Tobramycin

TOBI Podhaler is indicated for the management of cystic fibrosis patients with Pseudomonas aeruginosa . Safety and efficacy have not been demonstrated in patients under the age of 6 years, patients with forced expiratory volume in 1 second (FEV 1 ) <25% or >80% predicted, or patients colonized with Burkholderia cepacia [see Clinical Studies (14) ] . TOBI Podhaler is an aminoglycoside antibacterial indicated for the management of cystic fibrosis patients with Pseudomonas aeruginosa . Safety and efficacy have not been demonstrated in patients under the age of 6 years, patients with forced expiratory volume in 1 second (FEV 1 ) <25% or >80%, or patients colonized with Burkholderia cepacia ( 1 )

Inhalation powder: 28 mg: clear, colorless hypromellose capsule with “MYL TPH” in blue radial imprint on one part of the capsule and the Mylan logo in blue radial imprint on the other part of the capsule. Inhalation powder: 28 mg in a capsule ( 3 )

TOBI Podhaler is contraindicated in patients with a known hypersensitivity to any aminoglycoside. Known hypersensitivity to any aminoglycoside ( 4 )

• Caution should be exercised when prescribing TOBI Podhaler to patients with known or suspected auditory, vestibular, renal, or neuromuscular dysfunction ( 5.2 , 5.3 , 5.4 )
• Ototoxicity, as measured by complaints of hearing loss or tinnitus, was reported in clinical trials ( 5.2 )
• Aminoglycosides may aggravate muscle weakness because of a potential curare-like effect on neuromuscular function ( 5.6 )
• Bronchospasm can occur with inhalation of TOBI Podhaler ( 5.1 )
• Audiograms, serum concentrations, and renal function should be monitored as appropriate ( 5.3 , 5.5 , 5.6 )
• Embryo-Fetal Toxicity: Aminoglycosides can cause fetal harm Apprise women of the potential hazard to the fetus ( 5.6 , 8.1 )

5.1 Bronchospasm Bronchospasm has been reported with inhalation of TOBI Podhaler [see Adverse Reactions (6.1) ] . Bronchospasm should be treated as medically appropriate.

5.2 Ototoxicity Ototoxicity with use of TOBI Podhaler Caution should be exercised when prescribing TOBI Podhaler to patients with known or suspected auditory or vestibular dysfunction. Ototoxicity, as measured by complaints of hearing loss or tinnitus, was reported by patients in the TOBI Podhaler clinical studies [see Adverse Reactions (6.1) ] . Tinnitus may be a sentinel symptom of ototoxicity, and therefore the onset of this symptom warrants caution. Ototoxicity, manifested as both auditory (hearing loss) and vestibular toxicity, has been reported with parenteral aminoglycosides. Vestibular toxicity may be manifested by vertigo, ataxia or dizziness. Risk of Ototoxicity Due to Mitochondrial DNA Variants Cases of ototoxicity with aminoglycosides have been observed in patients with certain variants in the mitochondrially encoded 12S rRNA gene (MT-RNR1) , particularly the m.1555A>G variant. Ototoxicity occurred in some patients even when their aminoglycoside serum levels were within the recommended range. Mitochondrial DNA variants are present in less than 1% of the general US population, and the proportion of the variant carriers who may develop ototoxicity as well as the severity of ototoxicity is unknown. In case of known maternal history of ototoxicity due to aminoglycoside use or a known mitochondrial DNA variant in the patient, consider alternative treatments other than aminoglycosides unless the increased risk of permanent hearing loss is outweighed by the severity of infection and lack of safe and effective alternative therapies.

5.3 Nephrotoxicity Caution should be exercised when prescribing TOBI Podhaler to patients with known or suspected renal dysfunction. Nephrotoxicity was not observed during TOBI Podhaler clinical studies but has been associated with aminoglycosides as a class.

5.4 Neuromuscular Disorders Caution should be exercised when prescribing TOBI Podhaler to patients with known or suspected neuromuscular dysfunction. TOBI Podhaler should be used cautiously in patients with neuromuscular disorders, such as myasthenia gravis or Parkinson’s disease, since aminoglycosides may aggravate muscle weakness because of a potential curare-like effect on neuromuscular function.

5.5 Embryo-Fetal Toxicity Aminoglycosides can cause fetal harm when administered to a pregnant woman. Aminoglycosides cross the placenta, and streptomycin has been associated with several reports of total, irreversible, bilateral congenital deafness in pediatric patients exposed in utero. However, systemic absorption of tobramycin following inhaled administration is expected to be minimal [see Clinical Pharmacology (12.3) ] . Patients who use TOBI Podhaler during pregnancy, or become pregnant while taking TOBI Podhaler should be apprised of the potential hazard to the fetus [see Use in Specific Populations (8.1) ] .

5.6 Concomitant Use of Systemic Aminoglycosides Patients receiving concomitant TOBI and parenteral aminoglycoside therapy should be monitored as clinically appropriate for toxicities associated with aminoglycosides as a class. Serum tobramycin levels should be monitored.

The most common adverse reactions (≥10 % of TOBI Podhaler and TOBI patients in primary safety population) are cough, lung disorder, productive cough, dyspnea, pyrexia, oropharyngeal pain, dysphonia, hemoptysis, and headache ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Viatris at 1-877-446-3679 (1-877-4-INFO-RX) 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. TOBI Podhaler has been evaluated for safety in 425 cystic fibrosis patients exposed to at least one dose of TOBI Podhaler, including 273 patients who were exposed across three cycles (6 months) of treatment. Each cycle consisted of 28 days on-treatment (with 112 mg administered twice-daily) and 28 days off-treatment. Patients with serum creatinine ≥2 mg/dL and blood urea nitrogen (BUN) ≥40 mg/dL were excluded from clinical studies. There were 218 males and 207 females in this population, and reflecting the cystic fibrosis population in the U.S., the vast majority of patients were Caucasian. There were 221 patients ≥20 years old, 121 patients ≥13 to <20 years old, and 83 patients ≥6 to <13 years old. There were 239 patients with screening FEV 1 % predicted ≥50%, 156 patients with screening FEV 1 % predicted <50%, and 30 patients with missing FEV 1 % predicted. The primary safety population reflects patients from Study 1, an open-label study comparing TOBI Podhaler with TOBI (tobramycin inhalation solution, USP) over three cycles of 4 weeks on treatment followed by 4 weeks off treatment. Randomization, in a planned 3:2 ratio, resulted in 308 patients treated with TOBI Podhaler and 209 patients treated with TOBI. For both the TOBI Podhaler and TOBI groups, mean exposure to medication for each cycle was 28 to 29 days. The mean age for both arms was between 25 and 26 years old. The mean baseline FEV 1 % predicted for both arms was 53%. Table 1 displays adverse drug reactions reported by at least 2% of TOBI Podhaler patients in Study 1, inclusive of all cycles (on and off treatment). Adverse drug reactions are listed according to MedDRA system organ class and sorted within system organ class group in descending order of frequency. Table 1: Adverse Reactions Reported in Study 1 (Occurring in ≥2% of TOBI Podhaler Patients) Primary System Organ Class Preferred Term TOBI Podhaler N=308 % TOBI N=209 % Respiratory, thoracic, and mediastinal disorders Cough 48.4

31.1 Lung disorder This includes adverse events of pulmonary or cystic fibrosis exacerbations 33.8

30.1 Productive cough 18.2

19.6 Dyspnea 15.6

12.4 Oropharyngeal pain 14.0

10.5 Dysphonia 13.6

3.8 Hemoptysis 13.0

12.4 Nasal congestion 8.1

7.2 Rales 7.1

6.2 Wheezing 6.8

6.2 Chest discomfort 6.5

2.9 Throat irritation 4.5

1.9 Gastrointestinal disorders Nausea 7.5

9.6 Vomiting 6.2

5.7 Diarrhea 4.2

1.9 Dysgeusia 3.9

0.5 Infections and infestations Upper respiratory tract infection 6.8

8.6 Investigations Pulmonary function test decreased 6.8

8.1 Forced expiratory volume decreased 3.9

1.0 Blood glucose increased 2.9

0.5 Vascular disorders Epistaxis 2.6

1.9 Nervous system disorders Headache 11.4

12.0 General disorders and administration site conditions Pyrexia 15.6

12.4 Musculoskeletal and connective tissue disorders Musculoskeletal chest pain 4.5

4.8 Skin and subcutaneous tissue disorders Rash 2.3

2.4 Adverse drug reactions that occurred in <2% of patients treated with TOBI Podhaler in Study 1 were: bronchospasm (TOBI Podhaler 1.6%, TOBI 0.5%); deafness including deafness unilateral (reported as mild to moderate hearing loss or increased hearing loss) (TOBI Podhaler 1.0%, TOBI 0.5%); and tinnitus (TOBI Podhaler 1.9%, TOBI 2.4%). Discontinuations in Study 1 were higher in the TOBI Podhaler arm compared to TOBI (27% TOBI Podhaler versus 18% TOBI). This was driven primarily by discontinuations due to adverse events (14% TOBI Podhaler versus 8% TOBI). Higher rates of discontinuation were seen in subjects ≥20 years old and those with baseline FEV 1 % predicted <50%. Respiratory related hospitalizations occurred in 24% of the patients in the TOBI Podhaler arm and 22% of the patients in the TOBI arm. There was an increased new usage of antipseudomonal medication in the TOBI Podhaler arm (65% TOBI Podhaler versus 55% TOBI). This included oral antibiotics in 55% of TOBI Podhaler patients and 40% of TOBI patients and intravenous antibiotics in 35% of TOBI Podhaler patients and 33% of TOBI patients. Median time to first antipseudomonal usage was 89 days in the TOBI Podhaler arm and 112 days in the TOBI arm. The supportive safety population reflects patients from two studies: Study 2, a double-blind, placebo-controlled design for the first treatment cycle, followed by all patients receiving TOBI Podhaler (replaced placebo) for two additional cycles, and Study 3, a double-blind, placebo-controlled trial for one treatment cycle only. Placebo in these studies was inhaled powder without the active ingredient, tobramycin. The patient population for these studies was much younger than in Study 1 (mean age 13 years old). Adverse drug reactions reported more frequently by TOBI Podhaler patients in the placebo-controlled cycle (Cycle 1) of Study 2, which included 46 TOBI Podhaler and 49 placebo patients, were: Respiratory, thoracic, and mediastinal disorders Pharyngolaryngeal pain (TOBI Podhaler 10.9%, placebo 0%); dysphonia (TOBI Podhaler 4.3%, placebo 0%) Gastrointestinal disorders Dysgeusia (TOBI Podhaler 6.5%, placebo 2.0%) Adverse drug reactions reported more frequently by TOBI Podhaler patients in Study 3, which included 30 TOBI Podhaler and 32 placebo patients, were: Respiratory, thoracic, and mediastinal disorders Cough (TOBI Podhaler 10%, placebo 0%) Ear and labyrinth disorders Hypoacusis (TOBI Podhaler 10%, placebo 6.3%) Audiometric Assessment In Study 1, audiology testing was performed in a subset of approximately 25% of TOBI Podhaler (n=78) and TOBI (n=45) patients. Using the criteria for either ear of ≥10 dB loss at two consecutive frequencies, ≥20 dB loss at any frequency, or loss of response at three consecutive frequencies where responses were previously obtained, five TOBI Podhaler patients and three TOBI patients were judged to have ototoxicity, a ratio similar to the planned 3:2 randomization for this study. Audiology testing was also performed in a subset of patients in both Study 2 (n=13 from the TOBI Podhaler group and n=9 from the placebo group) and Study 3 (n=14 from the TOBI Podhaler group and n=11 from the placebo group). In Study 2, no patients reported hearing complaints but two TOBI Podhaler patients met the criteria for ototoxicity. In Study 3, three TOBI Podhaler and two placebo patients had reports of ‘hypoacusis.’ One TOBI Podhaler and two placebo patients met the criteria for ototoxicity. In some patients, ototoxicity was transient or may have been related to a conductive defect. Cough Cough is a common symptom in cystic fibrosis, reported in 42% of the patients in Study 1 at baseline. Cough was the most frequently reported adverse event in Study 1 and was more common in the TOBI Podhaler arm (48% TOBI Podhaler versus 31 % TOBI). There was a higher rate of cough adverse event reporting during the first week of active treatment with TOBI Podhaler (i.e., the first week of Cycle 1). The time to first cough event in the TOBI Podhaler and TOBI groups were similar thereafter. In some patients, cough resulted in discontinuation of TOBI Podhaler treatment. Sixteen patients (5%) receiving treatment with TOBI Podhaler discontinued study treatment due to cough events compared with 2 (1%) in the TOBI treatment group. […]

No clinical drug interaction studies have been performed with TOBI Podhaler. In clinical studies, patients receiving TOBI Podhaler continued to take dornase alfa, bronchodilators, inhaled corticosteroids, and macrolides. No clinical signs of drug interactions with these medicines were identified. Concurrent and/or sequential use of TOBI Podhaler with other drugs with neurotoxic, nephrotoxic, or ototoxic potential should be avoided. Some diuretics can enhance aminoglycoside toxicity by altering antibiotic concentrations in serum and tissue. TOBI Podhaler should not be administered concomitantly with ethacrynic acid, furosemide, urea, or intravenous mannitol. The interaction between inhaled mannitol and TOBI Podhaler has not been evaluated. Concurrent and/or sequential use of TOBI Podhaler with other drugs with neurotoxic, nephrotoxic, or ototoxic potential should be avoided ( 7 )

8.1 Pregnancy Risk Summary Aminoglycosides can cause fetal harm. Published literature reports that use of streptomycin, an aminoglycoside, can cause total, irreversible, bilateral congenital deafness when administered to a pregnant woman [ Warnings and Precautions (5.5) ] . Although there are no available data on TOBI Podhaler use in pregnant women to inform a drug-associated risk of major birth defects, miscarriage or adverse maternal or fetal outcomes, systemic absorption of tobramycin following inhaled administration is expected to be minimal [see Clinical Pharmacology (12.3) ] . There are risks to the mother associated with cystic fibrosis in pregnancy (see Clinical Considerations ) . In animal reproduction studies with subcutaneous administration of tobramycin in pregnant rats and rabbits during organogenesis there were no adverse developmental outcomes; however, ototoxicity was not evaluated in the offspring from these studies (see Data ) . Advise pregnant women of the potential risk to a fetus. The estimated background risk of major birth defects and miscarriage for the indicated populations are 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 Cystic fibrosis may increase the risk for preterm delivery. Data Animal Data No reproduction toxicology studies have been conducted with TOBI Podhaler. However, subcutaneous administration of tobramycin at doses of up to 100 (rat) or 20 (rabbit) mg/kg/day during organogenesis was not associated with adverse developmental outcomes. Doses of tobramycin ≥40 mg/kg/day were severely maternally toxic to rabbits and precluded the evaluation of adverse developmental outcomes. Ototoxicity was not evaluated in offspring during non-clinical reproductive toxicity studies with tobramycin.

8.2 Lactation Risk Summary There are no data on the presence of tobramycin following administration of TOBI Podhaler in either human or animal milk, the effects on the breastfed infant, or the effects on milk production. Limited published data on other formulations of tobramycin in lactating women indicate that tobramycin is present in human milk. However, systemic absorption of tobramycin following inhaled administration is expected to be minimal [see Clinical Pharmacology (12.3) ] . Tobramycin may cause alteration in the intestinal flora of the breastfeeding infant (see Clinical Considerations ) . The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for TOBI Podhaler and any potential adverse effects on the breastfed infant from TOBI Podhaler or from the underlying maternal condition. Clinical Considerations Tobramycin may cause intestinal flora alteration. Advise a woman to monitor the breastfed infant for loose or bloody stools and candidiasis (thrush, diaper rash).

8.4 Pediatric Use Patients 6 years and older were included in the Phase 3 studies with TOBI Podhaler; 206 patients below 20 years of age received TOBI Podhaler. No dosage adjustments are needed based on age. The overall pattern of adverse events in pediatric patients was similar to the adults. Dysgeusia (taste disturbance) was more commonly reported in younger patients six to 19 years of age than in patients 20 years and older, 7.4% versus 2.7%, respectively. Safety and effectiveness in pediatric patients below the age of 6 years have not been established.

8.5 Geriatric Use Clinical studies of TOBI Podhaler did not include sufficient numbers of subjects aged 65 years and over to determine whether they respond differently from younger subjects. Tobramycin is known to be substantially excreted by the kidney, and the risk of adverse reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, it may be useful to monitor renal function [see Warnings and Precautions (5.2 , 5.5) ].

8.6 Renal Impairment Tobramycin is primarily excreted unchanged in the urine and renal function is expected to affect the exposure to tobramycin. The risk of adverse reactions to this drug may be greater in patients with impaired renal function. Patients with serum creatinine ≥2 mg/dL and blood urea nitrogen (BUN) ≥40 mg/dL have not been included in clinical studies and there are no data in this population to support a recommendation regarding dose adjustment with TOBI Podhaler [see Warnings and Precautions (5.2 , 5.5) ] .

8.7 Hepatic Impairment No studies have been performed in patients with hepatic impairment. As tobramycin is not metabolized, an effect of hepatic impairment on the exposure to tobramycin is not expected.

8.8 Organ Transplantation Adequate data do not exist for the use of TOBI Podhaler in patients after organ transplantation.

Tobramycin is an aminoglycoside antibacterial [see Clinical Pharmacology (12.4) ] .

Mechanism of Action Tobramycin is an aminoglycoside antibacterial produced by Streptomyces tenebrarius . It acts primarily by disrupting protein synthesis leading to altered cell membrane permeability, progressive disruption of the cell envelope, and eventual cell death. Tobramycin has in vitro activity against Gram-negative bacteria including P. aeruginosa . It is bactericidal in vitro at peak concentrations equal to or slightly greater than the minimum inhibitory concentration (MIC).