clinical trials, the overall incidence and severity of anemia increased with INCIVEK combination treatment compared to peginterferon alfa and ribavirin alone. The incidence of anemia adverse events was 36% with INCIVEK combination treatment compared to 17% with peginterferon alfa and ribavirin alone. A decrease in hemoglobin levels occurred during the first 4 weeks of treatment, with lowest values reached at the end of INCIVEK dosing. Hemoglobin values gradually returned to levels observed with peginterferon alfa and ribavirin after INCIVEK dosing was completed [see Warnings and Precautions (5.4) ].
Anorectal Signs and Symptoms
In the controlled clinical trials, 29% of subjects treated with INCIVEK combination treatment experienced anorectal adverse events, compared to 7% of those treated with peginterferon alfa and ribavirin alone. The majority of these events (e.g., hemorrhoids, anorectal discomfort, anal pruritus, and rectal burning) were mild to moderate in severity; less than 1% led to treatment discontinuation and all resolved during or after completion of INCIVEK dosing.
Laboratory abnormalities
White Blood Cells: Treatment with peginterferon alfa is associated with decreases in mean values for total white blood cell, absolute neutrophil, and absolute lymphocyte count. More INCIVEK-treated subjects had decreases in lymphocyte counts to 499/mm3 or less (15% compared to 5%). Decreases in total white cell counts to 1,499/mm3 or less were comparable (8% compared to 5%). The incidence of decreases in absolute neutrophil counts to 749/mm3 or less was 15% in subjects treated with peginterferon alfa and ribavirin alone compared to 12% among those treated with INCIVEK combination treatment.
Platelets: Treatment with peginterferon alfa is associated with decreases in mean platelet counts. More patients treated with INCIVEK combination treatment had decreases in mean platelet values of all grades: 47% compared to 36% treated with peginterferon alfa and ribavirin alone. Three percent of INCIVEK combination treatment subjects had decreases to 49,999/mm3 or less compared to 1% of those treated with peginterferon alfa and ribavirin-treated alone.
Bilirubin: Forty one percent of INCIVEK-treated subjects compared to 28% of peginterferon alfa and ribavirin-treated subjects had all grade elevations in bilirubin levels; 4% and 2% of subjects, respectively, had greater than or equal to 2.6 × ULN elevations. Bilirubin levels increased most steeply during the first 1 to 2 weeks of INCIVEK dosing, stabilized and between Weeks 12 and 16 were at baseline levels.
Uric Acid: During the INCIVEK combination treatment period, 73% of subjects had elevated uric acid levels compared to 29% for those treated with peginterferon alfa and ribavirin alone. Shifts to greater than or equal to 12.1 mg/dL from baseline in uric acid levels were also more frequent among subjects treated with INCIVEK (7%) compared to peginterferon alfa and ribavirin (1%). Less than 1% of subjects had clinical events of gout/gouty arthritis; none were serious and none resulted in treatment discontinuation.
7 DRUG INTERACTIONS
7.1 Potential for INCIVEK to Affect Other Drugs
INCIVEK is an inhibitor of CYP3A. Co-administration of INCIVEK with drugs that are primarily metabolized by CYP3A may result in increased plasma concentrations of such drugs, which could increase or prolong their therapeutic effect and adverse reactions (see Table 5). INCIVEK is also an inhibitor of P-gp. |
