A Study to Evaluate the Pharmacokinetics, Safety, and Efficacy of Glecaprevir/Pibrentasvir in Pediatric Subjects With Genotypes 1-6 Chronic Hepatitis C Virus (HCV) Infection

The area under the plasma concentration-time curve (AUC) is a method of measurement of the total exposure of a drug in blood plasma. The steady-state exposure of GLE was measured up to 24 hours after dosing at Week 2 and estimated using non-compartmental analysis.

The area under the plasma concentration-time curve (AUC) is a method of measurement of the total exposure of a drug in blood plasma. The steady-state exposure of PIB was measured up to 24 hours after dosing at Week 2 and estimated using non-compartmental analysis.

SVR12 is defined as hepatitis C virus ribonucleic acid (HCV RNA) less than the lower limit of quantification (LLOQ; 15 IU/mL) 12 weeks after the last actual dose of study drug. Plasma HCV RNA levels were collected using the COBAS AmpliPrep/COBAS TaqMan HCV Quantitative Test v2.0.

SVR12 was considered a primary efficacy endpoint by the United States (US) regulatory agency and was considered secondary outside of the US.

Cmax is the peak concentration that a drug or drug metabolite achieves in a specified compartment after the drug has been administered and before administration of a second dose.

CL/F is a quantitative measure of the rate at which a drug substance is removed from the body. It was estimated by non-compartmental pharmacokinetic analysis.

Cmax is the peak concentration that a drug or drug metabolite achieves in a specified compartment after the drug has been administered and before administration of a second dose.

CL/F is a quantitative measure of the rate at which a drug substance is removed from the body. It was estimated by non-compartmental pharmacokinetic analysis.

On-treatment virologic failure is defined as meeting one of the following:

• A confirmed (defined as two consecutive HCV RNA measurements) increase of > 1 log₁₀ IU/mL above nadir during treatment;
• Confirmed HCV RNA ≥ 100 IU/mL after HCV RNA < 15 IU/mL during treatment;
• HCV RNA ≥ 15 IU/mL at the end of treatment with at least 6 weeks of treatment.

Post-treatment relapse is defined as confirmed HCV RNA ≥ 15 IU/mL between the end of treatment and 12 weeks after the last dose of study drug among participants who completed treatment as planned with HCV RNA < 15 IU/mL at the end of treatment; excluding participants who had been shown to be re-infected.

Reinfection is defined as confirmed HCV RNA ≥ 15 IU/mL in the post-treatment period in a participant who had HCV RNA < 15 IU/mL at the Final Treatment Visit, along with post-treatment detection of a different HCV genotype, subtype, or clade compared with Baseline, as determined by phylogenetic analysis of the nonstructural viral protein 3 (NS3) or NS5A, and/or NS5B gene sequences.

For each participant who received the pediatric formulation (Cohorts 2 - 4), the parent(s)/guardian(s) completed a Palatability Questionnaire to provide feedback on the perception of the dosage form. The Palatability Questionnaire included 6 questions related to the administration and ingestion of the pediatric GLE + PIB formulation.

Question 1 "How Convenient or Inconvenient Was it to Prepare the Dose?" was answered as "very convenient", "convenient", "borderline", "inconvenient", or "very inconvenient".

For each participant who received the pediatric formulation (Cohorts 2 - 4), the parent(s)/guardian(s) completed a Palatability Questionnaire to provide feedback on the perception of the dosage form. The Palatability Questionnaire included 6 questions related to the administration and ingestion of the pediatric GLE + PIB formulation.

Question 2 "How Long Did it Typically Take for the Child to Take the Dose?" was answered as "5 minutes or less", "5 to 15 minutes", "15 to 30 minutes", or "more than 30 minutes".

For each participant who received the pediatric formulation (Cohorts 2 - 4), the parent(s)/guardian(s) completed a Palatability Questionnaire to provide feedback on the perception of the dosage form. The Palatability Questionnaire included 6 questions related to the administration and ingestion of the pediatric GLE + PIB formulation.

Question 3 "Were You Able to Successfully Administer the Whole Dose to the Child With 1 to 2 Teaspoons (5 to 10 mL) of Soft Food?" was answered as "Yes" or "No".

For each participant who received the pediatric formulation (Cohorts 2 - 4), the parent(s)/guardian(s) completed a Palatability Questionnaire to provide feedback on the perception of the dosage form. The Palatability Questionnaire included 6 questions related to the administration and ingestion of the pediatric GLE + PIB formulation. Question 4 "Did You Experience Any Resistance When Feeding the Child the Medicine?" was answered as "Yes" or "No".

For each participant who received the pediatric formulation (Cohorts 2 - 4), the parent(s)/guardian(s) completed a Palatability Questionnaire to provide feedback on the perception of the dosage form. The Palatability Questionnaire included 6 questions related to the administration and ingestion of the pediatric GLE + PIB formulation. Question 4a "Type of feeding resistance?" tracks feeding resistance experienced at any time during treatment, and was answered as "Did not like taste of medicine", "Did not like texture of medicine", "Did not like the soft food used", "Did not like to swallow the amount of medicine", or "Unrelated to the medicine".

For each participant who received the pediatric formulation (Cohorts 2 - 4), the parent(s)/guardian(s) completed a Palatability Questionnaire to provide feedback on the perception of the dosage form. The Palatability Questionnaire included 6 questions related to the administration and ingestion of the pediatric GLE/PIB formulation. Question 5 "How Easy or Difficult Was it for the Child to Swallow the Medicine?" was answered as "very easy", "easy", "borderline", "difficult", or "very difficult."