Hepatitis C
Conditions
Brief summary
The purpose of the study is to look at whether taking a new medication for hepatitis C (boceprevir) together with a herbal remedy commonly used for the treatment of depression (SJW) has any effect on the levels of boceprevir in the blood, compared to when boceprevir is taken on its own. Treatment of hepatitis C genotype-1, has recently been significantly improved with the addition of a new class of drugs called protease inhibitors (PIs). Boceprevir belongs to this class of antiviral drugs and it is administered in combinations with other drugs to treat hepatitis C. One of the common side effects of treatment for hepatitis C is low mood (depression) for which treated patients may self-medicate with preparations containing St. Johns Wort (SJW). SJW is known to cause drug interactions, so taking SJW at the same time as boceprevir may result in a change in how both of these drugs usually work. It is therefore important to find out if the levels of boceprevir in the blood are significantly affected by taking SJW. The study aims to help us understand whether it will be safe to take SJW whilst being simultaneously treated for hepatitis C with boceprevir.
Detailed description
Boceprevir is a strong inhibitor of CYP3A4/5. Medicines metabolized primarily by CYP3A4/5 may have increased exposure when administered with boceprevir, which could increase or prolong their therapeutic and adverse reactions. Boceprevir does not inhibit or induce the other enzymes of the CYP450 family. Boceprevir has been shown to be a P-glycoprotein and breast cancer resistant protein (BCRP) substrate in vitro. There is potential for inhibitors or inducers of these transporters to alter the concentrations of boceprevir; the clinical implications of these interactions are not known.Boceprevir is partly metabolized by CYP3A4/5. Co-administration of boceprevir with medicines that induce or inhibit CYP3A4/5 could increase or decrease exposure to boceprevir and affect its efficacy.Boceprevir, in combination with peginterferon and ribavirin, is contraindicated when coadministered with medicines that are highly dependent on CYP3A4/5 for clearance, and for which elevated plasma concentrations are associated with serious and/or life-threatening events. Examples may include; orally administered midazolam and triazolam, bepridil, pimozide, lumefantrine, halofantrine, and tyrosine kinase inhibitors, and ergot derivatives (dihydroergotamine, ergonovine, ergotamine, methylergonovine). Boceprevir is primarily metabolized by aldoketo reductase (AKR). In medicine interaction trials conducted with AKR inhibitors diflunisal and ibuprofen, boceprevir exposure did not increase to a clinically significant extent. Boceprevir may be co-administered with AKR inhibitors. The concomitant use of boceprevir with stong CYP3A4 inducers such as rifampicin or anticonvulsants (such as phenytoin, phenobarbital or carbamazepine) may significantly reduce the plasma exposure of boceprevir. As no data is available, the combination of boceprevir with these medicines is not recommended. The metabolism of St John's Wort is not currently known. Treatment with St John's wort for 14 days resulted in significant increases in the urinary 6-beta-hydroxycortisol/ cortisol ratio, suggesting that St John's wort is an inducer of CYP3A4. For this reason, it is not recommended to administer SJW with CYP3A4 metabolized drugs. Furthermore,interactions may occur with P-glycoprotein substrates, as St. John's wort can induce the activity of transmembrane transporters. This might decrease the effectiveness of some medications. For the reasons illustrated above, the potential for a drug interaction between SJW and boceprevir is high and the co-administration must be studied in order to gain information on whether: i) SJW leads to a decrease in boceprevir concentrations and therefore efficacy; ii) boceprevir leads to an increase in SJW (hypericin) exposure with risk of toxicity. The safety and PK of the combination should be known especially in view of the common side effects caused by interferon, which is co-administered with boceprevir for the treatment of hepatitis C: as interferon causes depression, patients may chose to take SJW rather than prescribed anti-depressants to manage their mood changes during antihepatitis treatment.
Interventions
DRUGBoceprevir
Boceprevir as Victrelis(r) 200mg capsules
DRUGSt John's Wort
Each Ucalm(r) tablet contains 300mg of St Johns Wort extract
Sponsors
University of Liverpool
University of Turin, Italy
St Stephens Aids Trust
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
PREVENTION
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
Yes
Inclusion criteria
Subjects must meet all of the following inclusion criteria within 28 days prior to day 0: 1. The ability to understand and sign a written informed consent form, prior to participation in any screening procedures and must be willing to comply with all study requirements 2. Male or non-pregnant, non-lactating females 3. Between 18 to 65 years, inclusive 4. Body Mass Index (BMI) of 18 to 35 kg/m2, inclusive. 5. Women of childbearing potential (WOCBP), who are sexually active, must be using an adequate method of contraception to avoid pregnancy throughout the study and for a period of at least one month after the study in addition to the consistent and correct use of a condom. Examples of adequate methods of contraception for females in this trial are diaphragm with spermicide, substance and intra-uterine device. Hormonal contraceptives should not be considered a method of contraception and should be avoided if containing drospirenone. 6. Willing to consent to their personal details being entered onto The Over volunteering Prevention Scheme (TOPS) database. 7. Registered with a GP in the UK 8. Willing to bring photo ID to each visit
Exclusion criteria
Subjects who meet any of the following
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Pharmacokinetic of Boceprevir in the Presence of Ucalm (St John's Wort) | 6 months | Pharmacokinetic parameters (maximum and trough concentrations, and area under concentratof boceprevir and SJW will be evaluated when given in combination at steady-state to evaluate possible differences in concentrations during co-administration versus drug given alone. The pharmacokinetic parameters calculated for boceprevir and SJW will be Ctrough,the maximum observed plasma concentration (Cmax), time point at Cmax (Tmax), and total drug exposure, expressed as the area under the plasma concentration-time curve. All pharmacokinetic parameters will be calculated using non-compartmental modelling techniques (WinNonlin®) and all statistical calculations performed within-participant changes in the assessed pharmacokinetic parameters (drug alone vs drug combination) will be evaluated by calculating geometric mean ratios. |
Countries
United Kingdom
Participant flow
Recruitment details
All volunteers were recruited at a single centre, SSAT Research Unit, Chelsea & Westminster Hospital, London, UK.
Pre-assignment details
Eligible participants took: SJW for 14 days Group A D1-D14 or boceprevir(BCP) for 5 D10-D14 days Group B (D 10-14); PK profile on D14 then 7 day washout period to D21 D22-D35, all took SJW (+ BCP on D31-D35); PK on D35 then washout to D42 Group A took BCP on D52-D56; Group B SJW on D43-D56; PK profile on D56.
Participants by arm
| Arm | Count |
|---|---|
| All Participants Descriptive analysis of combined groups | 17 |
| Total | 17 |
Baseline characteristics
| Characteristic | All Participants |
|---|---|
| Age, Categorical <=18 years | 0 Participants |
| Age, Categorical >=65 years | 0 Participants |
| Age, Categorical Between 18 and 65 years | 17 Participants |
| Region of Enrollment United Kingdom | 17 participants |
| Sex: Female, Male Female | 11 Participants |
| Sex: Female, Male Male | 6 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — |
| other Total, other adverse events | 6 / 8 | 9 / 9 |
| serious Total, serious adverse events | 0 / 8 | 0 / 9 |
Outcome results
Primary
Pharmacokinetic of Boceprevir in the Presence of Ucalm (St John's Wort)
Pharmacokinetic parameters (maximum and trough concentrations, and area under concentratof boceprevir and SJW will be evaluated when given in combination at steady-state to evaluate possible differences in concentrations during co-administration versus drug given alone. The pharmacokinetic parameters calculated for boceprevir and SJW will be Ctrough,the maximum observed plasma concentration (Cmax), time point at Cmax (Tmax), and total drug exposure, expressed as the area under the plasma concentration-time curve. All pharmacokinetic parameters will be calculated using non-compartmental modelling techniques (WinNonlin®) and all statistical calculations performed within-participant changes in the assessed pharmacokinetic parameters (drug alone vs drug combination) will be evaluated by calculating geometric mean ratios.
Time frame: 6 months
Population: All participants who completed the three PK assessments were included in the analysis. BCP metabolites (SCH534128 \& SCH523129) PK parameters were determined in the presence and absence of SJW, and hypericin PK parameters in the presence and absence of BCP; for the total study population.
| Arm | Measure | Group | Value (GEOMETRIC_MEAN) |
|---|---|---|---|
| All Participants | Pharmacokinetic of Boceprevir in the Presence of Ucalm (St John's Wort) | Total Boceprevir alone | 4588 ng*h/mL |
| All Participants | Pharmacokinetic of Boceprevir in the Presence of Ucalm (St John's Wort) | Boceprevir in presence of St Johns Wort) | 4204 ng*h/mL |
| All Participants | Pharmacokinetic of Boceprevir in the Presence of Ucalm (St John's Wort) | Hypericin alone | 11.6 ng*h/mL |
| All Participants | Pharmacokinetic of Boceprevir in the Presence of Ucalm (St John's Wort) | Hypericin in presence of boceprevir | 14.3 ng*h/mL |
| All Participants | Pharmacokinetic of Boceprevir in the Presence of Ucalm (St John's Wort) | SCH534128 alone | 3222 ng*h/mL |
| All Participants | Pharmacokinetic of Boceprevir in the Presence of Ucalm (St John's Wort) | SCH534128 in presence of St. Johns Wort | 2935 ng*h/mL |