Z Gastroenterol 2015; 53 - A5_7
DOI: 10.1055/s-0034-1397211

Baseline gamma-GT levels within the normal range predict high virologic response rates in treatment-naïve patients undergoing boceprevir triple therapy for HCV genotype 1 (G1) infection

P Buggisch 1, HF Löhr 2, G Teuber 3, H Steffens 4, MR Kraus 5, C John 6, PR Geyer 7, B Weber 8, T Witthöft 9, A Herrmann 10, M Hoesl 11, U Naumann 12, E Zehnter 13, D Hartmann 14, B Dreher 14, M Bilzer 14
  • 1IFI Institute, Hamburg, Germany
  • 2Gastroenterological Practice, Wiesbaden, Germany
  • 3Gastroenterological Practice, Frankfurt, Germany
  • 4Practice of internal Medicine, Berlin, Germany
  • 5Klinium Burghausen, Medical Department II, Burghausen, Germany
  • 6Practice of Internal Medicine, Berlin, Germany
  • 7Gastroenterological Practice, Fulda, Germany
  • 8Competence Center Addiction, Kassel, Germany
  • 9Gastroenterological Practice, Stade, Germany
  • 10Friedrich-Schiller-University, Jena, Germany
  • 11Gastroenterological Practice, Nuremberg, Germany
  • 12Center of Medicine, Berlin, Germany
  • 13Gastroenterological Practice, Dortmund, Germany
  • 14MSD Pharma GmbH, Haar, Germany

Background: A considerable number of patients (pts) with chronic HCV G1 infection will present with elevated serum gamma-GT levels. However, the impact of gamma-GT elevation on virologic response to boceprevir triple therapy has not been investigated until yet and was therefore the aim of the present interim analysis of the German NOVUS observational study.

Methods: From April 2012 until January 2014, 536 pts with G1 infection were recruited in the ongoing NOVUS study by 97 practices and hospitals in Germany. Pts were treated with pegylated interferons (PegIFN) and ribavirin (RBV) together with BOC for 24 to 44 weeks after a 4 weeks lead-in period with PegIFN/RBV. The present interim analysis was restricted to 257 previously untreated patients with documented gamma-GT levels at baseline.

Results: Overall, 122 of 257 patients (47.5%) had elevated gamma-GT levels at baseline (66.4% male, 41.0% > 50 years, 74.6% with baseline viral load > 400.000 IU/mL) while 135 pts (52.5%) had gamma-GT levels within the normal range (48.9% male, 34.1% > 50 years, 62.2% with baseline viral load > 400.000 IU/mL). Pts with baseline gamma-GT values in the normal range showed a better virologic response to PegIFN/RBV lead-in at the end of treatment week (TW) 4 as demonstrated by a higher proportion of pts with a HCV-RNA decline > 1log10 in comparison to pts with elevated gamma-GT levels (86.8% vs. 69.0%, p = 0.0008). In line with this observation a higher proportion of pts with normal gamma-GT values achieved an early virologic response (EVR) at TW8 (83.1% vs. 58.7%, p < 0.0001) as well as a better virologic response at TW12 (93.4% vs. 84.5%, p = 0.0425) and at the end of treatment (EOT) (93.8% vs. 83.1%, p = 0.0216) when compared with pts with elevated gamma-GT levels. Documented follow-up data were available from 133 pts. Until now, 51 of 61 pts (83.6%) with normal gamma-GT levels achieved a sustained virologic response (SVR) in contrast to 41 of 62 pts (66.1%) with elevated gamma-GT levels (p = 0.0256).

Conclusions: Baseline gamma-GT levels within the normal range in more than 50% of pts with HCV G1 infection are associated with a better response to BOC triple therapy. In particular the high proportion of pts who achieve an EVR (83%) may profit from a shortage of treatment duration. The stronger HCV-RNA decline at the end of lead-in suggests a higher sensitivity to PegIFN/RBV backbone in pts with normal gamma-GT values at baseline.

Corresponding author: Bilzer, Manfred

E-Mail: manfred.bilzer@bilzer-consulting.de