2.1 Required Testing and Evaluation Prior to Prescribing BRONCHITOL (BRONCHITOL Tolerance Test)

Prior to prescribing BRONCHITOL for treatment of cystic fibrosis, the BRONCHITOL Tolerance Test (BTT) must be administered and performed under the supervision of a healthcare practitioner who is able to manage acute bronchospasm, to identify patients who are suitable candidates for BRONCHITOL maintenance therapy.

• Perform BTT to identify patients who experience bronchospasm, a decrease in FEV1, or a decrease in oxygen saturation with administration of BRONCHITOL. If a patient experiences any of these events during the BTT, the patient has failed the BTT. Do not prescribe BRONCHITOL. If a patient does not experience any of these events during BTT, the patient has passed the BTT and is a candidate for BRONCHITOL therapy.
• Ensure that rescue medication and resuscitation equipment are available for immediate use during the BTT.
• Do not perform the BTT if the patient is considered clinically unstable.

See the BTT Healthcare Practitioner (HCP) Instructions for Use (IFU) for complete instructions and to avoid medication errors associated with BTT dosing and procedures.

Do not use BRONCHITOL add-on maintenance therapy in patients who fail the BTT [see Contraindications (4)].

2.2 Recommended Dosage for Treatment of Cystic Fibrosis

For patients who have passed the BTT, the recommended dosage of BRONCHITOL is 400 mg twice a day by oral inhalation (the contents of 10 capsules administered individually) via the inhaler [see Dosage and Administration (2.1)].

A short-acting bronchodilator should be administered by oral inhalation, 5-15 minutes before every dose of BRONCHITOL.

BRONCHITOL should be taken once in the morning and once in the evening, with the later dose taken at least 2-3 hours before bedtime.

2.3 Use and Maintenance of Inhaler

Instruct patients on safe hygiene practices (clean and dry hands thoroughly) and correct inhaler use, including loading of capsules and proper inhalation technique per the Patient Instructions for Use.

The BRONCHITOL inhaler should be discarded and replaced after 7 days of use. If the inhaler does need to be washed, the patient should allow the inhaler to thoroughly air dry before next use.

5.1 Bronchospasm

BRONCHITOL Tolerance Test

BRONCHITOL can cause bronchospasm, which can be severe in susceptible individuals. Because of the risk of bronchospasm, prior to prescribing BRONCHITOL, perform the BRONCHITOL Tolerance Test (BTT), to identify patients who are appropriate for maintenance treatment with BRONCHITOL. The BTT must be administered under the supervision of a healthcare practitioner who can treat severe bronchospasm. In clinical trials, 896 adult patients with cystic fibrosis underwent the BTT and 72 patients (8%) failed or did not complete the BTT. Do not prescribe BRONCHITOL if the patient fails the BTT.

Maintenance Therapy

Bronchospasm may occur during inhalation of BRONCHITOL, even in patients who have passed the BTT. An inhaled short-acting bronchodilator must be administered 5-15 minutes before administration of each dose during maintenance therapy. In clinical studies, bronchospasm or bronchial hyperreactivity was reported in 4 of 414 adult patients (1.0%) receiving BRONCHITOL as maintenance therapy and in 2 of 347 adult patients (0.6%) receiving control (50 mg inhaled mannitol), even though these patients had passed the BTT. If bronchospasm occurs following dosing of BRONCHITOL, it should immediately be discontinued and treated with an inhaled short-acting bronchodilator or as medically appropriate.

5.2 Hemoptysis

Hemoptysis may occur with BRONCHITOL use. Hemoptysis was reported in 43 (10.4%) adult patients receiving BRONCHITOL and in 33 (9.5%) adult patients receiving control (50 mg inhaled mannitol) during clinical studies. In patients aged 6 years to 17 years, hemoptysis was reported in 12 of 154 (7.8%) patients who received BRONCHITOL and in 2 of 105 (1.9%) patients who received control. BRONCHITOL has not been studied in patients with a history of episodes of significant hemoptysis (volume greater than 60 mL) in the previous 3 months. BRONCHITOL should be discontinued in the event of hemoptysis. BRONCHITOL is not indicated for use in children and adolescents.

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 overall safety profile for BRONCHITOL is based on data from 1,020 CF patients from three 26-week, randomized, double-blind, controlled trials (Trials 1, 2, and 3). While CF patients aged 6 to 17 years were included in two of the three trials, BRONCHITOL is not indicated for use in this age group [see Indications (1), Use in Specific Populations (8)]. The safety data described below are based on 761 adult patients who received at least one dose of study drug in the three trials.

Of the 761 adult patients, 45% of patients were female and 98% were Caucasian; 414 received BRONCHITOL and 347 received control (50 mg inhaled mannitol) for up to 26 weeks. Adult patients treated with BRONCHITOL were ages 18 to 59 years with a mean baseline FEV1 of 62.0% of predicted.

In these three trials, the proportion of adult patients who prematurely discontinued study drug due to adverse reactions was 12.3% for patients treated with BRONCHITOL and 8.6% for patients treated with control. Serious adverse reactions occurred in 18.8% of patients treated with BRONCHITOL and 18.4% of patients treated with control. Serious adverse reactions occurring with greater than 1% incidence and more frequently in BRONCHITOL-treated adult patients compared to control-treated patients were CF exacerbations (13.3% vs. 11.2%), hemoptysis (1.4% vs. 1.2%) and lower respiratory tract infection (1.2% vs 0.9%).

The incidence of Adverse Reactions in adults during the 26 week treatment period with BRONCHITOL across the three trials is shown in Table 1.

In Trials 1, 2, and 3, exacerbations of cystic fibrosis (reported as condition aggravated) occurred in 132 of 414 (32%) adult patients receiving BRONCHITOL and in 114 of 347 (33%) adult patients receiving control (50 mg inhaled mannitol). Exacerbations of cystic fibrosis reported as serious adverse reactions occurred in 55 of 414 adult patients (13%) receiving BRONCHITOL and in 39 of 347 adult patients (11%) receiving control. Within the U.S. adult subgroup (comprising 27% of adults enrolled), exacerbations of cystic fibrosis reported as serious adverse reactions occurred in 23 of 110 (21%) patients receiving BRONCHITOL and in 10 of 93 (11%) patients receiving control. Among the non-U.S. adult subgroup (comprising 73% of adults enrolled), exacerbations of cystic fibrosis reported as serious adverse reactions occurred in 11% of patients in each treatment arm.

8.1 Pregnancy

Risk Summary

There are no adequate and well-controlled studies of BRONCHITOL in pregnant women. The available data on BRONCHITOL use in pregnant women are not sufficient to inform any drug-associated risks for major birth defects and miscarriage. Based on animal reproduction studies, no evidence of structural alterations was observed when mannitol was administered to pregnant rats and mice during organogenesis at doses up to approximately 20 and 10 times, respectively, the maximum recommended daily inhalation dose (MRDID) in humans [see Data]. There are risks to the mother associated with cystic fibrosis in pregnancy [see Clinial Considerations]. BRONCHITOL should be used during pregnancy only if the potential benefit justifies the potential risk to the mother and fetus.

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 United States 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

Cystic fibrosis may increase the risk for preterm delivery.

Data

Animal Data

In animal reproduction studies, oral administration of mannitol to pregnant rats and mice during the period of organogenesis did not cause fetal structural alterations. The mannitol dose in rats and mice was approximately 20 and 10 times the maximum recommended human daily inhalation dose (MRDID) in humans, respectively, (on a mg/m2 basis at maternal doses of 1600 mg/kg/day in both species).

8.2 Lactation

Risk Summary

It is not known whether BRONCHITOL is excreted in human breast milk. The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for BRONCHITOL and any potential adverse effects on the breastfed child from BRONCHITOL or from the underlying maternal condition.

8.4 Pediatric Use

BRONCHITOL is not indicated for use in children and adolescents. The safety and effectivenss of BRONCHITOL have not been established in pediatric patients for cystic fibrosis. Patients aged 6 years to 17 years were included in two 26-week, double-blind clinical trials (Trials 2 and 3). In these trials, 154 patients under 18 years of age received BRONCHITOL and 105 patients received control (50 mg inhaled mannitol). Hemoptysis was reported in 12 of 154 (7.8%) patients who received BRONCHITOL and in 2 of 105 (1.9%) patients who received control.

8.5 Geriatric Use

Clinical trials of BRONCHITOL did not include sufficient numbers of patients with cystic fibrosis who were 65 years of age and older to allow evaluation of safety and efficacy in this population.

8.6 Hepatic and Renal Impairment

Clinical trials of BRONCHITOL did not include patients with hepatic or renal impairment. No specific dose recommendations for these patient populations are available. However, an increase in systemic exposure of mannitol can be expected in patients with renal impairment based on the kidney being its primary route of elimination.

12.1 Mechanism of Action

The precise mechanism of action of BRONCHITOL in improving pulmonary function in cystic fibrosis patients is unknown.

12.2 Pharmacodynamics

The pharmacodynamics of mannitol are unknown.

12.3 Pharmacokinetics

Absorption

Following oral inhalation of 635 mg, the mean mannitol peak plasma concentration (Cmax) was 13.71 mcg/mL while the mean extent of systemic exposure (AUC) was 73.15 mcg•hr/mL. The mean time to peak plasma concentration (Tmax) after oral inhalation was 1.5 hour.

Distribution

Based on intravenous administration, the volume of distribution of mannitol was 34.3 L.

Elimination

Metabolism

Mannitol is metabolized in a CYP-independent manner through the glycolytic pathway via dehydrogenation to fructose. The extent of metabolism of mannitol appears to be small. This is evident from a urinary excretion of about 87% of unchanged drug after an intravenous dose to healthy patients.

Excretion

Following oral inhalation, the elimination half-life of mannitol was 4.7 hours. The mean terminal elimination half-life for mannitol in plasma remained unchanged regardless of the route of administration (oral, inhalation, and intravenous). The urinary excretion rate versus time profile for mannitol was consistent for all routes of administration. The total clearance after intravenous administration was 5.1 L/hr while the renal clearance was 4.4 L/hr. Therefore, the clearance of mannitol was predominately via the kidney. Following inhalation of 635 mg of mannitol in 18 healthy patients, about 55% of the total dose was excreted in the urine as unchanged mannitol. Following oral or intravenous administration of a 500 mg dose, the corresponding values were 54% and 87% of the dose, respectively.

Specific Populations

Patients with Hepatic and Renal Impairment: Formal pharmacokinetic studies using BRONCHITOL have not been conducted in patients with hepatic or renal impairment. Since the drug is eliminated primarily via the kidney, an increase in systemic exposure can be expected in renally impaired patients.

Drug Interaction Studies

No formal drug interaction studies have been conducted with BRONCHITOL.

13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility

Carcinogenesis

In 2-year carcinogenicity studies in rats and mice mannitol did not show evidence of carcinogenicity at oral dietary concentrations up to 5% (or 7,500 mg/kg on a mg/kg basis). These doses were approximately 55 and 30 times the MRHDID, respectively, on a mg/m2 basis.

Mutagenesis

Mannitol tested negative in the following assays: bacterial gene mutation assay, in vitro mouse lymphoma assay, in vitro chromosomal aberration assay in WI-38 human cells, in vivo chromosomal aberration assay in rat bone marrow, in vivo dominant lethal assay in rats, and in vivo mouse micronucleus assay.

Impairment of Fertility

The effect of inhaled mannitol on fertility has not been investigated.