Victrelis

Overdose

Daily doses of 3600 mg have been taken by healthy volunteers for 5 days without untoward symptomatic effects.

There is no specific antidote for overdose with VICTRELIS. Treatment of overdosage with VICTRELIS should consist of general supportive measures, including monitoring of vital signs, and observation of the patient’s clinical status.

Victrelis price

Contraindications

Contraindications to peginterferon alfa and ribavirin also apply to VICTRELIS combination treatment. Refer to the respective prescribing information for a list of the contraindications for peginterferon alfa and ribavirin.

VICTRELIS in combination with peginterferon alfa and ribavirin is contraindicated in:

• Pregnant women and men whose female partners are pregnant because of the risks for birth defects and fetal death associated with ribavirin.
• Patients with a history of a hypersensitivity reaction to boceprevir.

Coadministration with drugs that are highly dependent on CYP3A4/5 for clearance, and for which elevated plasma concentrations are associated with serious and/or life-threatening events, including those in Table 2, is contraindicated.

Coadministration with potent CYP3A4/5 inducers, where significantly reduced boceprevir plasma concentrations may be associated with reduced efficacy, including those in Table 2, is contraindicated.

Table 2
Drugs that are contraindicated with VICTRELIS

Undesirable effects

See the peginterferon alfa and ribavirin prescribing information for description of adverse reactions associated with their use.

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in clinical trials of VICTRELIS cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

The following serious and otherwise important adverse drug reactions (ADRs) are discussed in detail in another section of the labeling:

• Anemia
• Neutropenia
• Pancytopenia
• Hypersensitivity

The most commonly reported adverse reactions (more than 35% of subjects regardless of investigator's causality assessment) in adult subjects were fatigue, anemia, nausea, headache, and dysgeusia when VICTRELIS was used in combination with PegIntron and REBETOL.

The safety of the combination of VICTRELIS 800 mg three times daily with PegIntron/REBETOL was assessed in 2095 subjects with chronic hepatitis C in one Phase 2, open-label trial and two Phase 3, randomized, double-blind, placebo-controlled clinical trials. SPRINT-1 (subjects who were previously untreated) evaluated the use of VICTRELIS in combination with PegIntron/REBETOL with or without a four-week lead-in period with PegIntron/REBETOL compared to PegIntron/REBETOL alone. SPRINT-2 (subjects who were previously untreated) and RESPOND-2 (subjects who had failed previous therapy) evaluated the use of VICTRELIS 800 mg three times daily in combination with PegIntron/REBETOL with a four-week lead-in period with PegIntron/REBETOL compared to PegIntron/REBETOL alone. The population studied had a mean age of 49 years (3% of subjects were older than 65 years of age), 39% were female, 82% were white and 15% were black.

During the four week lead-in period with PegIntron/REBETOL in subjects treated with the combination of VICTRELIS with PegIntron/REBETOL, 28/1263 (2%) subjects experienced adverse reactions leading to discontinuation of treatment. During the entire course of treatment, the proportion of subjects who discontinued treatment due to adverse reactions was 13% for subjects receiving the combination of VICTRELIS with PegIntron/REBETOL and 12% for subjects receiving PegIntron/REBETOL alone. Events resulting in discontinuation were similar to those seen in previous studies with PegIntron/REBETOL. Only anemia and fatigue were reported as events that led to discontinuation in more than 1% of subjects in any arm.

Adverse reactions that led to dose modifications of any drug (primarily PegIntron and REBETOL) occurred in 39% of subjects receiving the combination of VICTRELIS with PegIntron/REBETOL compared to 24% of subjects receiving PegIntron/REBETOL alone. The most common reason for dose reduction was anemia, which occurred more frequently in subjects receiving the combination of VICTRELIS with PegIntron/REBETOL than in subjects receiving PegIntron/REBETOL alone.

Serious adverse events were reported in 11% of subjects receiving the combination of VICTRELIS with PegIntron/REBETOL and in 8% of subjects receiving PegIntron/REBETOL.

Adverse events (regardless of investigator's causality assessment) reported in greater than or equal to 10% of subjects receiving the combination of VICTRELIS with PegIntron/REBETOL and reported at a rate of greater than or equal to 5% than PegIntron/REBETOL alone in SPRINT-1, SPRINT-2, and RESPOND2 are presented in Table 3.

Table 3
Adverse Events Reported in ≥10% of Subjects Receiving the Combination of VICTRELIS with PegIntron/REBETOL and Reported at a Rate of ≥5% than PegIntron/REBETOL alone

Among subjects (previously untreated subjects or those who failed previous therapy) who received VICTRELIS in combination with peginterferon alfa and ribavirin, the following adverse drug reactions were reported. These events are notable because of their seriousness, severity, or increased frequency in subjects who received VICTRELIS in combination with peginterferon alfa and ribavirin compared with subjects who received only peginterferon alfa and ribavirin.

Gastrointestinal Disorders

Dysgeusia (alteration of taste) was an adverse event reported at an increased frequency in subjects receiving VICTRELIS in combination with peginterferon alfa and ribavirin compared with subjects receiving peginterferon alfa and ribavirin alone (Table 3). Adverse events such as dry mouth, nausea, vomiting and diarrhea were also reported at an increased frequency in subjects receiving VICTRELIS in combination with peginterferon alfa and ribavirin.

Changes in selected hematological parameters during treatment of adult subjects with the combination of VICTRELIS with PegIntron and REBETOL are described in Table 4.

Decreases in hemoglobin may require a decrease in dosage or discontinuation of ribavirin. If ribavirin is permanently discontinued, then peginterferon alfa and VICTRELIS must also be discontinued.

Neutrophils and Platelets

The proportion of subjects with decreased neutrophil and platelet counts was higher in subjects treated with VICTRELIS in combination with PegIntron/REBETOL compared to subjects receiving PegIntron/REBETOL alone. Three percent of subjects receiving the combination of VICTRELIS with PegIntron/REBETOL had platelet counts of less than 50 x 109 per L compared to 1% of subjects receiving PegIntron/REBETOL alone. Decreases in neutrophils or platelets may require a decrease in dosage or interruption of peginterferon alfa, or discontinuation of therapy. If peginterferon alfa is permanently discontinued, then ribavirin and VICTRELIS must also be discontinued.

Table 4
Selected Hematological Parameters

The following adverse reactions have been identified during post-approval use of VICTRELIS in combination with peginterferon alfa and ribavirin. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

Blood and Lymphatic System Disorders: agranulocytosis, pancytopenia, thrombocytopenia

Gastrointestinal Disorders: mouth ulceration, stomatitis

Infections and Infestations: pneumonia, sepsis

Skin and Subcutaneous Tissue Disorders: angioedema, urticaria ; drug rash with eosinophilia and systemic symptoms (DRESS) syndrome, exfoliative rash, exfoliative dermatitis, Stevens-Johnson syndrome, toxic skin eruption, toxicoderma

Therapeutic indications

VICTRELIS® (boceprevir) is indicated for the treatment of chronic hepatitis C genotype 1 infection, in combination with peginterferon alfa and ribavirin, in adult patients with compensated liver disease, including cirrhosis, who are previously untreated or who have failed previous interferon and ribavirin therapy, including prior null responders, partial responders, and relapsers.

The following points should be considered when initiating VICTRELIS for treatment of chronic hepatitis C infection:

• VICTRELIS must not be used as monotherapy and should only be used in combination with peginterferon alfa and ribavirin.
• The efficacy of VICTRELIS has not been studied in patients who have previously failed therapy with a treatment regimen that includes VICTRELIS or other HCV NS3/4A protease inhibitors.
• Poorly interferon responsive patients who were treated with VICTRELIS in combination with peginterferon alfa and ribavirin have a lower likelihood of achieving a sustained virologic response (SVR), and a higher rate of detection of resistance-associated substitutions upon treatment failure, compared to patients with a greater response to peginterferon alfa and ribavirin.

Pharmacodynamic properties

The effect of boceprevir 800 mg and 1200 mg on QTc interval was evaluated in a randomized, multiple-dose, placebo-, and active-controlled (moxifloxacin 400 mg) 4-way crossover thorough QT study in 36 healthy subjects. In the study with demonstrated ability to detect small effects, the upper bound of the one-sided 95% confidence interval for the largest placebo-adjusted, baseline-corrected QTc based on individual correction method (QTcI) was below 10 ms, the threshold for regulatory concern. The dose of 1200 mg yields a boceprevir maximum exposure increase of approximately 15% which may not cover exposures due to coadministration with strong CYP3A4 inhibitors or use in patients with severe hepatic impairment. However, at the doses studied in the thorough QT study, no apparent concentration-QT relationship was identified. Thus, there is no expectation of a QTc effect under a higher exposure scenario.

Pharmacokinetic properties

VICTRELIS capsules contain a 1:1 mixture of two diastereomers, SCH534128 and SCH534129. In plasma the diastereomer ratio changes to 2:1, favoring the active diastereomer, SCH534128. Plasma concentrations of boceprevir described below consist of both diastereomers SCH534128 and SCH534129, unless otherwise specified.

In healthy subjects who received 800 mg three times daily alone, boceprevir drug exposure was characterized by AUC(т) of 5408 ng x hr per mL (n=71), Cmax of 1723 ng per mL (n=71), and Cmin of 88 ng per mL (n=71). Pharmacokinetic results were similar between healthy subjects and HCV-infected subjects.

Boceprevir was absorbed following oral administration with a median Tmax of 2 hours. Steady state AUC, Cmax, and Cmin increased in a less-than-dose-proportional manner and individual exposures overlapped substantially at 800 mg and 1200 mg, suggesting diminished absorption at higher doses. Accumulation is minimal (0.8-to 1.5-fold) and pharmacokinetic steady state is achieved after approximately 1 day of three times daily dosing.

The absolute bioavailability of boceprevir has not been studied.

Effects of Food on Oral Absorption

VICTRELIS should be administered with food. Food enhanced the exposure of boceprevir by up to 65% at the 800 mg three times daily dose, relative to the fasting state. The bioavailability of boceprevir was similar regardless of meal type (e.g., high-fat vs. low-fat) or whether taken 5 minutes prior to eating, during a meal, or immediately following completion of the meal. Therefore, VICTRELIS may be taken without regard to either meal type or timing of the meal.

Boceprevir has a mean apparent volume of distribution (Vd/F) of approximately 772 L at steady state in healthy subjects. Human plasma protein binding is approximately 75% following a single dose of boceprevir 800 mg. Boceprevir is administered as an approximately equal mixture of two diastereomers, SCH534128 and SCH534129, which rapidly interconvert in plasma. The predominant diastereomer, SCH534128, is pharmacologically active and the other diastereomer is inactive.

Studies in vitro indicate that boceprevir primarily undergoes metabolism through the aldo-keto reductase (AKR)-mediated pathway to ketone-reduced metabolites that are inactive against HCV. After a single 800-mg oral dose of 14C-boceprevir, the most abundant circulating metabolites were a diastereomeric mixture of ketone-reduced metabolites with a mean exposure approximately 4-fold greater than that of boceprevir. Boceprevir also undergoes, to a lesser extent, oxidative metabolism mediated by CYP3A4/5.

Date of revision of the text

Fertility, pregnancy and lactation

VICTRELIS must be administered in combination with peginterferon alfa and ribavirin.

Use with Ribavirin and Peginterferon Alfa

Significant teratogenic and/or embryocidal effects have been demonstrated in all animal species exposed to ribavirin; and therefore ribavirin is contraindicated in women who are pregnant and in the male partners of women who are pregnant. Interferons have abortifacient effects in animals and should be assumed to have abortifacient potential in humans.

Extreme caution must be taken to avoid pregnancy in female patients and female partners of male patients while taking this combination. W omen of childbearing potential and their male partners should not receive ribavirin unless they are using effective contraception (two reliable forms) during treatment with ribavirin and for 6 months after treatment. One of these reliable forms of contraception can be a combined oral contraceptive product containing at least 1 mg of norethindrone. Oral contraceptives containing lower doses of norethindrone and other forms of hormonal contraception have not been studied or are contraindicated.

In case of exposure during pregnancy, a Ribavirin Pregnancy Registry has been established to monitor maternal-fetal outcomes of pregnancies in female patients and female partners of male patients exposed to ribavirin during treatment and for 6 months following cessation of treatment. Physicians and patients are encouraged to report such cases by calling 1-800-593-2214.

VICTRELIS

VICTRELIS must not be used as a monotherapy. There are no adequate and well-controlled studies with VICTRELIS in pregnant women.

No effects on fetal development have been observed in rats and rabbits at boceprevir AUC exposures approximately 11.8-and 2.0-fold higher, respectively, than those in humans at the recommended dose of 800 mg three times daily.

Qualitative and quantitative composition

VICTRELIS 200 mg Capsules, red-colored cap with the Merck logo printed in yellow ink, and a yellow-colored body with “314” printed in red ink.

VICTRELIS 200 mg capsules are comprised of a red-colored cap with the Merck logo printed in yellow ink, and a yellow-colored body with "314" printed in red ink. The capsules are packaged into a carton with 28 bottles containing 12 capsules (NDC 0085-0314-02).

VICTRELIS Capsules should be refrigerated at 2-8°C (36-46°F) until dispensed. Avoid exposure to excessive heat. For patient use, refrigerated capsules of VICTRELIS can remain stable until the expiration date printed on the label. VICTRELIS can also be stored at room temperature up to 25°C (77°F) for 3 months. Keep container tightly closed.

Manufactured by: MSD International GmbH (Singapore Branch) Singapore 638414, Singapore. Revised: Jan 2017.

Special warnings and precautions for use

Included as part of the "PRECAUTIONS" Section

Ribavirin may cause birth defects and/or death of the exposed fetus. Extreme care must be taken to avoid pregnancy in female patients and in female partners of male patients. Ribavirin therapy should not be started unless a report of a negative pregnancy test has been obtained immediately prior to initiation of therapy. Refer to the prescribing information for ribavirin for additional information.

Women of childbearing potential and men must use at least two forms of effective contraception during treatment and for at least 6 months after treatment has concluded. One of these forms of contraception can be a combined oral contraceptive product containing at least 1 mg of norethindrone. Oral contraceptives containing lower doses of norethindrone and other forms of hormonal contraception have not been studied or are contraindicated. Routine monthly pregnancy tests must be performed during this time.

Anemia has been reported with peginterferon alfa and ribavirin therapy. The addition of VICTRELIS to peginterferon alfa and ribavirin is associated with an additional decrease in hemoglobin concentrations. Complete blood counts (with white blood cell differential counts) should be obtained pretreatment, and at Treatment Weeks 2, 4, 8, and 12, and should be monitored closely at other time points, as clinically appropriate. If hemoglobin is less than 10 g per dL, a decrease in dosage of ribavirin is recommended; and if hemoglobin is less than 8.5 g per dL, discontinuation of ribavirin is recommended. If ribavirin is permanently discontinued for management of anemia, then peginterferon alfa and VICTRELIS must also be discontinued.

Refer to the prescribing information for ribavirin for additional information regarding dose reduction and/or discontinuation.

In clinical trials with VICTRELIS, the proportion of subjects who experienced hemoglobin values less than 10 g per dL and less than 8.5 g per dL was higher in subjects treated with the combination of VICTRELIS with PegIntron®/REBETOL® than in those treated with PegIntron/REBETOL alone (see Table 4). W ith the interventions used for anemia management in the clinical trials, the average additional decrease of hemoglobin was approximately 1 g per dL.

In clinical trials, the median time to onset of hemoglobin less than 10 g per dL from the initiation of therapy was similar among subjects treated with the combination of VICTRELIS and PegIntron/REBETOL (71 days with a range of 15-337 days), compared to those who received PegIntron/REBETOL (71 days with a range of 8-337 days). Certain adverse reactions consistent with symptoms of anemia, such as dyspnea, exertional dyspnea, dizziness and syncope were reported more frequently in subjects who received the combination of VICTRELIS with PegIntron/REBETOL than in those treated with PegIntron/REBETOL alone.

In clinical trials with VICTRELIS, dose modifications (generally of PegIntron/REBETOL) due to anemia occurred twice as often in subjects treated with the combination of VICTRELIS with PegIntron/REBETOL (26%) compared to PegIntron/REBETOL (13%). The proportion of subjects who discontinued study drug due to anemia was 1% in subjects treated with the combination of VICTRELIS with PegIntron/REBETOL and 1% in subjects who received PegIntron/REBETOL. The use of erythropoiesis stimulating agents (ESAs) was permitted for management of anemia, at the investigator’s discretion, with or without ribavirin dose reduction in the Phase 2 and 3 clinical trials. The proportion of subjects who received an ESA was 43% in those treated with the combination of VICTRELIS with PegIntron/REBETOL compared to 24% in those treated with PegIntron/REBETOL alone. The proportion of subjects who received a transfusion for the management of anemia was 3% of subjects treated with the combination of VICTRELIS with PegIntron/REBETOL compared to less than 1% in subjects who received PegIntron/REBETOL alone.

Thromboembolic events have been associated with ESA use in other disease states; and have also been reported with peginterferon alfa use in hepatitis C patients. Thromboembolic events were reported in clinical trials with VICTRELIS among subjects receiving the combination of VICTRELIS with PegIntron/REBETOL, and among those receiving PegIntron/REBETOL alone, regardless of ESA use. No definite causality assessment or benefit risk assessment could be made for these events due to the presence of confounding factors and lack of randomization of ESA use.

A randomized, parallel-arm, open-label clinical trial was conducted in previously untreated CHC subjects with genotype 1 infection to compare use of an ESA versus ribavirin dose reduction for initial management of anemia during therapy with VICTRELIS in combination with peginterferon alfa-2b and ribavirin. Similar SVR rates were reported in subjects who were randomized to receive ribavirin dose reduction compared to subjects who were randomized to receive an ESA. In this trial, use of ESAs was associated with an increased risk of thromboembolic events including pulmonary embolism, acute myocardial infarction, cerebrovascular accident, and deep vein thrombosis compared to ribavirin dose reduction alone. The treatment discontinuation rate due to anemia was similar in subjects randomized to receive ribavirin dose reduction compared to subjects randomized to receive ESA (2% in each group). The transfusion rate was 4% in subjects randomized to receive ribavirin dose reduction and 2% in subjects randomized to receive ESA.

Ribavirin dose reduction is recommended for the initial management of anemia.

In Phase 2 and 3 clinical trials, seven percent of subjects receiving the combination of VICTRELIS with PegIntron/REBETOL had neutrophil counts of less than 0.5 x 109 per L compared to 4% of subjects receiving PegIntron/REBETOL alone (see Table 4). Three subjects experienced severe or life-threatening infections associated with neutropenia, and two subjects experienced life-threatening neutropenia while receiving the combination of VICTRELIS with PegIntron/REBETOL. Complete blood counts (with white blood cell differential counts) should be obtained at pretreatment, and at Treatment Weeks 2, 4, 8, and 12, and should be monitored closely at other time points, as clinically appropriate. Decreases in neutrophil counts may require dose reduction or discontinuation of peginterferon alfa and ribavirin. If peginterferon alfa and ribavirin are permanently discontinued, then VICTRELIS must also be discontinued.

Refer to the prescribing information for peginterferon alfa and ribavirin for additional information regarding dose reduction or discontinuation.

Serious cases of pancytopenia have been reported postmarketing in patients receiving VICTRELIS in combination with peginterferon alfa and ribavirin. Complete blood counts (with white blood cell differential counts) should be obtained at pretreatment, and at Treatment Weeks 2, 4, 8, and 12, and should be monitored closely at other time points, as clinically appropriate.

Refer to the prescribing information for ribavirin and peginterferon alfa for guidelines for discontinuation of therapy based on laboratory parameters.

Serious acute hypersensitivity reactions (e.g., urticaria, angioedema) have been observed during combination therapy with VICTRELIS, peginterferon alfa and ribavirin. If such an acute reaction occurs, combination therapy should be discontinued and appropriate medical therapy immediately instituted.

See Table 2 for a listing of drugs that are contraindicated for use with VICTRELIS due to potentially life-threatening adverse events, significant drug interactions or loss of virologic activity. Please refer to Table 5 for established and other potentially significant drug interactions.

HCV-RNA levels should be monitored at Treatment Weeks 4, 8, 12, and 24, at the end of treatment, during treatment follow-up, and for other time points as clinically indicated. Use of a sensitive real-time reverse-transcription polymerase chain reaction (RT-PCR) assay for monitoring HCV-RNA levels during treatment is recommended. The assay should have a lower limit of HCV-RNA quantification of equal to or less than 25 IU per mL, and a limit of HCV-RNA detection of approximately 10 to 15 IU per mL. For the purposes of assessing Response-Guided Therapy milestones, a confirmed “detectable but below limit of quantification” HCV-RNA result should not be considered equivalent to an “undetectable” HCV-RNA result (reported as “Target Not Detected” or “HCV-RNA Not Detected”).

Complete blood count (with white blood cell differential counts) should be obtained at pretreatment, and at Treatment Weeks 2, 4, 8, and 12, and should be monitored closely at other time points, as clinically appropriate.

Refer to the prescribing information for peginterferon alfa and ribavirin for pre-treatment, on-treatment and post-treatment laboratory testing recommendations including hematology, biochemistry (including hepatic function tests), and pregnancy testing requirements.

• Advise the patient to read the FDA-approved patient labeling (Medication Guide)

VICTRELIS must be used in combination with peginterferon alfa and ribavirin, and thus all contraindications and warnings for peginterferon alfa and ribavirin also apply. If peginterferon alfa or ribavirin is permanently discontinued, VICTRELIS must also be discontinued.

Ribavirin must not be used by women who are pregnant or by men whose female partners are pregnant. Ribavirin therapy should not be initiated until a report of a negative pregnancy test has been obtained immediately before starting therapy. Female patients of childbearing potential and male patients with female partners of childbearing potential must be advised of the teratogenic/embryocidal risks of ribavirin and must be instructed to practice effective contraception during therapy and for 6 months post-therapy. Patients should be advised to notify the healthcare provider immediately in the event of a pregnancy.

Women of childbearing potential and men must use at least two forms of effective contraception during treatment and for at least 6 months after treatment has been stopped; routine monthly pregnancy tests must be performed during this time. One of these reliable forms of contraception can be a combined oral contraceptive product containing at least 1 mg of norethindrone. Oral contraceptives containing lower doses of norethindrone and other forms of hormonal contraception have not been studied or are contraindicated.

To monitor maternal and fetal outcomes of pregnant women exposed to ribavirin, the Ribavirin Pregnancy Registry has been established. Patients should be encouraged to register by calling 1-800593-2214.

Patients should be informed that anemia may be increased when VICTRELIS is administered with peginterferon alfa and ribavirin. Patients should be advised that laboratory evaluations are required prior to starting therapy and periodically thereafter .

Patients should be informed that neutropenia may be increased when VICTRELIS is administered with peginterferon alfa and ribavirin. Patients should be advised that laboratory evaluations are required prior to starting therapy and periodically thereafter.

Patients should be informed that serious cases of pancytopenia have been reported during postmarketing when VICTRELIS was administered with peginterferon alfa and ribavirin. Patients should be advised that laboratory evaluations are required prior to starting therapy and periodically thereafter.

Patients should be informed that serious acute hypersensitivity reactions have been observed during combination therapy with VICTRELIS, peginterferon alfa, and ribavirin therapy. If symptoms of acute hypersensitivity reactions (e.g., itching; hives; swelling of the face, eyes, lips, tongue, or throat; trouble breathing or swallowing) occur, patients should seek medical advice promptly.

Patients should be advised that VICTRELIS must not be used alone due to the high probability of resistance without combination anti-HCV therapies. See the prescribing information for peginterferon alfa and ribavirin for additional patient counseling information on the use of these drugs in combination with VICTRELIS.

Patients should be informed of the potential for serious drug interactions with VICTRELIS, and that some drugs should not be taken with VICTRELIS.

Patients should be advised that the total daily dose of VICTRELIS is packaged into a single bottle containing 12-capsules and the patient should take four capsules three times daily with food.

If a patient misses a dose and it is less than 2 hours before the next dose is due, the missed dose should be skipped. If a patient misses a dose and it is 2 or more hours before the next dose is due, the patient should take the missed dose with food and resume the normal dosing schedule.

Patients should be informed that the effect of treatment of hepatitis C infection on transmission is not known, and that appropriate precautions to prevent transmission of the hepatitis C virus should be taken.

Use with Ribavirin and Peginterferon alfa

Ribavirin is genotoxic in in vitro and in vivo assays. Ribavirin was not oncogenic in mouse and rat carcinogenicity studies at doses less than the maximum recommended daily human dose. Please refer to the prescribing information for ribavirin for additional information.

Two-year carcinogenicity studies in mice and rats were conducted with boceprevir. Mice were administered doses of up to 500 mg per kg in males and 650 mg per kg in females, and rats were administered doses of up to 125 mg per kg in males and 100 mg per kg in females. In mice, no significant increases in the incidence of drug-related neoplasms were observed at the highest doses tested resulting in boceprevir AUC exposures approximately 2.3-and 6.0-fold higher in males and females, respectively, than those in humans at the recommended dose of 800 mg three times daily. In rats, no increases in the incidence of drug-related neoplasms were observed at the highest doses tested resulting in boceprevir AUC exposures similar to those in humans at the recommended dose of 800 mg three times daily.

Boceprevir was not genotoxic in a battery of in vitro or in vivo assays, including bacterial mutagenicity, chromosomal aberration in human peripheral blood lymphocytes and mouse micronucleus assays.

Use with Ribavirin and Peginterferon alfa

In fertility studies in male animals, ribavirin induced reversible testicular toxicity; while peginterferon alfa may impair fertility in females. Please refer to the prescribing information for ribavirin and peginterferon alfa for additional information.

Boceprevir-induced reversible effects on fertility and early embryonic development in female rats, with no effects observed at a 75 mg per kg dose level. At this dose, boceprevir AUC exposures are approximately 1.3-fold higher than those in humans at the recommended dose of 800 mg three times daily. Decreased fertility was also observed in male rats, most likely as a consequence of testicular degeneration. No testicular degeneration was observed at a 15 mg per kg dose level resulting in boceprevir AUC exposures of less than those in humans at the recommended dose of 800 mg three times daily. Testicular degeneration was not observed in mice or monkeys administered boceprevir for 3 months at doses of up to 900 or 1000 mg per kg, respectively. At these doses, boceprevir AUC exposures are approximately 6.8-and 4.4-fold higher in mice and monkeys, respectively, than those in humans at the recommended dose of 800 mg three times daily. Additionally, limited clinical monitoring has revealed no evidence of testicular toxicity in human subjects.

VICTRELIS must be administered in combination with peginterferon alfa and ribavirin.

Use with Ribavirin and Peginterferon Alfa

Significant teratogenic and/or embryocidal effects have been demonstrated in all animal species exposed to ribavirin; and therefore ribavirin is contraindicated in women who are pregnant and in the male partners of women who are pregnant. Interferons have abortifacient effects in animals and should be assumed to have abortifacient potential in humans.

Extreme caution must be taken to avoid pregnancy in female patients and female partners of male patients while taking this combination. W omen of childbearing potential and their male partners should not receive ribavirin unless they are using effective contraception (two reliable forms) during treatment with ribavirin and for 6 months after treatment. One of these reliable forms of contraception can be a combined oral contraceptive product containing at least 1 mg of norethindrone. Oral contraceptives containing lower doses of norethindrone and other forms of hormonal contraception have not been studied or are contraindicated.

In case of exposure during pregnancy, a Ribavirin Pregnancy Registry has been established to monitor maternal-fetal outcomes of pregnancies in female patients and female partners of male patients exposed to ribavirin during treatment and for 6 months following cessation of treatment. Physicians and patients are encouraged to report such cases by calling 1-800-593-2214.

VICTRELIS

VICTRELIS must not be used as a monotherapy. There are no adequate and well-controlled studies with VICTRELIS in pregnant women.

No effects on fetal development have been observed in rats and rabbits at boceprevir AUC exposures approximately 11.8-and 2.0-fold higher, respectively, than those in humans at the recommended dose of 800 mg three times daily.

It is not known whether VICTRELIS is excreted into human breast milk. Levels of boceprevir and/or metabolites in the milk of lactating rats were slightly higher than levels observed in maternal blood. Peak blood concentrations of boceprevir and/or metabolites in nursing pups were less than 1% of those of maternal blood concentrations. Because of the potential for adverse reactions from the drug in nursing infants, a decision must be made whether to discontinue nursing or discontinue treatment with VICTRELIS, taking into account the importance of the therapy to the mother.

The safety, efficacy, and pharmacokinetic profile of VICTRELIS in pediatric patients have not been studied.

Clinical studies of VICTRELIS did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. In general, caution should be exercised in the administration and monitoring of VICTRELIS in geriatric patients due to the greater frequency of decreased hepatic function, concomitant diseases and other drug therapy.

No dosage adjustment of VICTRELIS is required for patients with any degree of renal impairment.

No dose adjustment of VICTRELIS is required for patients with mild, moderate or severe hepatic impairment. Safety and efficacy of VICTRELIS have not been studied in patients with decompensated cirrhosis.

In published observational studies of patients with compensated cirrhosis treated with first generation HCV protease inhibitors, including boceprevir, in combination with peginterferon alfa and ribavirin, platelet count < 100,000/mm3 and serum albumin < 3.5 g/dL were baseline characteristics that were identified as predictors of death or serious complications (severe infection or hepatic decompensation) during therapy.

The potential risks and benefits of VICTRELIS in combination with peginterferon alfa and ribavirin should be carefully considered before initiating therapy in patients with compensated cirrhosis who have platelet count < 100,000/mm3 and serum albumin < 3.5 g/dL at baseline. If therapy is initiated, close monitoring for signs of infections and worsening liver function is warranted.

The safety and efficacy of VICTRELIS alone or in combination with peginterferon alfa and ribavirin for the treatment of chronic hepatitis C genotype 1 infection in liver or other organ transplant recipients have not been studied. For data regarding drug-drug interactions with immunosuppressants, see DRUG INTERACTIONS and CLINICAL PHARMACOLOGY.

Dosage (Posology) and method of administration

VICTRELIS must be administered in combination with peginterferon alfa and ribavirin. The dose of VICTRELIS is 800 mg (four 200-mg capsules) three times daily (every 7 to 9 hours) with food [a meal or light snack] (see Table 1). Refer to the prescribing information for peginterferon alfa and ribavirin for instructions on dosing.

The following dosing recommendations differ for some subgroups from the dosing studied in the Phase 3 trials. Response-Guided Therapy (RGT) is recommended for most individuals, but longer dosing is recommended in targeted subgroups (e.g., patients with cirrhosis).

• Initiate therapy with peginterferon alfa and ribavirin for 4 weeks (Treatment Weeks 1-4).
• Add VICTRELIS 800 mg (four 200-mg capsules) orally three times daily (every 7 to 9 hours) to peginterferon alfa and ribavirin regimen after 4 weeks of treatment. Based on the patient's HCV-RNA levels at Treatment Week (TW) 8, TW12 and TW24, use the following guidelines to determine duration of treatment (see Table 1).

Table 1
Duration of Therapy in Patients Without Cirrhosis Who Are Previously Untreated or Who Previously Failed Interferon and Ribavirin Therapy

Consideration should be given to treating previously untreated patients who are poorly interferon responsive (as determined at TW4) with 4 weeks peginterferon alfa and ribavirin followed by 44 weeks of VICTRELIS 800 mg orally three times daily (every 7 to 9 hours) in combination with peginterferon alfa and ribavirin in order to maximize rates of SVR.

Prior to initiating therapy in patients with compensated cirrhosis, see Use In Specific Populations for additional information.

Patients with compensated cirrhosis should receive 4 weeks peginterferon alfa and ribavirin followed by 44 weeks VICTRELIS 800 mg (four 200-mg capsules) three times daily (every 7 to 9 hours) in combination with peginterferon alfa and ribavirin.

Dose reduction of VICTRELIS is not recommended.

If a patient has a serious adverse reaction potentially related to peginterferon alfa and/or ribavirin, the peginterferon alfa and/or ribavirin dose should be reduced or discontinued. Refer to the prescribing information for peginterferon alfa and ribavirin for additional information about how to reduce and/or discontinue the peginterferon alfa and/or ribavirin dose. VICTRELIS must not be administered in the absence of peginterferon alfa and ribavirin. If peginterferon alfa or ribavirin is permanently discontinued, VICTRELIS must also be discontinued.

Discontinuation of therapy is recommended in all patients with 1) HCV-RNA levels of greater than or equal to 1000 IU per mL at TW8; or 2) HCV-RNA levels of greater than or equal to 100 IU per mL at TW12; or 3) confirmed detectable HCV-RNA levels at TW24.

Interaction with other medicinal products and other forms of interaction

See Table 2 for a listing of drugs that are contraindicated for use with VICTRELIS due to potentially life-threatening adverse events, significant drug interactions or loss of virologic activity. Please refer to Table 5 for established and other potentially significant drug interactions.