Victrelis: hints for success Katarnya Gilbert Hepatology MSL MSD 1
Some Facts: BOC has no clinically significant activity against other HCV genotypes. Resistance with protease inhibitor monotherapy can occur rapidly PegIFN reduces the rate of emergence of resistant strains.
Why have a Lead In phase? 1. Based on clinical protocol design (SPRINT and RESPOND) 2. Reduce viral load prior to the introduction of BOC 3. Reduce viral breakthrough 4. Reduce risk of viral resistance 5. Facilitate therapeutic plasma levels of ribavirin 6. Decline in viral load is indicative of SVR 7. Identify patients who may not tolerate triple therapy 7
Assessment of Lead In QUESTION? Should treatment be discontinued if HCV RNA decline is less than 1 log drop? ANSWER: No SVR = 38% (total of 95 patients) 8
PCR Not detected at week 4? May do equally as well without BOC? Decision to be made in conjunction with degree of fibrosis, baseline viral load, IL28b and patient tolerance 9
Dosing: 4 week lead in with PegIFN + RBV Introduce BOC @ week 5 Packaged separately BOC 200mg each capsule 800mg ( 4 capsules) tds = 12 tablets/day Administered with food/snack (7-9 hours) Pill burden/compliance issues? 10
Storage: Blister pack Each strip contains 12 capsules (one day) Each box contains a 1 month supply Store at room temperature < 30 degrees OR refrigerator ( 2-8 degrees) in the original strip Protect from light and humidity 11
Example of TID dosing 12
Missed a Dose of BOC? If a dose is missed and the patient realises this two or more hours before the next dose is due, they should take the assigned dose with food and resume the normal dosing schedule. < 2 hours before the next dose is due = skip the missed dose. 13
ADHERENCE TO ASSIGNED DOSING REGIMEN AND SUSTAINED VIROLOGIC RESPONSE AMONG HEPATITIS C-GENOTYPE 1 PREVIOUSLY UNTREATED AND PEGINTERFERON/RIBAVIRIN TREATMENT-FAILURE PATIENTS TREATED WITH BOCEPREVIR PLUS PEGINTERFERON ALFA-2B/RIBAVIRIN S.C. Gordon 1, E.J. Lawitz 2, B.R. Bacon 3, M.S. Sulkowski 4, E.M. Yoshida 5, M. Davis 6, N. Boparai 7, V. Sniukiene 7, M. Burroughs 7, C.A. Brass 7, J.K. Albrecht 7, K.R. Reddy 8 1 Henry Ford Hospital, Detroit, MI, USA, 2 Alamo Medical Research, San Antonio, TX, USA, 3 Saint Louis University School of Medicine, St. Louis, MO, USA, 4 Johns Hopkins University School of Medicine, Baltimore, MD, USA, 5 University of British Columbia and Vancouver General Hospital, Vancouver, BC, Canada, 6 South Florida Center of Gastroenterology, Wellington, FL, USA, 7 Merck Sharp & Dohme Corp., Whitehouse Station, NJ, USA 8 University of Pennsylvania, Philadelphia, PA, USA March 31, 2011 Click to add text Category 08c: Viral Hepatitis C: Clinical (therapy): Poster 428
Objective To examine the relationship between adherence to treatment dosage and duration and SVR in the SPRINT-2 and RESPOND-2 studies Adherence Calculated as cumulative number of doses divided by expected number of doses, based on actual treatment duration. (Stopping for futility per protocol placed some patients in nonadherent status) Defined as number of BOC dosing intervals within 7-9 hours in patients >80% adherent to dose Dosing data collected from patient e-diaries and drug dispensed/returned at the study sight
Adherence to treatment with BOC regimen in relation with SVR Adherence to duration of treatment with BOC+P/R appears to be the most important factor associated with SVR Patient who had completed 80% of assigned treatment duration had high SVR rates (83-86%) even with <80% adherence to BOC dose Gordon SC. et al. EASL 2011. J Hepatol 2011: 54: S173 (abstract 428)
Conclusions The majority of patients receiving BOC + P/R in SPRINT-2 and RESPOND were adherent to treatment duration and BOC dosing interval Adherence to duration of treatment with BOC + P/R appears to be the most important factor associated with SVR. Patients who had completed 80% of assigned treatment duration had high SVR rates (83-86%), even with <80% adherence to BOC dose. BOC TID dosing was effective; however, strict adherence to the 7-9- hour BOC dosing interval had minimal impact on SVR in patients who were otherwise adherent to therapy.
Take-home message Adherence to duration of treatment with BOC+P/R appears to be the most important factor associated with SVR BOC TID dosing was effective. However, strict adherence to 7-9 hour BOC dosing interval had minimal impact on SVR in patients who were otherwise adherent (in duration) to therapy Gordon SC. et al. EASL 2011. J Hepatol 2011: 54: S173 (abstract 428)
Monitoring of Patients During Treatment Complete blood counts should be obtained pretreatment, TW 2 (?),TW 4, TW 6 (?), TW 8, and monthly thereafter, or as clinically appropriate. If serum Hb is <10 g/dl, a decrease in dosage of RBV and/or administration with erythropoietin (epoetin alfa) may be warranted. HCV-RNA level should be monitored at TW 8 and TW 12 (Tx pts only). The results of these tests will be used to determine duration of treatment. A follow-up test is recommended 24 weeks after the completion of treatment. If the naive patient has detectable HCV-RNA at week 24 after the beginning of treatment with PR, i.e. 20 weeks after the initiation of therapy with BOC, all HCV medications are to be discontinued. If the treatment experienced patient has detectable HCV-RNA at week 12 or 24 after the beginning of treatment with PR, all HCV medications are to be discontinued. 19
Victrelis: Drug Drug Interactions 20
Boceprevir: Drug-drug interactions (DDIs) Boceprevir is a strong inhibitor of CYP3A4/5 and is partly metabolized by CYP3A4/5. Interaction with sensitive CYP3A4 substrate drugs should be expected Many drugs are CYP3A4 substrates These interactions are understood and can be managed appropriately Dose-titration Alternatives that are not CYP3A4 substrates No interaction with standard-of-care (peginterferon α-2b/ribavirin) The potential for drug-drug interactions must be considered prior to and during therapy. 21
Drug Metabolism Interactions: VICTRELIS (boceprevir) Is a Strong CYP3A4/5 Inhibitor CYP Substrate CYP Inhibitor CYP3A4/5 Substrate concentration Risk of toxicity CYP Substrate CYP Inducer CYP3A4/5 Substrate concentration Substrate efficacy CYP3A4/5 = cytochrome P450 3A4/5. 22
MSD DDI Chart This document should not be distributed without Cegedim authorization Copyright 2012 23
HCV Protease Inhibitor Drug-Drug Interactions by Drug Class Web Resource University of Liverpool HIV & Hepatology Pharmacology Group: April 2012. Available at: http://www.hep-druginteractions.org/. Accessed May 9, 2012. This document should not be distributed without Cegedim authorization Copyright 2012 24 24
Getting started.. Nurse plays a pivotal role Patient preparedness Pre treatment assessment Patient suitability for Victrelis DDI s Administration/compliance Strategies for missed doses Side effect prevention and management
Questions??? 26