an 8-fold increase in AUC of oral budesonide, compared to budesonide alone. Grapefruit juice, an inhibitor of gut mucosal CYP3A, approximately doubles the systemic exposure of oral budesonide. Conversely, induction of CYP3A4 can result in the lowering of budesonide plasma concentrations. The effect of CYP3A4 inhibitors and inducers on the pharmacokinetics of budesonide rectal foam have not been studied [see Dosage and Administration (2) and Drug Interactions (7)].

Oral contraceptives containing ethinyl estradiol, which are also metabolized by CYP3A4, do not affect the pharmacokinetics of oral budesonide. Budesonide does not affect the plasma concentrations of oral contraceptives (i.e., ethinyl estradiol).

In vitro interaction studies performed with budesonide showed that budesonide did not inhibit human cytochrome P450 isoenzymes CYP1A2, CYP2B6, CYP2C9, CYP2D6, or CYP2E1 at concentrations ranging from 0.11 to 1130 ng/mL. Isoenzyme CYP3A4 was inhibited at the highest concentration tested but the IC50 was >1130 ng/mL. Budesonide rectal foam is not expected to inhibit these enzymes in clinical use. No significant induction of CYP1A2, CYP2B6, CYP2C9 or CYP3A4/5 expression was observed in human hepatocytes in vitro at budesonide concentrations up to 9000 nM (3.88 mcg/mL).

In an in vitro study, budesonide was not a substrate of human transporters OATP1B3 and may be a weak substrate of OATP1B1. Budesonide at concentrations up to 300 nM (129 ng/mL) did not inhibit OATP1B1 or OATP1B3.

Budesonide was not a substrate of BCRP and was a weak substrate of P-glycoprotein. Budesonide was a weak inhibitor of P-glycoprotein (IC50 9.78 μM or 4.21 mcg/mL) and BCRP (IC50 43.1 μM or 18.6 mcg/mL). Budesonide rectal foam is not expected to inhibit these transporters in clinical use.

13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility

Carcinogenicity

Carcinogenicity studies with budesonide were conducted in rats and mice. In a 2-year study in Sprague-Dawley rats, budesonide caused a statistically significant increase in the incidence of gliomas in male rats at an oral dose of 50 mcg/kg (approximately 0.12 times the recommended intrarectal dose of 4 mg/day in humans, based on the body surface area). In addition, there were increased incidences of primary hepatocellular tumors in male rats at 25 mcg/kg (approximately 0.06 times the recommended intrarectal dose of 4 mg/day in humans, based on the body surface area) and above. No tumorigenicity was seen in female rats at oral doses up to 50 mcg/kg (approximately 0.12 times the recommended intrarectal dose of 4 mg/day in humans, based on the body surface area).

In an additional 2-year study in male Sprague-Dawley rats, budesonide caused no gliomas at an oral dose of 50 mcg/kg (approximately 0.12 times the recommended intrarectal dose of 4 mg/day in humans, based on the body surface area). However, it caused a statistically significant increase in the incidence of hepatocellular tumors at an oral dose of 50 mcg/kg (approximately 0.12 times the recommended intrarectal dose of 4 mg/day in humans, based on the body surface area). The concurrent reference glucocorticosteroids (prednisolone and triamcinolone acetonide) showed similar findings. In a 91-week study in mice, budesonide caused no treatment-related carcinogenicity at oral doses up to 200 mcg/kg (approximately 0.24 times the recommended intrarectal dose of 4 mg/day in humans, based on the body surface area).

Mutagenesis

Budesonide showed no evidence of mutagenic potential in the Ames test, the mouse lymphoma cell forward gene mutation (TK+/-) test, the human lymphocyte chromosome aberration test, the Drosophila melanogaster sex-linked recessive lethality test, the rat hepatocyte UDS test or the mouse micronucleus test.

Impairment of Fertility

In rats, budesonide had no effect on fertility at subcutaneous doses up to 80 mcg/kg (approximately 0.20 times recommended intrarectal dose of 4 mg/day in humans, based on the body surface area). However, it caused a decrease in prenatal viability and viability in pups at birth and during lactation, along with a decrease in maternal body-weight gain, at subcutaneous doses of 20 mcg/kg (approximately 0.05 times recommended intrarectal dose of 4 mg/day in humans, based on the body surface area) and above. No such effects were noted at 5 mcg/kg.