Limitations of Use
The efficacy and safety of ORKAMBI have not been established in patients with CF other than those homozygous for the F508del mutation.
Substrates of CYP3A
Lumacaftor is a strong inducer of CYP3A. Administration of ORKAMBI may decrease systemic exposure of medicinal products that are substrates of CYP3A, which may decrease therapeutic effect. Co-administration with sensitive CYP3A substrates or CYP3A substrates with a narrow therapeutic index is not recommended.
ORKAMBI may substantially decrease hormonal contraceptive exposure, reducing their effectiveness and increasing the incidence of menstruation-associated adverse reactions, e.g., amenorrhea, dysmenorrhea, menorrhagia, menstrual irregular (27% in women using hormonal contraceptives compared with 3% in women not using hormonal contraceptives). Hormonal contraceptives, including oral, injectable, transdermal, and implantable, should not be relied upon as an effective method of contraception when co-administered with ORKAMBI [see Adverse Reactions (6.1), Drug Interactions (7.3, 7.11), and Clinical Pharmacology (12.3)].
Strong CYP3A Inducers
Ivacaftor is a substrate of CYP3A4 and CYP3A5 isoenzymes. Use of ORKAMBI with strong CYP3A inducers, such as rifampin, significantly reduces ivacaftor exposure, which may reduce the therapeutic effectiveness of ORKAMBI. Therefore, co-administration with strong CYP3A inducers (e.g., rifampin, St. John's wort [Hypericum perforatum]) is not recommended [see Drug Interactions (7.2) and Clinical Pharmacology (12.3)].
Description of Selected Adverse Drug Reactions
Liver-related Adverse Reactions
In Trials 1 and 2, the incidence of maximum transaminase (ALT or AST) levels >8, >5, and >3 × ULN elevations was similar between patients treated with ORKAMBI and those who received placebo. Three patients who received ORKAMBI had liver-related serious adverse reactions, including 2 reported as transaminase elevations and 1 as hepatic encephalopathy, compared to none in the placebo group. Of these three, one had elevated transaminases (>3 × ULN) associated with bilirubin elevation >2 × ULN. Following discontinuation or interruption of ORKAMBI, transaminases decreased to <3 × ULN.
Among 6 patients with pre-existing cirrhosis and/or portal hypertension who received ORKAMBI, worsening liver function with increased ALT, AST, bilirubin, and hepatic encephalopathy was observed in one patient. The event occurred within 5 days of the start of dosing and resolved following discontinuation of ORKAMBI [see Warnings and Precautions (5.1, 5.2)].
During the 24-week, open-label Phase 3 clinical trial in 58 patients aged 6 through 11 years (Trial 3), the incidence of maximum transaminase (ALT or AST) levels >8, >5, and >3 × ULN was 5%, 9%, and 19%. No patients had total bilirubin levels > 2 × ULN. Lumacaftor/ivacaftor dosing was maintained or successfully resumed after interruption in all patients with transaminase elevations, except 1 patient who discontinued treatment permanently.
During the 24 week, placebo-controlled Phase 3 clinical trial in 204 patients aged 6 through 11 years (Trial 4), the incidence of maximum transaminase (ALT or AST) levels >8, >5, and >3 × ULN was 1%, 5%, and 13% in the lumacaftor/ivacaftor patients, and 2%, 3%, and 8% in the placebo treated patients. No patients had total bilirubin levels > 2 × ULN. Two patients in the lumacaftor/ivacaftor group and two patients in the placebo group discontinued treatment permanently due to transaminase elevations.
Respiratory Adverse Reactions
In Trials 1 and 2, the incidence of respiratory symptom-related adverse reactions (e.g., chest discomfort, dyspnea, and respiration abnormal) was more common in patients treated with ORKAMBI (22%) compared to patients who received placebo (14%). The incidence of these adverse reactions was more common in patients treated with ORKAMBI with lower pre-treatment FEV1. In patients treated with ORKAMBI, the majority of the events began during the first week of treatment [see Warnings and Precautions (5.3)].
During a 24-week, open label, Phase 3b clinical trial in 46 patients aged 12 years and older (Trial 5) with advanced lung disease (ppFEV1 <40) [mean ppFEV1 29.1 at baseline (range: 18.3 to 42.0)], the incidence of respiratory symptom-related adverse reactions was 65%. [see Warnings and Precautions (5.3)].
During the 24-week, open-label Phase 3 clinical trial (Trial 3) in 58 patients aged 6 through 11 years (mean baseline ppFEV1 was 91.4), the incidence of respiratory symptom-related adverse reactions was 3% (2/58).
During the 24 week, placebo-controlled Phase 3 clinical trial (Trial 4) in patients aged 6 through 11 years (mean ppFEV1 89.8 at baseline [range: 48.6 to 119.6]), the incidence of respiratory symptom-related adverse reactions was 11% in lumacaftor/ivacaftor patients and 9% in placebo patients1. A decline in ppFEV1 at initiation of therapy was observed during serial post dose spirometry assessments. The absolute change from pre-dose at 4-6 hours post-dose was -7.7 on Day 1 and -1.3 on Day 15 in lumacaftor/ivacaftor patients. The post-dose decline was resolved by Week 16.
Menstrual Abnormalities
In Trials 1 and 2, the incidence of combined menstrual abnormality adverse reactions (e.g., amenorrhea, dysmenorrhea, menorrhagia, menstrual irregular) was more common in female patients treated with ORKAMBI (10%) compared to placebo (2%). These events occurred more frequently in the subset of female patients treated with ORKAMBI who were using hormonal contraceptives (27%) compared to those not using hormonal contraceptives (3%) [see Warnings and Precautions (5.5) and Drug Interactions (7.11)].
Increased Blood Pressure
In Trials 1 and 2, adverse reactions related to increases in blood pressure (e.g., hypertension, blood pressure increased) were reported in 1.1% (4/369) of patients treated with ORKAMBI and in no patients who received placebo.
The proportion of patients who experienced a systolic blood pressure value >140 mmHg or a diastolic blood pressure >90 mmHg on at least two occasions was 3.6% and 2.2% in patients treated with ORKAMBI, respectively, compared with 1.6% and 0.5% in patients who received placebo [see Warnings and Precautions (5.4)].
Potential for Other Drugs to Affect Lumacaftor/Ivacaftor
Potential for Lumacaftor/Ivacaftor to Affect Other Drugs
Risk Summary
There are limited and incomplete human data from clinical trials and post-marketing reports on use of ORKAMBI or its individual components, lumacaftor or ivacaftor, in pregnant women to inform a drug-associated risk. In animal reproduction studies, oral administration of lumacaftor to pregnant rats and rabbits during organogenesis demonstrated no teratogenicity or adverse effects on fetal development at doses that produced maternal exposures up to approximately 8 (rats) and 5 (rabbits) times the exposure at the maximum recommended human dose (MRHD). Oral administration of ivacaftor to pregnant rats and rabbits during organogenesis demonstrated no teratogenicity or adverse effects on fetal development at doses that produced maternal exposures up to approximately 7 (rats) and 45 (rabbits) times the exposure at the MRHD. No adverse developmental effects were observed after oral administration of either lumacaftor or ivacaftor to pregnant rats from organogenesis through lactation at doses that produced maternal exposures approximately 8 and 5 times the exposures at the MRHD, respectively (see Data). There are no animal reproduction studies with concomitant administration of lumacaftor and ivacaftor.
The background risk of major birth defects and miscarriage for the indicated population is unknown. 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.
Data
Lumacaftor
In an embryo-fetal development study in pregnant rats dosed during the period of organogenesis from gestation days 7-17, lumacaftor was not teratogenic and did not affect fetal development or survival at exposures up to 8 times the MRHD (on an AUC basis at maternal oral doses up to 2000 mg/kg/day). In an embryo-fetal development study in pregnant rabbits dosed during the period of organogenesis from gestation days 7-19, lumacaftor was not teratogenic and did not affect fetal development or survival at exposures up to 5 times the MRHD (on an AUC basis at maternal oral doses up to 200 mg/kg/day). In a pre- and postnatal development study in pregnant female rats dosed from gestation day 6 through lactation day 20, lumacaftor had no effects on delivery or growth and development of offspring at exposures up to 8 times the MRHD (on an AUC basis at maternal oral doses up to 1000 mg/kg/day). Placental transfer of lumacaftor was observed in pregnant rats and rabbits.
Ivacaftor
In an embryo-fetal development study in pregnant rats dosed during the period of organogenesis from gestation days 7-17, ivacaftor was not teratogenic and did not affect fetal survival at exposures up to 7 times the MRHD (based on summed AUCs for ivacaftor and its metabolites at maternal oral doses up to 200 mg/kg/day). In an embryo-fetal development study in pregnant rabbits dosed during the period of organogenesis from gestation days 7-19, ivacaftor was not teratogenic and did not affect fetal development or survival at exposures up to 45 times the MRHD (on an ivacaftor AUC basis at maternal oral doses up to 100 mg/kg/day). In a pre- and postnatal development study in pregnant female rats dosed from gestation day 7 through lactation day 20, ivacaftor had no effects on delivery or growth and development of offspring at exposures up to 5 times the MRHD (based on summed AUCs for ivacaftor and its metabolites at maternal oral doses up to 100 mg/kg/day). Decreased fetal body weights were observed at a maternally toxic dose that produced exposures 7 times the MRHD (based on summed AUCs for ivacaftor and its metabolites at a maternal oral dose of 200 mg/kg/day). Placental transfer of ivacaftor was observed in pregnant rats and rabbits.
Risk Summary
There is no information regarding the presence of lumacaftor or ivacaftor in human milk, the effects on the breastfed infant, or the effects on milk production. Both lumacaftor and ivacaftor are excreted into the milk of lactating rats; however, due to species-specific differences in lactation physiology, animal lactation data may not reliably predict levels in human milk (see Data). The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for ORKAMBI and any potential adverse effects on the breastfed child from ORKAMBI or from the underlying maternal condition.
Data
Lumacaftor
Lacteal excretion of lumacaftor in rats was demonstrated following a single oral dose (100 mg/kg) of 14C-lumacaftor administered 9 to 11 days postpartum to lactating mothers (dams). Exposure (AUC0-24h) values for lumacaftor in milk were approximately 40% of plasma levels.
Ivacaftor
Lacteal excretion of ivacaftor in rats was demonstrated following a single oral dose (100 mg/kg) of 14C-ivacaftor administered 9 to 10 days postpartum to lactating mothers (dams). Exposure (AUC0-24h) values for ivacaftor in milk were approximately 1.5 times higher than plasma levels.
Juvenile Animal Toxicity Data
In a juvenile toxicology study in which ivacaftor was administered to rats from postnatal days 7 to 35, cataracts were observed at all dose levels, ranging from 0.3 to 2 times the MRHD (based on summed AUCs for ivacaftor and its metabolites at oral doses of 10-50 mg/kg/day). This finding has not been observed in older animals.
Sweat Chloride Evaluation
Changes in sweat chloride in response to relevant doses of lumacaftor alone or in combination with ivacaftor were evaluated in a double-blind, placebo-controlled, Phase 2 clinical trial in patients with CF 18 years of age and older either homozygous or heterozygous for the F508del mutation. In that trial, 10 patients (homozygous for F508del) completed dosing with lumacaftor alone 400 mg q12h for 28 days followed by the addition of ivacaftor 250 mg q12h for an additional 28 days and 25 patients (homozygous or heterozygous for F508del) completed dosing with placebo. The treatment difference between lumacaftor 400 mg q12h alone and placebo evaluated as mean change in sweat chloride from baseline to Day 28 compared to placebo was -8.2 mmol/L (95% CI -14, -2). The treatment difference between the combination of lumacaftor 400 mg/ivacaftor 250 mg q12h and placebo evaluated as mean change in sweat chloride from baseline to Day 56 compared to placebo was -11 mmol/L (95% CI -18, -4).
Changes in sweat chloride in response to lumacaftor/ivacaftor were also evaluated in a 24-week, open-label Phase 3 clinical trial (Trial 3) in 58 patients with CF, aged 6 through 11 years (homozygous for F508del) who received lumacaftor 200 mg/ivacaftor 250 mg q12h for 24 weeks. Patients treated with lumacaftor/ivacaftor had a reduction in sweat chloride at Day 15 that was sustained through Week 24. The within-group LS mean absolute change from baseline in sweat chloride was -20.4 mmol/L at Day 15 and -24.8 mmol/L at Week 24. In addition, sweat chloride was also assessed after a 2-week washout period to evaluate the off-drug response. The within-group LS mean absolute change in sweat chloride from Week 24 at Week 26 following the 2-week washout period was 21.3 mmol/L.
There was no direct correlation between decrease in sweat chloride levels and improvement in lung function (ppFEV1).
Cardiac Electrophysiology
The effect of multiple doses of lumacaftor 600 mg once daily/ivacaftor 250 mg q12h and lumacaftor 1000 mg once daily/ivacaftor 450 mg q12h on QTc interval was evaluated in a randomized, placebo- and active-controlled (400 mg moxifloxacin), parallel, thorough QT study in 168 healthy subjects. No meaningful changes in QTc interval were observed with either lumacaftor 600 mg once daily/ivacaftor 250 mg q12h and lumacaftor 1000 mg once daily/ivacaftor 450 mg q12h dose groups. A maximum decrease in mean heart rate of up to 8 beats per minute (bpm) from baseline was observed with lumacaftor/ivacaftor treatment. In Trials 1 and 2, a similar decrease in heart rate was observed in patients during initiation of ORKAMBI (lumacaftor 400 mg/ivacaftor 250 mg q12h).
Absorption
When a single dose of lumacaftor/ivacaftor was administered with fat-containing foods, lumacaftor exposure was approximately 2 times higher and ivacaftor exposure was approximately 3 times higher than when taken in a fasting state.
Following multiple oral dose administration of lumacaftor in combination with ivacaftor, the exposure of lumacaftor generally increased proportional to dose over the range of 200 mg every 24 hours to 400 mg every 12 hours. The median (range) tmax of lumacaftor is approximately 4.0 hours (2.0; 9.0) in the fed state.
Following multiple oral dose administration of ivacaftor in combination with lumacaftor, the exposure of ivacaftor generally increased with dose from 150 mg every 12 hours to 250 mg every 12 hours. The median (range) tmax of ivacaftor is approximately 4.0 hours (2.0; 6.0) in the fed state.
Distribution
Lumacaftor is approximately 99% bound to plasma proteins, primarily to albumin. After oral administration of 200 mg every 24 hours for 28 days to patients with CF in a fed state, the mean (±SD) for apparent volumes of distribution was 86.0 (69.8) L.
Ivacaftor is approximately 99% bound to plasma proteins, primarily to alpha 1-acid glycoprotein and albumin.
Elimination
The half-life of lumacaftor is approximately 26 hours in patients with CF. The typical apparent clearance, CL/F (CV), of lumacaftor was estimated to be 2.38 L/hr (29.4%) for patients with CF. The half-life of ivacaftor when given with lumacaftor is approximately 9 hours in healthy subjects. The typical CL/F (CV) of ivacaftor when given in combination with lumacaftor was estimated to be 25.1 L/hr (40.5%) for patients with CF.
Metabolism
Lumacaftor is not extensively metabolized in humans with the majority of lumacaftor excreted unchanged in the feces. In vitro and in vivo data indicate that lumacaftor is mainly metabolized via oxidation and glucuronidation.
Ivacaftor is extensively metabolized in humans. In vitro and in vivo data indicate that ivacaftor is primarily metabolized by CYP3A. M1 and M6 are the two major metabolites of ivacaftor in humans.
Excretion
Following oral administration of lumacaftor, the majority of lumacaftor (51%) is excreted unchanged in the feces. There was minimal elimination of lumacaftor and its metabolites in urine (only 8.6% of total radioactivity was recovered in the urine with 0.18% as unchanged parent).
Following oral administration of ivacaftor alone, the majority of ivacaftor (87.8%) is eliminated in the feces after metabolic conversion. There was minimal elimination of ivacaftor and its metabolites in urine (only 6.6% of total radioactivity was recovered in the urine).
Specific Populations
Age: Pediatric Population
The following conclusions about exposures between adults and the pediatric population are based on population pharmacokinetics (PK) analyses:
Pediatric patients 6 through 11 years of age
Following oral administration of ORKAMBI tablets, lumacaftor 200 mg/ivacaftor 250 mg every 12 hours, the mean lumacaftor (±SD) AUCss was 203 (57.4) µg/mL*h and is comparable to the mean AUCss in patients 12 years and older administered ORKAMBI tablets, lumacaftor 400 mg/ivacaftor 250 mg every 12 hours. The mean ivacaftor (±SD) AUCss was 5.26 (3.08) µg/mL*h and is comparable to the mean AUCss in patients 12 years and older administered ORKAMBI tablets, lumacaftor 400 mg/ivacaftor 250 mg every 12 hours [see Use in Specific Populations (8.4)].
Pediatric patients 12 to less than 18 years of age
Following oral administration of ORKAMBI tablets, lumacaftor 400 mg/ivacaftor 250 mg every 12 hours, the mean lumacaftor (±SD) AUCss was 241 (61.4) µg/mL*h and is comparable to the mean AUCss in adult patients administered ORKAMBI tablets, lumacaftor 400 mg/ivacaftor 250 mg every 12 hours. The mean ivacaftor (±SD) AUCss was 3.90 (1.56) µg/mL*h and is comparable to the mean AUCss in adult patients administered ORKAMBI tablets, lumacaftor 400 mg/ivacaftor 250 mg every 12 hours [see Use in Specific Populations (8.4)].
Sex
The pharmacokinetics of ORKAMBI was evaluated using a population PK analysis of data from clinical studies of lumacaftor given in combination with ivacaftor. Results indicate no clinically relevant difference in pharmacokinetic parameters for lumacaftor and ivacaftor between males and females.
Renal Impairment
Pharmacokinetic studies have not been performed with ORKAMBI in patients with renal impairment [see Use in Specific Populations (8.7)].
Hepatic Impairment
Following multiple doses of lumacaftor/ivacaftor for 10 days, subjects with moderately impaired hepatic function (Child-Pugh Class B, score 7 to 9) had approximately 50% higher exposures (AUC0-12h) and approximately 30% higher Cmax for both lumacaftor and ivacaftor compared with healthy subjects matched for demographics. Pharmacokinetic studies have not been conducted in patients with mild (Child-Pugh Class A, score 5 to 6) or severe hepatic impairment (Child-Pugh Class C, score 10 to 15) receiving ORKAMBI [see Dosage and Administration (2.2), Warnings and Precautions (5.1), Adverse Reactions (6), and Use in Specific Populations (8.6)].
Drug Interaction Studies
Drug interaction studies were performed with lumacaftor/ivacaftor and other drugs likely to be co-administered or drugs commonly used as probes for pharmacokinetic interaction studies [see Drug Interactions (7)].
Potential for Lumacaftor/Ivacaftor to Affect Other Drugs
Lumacaftor is a strong inducer of CYP3A. Co-administration of lumacaftor with ivacaftor, a sensitive CYP3A substrate, decreased ivacaftor exposure by 80%. Ivacaftor is a weak inhibitor of CYP3A when given as monotherapy. The net effect of lumacaftor/ivacaftor therapy is strong CYP3A induction [see Drug Interactions (7.3)].
Based on in vitro results which showed P-gp inhibition and PXR activation, lumacaftor has the potential to both inhibit and induce P-gp. A clinical study with ivacaftor monotherapy showed that ivacaftor is a weak inhibitor of P-gp. Therefore, concomitant use of ORKAMBI with P-gp substrates may alter the exposure of these substrates [see Drug Interactions (7.5)].
In vitro studies suggest that lumacaftor has the potential to induce CYP2B6, CYP2C8, CYP2C9, and CYP2C19; inhibition of CYP2C8 and CYP2C9 has also been observed in vitro. In vitro studies suggest that ivacaftor may inhibit CYP2C9. Therefore, concomitant use of ORKAMBI with CYP2B6, CYP2C8, CYP2C9, and CYP2C19 substrates may alter the exposure of these substrates [see Drug Interactions (7.4)].
Potential for Other Drugs to Affect Lumacaftor/Ivacaftor
Lumacaftor exposure is not affected by concomitant CYP3A inducers or inhibitors. Exposure of ivacaftor when given in combination with lumacaftor is reduced by concomitant CYP3A inducers and increased by concomitant CYP3A inhibitors [see Dosage and Administration (2.3), Warnings and Precautions (5.5), and Drug Interactions (7)].
The effects of co-administered drugs on the exposure of lumacaftor and ivacaftor are shown in Table 4 [see Dosage and Administration (2.3), Warnings and Precautions (5.5), and Drug Interactions (7)].
Table 4: Impact of Other Drugs on Lumacaftor 200 mg q12h/Ivacaftor 250 mg q12h| Co-administered Drug | Dose of Co-administered Drug | Effect on PK ↑ = increase, ↓ = decrease, ↔ = no change. | Mean Ratio (90% CI) of Lumacaftor and Ivacaftor No Effect=1.0 |
|---|
| AUC | Cmax |
|---|
| CI = Confidence interval; PK = Pharmacokinetics |
CYP3A inhibitor: itraconazole | 200 mg once daily | ↔ Lumacaftor | 0.97 (0.91, 1.02) | 0.99 (0.92, 1.05) |
| ↑ Ivacaftor | 4.30 The net exposure of ivacaftor is not expected to exceed that when given in the absence of lumacaftor at a dose of 150 mg every 12 hours, the approved dose of ivacaftor monotherapy. (3.78, 4.88) | 3.64 (3.19, 4.17) |
CYP3A inducer: rifampin | 600 mg once daily | ↔ Lumacaftor | 0.87 (0.81, 0.93) | 0.96 (0.87, 1.05) |
| ↓ Ivacaftor | 0.43 (0.38, 0.49) | 0.50 (0.43, 0.58) |
Other: ciprofloxacin | 750 mg q12h | ↔ Lumacaftor | 0.86 (0.79, 0.95) | 0.88 (0.80, 0.97) |
| ↔ Ivacaftor | 1.29 (1.12, 1.48) | 1.29 (1.11, 1.49) |
Lumacaftor
A two-year study in Sprague-Dawley rats and a 26-week study in transgenic Tg.rasH2 mice were conducted to assess carcinogenic potential of lumacaftor. No evidence of tumorigenicity was observed in rats at lumacaftor oral doses up to 1000 mg/kg/day (approximately 5 and 13 times the MRHD on a lumacaftor AUC basis in males and females, respectively). No evidence of tumorigenicity was observed in Tg.rasH2 mice at lumacaftor oral doses up to 1500 and 2000 mg/kg/day in female and male mice, respectively. Lumacaftor was negative for genotoxicity in the following assays: Ames test for bacterial gene mutation, in vitro chromosomal aberration assay in Chinese hamster ovary cells, and in vivo mouse micronucleus test.
Lumacaftor had no effects on fertility and reproductive performance indices in male and female rats at an oral dose of 1000 mg/kg/day (approximately 3 and 8 times, respectively, the MRHD on a lumacaftor AUC basis).
Ivacaftor
Two-year studies were conducted in mice and rats to assess carcinogenic potential of ivacaftor. No evidence of tumorigenicity was observed in mice and rats at ivacaftor oral doses up to 200 mg/kg/day and 50 mg/kg/day, respectively (approximately equivalent to 3 and 10 times the MRHD based on summed AUCs of ivacaftor and its metabolites).
Ivacaftor was negative for genotoxicity in the following assays: Ames test for bacterial gene mutation, in vitro chromosomal aberration assay in Chinese hamster ovary cells, and in vivo mouse micronucleus test.
Ivacaftor impaired fertility and reproductive performance indices in male and female rats at an oral dose of 200 mg/kg/day (approximately 15 and 7 times the MRHD based on summed AUCs of ivacaftor and its metabolites). Increases in prolonged diestrus were observed in females at 200 mg/kg/day. Ivacaftor also increased the number of females with all nonviable embryos and decreased corpora lutea, implantations, and viable embryos in rats at 200 mg/kg/day (approximately 7 times the MRHD based on summed AUCs of ivacaftor and its metabolites) when dams were dosed prior to and during early pregnancy. These impairments of fertility and reproductive performance in male and female rats at 200 mg/kg/day were attributed to severe toxicity. No effects on male or female fertility and reproductive performance indices were observed at an oral dose of ≤100 mg/kg/day (approximately 8 and 5 times the MRHD based on summed AUCs of ivacaftor and its metabolites).
Dose Ranging
Dose ranging for the clinical program consisted primarily of one double-blind, placebo-controlled, multiple-cohort trial which included 97 Caucasian patients with CF (homozygous for the F508del mutation) 18 years of age and older with a screening ppFEV1 ≥40. In the trial, 76 patients (homozygous for the F508del mutation) were randomized to receive lumacaftor alone at once-daily doses of 200 mg, 400 mg, or 600 mg or 400 mg q12h for 28 days followed by the addition of ivacaftor 250 mg q12h and 27 patients (homozygous or heterozygous for the F508del mutation) received placebo. During the initial 28-day lumacaftor monotherapy period, treatment with lumacaftor demonstrated a dose-dependent decrease in ppFEV1 compared to placebo. Changes from Day 1 at Day 28 in ppFEV1 compared to placebo were 0.24, -1.4, -2.7, and -4.6 for the 200 mg once daily, 400 mg once daily, 600 mg once daily, and 400 mg q12h lumacaftor doses, respectively. Following the addition of ivacaftor 250 mg q12h, the changes from Day 1 at Day 56 in ppFEV1 compared to placebo were 3.8, 2.7, 5.6, and 4.2, respectively.
Sweat chloride was also assessed in this trial. Following the initial 28 days of lumacaftor monotherapy, the changes from Day 1 at Day 28 in sweat chloride compared to placebo were -4.9, -8.3, -6.1, and -8.2 mmol/L for the 200 mg once daily, 400 mg once daily, 600 mg once daily, and 400 mg q12h lumacaftor doses, respectively. Following the addition of ivacaftor 250 mg q12h, the changes from Day 1 at Day 56 in sweat chloride compared to placebo were -5.0, -9.8, -9.5, and -11 mmol/L, respectively.
These data supported the evaluation of lumacaftor 400 mg/ivacaftor 250 mg q12h (ORKAMBI) and lumacaftor 600 mg once daily/ivacaftor 250 mg q12h in the confirmatory trials.
Confirmatory
The efficacy of ORKAMBI in patients with CF who are homozygous for the F508del mutation in the CFTR gene was evaluated in two randomized, double-blind, placebo-controlled, 24-week clinical trials (Trials 1 and 2) in 1108 clinically stable patients with CF of whom 369 patients received ORKAMBI twice daily.
Trial 1 evaluated 549 patients with CF who were aged 12 years and older (mean age 25.1 years) with ppFEV1 at screening between 40-90 [mean ppFEV1 60.7 at baseline (range: 31.1 to 94.0)]. Trial 2 evaluated 559 patients aged 12 years and older (mean age 25.0 years) with ppFEV1 at screening between 40-90 [mean ppFEV1 60.5 at baseline (range: 31.3 to 99.8)]. Patients with a history of colonization with organisms such as Burkholderia cenocepacia, Burkholderia dolosa, or Mycobacterium abscessus, or who had 3 or more abnormal liver function tests (ALT, AST, AP, GGT ≥3 × the ULN or total bilirubin ≥2 × the ULN) were excluded.
Patients in both trials were randomized 1:1:1 to receive either ORKAMBI (lumacaftor 400 mg q12h/ivacaftor 250 mg q12h; or lumacaftor 600 mg once daily/ivacaftor 250 mg q12h) or placebo. Patients took the study drug with fat-containing food for 24 weeks in addition to their prescribed CF therapies (e.g., bronchodilators, inhaled antibiotics, dornase alfa, and hypertonic saline).
The primary efficacy endpoint in both trials was change in lung function as determined by absolute change from baseline in ppFEV1 at Week 24, assessed as the average of the treatment effects at Week 16 and at Week 24. In both trials, treatment with ORKAMBI resulted in a statistically significant improvement in ppFEV1. The treatment difference between ORKAMBI and placebo for the mean absolute change in ppFEV1 from baseline at Week 24 (assessed as the average of the treatment effects at Week 16 and at Week 24) was 2.6 percentage points [95% CI (1.2, 4.0)] in Trial 1 (P=0.0003) and 3.0 percentage points [95% CI (1.6, 4.4)] in Trial 2 (P<0.0001). These changes persisted throughout the 24-week treatment period (Figure 1). Improvements in ppFEV1 were observed regardless of age, disease severity, sex, and geographic region.
| Figure 1. Absolute Change From Baseline at Each Visit in Percent Predicted FEV1 in Trial 1 and Trial 2. |
| |
| LS = least squares; q12h = every 12 hours | |
Key secondary efficacy variables included relative change from baseline in ppFEV1 at Week 24, assessed as the average of the treatment effects at Week 16 and at Week 24; absolute change from baseline in BMI at Week 24; absolute change from baseline in Cystic Fibrosis Questionnaire-Revised (CFQ-R) Respiratory Domain score at Week 24, a measure of respiratory symptoms relevant to patients with CF such as cough, sputum production, and difficulty breathing; proportion of patients achieving ≥5% relative change from baseline in ppFEV1 using the average of Week 16 and Week 24; and number of pulmonary exacerbations through Week 24. For the purposes of these trials, a pulmonary exacerbation was defined as a change in antibiotic therapy (IV, inhaled, or oral) as a result of 4 or more of 12 pre-specified sino-pulmonary signs/symptoms.
Table 5: Summary of Other Efficacy Endpoints in Trials 1 and 2In each trial, a hierarchical testing procedure was performed within each active treatment arm for primary and secondary endpoints vs. placebo; at each step, P≤0.0250 and all previous tests also meeting this level of significance was required for statistical significance.
| Trial 1 | Trial 2 |
|---|
Placebo (n=184) | ORKAMBI LUM 400 mg q12h/IVA 250 mg q12h (n=182) | Placebo (n=187) | ORKAMBI LUM 400 mg q12h/IVA 250 mg q12h (n=187) |
|---|
| Relative change in ppFEV1 at Week 24 Assessed as the average of the treatment effects at Week 16 and Week 24. (%) | Treatment difference (95% CI) | – | 4.3 (1.9, 6.8) P=0.0006Indicates statistical significance confirmed in the hierarchical testing procedure. Other efficacy measures considered not statistically significant. | – | 5.3 (2.7, 7.8) P<0.0001 |
| Absolute change in BMI at Week 24 (kg/m2) | Treatment difference (95% CI) | – | 0.1 (-0.1, 0.3) | – | 0.4 (0.2, 0.5) P=0.0001 |
| Absolute change in CFQ-R Respiratory Domain Score (Points) at Week 24 | Treatment difference (95% CI) | – | 1.5 (-1.7, 4.7) | – | 2.9 (-0.3, 6.0) |
| Proportion of patients with ≥5% relative change in ppFEV1 at Week 24 | % | 22% | 37% | 23% | 41% |
Odds ratio (95% CI) | – | 2.1 (1.3, 3.3) | – | 2.4 (1.5, 3.7) |
| Number of pulmonary exacerbations through Week 24 | # of events (rate per 48 weeks) | 112 (1.1) | 73 (0.7) | 139 (1.2) | 79 (0.7) |
Rate ratio (95% CI) | – | 0.7 (0.5, 0.9) | – | 0.6 (0.4, 0.8) |
Advanced Liver Disease
Inform patients that worsening of liver function, including hepatic encephalopathy, in patients with advanced liver disease occurred in some patients treated with ORKAMBI. Liver function decompensation, including liver failure leading to death, has been reported in CF patients with pre-existing cirrhosis with portal hypertension while receiving ORKAMBI. If ORKAMBI is used in these patients, they should be closely monitored after the initiation of treatment and the dose should be reduced [see Dosage and Administration (2.2) and Warnings and Precautions (5.1)].
Abnormalities in Liver Function and Testing
Inform patients that abnormalities in liver function have occurred in patients treated with ORKAMBI. Blood tests to measure transaminases (ALT and AST) and bilirubin will be performed prior to initiating ORKAMBI, every 3 months during the first year of therapy, and annually thereafter [see Warnings and Precautions (5.2)].
Respiratory Events
Inform patients that chest discomfort, dyspnea, and respiration abnormal were more common during initiation of ORKAMBI therapy, especially in patients with advanced lung disease. Additional monitoring of patients with ppFEV1 <40 is recommended during initiation of therapy [see Warnings and Precautions (5.3)].
Effect on Blood Pressure
Inform patients that increased blood pressure has been observed in some patients treated with ORKAMBI and that periodic monitoring of their blood pressure during treatment is recommended [see Warnings and Precautions (5.4)].
Drug Interactions with CYP3A Inhibitors and Inducers
Ask patients to tell you all the medications they are taking, including any herbal supplements or vitamins. Co–administration with sensitive CYP3A substrates or CYP3A substrates with a narrow therapeutic index is not recommended [see Warnings and Precautions (5.5), Drug Interactions (7), and Clinical Pharmacology (12.3)].
Instruct patients on alternative methods of birth control because hormonal contraceptives should not be relied upon as an effective method of contraception and there is an increased incidence of menstruation-related adverse reactions when co-administered with ORKAMBI [see Warnings and Precautions (5.5), Adverse Reactions (6.1), and Drug Interactions (7.11)].
When initiating ORKAMBI in patients taking strong CYP3A inhibitors (e.g., itraconazole), instruct the patient to reduce the dose of ORKAMBI to 1 tablet daily for the first week of treatment. Following this period, continue with the recommended daily dose [see Dosage and Administration (2.3), Drug Interactions (7.1), and Clinical Pharmacology (12.3)].
Patients should be instructed to tell their doctor if they stop ORKAMBI for more than 1 week while they are also taking a strong CYP3A inhibitor because the dose of ORKAMBI would need to be reduced upon re-initiation. The dose of ORKAMBI should be reduced to 1 tablet daily for the first week upon treatment re-initiation. Following this period, continue with the recommended daily dose [see Dosage and Administration (2.3), Drug Interactions (7.1), and Clinical Pharmacology (12.3)].
Use in Patients with Hepatic Impairment
Inform patients with moderate hepatic impairment (Child-Pugh Class B) to reduce the dose of ORKAMBI to 2 tablets in the morning and 1 tablet in the evening.
If initiating ORKAMBI in a patient with severe hepatic impairment, after weighing the risks and benefits of treatment, instruct the patient to take a maximum dose of 1 tablet every 12 hours, or less [see Dosage and Administration (2.2), Warnings and Precautions (5.1), Adverse Reactions (6.1), and Clinical Pharmacology (12.3)].
Administration
Inform patients that ORKAMBI is best absorbed by the body when taken with fat-containing food. A typical CF diet will satisfy this requirement. Examples of fat-containing foods include eggs, avocados, nuts, butter, peanut butter, cheese pizza, whole-milk dairy products (such as whole milk, cheese, and yogurt), etc. [see Dosage and Administration (2.1) and Clinical Pharmacology (12.3)].
Inform patients that if a dose is missed and they remember the missed dose within 6 hours, the patients should take the dose with fat-containing food. If more than 6 hours elapsed after the usual dosing time, the patients should skip that dose and resume the normal schedule for the following dose. Patients should be informed not to take a double dose to make up for the forgotten dose [see Dosage and Administration (2.1)].
Cataracts
Inform patients that abnormalities of the eye lens (cataract) have been noted in some children and adolescents receiving ORKAMBI and ivacaftor, a component of ORKAMBI. Baseline and follow-up ophthalmological examinations are recommended in pediatric patients initiating ORKAMBI treatment [see Warnings and Precautions (5.6)].
Manufactured for
Vertex Pharmaceuticals Incorporated
Boston, MA 02210
ORKAMBI, the ORKAMBI logo, VERTEX, and the VERTEX triangle logo are registered trademarks of Vertex Pharmaceuticals Incorporated.
All other trademarks referenced herein are the property of their respective owners.
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104508-03