Pharmacokinetic Effects of QTI571 on Sildenafil and Bosentan in Pulmonary Arterial Hypertension Participants

Study Overview
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Brief Summary
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The purpose of this study was to investigate the effects of QTI571 (imatinib) on pharmacokinetics of bosentan and sildenafil at steady state when co-administered to participants with pulmonary arterial hypertension.

Official Title
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A Non-Randomized, Multiple Dose, Three Treatment Period, Open-Label, Single Sequence, Single Group Study to Evaluate the Pharmacokinetic Effect of Two Doses of QTI571 (Imatinib) on the Co-administered Drugs Sildenafil and Bosentan in Pulmonary Arterial Hypertension (PAH) Patients

Conditions
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Pulmonary Arterial Hypertension

Intervention / Treatment
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* Drug: Imatinib
* Drug: Sildenafil
* Drug: Bosentan


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Participants with Pulmonary arterial hypertension (PAH) in World Health Organization (WHO) Diagnostic Group 1, with pulmonary vascular resistance > 800 dyne*sec*cm^-5, On stable doses of bosentan and sildenafil Exclusion Criteria: Other diagnosis of PAH in World Health Organization (WHO) Diagnostic Group 1 such as congenital large or small unrepaired systemic to pulmonary shunts, portal hypertension, Human Immunodeficiency Virus (HIV) infection, glycogen storage disease, Gaucher's disease, hereditary hemorrhagic teleangiectasia, hemoglobinopathies, myeloproliferative disorders, veno-occlusive pulmonary disease Significant lung diseases not related to PAH Significant cardiovascular system disorders, hematological system disorders, liver insufficiency Significant diseases in other organ system. Other protocol-defined inclusion/exclusion criteria may apply

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Imatinib + Bosentan + Sildenafil<br>Participants received treatment with bosentan 125 milligrams (mg) twice daily and sildenafil thrice daily for 8 days in treatment period 1. Participants were on the same sildenafil dose level (20, 40, 50 or 60 mg) they had been at study entry which was well tolerated in conjunction with bosentan. Following treatment period 1, the participants received concomitant treatment of oral imatinib 200 mg daily, bosentan 125 mg twice daily and sildenafil thrice daily for 14 days in treatment period 2. Following treatment period 2, the participants received concomitant treatment of oral imatinib 400 mg daily, bosentan 125 mg twice daily and sildenafil thrice daily for 14 days in treatment period 3. | Drug: Imatinib<br>* Film coated tablets, oral administration<br>* Other names: QTI571;Drug: Sildenafil<br>* Oral Administration<br>Drug: Bosentan<br>* Oral Administration<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Geometric Mean Ratio of Dose Normalized Area Under the Curve From Time Zero to Tau (AUCtau) for Bosentan Before and After Imatinib Administrations | AUCtau was the area under the curve calculated to the end of the dosing interval, tau. The effect of co-administration of imatinib at two doses (200 and 400 mg) on the pharmacokinetics of bosentan was performed on dose normalized AUCtau of bosentan. A mixed effects linear model was fitted to the log-transformed PK parameters. This model included treatment (i.e., dose of imatinib) as a fixed effect, and participant as a random effect. Estimates for the treatment differences and associated 90% confidence intervals were obtained from the above model. These estimates and confidence intervals were then back-transformed to the original scale, giving, for each dose level of imatinib, the ratio of imatinib + co-administered sildenafil and bosentan (test) relative to the co-administered drugs alone (sildenafil + bosentan) (reference). | Day 1: pre-dose, Day 8: pre-dose, 0.5, 1, 2, 3, 4, 6, 8, 10 and 12 hours post-dose, Day 9: pre-dose, Days 22 and 36: pre-dose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12 and 24 hours post-dose | 
| Geometric Mean Ratio of Dose Normalized AUCtau for Sildenafil Before and After Imatinib Administrations | AUCtau was the area under the curve calculated to the end of the dosing interval, tau. The effect of co-administration of imatinib at two doses (200 and 400 mg) on the pharmacokinetics of sildenafil was performed on dose normalized AUCtau of sildenafil. A mixed effects linear model was fitted to the log-transformed PK parameters. This model included treatment (i.e., dose of imatinib) as a fixed effect, and participant as a random effect. Estimates for the treatment differences and associated 90% confidence intervals were obtained from the above model. These estimates and confidence intervals were then back-transformed to the original scale, giving, for each dose level of imatinib, the ratio of imatinib + co-administered sildenafil and bosentan (test) relative to the co-administered drugs alone (sildenafil + bosentan) (reference). | Day 1: pre-dose, Day 8: pre-dose, 0.5, 1, 2, 3, 4, 6, 8, 10 and 12 hours post-dose, Day 9: pre-dose, Days 22 and 36: pre-dose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12 and 24 hours post-dose | 
| Geometric Mean Ratio of Dose Normalized Maximum Plasma Concentration (Cmax) for Bosentan Before and After Imatinib Administrations | Cmax was the maximum (peak) observed plasma, blood, serum, or other body fluid drug concentration after dose administration. The effect of co-administration of imatinib at two doses (200 and 400 mg) on the pharmacokinetics of bosentan was performed on dose normalized Cmax of bosentan. A mixed effects linear model was fitted to the log-transformed PK parameters. This model included treatment (i.e., dose of imatinib) as a fixed effect, and participant as a random effect. Estimates for the treatment differences and associated 90% confidence intervals were obtained from the above model. These estimates and confidence intervals were then back-transformed to the original scale, giving, for each dose level of imatinib, the ratio of imatinib + co-administered sildenafil and bosentan (test) relative to the co-administered drugs alone (sildenafil + bosentan) (reference). | Day 1: pre-dose, Day 8: pre-dose, 0.5, 1, 2, 3, 4, 6, 8, 10 and 12 hours post-dose, Day 9: pre-dose, Days 22 and 36: pre-dose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12 and 24 hours post-dose | 
| Geometric Mean Ratio of Dose Normalized Cmax for Sildenafil Before and After Imatinib Administrations | Cmax was the maximum (peak) observed plasma, blood, serum, or other body fluid drug concentration after dose administration. The effect of co-administration of imatinib at two doses (200 and 400 mg) on the pharmacokinetics of sildenafil was performed on dose normalized Cmax of sildenafil. A mixed effects linear model was fitted to the log-transformed PK parameters. This model included treatment (i.e., dose of imatinib) as a fixed effect, and participant as a random effect. Estimates for the treatment differences and associated 90% confidence intervals were obtained from the above model. These estimates and confidence intervals was then back-transformed to the original scale, giving, for each dose level of imatinib, the ratio of imatinib + co-administered sildenafil and bosentan (test) relative to the co-administered drugs alone (sildenafil + bosentan) (reference). | Day 1: pre-dose, Day 8: pre-dose, 0.5, 1, 2, 3, 4, 6, 8, 10 and 12 hours post-dose, Day 9: pre-dose, Days 22 and 36: pre-dose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12 and 24 hours post-dose | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of Participants With At Least One or More Adverse Events (AEs) | An adverse event was the appearance or worsening of any undesirable sign, symptom, or medical condition that occurred after starting the study drug even if the event was not considered to be related to study drug. Number of participants with AEs were reported by treatment period. | From time of first administration of study drug until end of study (up to approximately 18 months) | 
| Dose Normalized Cmax of Imatinib and CGP74588 (Active Metabolite of Imatinib) |  | Day 1: pre-dose, Day 8: pre-dose, 0.5, 1, 2, 3, 4, 6, 8, 10 and 12 hours post-dose, Day 9: pre-dose, Days 22 and 36: pre-dose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12 and 24 hours post-dose | 
| Dose Normalized AUCtau of Imatinib and CGP74588 (Active Metabolite of Imatinib) |  | Day 1: pre-dose, Day 8: pre-dose, 0.5, 1, 2, 3, 4, 6, 8, 10 and 12 hours post-dose, Day 9: pre-dose, Days 22 and 36: pre-dose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12 and 24 hours post-dose | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Pulmonary Arterial Hypertension, Pulmonary Vascular Resistance, Imatinib, Bosentan, Sildenafil