Low Dose Infliximab for Prevention of Postoperative Recurrence of Crohn's Disease: Long Term Follow-Up and Impact of Infliximab Trough Levels and Antibodies to Infliximab.

OBJECTIVE: In patients with postoperative recurrence of Crohn's disease endoscopic and clinical remission can be maintained for up to 1 year with low infliximab doses (3 mg/Kg). However, in theory low-dose infliximab treated patients could develop subtherapeutic trough levels, infiximab antibodies, and might loose response to therapy. To verify this hypothesis infliximab pharmacokinetics and clinical/endoscopic response were checked in a group of patients treated in the long term with low infliximab doses. DESIGN: Infliximab antibodies, infliximab levels, highly-sensitive CRP and fecal calprotectin were measured during the 8-week interval in 5 consecutive patients in clinical (Crohn's Disease Activity Index < 150) and endoscopic (Rutgeerts scores 0-1) remission after one year of therapy with infliximab 3 mg/Kg. For comparison with reported standards, infliximab pharmacokinetics and inflammatory parameters were also tested in 6 Crohn's disease patients who did not undergo surgery and who were in clinical remission while on infliximab 5 mg/Kg. Patients on low infliximab dose also underwent colonoscopy after 18 additional months of therapy. RESULTS: Highly sensitive CRP and fecal calprotectin increased in all patients during the 8-week interval. Infliximab trough levels were lower in patients treated with the low dose compared to controls (mean±SE: 2.0±0.3 vs 4.75±0.83 µg/mL respectively p<0.05). Infliximab antibodies were present in two of the subjects treated with low infliximab dose and in none of the controls. However, in low dose-treated patients after 18 additional months of therapy endoscopy continued to show mucosal remission and none of them developed clinical recurrence or side effects. CONCLUSIONS: Patients treated with low infliximab doses had lower trough levels compared to patients treated with 5 mg/Kg and some developed antibodies to infliximab. However, low infliximab doses sustained clinical and endoscopic remission for a total of 30 months of treatment.

Therapy of chronic hepatitis C with PEG-IFN α-2b plus ribavirin in patients with genotype 2 or 3: 16 versus 24 weeks, clinical outcome and direct cost analyses.

INTRODUCTION: Short antiviral therapy has been proposed for patients with chronic hepatitis C, easy genotypes, low fibrosis score, low viral load at baseline, and rapid virological response (RVR). However, this approach is not completely accepted. OBJECTIVES: The aims of this study were (a) to evaluate the sustained virological response (SVR) in noncirrhotic patients with genotype 2 or 3, achieving an RVR, randomized to receive pegylated-interferon (IFN) α-2b plus ribavirin for either 16 or 24 weeks and (b) to carry out direct cost analysis comparing patients treated for 16 versus 24 weeks. RESULTS: Of the 142 initially evaluated patients, 130 were enrolled according to the selection criteria, but independent of the viral load. According to the intention-to-treat analysis, SVR was achieved in 104 patients (80%). Logistic regression analysis showed that RVR (P<0.001) and genotype 2 (P<0.03) were the most important factors independently associated with SVR. Among patients with RVR, SVR was comparable between patients treated for 16 weeks and those treated for 24 weeks (86.2 vs. 89.7%, P=NS). The mean direct costs were €4003.7 for patients treated for 16 weeks and €5676.7 for those treated for 24 weeks, with a 30% difference between the two arms. CONCLUSION: In patients achieving an RVR, a 16-week treatment with pegylated-interferon plus ribavirin was comparable to a 24-week treatment. Short treatment in patients with RVR allows us to save 30% of the direct costs, independent of the viral load at baseline.