Long-term studies were conducted in mice and rats with admixture of pirfenidone to the diet to evaluate its carcinogenic potential.
In a 24-month carcinogenicity study in B6C3F1 mice, pirfenidone caused statistically significant dose-related increases of the combination of hepatocellular adenoma and carcinoma and hepatoblastoma in male mice at doses of 800 mg/kg and above (AUC exposure approximately 0.4 times adult exposure at the MRDD). There were statistically significant dose-related increases of the combination of hepatocellular adenoma and carcinoma in female mice at doses of 2,000 mg/kg and above (AUC exposure approximately 0.7 times adult exposure at the MRDD).
In a 24-month carcinogenicity study in Fischer rats, pirfenidone caused statistically significant dose-related increases of the combination of hepatocellular adenoma and carcinoma in male rats at doses of 750 mg/kg and above (AUC exposure approximately 1.9 times adult exposure at the MRDD). There were statistically significant increases of the combination of hepatocellular adenoma and carcinoma and the combination of uterine adenocarcinoma and adenoma at a dose of 1,500 mg/kg/day (AUC exposure approximately 3.0 times adult exposure at the MRDD).
The relevance of these tumor findings in rodents to humans is unknown.
Pirfenidone was not mutagenic or clastogenic in the following tests: mutagenicity tests in bacteria, a chromosomal aberration test in Chinese hamster lung cells, and a micronucleus test in mice.
Impairment of Fertility
Pirfenidone had no effects on fertility and reproductive performance in rats at dosages up to 1,000 mg/kg/day (approximately 3 times the MRDD in adults on a mg/m2 basis).
The efficacy of pirfenidone was evaluated in patients with IPF in three phase 3, randomized, double-blind, placebo-controlled, multicenter trials (Studies 1, 2, and 3).
Study 1 was a 52-week trial comparing pirfenidone 2,403 mg/day (n=278) versus placebo (n=277) in patients with IPF. Study 2 and Study 3 were nearly identical to each other in design, with few exceptions, including an intermediate dose treatment arm in Study 2. Study 2 compared treatment with either pirfenidone 2,403 mg/day (n=174) or pirfenidone 1,197 mg/day (n=87) to placebo (n=174), while Study 3 compared pirfenidone
2,403 mg/day (n=171) to placebo (n=173). Study drug was administered three times daily with food for a minimum of 72 weeks. Patients continued on treatment until the last patient completed 72 weeks of treatment, which included observations to approximately 120 weeks of study treatment. The primary endpoint was the change in percent predicted forced vital capacity (%FVC) from baseline to study end, measured at 52 weeks in Study 1, and at 72 weeks in Studies 2 and 3.
Studies 1, 2 and 3 enrolled adult patients who had a clinical and radiographic diagnosis of IPF (with or without accompanying surgical lung biopsy), without evidence or suspicion of an alternative diagnosis for interstitial lung disease. Eligible patients were to have %FVC greater than or equal to 50% at baseline and a percent predicted diffusing capacity of the lungs for carbon monoxide (%DLCO ) greater than or equal to 30% (Study 1) or 35% (Studies 2 and 3) at baseline. In all three trials, over 80% of patients completed study treatment.
A total of 1,247 patients with IPF were randomized to receive pirfenidone 2,403 mg/day (n=623) or placebo (n=624) in these three trials. Baseline characteristics were generally balanced across treatment groups. The study population ranged from 40 to 80 years of age (mean age 67 years). Most patients were male (74%), white (95%), and current or former smokers (65%). Approximately 93% of patients met criteria for definite IPF on high resolution computed tomography (HRCT). Baseline mean %FVC and %DLCO were 72% and 46%, respectively. Approximately 15% subjects discontinued from each treatment group.
Change from Baseline in Percent Predicted Forced Vital Capacity
In Study 1, the primary efficacy analysis for the change in %FVC from baseline to Week 52 demonstrated a statistically significant treatment effect of pirfenidone 2,403 mg/day (n=278) compared with placebo (n=277) using a rank ANCOVA with the lowest rank imputation for missing data due to death. In Study 2, there was a statistically significant difference at Week 72 for the change in %FVC from baseline. In Study 3, there was no statistically significant difference at Week 72 for the change in %FVC from baseline.
Figure 1 presents the cumulative distribution for all cut-offs for the change from baseline in %FVC at Week 52 for Study 1. For all categorical declines in lung function, the proportion of patients declining was lower on pirfenidone than on placebo. Study 2 showed similar results.
Figure 1. Cumulative Distribution of Patients by Change in Percent Predicted FVC from Baseline to Week 52 (Study 1). The Dashed Lines Indicate ≥10% Decline or ≥0% Decline.
Mean Change from Baseline in FVC (mL)
In Study 1, a reduction in the mean decline in FVC (in mL) was observed in patients receiving pirfenidone 2,403 mg/day (-235 mL) compared to placebo (-428 mL) (mean treatment difference 193 mL) at Week 52 (see Figure 2). In Study 2, a reduction in the decline in FVC volume was also observed in patients receiving pirfenidone 2,403 mg/day compared with placebo (mean treatment difference 157 mL) at Week 72. There was no statistically significant difference in decline in FVC volume seen in Study 3.
Figure 2. Mean Change from Baseline in Forced Vital Capacity (Study 1)
Survival was evaluated for pirfenidone compared to placebo in Studies 1, 2, and 3 as an exploratory analysis to support the primary endpoint (FVC). All-cause mortality was assessed over the study duration and available follow-up period, irrespective of cause of death and whether patients continued treatment. All-cause mortality did not show a statistically significant difference (see Figure 3).
Figure 3. Kaplan-Meier Estimates of All-Cause Mortality at Vital Status – End of Study: Studies 1, 2, and 3
Pirfenidone tablets are supplied as follows:
267 mg — Each yellow, biconvex, oval shaped, film-coated tablet debossed with “3610” on one side and “TEVA” on the other side contains 267 mg of pirfenidone. Tablets are supplied in:
- Bottles of 270 (NDC 0480-3610-87)
801 mg — Each purple, biconvex, oval shaped, film-coated tablet debossed with “3611” on one side and “TEVA” on the other side contains 801 mg of pirfenidone. Tablets are supplied in:
- Bottles of 90 (NDC 0480-3611-98)
Store at 25°C (77°F); excursions permitted to 15° to 30°C (59° to 86°F) [see USP Controlled Room Temperature].
Keep the bottles tightly closed. Do not use if the seal over the bottle opening is broken or missing. Safely throw away any pirfenidone tablets that are out of date or no longer needed.
KEEP THIS AND ALL MEDICATIONS OUT OF THE REACH OF CHILDREN.
Advise the patient to read the FDA-approved patient labeling (Patient Information).
Liver Enzyme Elevations
Advise patients that they may be required to undergo liver function testing periodically. Instruct patients to immediately report any symptoms of a liver problem (e.g., skin or the white of eyes turn yellow, urine turns dark or brown [tea colored], pain on the right side of stomach, bleed or bruise more easily than normal, lethargy) [see Warnings and Precautions (5.1)].
Photosensitivity Reaction or Rash
Advise patients to avoid or minimize exposure to sunlight (including sunlamps) during use of pirfenidone tablets because of concern for photosensitivity reactions or rash. Instruct patients to use a sunblock and to wear clothing that protects against sun exposure. Instruct patients to report symptoms of photosensitivity reaction or rash to their physician. Temporary dosage reductions or discontinuations may be required [see Warnings and Precautions (5.2)].
Instruct patients to report symptoms of persistent gastrointestinal effects including nausea, diarrhea, dyspepsia, vomiting, gastro-esophageal reflux disease, and abdominal pain. Temporary dosage reductions or discontinuations may be required [see Warnings and Precautions (5.3)].
Encourage patients to stop smoking prior to treatment with pirfenidone tablets and to avoid smoking when using pirfenidone tablets [see Clinical Pharmacology (12.3)].
Take with Food
Instruct patients to take pirfenidone tablets with food to help decrease nausea and dizziness.
Manufactured In India By:
Watson Pharma Private Limited
Verna, Salcette Goa 403 722 INDIA
Parsippany, NJ 07054
Rev. A 2/2022
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